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.