Speaker Placement

Speaker Placement

دوشنبه 30 آوریل 2018
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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.

http://www.goodsoundclub.com/Forums/ShowPost.aspx?PageIndex=2&postID=15015

http://www.goodsoundclub.com/Forums/ShowPost.aspx?PageIndex=1&postID=4421#4421

http://www.goodsoundclub.com/Forums/ShowPost.aspx?PageIndex=12&postID=14757

http://www.goodsoundclub.com/Forums/ShowPost.aspx?PageIndex=1&postID=2073#2073

http://www.goodsoundclub.com/Forums/ShowPost.aspx?PageIndex=1&postID=13774#13774

http://www.goodsoundclub.com/Forums/ShowPost.aspx?PageIndex=15&postID=24789

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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