خیلی وقتمو گرفت و بهتر دیدم خلاصه هرچی در مورد جابجایی بلندگو تو سایت رومی و کتاب جیم اسمیت دیدم رو بنویسم:

اين وقت و هزينه هايي كه از سمت من انجام ميشه و با حاشيه هم همراه هست اميدوارم حداقل شما مخاطب عزيز بهره لازم از اين نوشته هارو ببريد.

اخر هر جمله يه ستاره * گذاشتم كه تفكيك مطالب انجام شده باشه.

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It is my strong conviction that an acoustic system (and practically horn) should sit in the middle of a room. *

We are always careful to place the speakers equal distance from the listening position. *

when the loudspeakers are closeting to the DPoLS then the narrowing speakers or toeing then out create a wider soundstage AND at the same time the center image movies FORWARD. *

The inspiration suggests that time alignment is the key for DPoLS setting. *

ou set up left loudspeaker (left for you) where I need to be. I always suggest starting from left loudspeaker as it cares the fist violins, sopranos of choruses and generally in western culture is associated with HF lead. *

the loudspeaker should not be source of sound in your room. *

in fact any speaker should be kept at least 3’-5’ from the walls to let “imaging to breathe”. *

When you walk into a good room it clearly heard as a different acoustic event. It is very pleasant to be and very pleasant to talk in a good room. I am always aware of its acoustics in good room. *

The inspiration suggests that time alignment is the key for DPoLS setting *

1) Alignment of the Channels of the same loudspeaker
2) Alignment of BOTH loudspeaker in the room
3) First major reflections of the room for both loudspeakers. *

Sure the DPoLS are practically not known techniques and it is great to “handle” it but there is something else in there. The DPoLS sure is very powerful and superbly influential but they are the last stork of brash, the final kink in the art of playback positioning. However, the majority of the installations out there do not even approach to the point of failure at the DPoLS level as they fail at much lover level – the macro-positioning. *

if the Imbedded Macro-Positioning is well-thought and properly implemented then whatever the common audio-knowledge suggest about speakers positioning become … irrelevant. *

Acoustic system is not only loudspeakers and not the loudspeaker-room interaction but rather the sound of the room itself. The loudspeakers juts trigger the room… if the loudspeakers in-phase with room *

3) If your objectives are the “ADVANCED AUDIO AND EVOLVED MUSIC REPRODUCTION TECHNIQUES” THEN practically all Commercial loudspeakers are compromised. It is not necessary because they are bad but because any Commercial off the shelf loudspeaker does not utilizes the “Imbedded Macro-Positioning” and therefore fundamentally underperforms. (Unless the specially built rooms that it very different subjects). I am very much NOT against the Commercial loudspeakers – they just should be designed differently for the “evolved music reproduction”. *

4) There are no such a things as bad sounding rooms, at least at the Macro-Positioning level. The rooms sound bad because the Imbedded techniques were not used properly or were not used at all. *

5) Acoustic treatment as it exists in today Hi-Fi (unless we are talking about VERY large diffusers and very large resonators… that never used) are not applicable at sub approximately 700Hz. The carp that the Morons use for bass and upper bass control is juts horrible as it shrink reverberation time at higher frequencies. Unless we do for VERY high expense and large custom made solutions the sub 700Hz are not intentionally controllable. The irony is that with the Imbedded Macro-Positioning … it is good they are controllable because it becomes the… benefit. *

Yes, a cheep but good consumer amplifier with a inexpensive old JBL monitor, properly Macro-Positioned, will literally destroy a performance of $250.000.00 high-end installation of the installation is … against the interests of the room. Do I have to pump you up more? *

So, what to do next? Let forgot whatever crap you have heard about better and worst rooms for Sound, unless you build a listening dedicated rooms from scratch, that, as a concept, has it’s own problems. Let forgot a point about the topologies of loudspeaker. Also, let forgot the idiotic idea that the industry have implanted in you – “you have to find best position in your room for your given loudspeaker”. *

one of the major task of the Imbedded Macro-Positioning to place your loudspeaker in-wide-phase with the Room Polarity. This is the absolutely mandatory. Without your acoustic system (or at least the fundamental channels of your loudspeakers) operating in-wide-phase with your room to get an “interesting sound” is practically impossible. *

Ok, how to start. First of all we have to understand that out subject of attention will be a region between approximately 80Hz and 500Hz or something that shape the fundamentals of the “melody range” within your playback. Search my site I have written about the prominence of the upperbass a lot ….

Most of the mid and small size rooms (very large room is a separate subject) have two types of the room modes: narrow modes and wide modes. Your primary task at this point is to find where those wide modes in your room will be. As you understand when I talk about the room modes I mean the modes in the Melody Range. The narrow modes are 1/4 octave wide and you should discard them. You need to search for picks that would be wider then ½ octaves. I have seen some rooms that have plus 5-6dB at 130Hz and 1.5 octaves wide. The smaller room the more room modes might be and the more “problem” the room most likely will have. Do not worry about it – search for the wildest bandwidth and for the highest amplitude of modes in your room and those “problem” will not be problems if you use them properly.

How to search it? It is deepens of many parameters. Your listening expertise and topology of your loudspeakers (the Melody Range channels) are not the last among all variables. Generally a simple RTA with 1/6 octave and higher will do. You do not need any good quality microphone as you do not care about absolute number but rather about the relative values. Running pink noise with very fast averaging and resetting itself after, I would say, 15 seconds is a good tool. You need to connect one channel of your Melody Range and to let your friend to tango with the speaker (or with a Melody Range substitute this will be even better) across your room. Do not forget moving your microphone and well if it is necessary. You should sit at your desirable listing spot with microphone, looking at your RTA and to listen the sound. The combination of what you hear and what the RTA shows is be a good tool for you to get a sense of directions. Change at least a half of dozen listening positions until you feel that you found the SECOND UGLIEST LOCATION IN YOU ROOM. What does it mend the “second ugliest”. The first the most ugliest location for your Melody Range will have a maximum amplitude of the narrow modes (Do not approach to the room’s walls closer then 3 feet). Keep looking you need to look for the WIDEST BANDWIDTH, EVEN AT SLIGHTLY LOVER AMPLITUDE.

If you are ability lucks of any sensibility and hearing then you might use you loudspeaker as a microphone. Fill your room with band-pass noise (Melody Range) and look with a meter or scope how much signal you your speaker pick up at their output. It is very erroneous way but it juts a handicapped way for the deaf beginners. Do not forget that in this case you will need to conduct a number of discrete measurements at different very narrow band-pass frequencies in order to determine how wide bandwidth of the room gain. Do not forget also that the position of room noise-filing speaker should be at the position where you will be listening from.

Anyhow, some people might propose to use some kind of modeling software but I personally have no positive experience with software and I considering then superfluous toys. Perhaps it is juts me. You might use whatever means are available in your disposal to found the “boomiest”, across wide bandwidth, spot in your room. *

Two important comments. This relatively-wide bandwidth “agilest” spot in your room will not be a spot but rather a quite large space. It is very difficult to make a generalization about it but generally this quite “large bloomy space” will be a space equal to, I would say, 1/8-1/12 of the room dimensions. I call this large bloomy space as ACOUSTICAL EROGENOUS ZONE (AEZ) of your listening room. Now you need to found the AEZ’s dimensions. Mark the found location of your AEZ and move your speakers a few feet in all direction measuring loosing the room gain within the Melody Range. Eventually you will discover an approximate relatively large region in your room that might be considered as AEZ. Now, you need to find the AEZ’s polarity. The AEZ’s polarity is the AEZ’s side where the room gain in the Melody Range would be at maximum. The AEZ might be right-polarized or left-polarized.

So, what to do next? Now you need…. to place both of your loudspeakers in the AEZ, trying to position the right channel in the most polarized region of your AEZ. Regardless speaker’s topology is used your loudspeaker’s Melody Range they, the loudspeakers, must be INSIDE of the AEZ. It is not only because you have extra feed db gain in there – this it beneficial but very secondary. The key is that now your artificial room transducer (speaker) is in-phase with nativity of your listening room and then do not work against each other.

If your Melody Range channel (or live instrument as well) are in AEZ then they are capable of wonderful thing by “TURNING THE ENTIRE ROOM ON” – you can’t not accomplish it with better speakers or better amplifiers. Let dive slightly in the dangers territory. Driving your room by loudspeakers from outside AEZ location is like pleasing different parts of female body – it gives positive and effective atomic (individual, isolated) effects to her gratification. However, but performing necessary actions on women G-spot is capable to create for some women not atomic but a FULL-BODY REACTION. The Melody Range lodging a room from AEZ is very much hits the G-spot of your listening room and allows you get a VERY different and very evolved result of the room loading that is unimaginable if you drive your room from outside of AEZ. I can assure you that if you are not a Moron™ and each time you heard any more or less interesting sound from any playbacks then the loudspeakers, in one way or other and in most of cases completely accidentally, were near the AEZ.

The very next actions will be removing all filters, impedance normalizes, resonators from your upperbass driver (and perhaps your lower midrange driver) and let your upperbass installed in the enclosure-topology of your choose to play full range. In the next my post I will continue describing the next steps… *

BTW, I forgot to mention one very important thing that might be very easily overlooked: the Imbedded Macro-Positioning Reality lives in three dimensions. It is not about the right, left, closer and further but also up and down. In fact the vertical positioning usually has much less tolerance then tolerance in other dimensions and I have seen situation when moving a speaker latterly 5 inches up of down quite hugely affected “room loading”. So, do not overlook the vertical positioning… *

Currently the speakers are 12.5 feet apart and I put my listing chair 10 feet apart. The Macondo is pointed just behind the shoulders – my regular configuration. *

it would be a good idea to separate LF section of two channels –Upper LF and Lower LF. Then the lower LF would go to the corner of the room where the bass is the best *

Bill, first reflection of your horn might be from the back wall but when you are talking about reflection you imply HF that propagates according to the rules of transverse waves. The LF waver act more like pressure (longitudinal) wave and they do not have definitive first reflection in your case. The first reflection is more applicable to the HF content of your horn. *

in bad position : 1) There is no proper tone
2) Horizontal imaging is less refined then I would like it to be.
3) Sound is not wet enough.
4) At high volumes room can’t dissipate HF
5) Sound does not have uniformed density and more reminds a dug and raked backyard.
6) Strenuous and laborious presentation.
7) Playback does not sound with the room but in the room. *

The room is larger and has consequentially longer reverberation time at HF. It is absolutely not treated in a typical sense of this word and has naked walls as now. The room does not sound “bright” but I think the HF reflections inject the HF noise into MF, producing HF mist that dilute the tone. I still do not want to treat the wall and ceiling with explicit treatment. *

If your channels, particularly above 200Hz, are time-misaligned then your playback sounds like shit. *

In fact, after the measurements, the bass in this room is not useful and I unfortunately have to recognize that I will not be able to use Melquiades SET to handle bass. *

It looks like everything suggests that I would need to get rid in my new room my LF line arrays and go for smaller dedicated ULF sections, made to fit to the specific of the given room. Here was what I predicted years back that it will be the next manifestation of my playback. (Amir: it means You may need design new bass channel in a room to have good response below 100hz) *

I might to use digital correction of open-end analog notching but only on lower bass channel. (Amir: Romy may use both Class D amplifier and Digital EQ for below 100hz) *

LF the digital EQ will flatten the response for a single listening location. It will do it with no problem. Will it result sonic improvement? This is more complicated question. Let pretend that EQ does not destroy sound by DSP in case it is digital and does not spin phase. Still, flat response is not the objective. I have seen in some rooms very un-flat response that did not affect listening. Some peaks and some dives in the response are fine – it all depends how wide, where, how they related to the rest of the room response and how they masked out. No one advocate running digital IQ to flat bass (it is not complex) but to use digital IQ discreetly, fixing the major problems I think would worth to explore. BTW, what you do is not much different – only you use resonating limp panels. I consider your way of doing the thing is preferable but you endure a lot of acoustic treatment in your room. If it is a dedicated or demo room then it is fine but I do not have an objective to have DEMO room, I am looking for to make it living room.

Frankly I think that my way to do the ROOM is more preferable: do not fine with room and do not treat the room but rather to design the accustom system around the specific room behavior. I admit that so far I do not have in my room success but I just started. I think the final result might use some of your limp methods but the EQ ONLY for LF doe not sound too absurdish as well. My problem not is not with EQ but with absent of ULF channel with which I would model some lower bass behavior. Again, the jury is out but I still would not put the treated room in the epicenter of attention. *

OK, I decided to stop today to do what I do as it does not feel like me anymore. For a month as I live in here and have the playback up my playback is a source of great pain and I do not like it. I am accustomed that I turn the thing on and USE it. I did many experiments and had weeks or month playback in bad shape but I know what is going on and I had no problem with it. Now, in new house I for some reasons constantly fight with playback and practical do not USE it as I would like to. The audio experiments I fine, I like them but today I convinced myself the unit I have a dictated midbass channel I will not get the sound I would like to get. So, what people do after they have a strike of revelation? Right, they begin to re-read my site.
So, I look at my comments in the Audio For Dummies section: do not pursue full-range without being ready, do not go for lower bass without being ready and I asked myself – what I am doing? *

The ASC tube traps do show it as phenomenal HF consumption tool but I absolutely do not want them to deal with my sub 1000Hz *

Tube traps are very powerful HF consumer and the need to be use VERY cautiously, it easy to over dry my room and it need some attention what and how to use the tube traps. *

Thinking about tube traps more I conceded that they are no properly designed. *

ASC Tube Traps , They kind if insert a very fine file of oil on surface of bass water, eating up all micro dymick of bass. *

This is very unpleasant feeling. I think the problem that tube traps has is that they are trying to do for bass and I think this is a mistake. The tube traps are super good HF consumers and this is where they need to be. *

The perfect location of my listening chair had found, this is a huge move forward to me. Now I need lock everything on this location and bring the Macondo to the proper calibrated level with respect to this listening location. *

There are however some constrains. For instance I would like to keep Macondo islands as far as possible from back wall. I would like to have the Macondo islands to be spread as wide as possible but without deformation of center image. I would like the chair to be equidistant between crossover altered midbass and the rest MF channels. There are many other constrains and wishes. Sure putting up room treatment and by other means the critical listening position might be adjusted and it will be adjusted but the main skeleton will be pretty much remain. *

For those who both chair and speaker I would advise to find one stationary objects. For me in most of the case it is the back wall of the speaker when I know how far my speaker needs to be from there. This would give to you the base line for the speaker. Everything comes from there. You know your base line, you know your spread of the R/L channels, so you know more or less your listening distance. In many way it is back and forth ceremony…. *

It is well known that the requirements to acoustic environment for life music and for audio installations are very different. For life music we need much more what we would call in audio “live” acoustic setting, letting the instruments to breathe. For audio we need much more controlled environment, with much- much shorter reverberation time. What we in audio consider “too live” room would be “super dead” even for a string trio and in the environment those musicians would consider live enough for them audio out would hardly be able to operate as it will be too life for us. *

However, not a lot of people know that listening room compress dynamic. The compression is less visible and not as much “in your face” as the imaging. The irony is that the settings for best imaging most frequency (in context of conventional box loudspeakers) directly contradict the best settings for the least dynamic compression. *

The DpoLS is the ONLY one setting where there is no conflict between the dynamic and imaging. *

Interesting that the search for the least dynamic compression eventually do leads to the DPoLS, and whan the loudspeakers are in the DPoLS position then all aspect of “imaging” get resolved at orders of magnitude more interesting level then the people practicing the “imaging positioning” even could imagine. *

One more tip. The “least dynamic compression positioning” mostly managed by upper bass and bass channels while in the “imaging positioning” the MF and HF channels play more dominating roles. Therefore, if you use a typical single box loudspeaker then you most likely have quite few tools to manage the situation as the different channels would most likely demand the different optimum positions in your room (unless you are incredibly lucky!!!). Still, even is you do have a separation of the enclosures between the channels then it might be quite complex to take care of the LF’s “dynamic compression” the MF’s “imaging”, the phase consistency and many other this… at the same time and within the very same installation…. *

Would a properly, DPoLS-based, playback installation enrich a listener ability “to be lost in music”? Unquestionably would. How a listener without knowing the expressive methods of audio might bring up his/her system up to the DpoLS level? To do it requires a ceremony of connected sensations, actions and motivations… and this I try to make someone to think about. All that I was saying was that by perusing the “imaging minded” ceremony it is hardly possible to produce decisions leading to the actions that might produces any DPoLS-fruitful results. Contrary to this the training to recognize the dynamic compression of listening rooms take the DpoLS searching skills through the roof. *

The DpoLS is not a “newfound musical significance” but the only existing ways to get the “real audio sound”. *

The DPOLS is an art of the speakers setting. *

At the level #1 I concern about the sonic performance of the playback. Imaging, soundstage, separations, presentations, tonal balances, stereo tricks, sizes, deferent type of dynamics, relationship with room, dynamic imaging with volume fluctuation and the rest of the typical audio routine. At this level the calculators, measuring tapes and high resolution RTA really help. At this level it is possible to get a very good hi-fi sound. The precision of the DPLOS proximity I would say around 4”-15”

At the level #2 I look for the relationship between the audible and sensible sensation and the relationship between the tonal pressure and acoustic dB pressure. The DPLOS proximity I at this level around 1.5”-4”. At this level a new listing awareness is born (including the organic “phantom” sensations that you very accurately described) and the each characteristics of the level #1 get magnified and improved.

At the level #3 I look for the preservation of all that was accomplished of the level #2 but in addition I look for the amplitude of produced intentions. If music calls for thinking, sorrow, joy, melancholy or pomposity then it should be very extreme thinking, sorrow, joy, melancholy or pomposity. At this level the quality of the composition or performance become prominent and better performances should yield higher listing amplitude. At this level the playback system should AMPLIFY not sound but the musicality of a performance. Interestingly that when a system is made up to operate properly at the level #3 then some qualities of the level #1 and level #2 do over the roof. For instance, a listening perception get a possibility to accommodate itself to any aspect of Sound (for instance any single instrument, or any single phrase) and to abstract the selected “item” out of everything. At the level #3 the precision of the DPLOS proximity (if everything else was made correctly) would be less than 1”.

At the level #4 all bets are off and the precision of the DPLOS proximity is around 1/16”… and most like at the different location then it was the previous levels. 🙂 At this level the dynamics, imaging, soundstage, separations, presentations, tonal balances, and the rest things from level #1 return back not now, they have totally different meaning as they become connected to the physical experiences of a listener. When a listening awareness operates at the level of RECOMPOSING or RE-PERFORMING then the synchronization between the cerebral processes of a listener with the “heard sound reproduction” becomes an important expressive tool. There are many other things that are going on at this level and how the DPLOS proximity might affect it. I try do not share them publicly in order do not feed the reviewers and other industry dirt from stealing the evaluation points and then, using them for their primitive objectives while having no comprehending what it all might means (there was a few occurrences).

I also generally keep these thoughts to myself, particularly about the level #3 and level #4, because there are not a lot of people who might understand it (and are some other reasons…) *

جيم اسميت ميگه كف اتاق حتما حتما چوب يا پاركت باشه چون صدا خيلي موزيكال تره. حتما چوب ساليد و محكم بچسبه به كف. ميگه هيچ دستگاه بهتري نميتونه چنين تاثير مثبتي روي توناليته بزاره.

تو گوشه هاي ٩٠ درجه كه كنج هست ميگه بيس ترپ و اكوستيك نگذاريد و كتابخانه مثلثي استفاده كنيد.

اگر محل نشستن به ديوار پشت نزديكه حتما بايد اولين رفلكت بلندگو كه از طريق ديوار پشت سر شنونده به گوش تابيده ميشه كاملا با مواد جاذب گرفته بشه.

جيم ميگه براي اتاق هاي داخل خانه كه بدليل وجود فرش و مبل به اندازه كافي جذب صدا دارند ميشه از درختچه و گياه در اولين رفلكت ها استفاده كرد.
جيم با استفاده زياد از مواد جاذب موافق نيست.

مهمترين قسمتهايي كه در اتاق بايد كنترل شوند

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اهمیت آکوستیک :

اهمیت آکوستیک

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نظر من اینه اگه آکوستیک ندارید (مثلا تو خونه بابا هستید و نمیگذارند از این کارها بکنید) بیخیال شوید.
اساس استفاده از های فای یک محیط خوب هست چون اتاق پر بازگشت به شما صدا نمیده و از نظر من آکوستیک مثل یک کامپوننت نیست که بهتر یا بدتر بودنش روی صدا تاثیر محدودی بگذاره. آکوستیک بستر انتشار موج صوتی است و مهمترین عامل در مساله صدا.
اگه حتی صدای یک ضبط کوچک رو در محیطی ایده ال شنیده باشید اون صدا رو به شنیدن بهترین سیستم در محیطی غیر ایده ال ترجیح میدهید.
هر چقدر تاکید کنم باز هم احساس میکنم کم هست و فکر میکنم شما خیلی این موضوع رو جدی نمیگیرید. اکثر کسانی رو که دیدم، حتی با سیستمهای خیلی گران به این مساله توجه نمیکنند و فکر میکنند صدا رو باید همینجوری تو یک اتاق معمولی شنید.

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اون موقع نمیدونستم مفهوم آکوستیک یه جورایی به تنهایی معنا پیدا نمیکنه و بحث آکوستیک رو باید در قالب آکوستیک بعلاوه مکان بلندگو درک کرد.

همون مفهومی که رومی به نام DPOLS معرفی میکنه.

کلا در گذشته من هم روی آکوستیک و هم روی مچینگ تاکید بیشتری نسبت به کامپوننت ها داشتم.

هزار بار گفتم هیچ چیزی نمیتونه جای آکوستیک و مکان بلندگو رو بگیره و اگر یادتون باشه نوشتم همه سیستم ها اگر بین 0 تا 100 امتیازدهی شوند تو آکوستیک خوب و با Placement خوب این درجات بین 100 تا 1000 شیفت پیدا میکنه. چه 500 میلیون پول سیستم صوتی بدید چه 500 هزار تومن تو شرایط نامناسب آکوستیکی بین 0 تا 100 درجا میزنید و فقط چیزی که رومی و جیم میگویند میتونه این معادلات رو به هم بریزه.

از ما گفتن از شما پول بیخود خرج کردن …

این ایده احمقانه باید عوض بشه که سیستم بدون Setup درست میتونه درست صدا بده. از نگاه من هر سیستمی نیاز به Setup درست بلندگو ، آکوستیک کردن اتاق و حذف لرزش و به حداکثر رسوندن وضعیت برق داره. بدون این کارها 500 میلیون هم پول بدید همون 0 تا 100 درجا زدید.

جیم اسمیت شروع کرده به نوشتن در مورد موضوع مکان بلندگو و با ابزاری که در اختیار داره سعی میکنه بهترین نقطه رو برای بلندگو بدست بیاره . مفهوم Play the room رو من اولین بار تو سایت رومی دیدم و همونطور که میدونید هم رومی هم جیم اسمیت هر دو تاثیر آکوستیک و مکان بلندگو رو خیلی خیلی بیشتر از بقیه اجزا میبینند.

درسته مورون ها (90 درصد آئودیوفیل های دنیا مورون طبقه بندی میشن) تو همه جای دنیا همش بحث های مورونی میکنند و صدای خوب رو فقط تابع کامپوننت میبینند اما شما باید بدونید اساس صدای خوب آکوستیک سیستم خوب هست و اگر اون نباشه هیچ تلاشی نتیجه ای که باید رو نمیده.

http://getbettersound.com/

http://getbettersound.com/consultation.html

Does your system “Play the Room?”

Introducing RoomPlay™ custom voicing (aka In-Home Consultation & System Voicing).

In a recent ad in Stereophile, Jim Smith said,

“Dear Audiophile:

As I’ve traveled around North America, voicing readers’ systems, three things have become very obvious:

1) Audiophiles have standards that are simply too low. They accept much less than they deserve (and much less than they paid to get).

2) It’s not really their fault. They simply don’t have a reference for how good their system can be.

3) Addressing how electrons travel in wire and electronics is one thing—addressing how sound waves are launched into the room and how they are received at the listening seat is far more critical and pays far bigger dividends.

Playing the Room

RoomPlay™ is my custom voicing service. Imagine that your listening room has no walls, no ceilings, and no speakers. The musicians have assembled to play a special concert, just for you. You feel the emotional impact of the music the next day, as if it had been a live concert.

I call it “playing the room.” Hence, RoomPlay.

Srajan Ebaen, Editor & Publisher at 6Moons.com, commented on my personal system:

“With my eyes closed, I attempted to obtain an aural signature of the room. I couldn’t. Nothing. There was very tacit recording venue data, yes—but none that portrayed the room itself. It had been entirely subtracted from the listening equation!

“This ‘no speaker!’ sensation was uncanny. Moreover, it was exceedingly tactile. That was clearly the result of meticulous setup… In short, Jim had banished from my awareness all reminders of mechanical sound sources and actual versus virtual environs.”*

Listen, a $10,000 system properly playing the room is vastly superior to a $100,000 system that isn’t.

Your most important component

Your most important component will always be your room. Proper voicing yields greatly enhanced dynamics,presence, live-liness, tone, and soundstaging. Therefore, your musical involvement is enhanced as well. That’s why the thing that’s been most edifying—and gratifying—to me is that my voicing clients are no longer replacing components. They are off the equipment merry-go-round. These days, they shop for music.

Glen F.: “Jim, I can’t tell you how much more involving my system is now. [My wife] listened to one of her favorite records last night and she was astonished with the changes. She even sent a text mess-age explaining to me how she now feels more part of the music.”*

Jerry P.: “It easily represented the best “bang for the buck” that I’ve spent on my system over the years. That’s as glowing an endorsement as I could make and I make it willingly.”*

All the best in music and sound,

PS—If you have a significant investment in your system, doesn’t it make sense to finally hear what you paid for?”

To learn more about RoomPlay, and why a custom voicing session can be the biggest improvement you can make in your system, read more below. If you have already read enough to know that this is something that interests you, contact Jim Smith – jim@getbettersound.com

Who is the typical RoomPlay client?

It’s someone who wants to extract far higher performance from his or her existing system.

Someone who has had little or no voicing assistance.

Someone who – more often than not – is time-poor.  They want to move their system to the next level.  But they want someone to come in and get it done.  They don’t have the time to do it themselves.  And they’ve finally realized that throwing more money at still another highly reviewed component will be money wasted, at least until the foundation for their system is built.

RoomPlay Details

Jim’s custom voicing service includes, but isn’t limited to, the following tools:

1/3 Octave Real Time Analyzer
Calibrated Microphone
15” MacBook Pro, optimized specifically for RoomPlay Applications
Bosch Laser Distance Meter
Four Laser Levels
Custom Grid System
Grid Tripods
Woodworx Acoustic Polarity Indicator
Ayre QB-9 DAC
Fluke VTVM
Mark-free Marking Tape
Marking Labels
First Reflection Point System
Selected Music from Top 185 Reference Disc List
Jim Smith’s 35 years of voicing experience and knowledge

The tools for this voicing kit are worth well over $10,000. You get the full benefits of it, but you don’t have to buy it, nor do you have to learn how to use these items (unless it interests you to so).

Contact Jim Smith to schedule or to make any inquiries

After your RoomPlay Session…

RoomPlay clients often get more excited about their systems than they have been previously.  So they have questions.  The price of the RoomPlay session includes free consultations by phone or e-mail for 12 months following the session.

RoomPlay™ Testimonials

Caution – unless you are considering having your system voiced, this section is long and perhaps more detailed than a casual reader would enjoy reading.

In addition to serving his long-time personal clients, recently Jim has been able to help a significant number of new people – mostly readers of Get Better Sound – in their homes, working in their rooms, voicing their systems.

The results have been consistently gratifying, not just for his clients, who can best be described as ecstatic over the improvements, but perhaps to his surprise, for Jim as well.

He has especially appreciated the ongoing contact with these clients and especially the fact that they really love their sound now, that they spent far less than they would have spent to buy almost any component, and perhaps most gratifying – that since the voicing session, they haven’t spent a dime on any more components!

Having received a large number of inquiries about in-home system voicing, Jim thought this description of a typical job would be useful. But he wouldn’t exactly call this a program. Because he never knows what he may encounter. However, there are some generalities that are illustrative:

“I’ve been doing these installations/voicings for years. In general, I like to arrive the evening before the day of the job – especially if I flew in, to give my hearing a break overnight. Depending on the time, it’s useful to check out the site and meet with the client that evening.

The next day is open, meaning that it may take as few as 6-8 hours or it may take 12 or more. For what it’s worth, in the past 30 years, I’ve never been able to complete a new system evaluation and voicing in less than about 8-10 hours. I don’t stop working until I know the system would satisfy me (which will be after you are already pleased). I do this within the context of using what you have on hand.

Also, we’ll create what I call a ‘roadmap’ in the manual. So you’ll have an idea of what you may want to do later, as well as what you shouldn’t…

I book a flight out the next morning.

Often I will drive, if it’s a drive of perhaps six hours or less.

I require my clients to commit the entire time to be with me when voicing a system. So if I came on a Wednesday, you’d have to be there all day.

Often a weekend is best for my clients, and I’m willing to do that at the same price.

If I fly, I ship in a kit of instruments/tools/recordings via FedEx Express or Ground that I’ll use, and I ask you to ship it back. The shipping is not expensive, but you would have to cover transportation both ways. Having insured this kit for voicing trips, I know that it’s worth (insured for) over $3,000. For you, it’s like getting the use of it without paying to rent or buy it.

Rarely, but once in a while, an unusually difficult situation might call for another day. Of course, I will share with you what I think needs doing if you don’t want to incur more expense at that time. If you opt to have me stay over, most of the time, it’s just a portion of the next day, and if I can still make my return trip later that same day, then the price for that second day is adjusted down accordingly.

But first and most important, we would need to have a phone conversation. From there, I can generally decide if I think it would be worth your time and expense. Occasionally, I have to tell folks that it might not be worth it based on certain restrictions they have.

I also recommend that folks get the Get Better Sound manual and go through it, both to get a feel for what I think is important, and – honestly speaking – for the feeling you get from reading how I write. If you are uncomfortable with what I say or how I say it, that should be a warning sign!”

The Concept

Virtually every audiophile that Jim has ever visited (many hundreds, if not thousands) has had a stereo system that was performing below – usually well below – the potential for that system in that room. This is true no matter how expensive the components are, whether or not the listening area is a dedicated room, or how knowledgeable the owner is reputed to be.

After 30+ years of installing and voicing systems that perform at a high level, Jim finally realized why this phenomenon was so depressingly true.

First, it had been apparent that he was working with many exceptionally bright people. People who were experts in their respective fields. But just as we wouldn’t recommend that you hire Jim to perform an intricate medical procedure, why would a cardiologist expect to be able to extract all of the performance from his/her music system? Reading magazines won’t impart the experience. Going to shows won’t either.

It all comes down to having a reference. The one universal comment that Jim reports hearing is that the client simply had no idea that the resulting sound was possible. He/she hadn’t heard it before, didn’t know if the room would be good enough, thought they needed “better equipment”, etc.

So not only do his voicing clients report vastly improved sound, now they have a reference for what is possible. It means that they can not only become far more involved in their music and the overall listening experience, they are now in a position to determine if a new component truly merits the expense.

If you’re unsure of what is entailed in a voicing session, perhaps reading the accounts below will be of assistance. Plus you can always Contact Jim Smith for more info.

Two additional points should be emphasized.

(1) It’s Jim’s goal to move your music system to another level of performance and involvement without replacing one single component.

(2) The improvement in your system should be by far the biggest you’ve ever experienced, well beyond that obtained by replacing any electronics or cables at any price.

The bottom line for clients

“…thought to myself that what you did was the best investment I had made for my Hi-Fi ever.”

“It easily represented the best “bang for the buck” that I’ve spent on my system over the years.”

Client accounts of what happened in a voicing a session

There have been some unsolicited posts on Internet Forums that describe Jim’s in-home voicing procedure.

The following is excerpted from one such account:

First off, Jim Smith is a class act all the way and is a walking encyclopedia of audio information. He was very professional and flexible from planning, execution and follow up. He did not know me at all until I gave him a phone call. If you have not bought his book yet then I would seriously recommend buying it and if you have the ability to pay for his on site services then I would highly recommend that as well. Jim was able to take my system to the next level with components I already had.

Keep in mind I am new to higher end audio so for me I needed to better understand what “good” is supposed to sound like. I had my own perception and felt my system was sounding great before Jim arrived.

This was Jim’s first exposure to Martin Logan CLX’s. He had read most of the reviews and talked with a few other people so he had a general idea of what to expect. Jim spent about 2.5 days with me and my system. Outside of phone conversations and a few photos and diagrams Jim was coming into an environment he had no experience with.

Upon arrival Jim focused solely on better understanding my environment. He asked pertinent questions and there was no music played until he understood the room, the components and the reasoning for certain positions and configurations. While I had always considered my room less than ideal, Jim thought it was just fine and not a real issue.

Jim then listened to a few tracks to determine what challenges he might have for the next 2 days. The tracks he selects are ones he knows very well and so he knew what to listen for. Now I was hoping I had them setup pretty good (they sounded damn good to me and anyone else to date I put in front of them) but the look on Jim’s face and body language told me otherwise. Jim’s initial thoughts boiled down to:

– Lack of body
– Lack of tone
– Lack of depth
– Lack of emotion
– Flat sound staging
– Thin presentation
– Lack of sound staging “Wall”
– Overwhelming bass (but controlled)
– Both male and female vocals lacked warmth, texture and realism

While I did not take offense to his comments I was a bit surprised that I was that far off. At the same time I was now excited at the prospects of making it sound better than it already had.

Once we discussed the game plan to “fix” the system then we addressed the bass first.

…………

I am very happy with the process and results of working with Jim. The system sounds great and I learned a ton throughout the process. It is good to know that I have the system sounding its best within its current environment.

I should note that my general preference was for a bit too much bass in my system which was destroying the details and tonality of most music. I can now appreciate a seamless bass and additional details in the music. I cannot even pinpoint where the bass is coming from now.

I should also note that I thought having the speakers further apart was the solution for a wider sound stage, which is not the case. I now get a much wider sound stage by having the speakers closer together. I now have a continuous “Wall” of music across the soundstage.

…………

To read more detail, you should go to the original website. To save time, we suggest starting at Post #190.

Here is the link:

http://www.martinloganowners.com/forum/showthread.php?t=7730&page=13

Contact Jim Smith to schedule or to make any inquiries

________________________

The following is another excerpt. The first part is from the evaluation of the system:

System Evaluation

As I promised in an earlier post, below are the results from Jim Smith’s observations concerning my listening room and setup. Jim really is a class act and all of the critiques he offered were professional and honest. My wife and I enjoyed his visit to our house immensely and felt very comfortable talking with him.

We are confident in his ability to take our system to the next level and to do so without buying anything new. While Jim has a lot of accolades to his name along with a list of references from many professionals in the business, he was very humble and patient with our questions.

I’m sure our setup does not even come close in cost to the systems he normally works with, but he was extremely kind in his compliments and treated my wife and me as if we were millionaires looking to spend a fortune.(Which we are not!)

The intent for his coming out was by design to be an evaluation of approximately 2 hrs.with some discussion of a future time to have him back out if his services were needed. The only negative about this approach was not being able to solve the issues immediately, but rather me having to display some patience on my part and wait for our next meeting.

Jim graciously gave me permission to post some of his critiques of my setup on this forum.

However let me add that there would have been much more work to be done if I had not read his book. It truly is a great value and a valuable reference to getting better sound. Even if I could not afford Jim’s services I would still enjoy a much more musical system due to the advice in his manual. I’m sure others that are more careful in their reading of his book, and follow his tips thoroughly concerning speaker placement, can be confident they will have a much more musical sounding system. So without further ado…..

1. Overall sound too soft, ill defined.

2. A bit muddy – bass “wooly”.

3. No deep fundamentals – no authority in the bass. Piano sounds emasculated.

4. Need to re-evaluate bass performance, based on seating, speaker position, and – to a minor extent – separation.

5. One reason the sound is lacking may be that the bass drivers are in opposite acoustic polarity to the screens. We’ll need to simply reverse it and see.

6. Speakers too close together (BTW – this is very rare – they are usually too far apart).

7. Too many absorptive wall treatments, sound is dead, lacking life.

8. 50-60Hz and down too low in amplitude.

9. Mid-bass peaks around 80-100 Hz.

10. Another peak around 200 Hz.

11. Another peak around 2-2.5 kHz, causing unwanted signature to string sound, and making loud female vocals a bit “shouty”.

12. Extreme top end a bit down. May need to toe in speakers very slightly to restore it.

13. Slight but pervasive “awk” coloration, probably related to the 200 Hz peak.

14. Speaker tilt may need to be addressed.

My biggest concern was with #5. I wonder if others have noticed this issue with your Logan’s. Is this by design from Martin Logan or are both my speakers unique in this regard? Just curious. The next visit with Jim will be in late August, and once we are finished I will post again about the differences he made along with some new photos. This will be a long wait for me, but I know it will be worth the wait.

Glen

The next section is excerpted from the actual voicing process:

Hifi setup

On August 20th Jim paid me a visit and spent nearly 6 hrs. voicing my system to the room. He already had a good idea of what to expect from a previous visit which entailed a brief listening session several weeks prior. There were several areas of concern that he noted in which my setup was deficient. He addressed these areas this past Thursday and provided me with an excellent reference point when listening to music. Anyway on to the good stuff:

First off Jim is highly focused and goal oriented when he is working. He does not stop to eat or drink anything until he is completely satisfied with the sound. I tried my hardest to get him to take even a glass of water, but to no avail, he was relentless in his goal and continued to work straight through to the end! When he first arrived he sat down and listened for a couple of minutes to familiarize himself with his previous visit and compared this to his notes.

OBSERVATIONS

Upon Jim’s exit I sat down and listened to multiple cd’s and quickly realized the changes that were made were much more pronounced than I had first thought. The improvement in the bass was absolutely huge. Never did I imagine that the Vantages’ were capable of such deep bass with well-defined definition.

I am not saying that the bass was louder, but there were now lower registers being played in the music that I had never noticed before. This added a new dimension to the music that was sorely missing. Jim had mentioned on his previous visit that there were notes missing and this contributed to the instruments sounding emasculated. I did not disagree with him, but since I had no reference I was not entirely sure what he meant by this at that time. Now I know!!! It’s amazing that when the bass is right how much this adds to ones listening pleasure.

As for the soundstage, I wish I had the vocabulary to describe the difference. There is just a certain rightness to it that you can’t help but wonder at how two speakers can do this. Of course I know there are many others out there that have even more magic in their systems than I do, but just to experience this in music you know backwards and forwards is extremely satisfying. The Vantages really do just get out of the way and play music.

Musical detail has increased along with a much livelier presentation. My theory is that because I had the panels leaning too far forward then this attributed to some of the details being lost or masked. I was probably realistically listening to only the top 1/3 of the panel and this was squashing some of the nuances that are so important to the music. Why I had decided on that rake a few months ago is beyond me, but it definitely opened back up when Jim used his method.

I could not be more satisfied with hiring Jim and his many years of experience. The enjoyment that I have gotten just these past few days has been more than worth the effort and cost. I don’t know if I will try to get that last 1% or not, but the difference he has made already makes me a satisfied customer!!!!

Glen

To read more detail, and there is a lot of it, you should go to the original website. To save time, we suggest starting at Post #79 and go to at least Post #97.

Here is the link, beginning at Post #79:

http://67.19.167.226/~tdacquis/forum/showthread.php?t=4868&page=6

Here is an example of unsolicited correspondence that Jim has received, this time from Glen – the poster above:

Jim, I can’t tell you how much more involving my system is now.  (My wife) listened to one of her favorite records last night and she was astonished with the changes.  She even sent a text message explaining to me how she now feels more part of the music.  Thanks again and keep up the good work.

And another:

Hey Jim,

I wanted to follow up with you since it’s been about three months when you last visited to voice my system.  This morning, like many other mornings, I was enjoying some vinyl and thought to myself that what you did was the best investment I had made for my Hi-Fi ever.  Thank you again for your help and providing me with many wonderful listening sessions.

Contact Jim Smith to schedule or to make any inquiries

________________________

Below is a report on another voicing session:

My Experience with System Voicing by Jim Smith of Get Better Sound

I won’t dwell on the mechanics and logistics of the experience, since those are well documented elsewhere, both online in various forums and on Jim’s own site. And the overall structure stays pretty consistent, as I understand it, even though each situation is unique and may call for changes in one way or another.

I think it is fair to assume that the “general” structure involves Jim arriving the day or evening before the primary working day in order to spend some time getting familiar with the existing setup—first impressions of how it sounds and lots of questions about what the client’s goals and priorities are with the system and why choices were made to arrive at the current equipment and configuration and layout in the room (audio preferences, financial restrictions, “bargain” purchases, etc.). In other words, to what extent is the current configuration the result of a conscious, strategic series of selective purchases and articulated audio (or aesthetic or practical) decisions, as opposed to a discrete set of haphazard or fairly random purchases over a period of time.

The goal of the initial discussion is not to pass judgment or encourage changes in equipment—Jim just wants to understand the client’s goals and how the current setup seems to reflect those audio objectives.

One of Jim’s great strengths as an independent consultant is that he is NOT pushing equipment changes or additional purchases on the client. The task he sets for himself is to understand the audio priorities of the client and then, within the scope of the current equipment and practical considerations of room (size, acoustical environment, etc.) and aesthetics (e.g. SAF), voice the system to best effect.

The second fairly unique characteristic and strength of Jim’s approach lies in his own superb ability to listen to known recordings, know what they should sound like, and then translate that knowledge into practical suggestions regarding setup. While that sounds fairly straight forward, I know from experience that it is FAR from as easy as it sounds. Otherwise we could all attend a few stereo shows, listen to a few great-sounding rooms listening to our own favorite test tracks, and return home knowing what it should sound like and tweak till we achieved that sound. Wish it were so.

Part of Jim’s magic lies no doubt in his year’s of experience as a recording engineer, dealer, and audiophile, of course. Developing a core set of source materials with which one is intimately familiar is part of the experience; knowing what it actually should sound like is a step beyond just being “familiar,” and I think that’s where Jim surpasses many others in the field.

So I’d say that’s the first big step in system voicing—getting the lay of the land, as it were, using KNOWN source materials—much of which might be accomplished on the day or evening before the hands-on day of active voicing.

Of course it is an iterative process, but knowing what one is hearing and what one should be hearing is the essential prerequisite to everything else. Having the extensive experience with a wide variety of equipment and environments and configurations is a prerequisite to the next step: deciding where to begin making changes in layout or positioning or environment or any one of many other factors (in my case, we spent much of our time on adjusting crossover parameters on my tri-amped, multi-speaker configuration).

There’s an efficiency of approach that’s really critical and usually undervalued, I believe, to making improvements in a reasonably logical, systematic, and therefore productive manner—as opposed to the more usual process of making individual changes, often seemingly random, over long periods of time, as I suspect most of us do on our own, with no time constraints.

I actually think there’s a qualitative benefit to systematically tackling the overall voicing process in a compressed time period. Try this, move that, listen, evaluate. Get this right first—or at least moving in the right direction—so that a) we confirm that we’re thinking correctly about cause and effect and b) we’ve corrected enough in one area to begin judging a dependent area meaningfully. Adjust the upper bass spike so we can *hear* the lower mid-range and know what it’s doing right or wrong. This is a system voicing PROCESS.

Never fear, I’m confident that it won’t replace the inevitable long-term tweaking and equipment changes to which we’re all willing slaves. I consider it a substantially different process, to be honest.

So the process is not just iterative but iterative with a plan, a strategy, and a known (to Jim, at least, since it’s his source material being used) result—so you know when you get there! Perhaps more than any other single feature, this is what separates Jim’s approach from the pretenders: he goes in with a game plan, determines a baseline (current sound) and a goal (what it should sound like, referenced to a client’s priorities), and then systematically works through an iterative process to get there in as efficient a manner as possible.

In my case, we spent maybe 4 or 5 hours in preliminary work (without changing anything) the evening before, and then another 5 or so hours actually voicing the following day. Your mileage may vary—I know Jim has spent longer and I suspect shorter time on other systems. But I also suspect that my experience was fairly typical.

It easily represented the best “bang for the buck” that I’ve spent on my system over the years. That’s as glowing an endorsement as I could make and I make it willingly.

Jerry P., Wimington, DE, Dec. 5, 2009

RTA نام اختصاری Real Time Analyzer وسیله ایست که مهندسان آکوستیک از اون برای اندازه گیری و مشاهده اطلاعات دامنه و فرکانس یک موج صوتی در یک نقطه از اتاق استفاده میکنند. یک RTA برای مهندس آکوستیک حکم یک ولتمتر رو برای مهندس الکترونیک داره و RTA اولین و ساده ترین ابزار اندازه گیری اطلاعات موج صوتی در فضاست.

قبل از 15 بهمن سال 88 که من هنوز تو دهکده بودم تصمیم گرفته بودم یک RTA سفارش بدم بیاد ایران اما بعد از خروج از دهکده فراموشش کردم. البته الان فکر میکنم استفاده از یک نوت بوک و یک میکروفن خوب و یک نرم افزار مثل True RTA جذابتره تا خریدن یک RTA .

ببینید هر موج صوتی در اتاق در هر نقطه یک شدت دامنه داره که با واحد SPL میسنجند و با تغییر این دامنه در طول زمان ما یک سیگنال رو با بردن تو حوزه فرکانس آنالیز میکنیم یعنی یک RTA هم میتونه به شما شدت دامنه موج رو تو هر نقطه بگه و هم با تعیین یک مدت زمان به شما پاسخ فرکانسی سیگنالی که تو این مدت پخش شده رو نشون میده. البته ممکنه پارامترهای دیگر آکوستیکی رو هم یک RTA نشون بده که من خیلی اطلاعاتی در مورد انواع اونها ندارم.

هر RTA یک میزان دقت و وضوح تو ناحیه فرکانسی داره و بعضی ها 1/3 اکتاو هستند و بعضی ها هم بیشتر از این مقدار دقت دارند (نرم افزار True RTA ای که من دارم تا 1/24 اکتاو دقت داره)  و از 20 تا 20 کیلو هرتز شما یک منحنی رو بر مبنای فرکانس میبینید.

برای استفاده از RTA ما به سیستم باید یک سیگنال رفرنس اعمال کنیم که بدونیم تو همه فرکانسها یک میزان انرژی مشخص داره و برای این کار یا از White noise استفاده میکنند و یا از Pink noise . وایت نویز از 20 تا 20 کیلو برای تمام فرکانسها یک دامنه ثابت داره اما چون تو طبیعت ما چنین سیگنالی تقریبا نداریم میاییم از پینک نویز استفاده میکنیم که با افزایش فرکانس دامنه هارمونیک بشکل مشخصی (عکس نسبت فرکانس) کم میشه.

وقتی سیگنال پینک نویز رو سیستم پخش میکنه میتونیم با RTA بفهمیم تو هر نقطه وضعیت پاسخ فرکانسی چگونه هست و مثلا اگر یک افت انرژی یا یک افزایش انرژی تو یک محدوده داریم میگردیم دنبال دلیل موضوع و سعی میکنیم با تغییر شرایط آکوستیکی و یا تغییر مکان بلندگو اون کاهش یا افزایش انرژی رو درست کنیم.

مثلا جیم میگفت یکی از مشتری هاش زنگ زده بود و گفته بود که قبلا صدا خوب بوده اما الان  صدا بد شده و جیم رفت خونه یارو دید تو یک نقطه از فرکانسهای پایین RTA یک دامنه زیاد رو نشون میده که فهمیدند صاحبخونه با جابجایی مبل این مشکل رو تو فرکانسهای پایین بوجود آورده (نمیدونم داستان رو درست نقل کردم یا نه اما حافظه من بیشتر از اینی که نوشتم رو بخاطر نداره).

همه ما میتونیم از RTA استفاده کنیم و ببینیم وضعیت فرکانسی جایی که صدا میشنویم چگونه هست و مرحله به مرحله سعی کنیم با ایجاد تغییرات پاسخ نهایی رو تا حد ممکن هموار و هم سطح کنیم. البته بعضی ها این روش رو دوست ندارند و فکر میکنند استفاده از یک اکولایزر دیجیتال مثل همونی که آکوفیض یا Tact زده خیلی راه حل راحت تر و بهتریه اما من فکر میکنم این راه حل ساده تر نتیجه اش به خوبی تغییر شرایط آکوستیکی نیست.

الانم دارم میرم پیش مهندس 😉

مدتی هست که چیزی ننوشتم و البته دلیلش گرفتاری هام بوده ، قبل از پایان تعطیلات عید چند تا مطلب نوشتم که خیالم راحت باشه اگر نتونستم تا مدتی مطلب ننویسم سرعت میانگین نوشتن ام پایین نیومده باشه.

اوضاع خوب و مرتبه و من دارم روی بقیه مطالب Subjective Audio Reviewing کار میکنم و دوست دارم بدلیل اهمیت موضوع تا حد ممکن نوشته هام فکر شده باشه و برای همین خیلی عجله ای براش ندارم.

توضیح اصطلاحات های فای هم بعد از نوشتن چند مطلب شروع خواهد شد و من سعی خواهم کرد هم یک توضیح ای در مورد مفاهیم داده باشم و هم اگر بتونم یک روشی رو برای تشخیص پیشنهاد بدم.

زیبایی صدای Audio Note Ankoru تو خونه مهندس پوینده هم دلیلی شد تا در مورد اینکه چرا از نگاه Subjective من این صدا رو خیلی دوست دارم بنویسم و اینکه چرا با کمک لامپ ها میشه چنین صدای زیبایی رو شنید. خیلی از مجلات در مورد تفاوت لامپ و ترانزیستور نوشتند که بنظرم خیلی جاها خیلی نوشته شون خوب نبود و کلا نوشته هایی که تابحال خوندم اونقدر جالب نبود که راضی ام کنه ، سعی میکنم ایده هام رو شرح بدم. فعلا اینجا رو ببینید.

اما مطلب امروز مربوط به پاسخی هست که آقای Michael L. Davis (به نام Mike میشناسیمش) به نامه من دادند. آقای Mike صاحب سایت Audio Federation و مجله Spintricity هست و میشه روی نگاهش حساب باز کرد. من نوشته هاشو دوست دارم و همیشه به سایتش سر میزنم.

من از مایک در مورد تجربه DPOLS پرسیدم و پاسخ ایشان چنین بود:

Hi Amir,

Yeah, I think Romy has something here. It makes sense anyway. Romy posted this a long time ago, and we’ve had some time to mull over the idea.

Some of the issues I see:

* It gets more confusing when there are multiple people with multiple tastes involved. Some prefer a fuller sound on the bottom so that the overall freq response is flat [more like live music] – some prefer the best possible transparency, etc.

* It is very easy to keep moving the speaker so that it appears to get better and better with each move – yet overall the sound gets worse. I’ve seen this with hardware modders too. I think this has to do with each move improving one area of the sound inadvertently at the expense of another

* It is very easy to just give up after finding a local maxima [using simulated annealing as a model of speaker position optimization]. I.E. you find the best spot within a particular inch or two and particular orientation and you just want to sit down and listen to some music 🙂

* The dpol changes if you change the amp, cd player, cables, power cords, etc. and probably when there are more people in the room. Some of these changes are minor – but dpol is all about minor changes having large impacts…

Anyway, as a store we change things all the time – and so DPOL is hard to maintain over time. We more or less just try to minimize any negative interactions with the room and be happy with that – though this is another approach to speaker placement in and of itself and it has paid off big time once in a while.

One thing I have not seen addressed is how to mark the position of speakers accurately. Tape on the floor is really horribly unhelpful when we start talking about positions more highly resolving than half an inch or so, and about, oh, 5 – 10 degrees of arc or so.

Happy to hear you all are getting good results. Have these results given you a deeper perspective on this subject that you would like to share?

Thanks,
Mike.

جالبه بدونید نظر آقای آرتور سالواتوره رو هم جویا شدم:

Dear Amir,
I’ve never met Romy, but we have communicated in the past, we have links to each other and I visit his website once a month or so.
I’m not sure about DPOLS, because I have never experienced a situation where 1/16 or 1/32 of an inch made such a huge difference, as described in the short essay, and I’ve heard many thousands of setups.
I obviously realize the critical importance of speaker positioning and room acoustics, and I have spent months, and sometimes even years, optimizing just one set-up (my own system of course), but not to the degree of an ultra tiny movement that I can not even see with my eyes or measure (for repeatability).
Sadly, most audiophiles are not even in “the optimum zone”, let alone the one perfect spot, and that should be addressed first before moving on to a goal which may not be feasible for most.
Best Regards,
Arthur Salvatore
www.high-endaudio.com

واقعا باید از رومی (www.goodsoundclub.com) تشکر کنیم بخاطر اون همه اطلاعات با ارزشی که در انجمنش میگذاره و سعی میکنه مسیر اشتباهی رو که خیلی از ماها رفتیم بهمون نشون بده.

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چند شب پیش که مشغول پیدا کردن نقطه مناسب بودیم که طی یک تغییر یک سانتی متری (عقب رفتن بلندگوی سمت چپ در راستای محور خودش) متوجه شدیم صدای بلندگوی سمت چپ خیلی خوب شده ، هم اصلا حالت فوروارد نداشتیم و هم انگار بلندگو تا حد زیادی disappear شده بود و صدا حتی وقتی گوش در فاصله 30 سانتی متری بلندگو بود انگار از بلندگو شنیده نمیشد و از یک نقطه ای در فضا به گوش میرسید. خیلی تعجب کردیم و البته خوشحال شدیم و تصمیم بر این شد به بلندگوی سمت چپ دست نزنیم و شروع کنیم به جابجایی بلندگوی سمت راست (با همان فاصله از دیوار عقب و با همان میزان toe-in) در راستای خط واصل بین دو بلندگو . یعنی فقط بلندگوی سمت راست را از بلندگوی سمت چپ دور یا نزدیک میکردیم. ما برای اینکار از فواصل بیشتر از 3 سانت استفاده کردیم، یعنی هر بار بلندگو را با گام های بزرگتر از 3 سانت از بلندگوی سمت چپ دور و یا نزدیک میکردیم که نتیجه ای نگرفتیم.

در شب بعدی تصمیم گرفتیم حداکثر گام حرکت رو یک سانتی متر در نظر بگیریم و بلندگوی سمت راست رو از دورترین فاصله ممکن با گام های یک سانت یک سانت به بلندگوی سمت چپ نزدیک کنیم. 9 سانت رو در 9 گام اومدیم به سمت چپ که تغییر مثبتی مشاهده نشد اما در دهمین سانت یک دفعه صدا فرق کرد و از اونجا شروع به تغییر با گام 3 میلی متر کردیم و در یک نقطه ای توقف کردیم.

الان صدا به اندازه بلندگوی سمت چپ خوب نیست اما خیلی وضعیت بهتری داره. من بر گشتم خونه و امروز به آقای الکساندریان زنگ زدم که ایشان به من در مورد تجربه امروز صبحشون گفتند.

آقای الکساندریان امروز صبح که ساعتی در خانه کسی نبود شروع به شنیدن یک قطعه موسیقی کردند و بعد از چند دقیقه احساس کردند انگار موسیقی داره ایشون رودر خودش غرق میکنه. هر چی بیشتر میگذشت این احساس بیشتر بود که کشش موسیقی خیلی بیشتر شده و مغز از حالت توجه به پارامترهای صدا مانند Soundstage و Timing و … کاملا خارج شده و مغز داره کاملا جذب موسیقی میشه.

انگار صدای Vocal کشش خیلی بالایی داشت که کاملا مغز رو در یک حالت غرق شدن در موسیقی و فراموش کردن هر چیزی غیر از لذت شنیداری قرار میداد. یک نوع از خود بیخود شدن و یکی شدن با موسیقی ، بقول خودشون absorb شدن.

انگار صدا در نقطه خوب یک دفعه مثل روشن شدن چراغ آدم رو متوجه نمیکنه و این موسیقی هست که بعد از مدت نیم ساعت شروع به کشیدن مغز و غرق کردنش در موسیقی میکنه.

شنونده بعد از دقایقی حس کشش بیشتر و غرق شدن پیدا میکنه و نه در لحظه اولی که سیستم رو Play میکنه.

خیلی جالبه ، موسیقی در این حالت تبدیل میشه به یک چیز سرمست کننده مثل آب شنگولی و شنونده دلش نمیخواد موسیقی به پایان برسه.

در مورد مکان بلندگو یک مساله ای رو تجربه کردم که رومی هم بهش اینجا اشاره کرده بود و لازم شد در موردش بنویسم. من یکبار دیگه دو جمله از رومی مینویسم تا کسانی که هنوز اهمیت نقطه قرار گیری بلندگو رو خیلی جدی نگرفتند نگاهی دوباره به این مساله مهم داشته باشند:

Generally ANY properly Macro-Positioned speakers should over perform in musical scale ANY improperly Macro-Positioned inhalation. Yes, a cheep but good consumer amplifier with a inexpensive old JBL monitor, properly Macro-Positioned, will literally destroy a performance of $250.000.00 high-end installation of the installation is … against the interests of the room. Do I have to pump you up more?

معنی جمله بالا اینه یک سیستم خیلی خیلی ارزان در نقطه DPOLS صدای خیلی خیلی بهتری از یک سیستم 250 هزار دلاری در نقطه غیر بهینه داره.

I can assure you that if you are not a Moron™ and each time you heard any more or less interesting sound from any playbacks then the loudspeakers, in one way or other and in most of cases completely accidentally, were near the AEZ.

معنی جمله بالا اینه رومی به ما اطمینان میده هربار که یک صدای تاثیرگذار شنیدید حتما بلندگو در آن زمان در نزدیکی نقطه ایده ال بوده.

اما جالبه بدونید من چند وقت گذشته که مهمان مهندس پوینده عزیز بودم و چند ساعتی برای پیدا کردن یک نقطه نسبتا خوب وقت صرف شد هم من و هم مهندس متوجه شدیم انگار ولوم صدای بلندگوی سمت راست (فکر کنم بلندگو سمت راستیه بود) بیشتر از بلندگوی سمت چپ هست که باعث شد کمی مهندس نگران بشه. من از روی Preamp بالانس بین دو کانال رو کمی تغییر دادم تا صدا درست بشه . اون موقع ما حدس زدیم ممکنه دو تا کانال آمپلی فایر Gain متفاوتی دارند و یا یک مشکلی در مدار هست که به کابل کربنی گیر دادیم و چون میدونستیم جدیدا کابل های Van Den Hul در ایران Terminate میشوند قرار شد این Interconnect ها با مدل Terminate شده در هلند تعویض شوند.

تجربه دیگر خانه آقای سماوات بود که بعد از پیدا کردن یک نقطه خوب من حس کردم ولوم صدای بلندگوی سمت چپ بیشتر از بلندگوی سمت راست هست و فکر کردم شاید مشکل از آمپلی فایر هست و به بایاسش گیر دادم که امکان تنظیمش نبود.

دیروز در خانه خودم کمی روی مکان بلندگو وقت گذاشتم که به یک نقطه نسبتا قابل قبول رسیدم و باز دیدم ولوم بلندگوی سمت راست از سمت چپ بیشتر هست و با Pre Krell با یک درجه تغییر دو کانال رو بالانس کردم. چون مطمئن بودم Krell ام مشکلی از این بابت نداره حدس زدم میتونه این مساله نتیجه مکان جدید بلندگو باشه که اتفاقا وقتی امروز مقاله رومی رو در خونه میخوندم به این مساله برخوردم.

اینجا رو ببینید ، رومی میگه در نقطه مناسب ممکنه Gain کل که حاصل جمع Gain سیستم با Gain اتاق هست برای یک بلندگو بیشتر بشه و این مساله اصلا مهم نیست و باید با تغییر در Gain سیستم اونرو بالانس کرد.

نکته جالبی بود که گفتم بد نباشه شما هم بدونید و هر وقت یک مکان مناسب پیدا کردید و دیدید ولوم صدای دو بلندگو با هم فرق میکنه نگران نباشید.

مساله بعدی اینه اگر یک نقطه خوب برای بلندگو پیدا کردید و بعدش تغییراتی در آکوستیک و یا سیستم ایجاد کردید (مثلا یک پنل جاذب پشت بلندگو قرار دادید و یا کابل ای رو در سیستم عوض کردید) ممکنه دوباره مجبور شوید کمی روی مکان بلندگو کار کنید.

این مساله رو من تجربه نکردم اما رومی اعتقاد داره تغییر شرایط (چه آکوستیک و چه کامپوننت) میتونه روی مکان نقطه بهینه تاثیر بگذاره.

خب ، این روزها هر جا میرم ، وقتی برای Speaker Placement میگذارم و سعی میکنم یک نقطه خوب برای بلندگو در خانه دوستان پیدا کنم.

هفته پیش مهمان دوست بسیار خوبم جناب مهندس پوینده عزیز بودم که به تازگی از امریکا برگشتند. سیستم ایشان متشکل از ویلسون مکس ، آودیو نت آنکورو با پری ام 3 و سورس دیجیتال آکوفیض و کابلهای کربنی ون دن هول هست.

مثل همیشه آودیو نت به زیباترین شکل ممکن موسیقی رو روایت میکنه و منو به این فکر فرو میبره که آیا ممکنه اون زیبایی و حسی که در صدای این آمپلی فایر هست رو جای دیگه ای تجربه کنم؟!

من و مهندس پوینده عزیز سه ساعتی مشغول جابجایی بلندگو بودیم و در انتها یک نقطه خوب برای بلندگو پیدا کردیم ، نکته جالب اینجا بود که بلندگو حتی با کمتر از یک سانتی متر جابجایی از اون نقطه صداش کاملا فرق میکرد و اصلا میشد یک چیز دیگه.

آقای مارتین کالمز میگویند چندین نقطه خوب برای بلندگو (Neutral zone) در اتاق وجود داره که در هر نقطه یک سری فرکانسها بهتر و یکسری غیر دقیق تر پخش میشوند و هر نقطه ای خوبیها و ضعف های خودش رو داره و ما اون روز فقط یک نقطه رو پیدا کردیم و علامت گذاری کردیم و سعی نکردیم نقاط دیگری رو هم پیدا کنیم. در اون نقطه ای که ما پیداش کردیم هم bass جریان راحت تری داشت و هم Mid و mid/high خوب بود اما بنظر من high کاملا راضی کننده نبود.

پیدا کردن یک نقطه دیگر بنظرم حداقل یکی دو ساعتی وقت میبرد که در اون جلسه امکانش نبود و به همون نقطه اکتفا کردیم.

من از مهندس پوینده عزیز بخاطر این تجربه خوب تشکر میکنم و امیدوارم بشه در اون فضا روزی به DPOLS برسیم هرچند کار خیلی راحتی نیست.

تجربه دیگه خانه دوست خوبمون جناب آقای سماوات بود که من گزارشی از صدا نوشتم و در پست بعدی قرارش میدم . اون تجربه هم جالب بود اما اجازه بدید در پست بعدی در موردش بنویسم.

دیشب هم یکی از دوستان بتازگی ویلسون مکس خریدند و از من دعوت کردند تا صدای سیستم شان را با مارک لوینسون بشنوم. اگر قبلا یادتان باشد من صدای مارک لوینسون با ویلسون سوفیا را جایی دیگر شنیده بودم و نوشته بودم دوست دارم بجای سوفیا بلندگویی دینامیک تر خصوصا در میکرو رو با مارک لوینسون بشنوم. چقدر خوب شد این اتفاق افتاد و من ویلسون مکس رو با مارک لوینسون مدل 383 و سورس 390s شنیدم.

این دوست عزیز تا بحال مدلهای ویلسون کاب ، دوئت ، سوفیا ، وات پاپی 7 رو هم در گذشته تجربه کرده بودند و الان از ویلسون وات پاپی هفت به ویلسون مکس سیستمشون رو ارتقا دادند.

الیته باید بگم ایشان یک فضای کاملا اختصاصی برای شنیدن تدارک دیدند و قرار است بعد از عید اتاق رو کاملا آکوستیک کنند تا بلندگوی مکس که ابعاد بزرگتری در مقایسه با وات پاپی 7 دارد در یک فضای بهینه و مناسب Setup شود و من از این بابت خیلی خوشحالم چون برای بلندگویی مانند مکس باید فضایی مناسب تدارک دید.

نکته جالب تلفیق بلندگوی دینامیک مکس با مارک لوینسون بود که صدا رو به همون سمتی که باید شیفت داد و صدا اون سرزندگی و Presence زنده رو با تلفیق مکس و مارک لوینسون پیدا کرد. مارک لوینسون با سوفیا صدایی slow داشت اما مکس خیلی خوب با مارک لوینسون Match شد و صداش در مقایسه با سوفیا Live up شد.

حتی ویلسون وات پاپی هفت هم تفاوت صداش با مکس زیاد بود ، این مقیاس تفاوت برای من جالب بود چرا که غیر از Stage بزرگ تر با عمق ، عرض و ارتفاع بیشتر ما شفافیت و وضوح بیشتری رو در صدا تجربه میکردیم. وات پاپی تا زمانی که صدا روی مکس سوئیچ نمیشد راضی کننده و خوب بود اما وقتی صدا روی مکس سوئیچ میشد تفاوت اونقدر بود که دلمون نخواد به سیستم 7 برگردیم.

ویلسون مکس کاملا bass متفاوتی داره و واقعا گسترش فرکانسی ناحیه پایینش با وات پاپی (چه 7 و چه 8 سری وات پاپی) قابل قیاس نیست اما مساله جالب برای من غیر از تصویر بزرگتر مساله Low distortion بودنش در مقایسه با ویلسون هفت بود. انگار صدا refine تر شد با خلوص و transparency بیشتری که ره یافت بیشتری به شنونده میداد تا اون low level Information صدا رو بدون از دست دادن کنترل در Micro صدا بشنویم.

دریچه بزرگتری از صدا در تمام نواحی فرکانسی (این شاخص در ناحیه mid خیلی مهم هست) بروی شنونده باز میشه و سکوت زیاد زمینه و دقت در کنترل میکرو دینامیک صدایی راحت اما با وضوح بالا به ما میده که decay های صدا براحتی تا پایان ای که محو میشوند شنیده میشه.

فقط دیستورشن پایین مهم نیست چرا که بلندگوهایی در دنیا هستند که خیلی Clean و Low distortion هستند اما Texture صداشون اون حالت راحت و Natural رو نداره اما ویلسون مکس در مقایسه با وات پاپی 7 در عین دادن جزئیات و وضوح بیشتر صدایی راحت و کنترل شده با Texture بی آزار داشت.

بنظر من ویلسون در مدل دوئت دینامیک هست اما کمی دینامیک رو به شکل Exaggerated ارائه میده و در مدل سوفیا بیشتر حالت Slow و Soft داره و به وات پاپی 8 که میرسه یک تعادل خوب بین دینامیک و راحتی ایجاد میکنه اما در مدل مکس صدا سرعت و وضوح بیشتری داره اما بدون از دست دادن Texture که برای من خیلی جالبه. برای صدا گرفتن از هر کدوم از این بلندگوها باید در پیدا کردن یک Upstream Match دقت کنیم و مثلا سوفیا رو به یک آمپلی فایر خیلی Soft و round نزنیم تا بتونیم نتیجه خوبی بگیریم. من تو این مدلهای ویلسون از کاب هم خیلی خوشم میاد که از طرح DAppolito استفاده میکنه و صدایی خوب داره.

نکته دیگه اینه ووفرهای مید و توییتر بلندگوی مکس هم به شکل D’Appolito Array (این طرح مال آقای Dr. Joseph D’Appolito طراح Snell هست) چیده شده که حسایتش رو به آکوستیک در یک محور میاره پایین. اگر دقت کرده باشید سری های بالای بلندگوهایی چون Tidal ، Kharma ، Dynaudio و Marten Design هم این نوع array هست.

Properly implemented, a D’Appolito array can produce a horizontal radiation pattern of widely dispersed sound while minimizing the music-blurring first reflections of soundwaves off the floor and ceiling

زیاد شلوغ کردم ، یک وقت باور نکنید من ویلسون هشت رو فراموش کردم ، نه ویلسون هشت رو دقیقا اندازه گذشته دوست دارم و شنیدن مکس نمیتونه تغییری در نظرم بده چون وات پاپی 8 یک بلندگویی است که خیلی خوب یک بالانسی در شاخص های صدا داره.

خب این اظهار نظرات در شرایطی بود که چند ساعتی صدا شنیده شد آنهم نه در شرایط مناسب. حرف زدن در مورد قابلیتهای میکرو یک بلندگو نیاز به شرایط مناسب تر و شنیدن دراز مدت تر داره. هر چقدر ما در شرایط مناسب تری و با کامپوننت های رفرنس تری از ویلسون مکس صدا بشنویم به درک بهتر و عمیق تری از توانایی های این بلندگو میرسیم.

بحث سر جابجایی بلندگو بود که به مقایسه وات پاپی با مکس کشیده شد. خب اونجا هم من و این دوست عزیز کمی روی placement کار کردیم و به نتایج جالبی رسیدیم. اون مکان هنوز هیچ کاری از نظر آکوستیک روش انجام نشده بود و قرار بود بعد عید درست بشه اما در همان فضا که تمامی سطوح سنگ و گچ بود بدون هیچ جاذب یا دیفیوزری یک صدای قابل قبول از مکس شنیده شد البته در نقطه ای که پیدا شد.

من دیدم بلندگوی سمت راست کمی صداش استرس بیشتری از سمت چپ داره و برای همین اول (اتاق هیچ تقارن و حالت مربع مستطیل ای به نسبت مکان بلندگو نداشت) بلندگوی سمت راست رو کمی جابجا کردم و سعی کردم بیارمش در نقطه ای که محور مستقیم موج صوتی هم در عقب و هم در جلو به یک شکستگی (تقاطع دو دیوار) منتهی میشد ، با تعجب دیدم صدای بلندگوی سمت راست خیلی راحت تر و آرام تر شد و دیگه اون استرس قبل رو نداشت.

یک نقطه خوب برای این بلندگو با جابجایی در مقیاس کوچک تر پیدا کردم و رفتم سراغ بلندگوی سمت چپ و اون رو بر اساس زاویه toe in و محور بلندگوی سمت راست با در نظر گرفتن نقطه شکست جابجا کردم. وسایل اندازه گیری دقیق در دسترس نبود تا فواصل رو دقیق تر تنظیم کنیم اما با کمی ور رفتن با بلندگو در مقیاس کوچک بلندگوی سمت چپ هم به یک نقطه خوب رسید.

وضعیت خیلی بهبود پیدا کرد و صدای کتی میولا در فضا بلند شد ، صدا وقتی بلندگو در جای خوبی هست چون استرس نداره میشه بهش خیلی ولوم داد بدون اینکه شنونده از صدا آزرده بشه.

خلاصه تو هر جلسه ای میشه با دو سه ساعت وقت یک نقطه خوب پیدا کرد و وقتی نتیجه خوب میشه آدم لذت میبره.

از این دوست خوبمون هم تشکر میکنم و بهشون بابت خرید ویلسون مکس تبریک میگم.

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