Detailed Speaker Setup and Optimization

[Amir]

Romy the Cat wrote :

1) When the loudspeakers are placed into the DPoLS then all characteristics of sound improving very strongly: imaging, space localization, transient, dynamic range, space presentation, tonal contrast and many other. Even the tonal imperfections of reproduction become way less notable and less prominent. What is characteristic that the improving takes abruptly, very expeditiously and swiftly.

2) The strongest improvement takes place in the subjective domain, reflecting the emotion and spiritual content of recording. The DPoLS highlights the energy of performance; boosts the ethical load of the musical content, highlight the intonations and the timbre connections of the musical phrases. Starting with a certain level of capacity of the rest reproduction chain it is possible to talk about not “reproduction” but about the reinstating and resurrection of the “original energy of live”.

3) A conversion from a regula-audio sound to the “alive sound” takes place very rapidly when the speakers enter the DPoLS. This conversion is greatly catalyzed by an ability of a playback to handle LF.

4) DPoLS exist for mono and stereo installations. In case of stereo the DPoLS is a correlation of both DPoLS for each channel. The DPoLS spots for the individual left and right channel might not have the same location when the system operates in stereo mode.

5) The relation between the towing-in and excursion the loudspeaker into the room, when the loudspeaker is located in DPoLS, is very high. In DPoLS this relation is way higher when in a satiation when the loudspeakers are juts positioned on the “optimum zone” of a given listening room.

6) The correction of “quietly of Sound” by moving loudspeaker within DPoLS is imposable. Any deviation from the DPoLS is worsening sound. Since the loudspeaker is in the DPoLS then the room/system operate in its absolute maximum capacity.

7) When the loudspeakers are in the DPoLS then the “sweat spot” increase very dramatically and in many cases it might spread across the entire room. If the output from one loudspeaker would be even blocked then it be less significantly impact sound compare to the impact if the loudspeaker were not in the DPoLS.

8) The sensitively of loudspeakers from the minute arrangements made in playback system become very high. The loudspeakers begin to act as a very strong magnifying glass that highlights everything. However, this emphasize, if it emphasizes the negative properties do not necessary have a negative impact to the listening experience. I would say that that if you system slightly off the mark after the “highlight” then the subjective affect of this emphasize would be very different then if the loudspeakers would be not in the DPoLS.

9) When the loudspeakers are installed into the DPoLS (disregarding the cost and typology of the loudspeakers) then listener is far sooner get “hypnotized” by sound. The playback become to sound “significant”, “important”, demonstrating the “playback pomposity” and some pretentious. The process of listening perceived by a listener at the very different level and it is practically imposable to do the “casual listening”. The carelessness and the inattentiveness of listening become practically imposable. Sound become not juts a “Sound in the room” but an absolute dominating and demanding force in the room

10) The sensitively of the loudspeakers installed into the DPoLS to the effect of Absolute Phase become incredibly strong. Flipping the Absolute Phase in the DPoLS does not just change the structure of bass removes the fog from the lower midrange and settle down the HF but kind of turn the entire room upside down. To discover the DPoLS is imposable if the system is not set in the correct acoustical and electrical Absolute Phase.

 

[Amir]

I wrote about DPOLS in my persian weblog around 2009 :

بخش اول The “Dead Points of Live Sound” or DPOLS – صدا و سیستم های صوتی

 

[Amir]

Translated to English language:

بخش اول The “Dead Points of Live Sound” or DPOLS – صدا و سیستم های صوتی

 

[sbnx]

Yes, we can hope to measure distances with accuracy up to 1mm at best using good laser systems when positioning speakers.



Are you sure? One arc second is a deviation of 5 micron at a distance of 1meter. Are you saying it is audible and affects sound quality?



How we get absolute localization by ear? We count taps?



Ok, let us admit we accept it. How can it used to make systematic meaningful adjustments? We need two hundred 5 micron displacements to displace 1mm.

As pointed bellow , adjustments must be repeatable and easy to check. We can't rely on audible memory to last forever.

In general, the approach is: listen to a snip of music, assess what is heard, identify sonic malidy, adjust the speaker to correct the issue. (For example, the adjustment could be to bump the speaker forward.) Listen again and see if the issue is corrected. Rinse and repeat until everything is in place.

What I mean by repeatable is: suppose in the example above the issue is corrected by a bump forward. If I go over to the speaker and give it a bump backward then the sonic malidy will re-appear.

I am not after absolute localization of the speaker. As was discussed we can't measure accurately enough anyway. What I am after is nudging, bumping, tapping etc the speaker into the position where everything is "correct".

 

[wil]

Hello microstrip,

Thanks for posting this. I had never even heard of this "cat" until a few months ago when someone metioned his DPoLs idea in another thread. I guess the internet is a big place.

Could you expand on this comment -- "I post it as I think the original concept is being manipulated and is being abusively used in audio debates." I don't understand abusively used idea. Maybe you can point me to a few posts so I can see what you mean.

You posted -- "his concept aligns with extreme audiophile practices but remains largely unexplored in mainstream acoustics research."

I agree with this. I have read many, many papers and texts on audiology and spatial hearing. Much of what the researchers report I observe in speaker setup. However, they are off by at least an order of magnitude in hearing perception. I reached out ot one audiologist to see if he was willing to engage in a conversation or allow me to demonstrate this for him. No resonse -- sigh. I may try a few others to see if anyone is interested.

Hi @sbnx

Would you elaborate about the order of magnitude regarding spatial hearing that the Audiologists are unaware of?
Thanks!

 

[wil]

I think DPOLS is not related to listener position and asymmetry of ears has no affect on sound. When speakers are in DPOLS the sound is good in all area of room not only in listener position.

Right, as I understand, it’s more about getting the speakers right in the room, and not so much as to a particular listening position.

 

[Elliot G.]

Right, as I understand, it’s more about getting the speakers right in the room, and not so much as to a particular listening position.

I agree with this as IMO there is no particular listening position that I look for or ever looked for. There is however IMO a proper/correct/excellent/great/and any other word one chooses for a pair of speakers in an individual room. The entire sound locks in place, the sensation of speakers is dramatical decreased and the sense of effortlessness and space is dramatically increased. As I have said before , a quote from Mozart and Debussy, that the music is in the spaces between the notes. When you can experience this then IMO you are on your way.

 

[microstrip]

In general, the approach is: listen to a snip of music, assess what is heard, identify sonic malidy, adjust the speaker to correct the issue. (For example, the adjustment could be to bump the speaker forward.) Listen again and see if the issue is corrected. Rinse and repeat until everything is in place.

What I mean by repeatable is: suppose in the example above the issue is corrected by a bump forward. If I go over to the speaker and give it a bump backward then the sonic malidy will re-appear.

I am not after absolute localization of the speaker. As was discussed we can't measure accurately enough anyway. What I am after is nudging, bumping, tapping etc the speaker into the position where everything is "correct".

Thanks, I got your points. It is a subjective finding of the type "you must experience it to accept" and it is no way traceable or repeatable, the fundamental aspect to assess subjective matters.

I appreciate reading from your experience with your speakers, that fortunately seems not to be biased by the old fantastic writings about live or dead points ...

 

[wil]

In general, the approach is: listen to a snip of music, assess what is heard, identify sonic malidy, adjust the speaker to correct the issue. (For example, the adjustment could be to bump the speaker forward.) Listen again and see if the issue is corrected. Rinse and repeat until everything is in place.

What I mean by repeatable is: suppose in the example above the issue is corrected by a bump forward. If I go over to the speaker and give it a bump backward then the sonic malidy will re-appear.

I am not after absolute localization of the speaker. As was discussed we can't measure accurately enough anyway. What I am after is nudging, bumping, tapping etc the speaker into the position where everything is "correct".

To tmallins point: my speakers are over 700 pounds each with spikes suspended on wellfloat footers— on concrete slab. Steel on concrete.

I may be wrong, but it’s hard for me to imagine this moving with nudging or knocking as I think the metal on concrete bonds a bit and gets sticky over time under thus kind of weight and would be resistant to sliding. ??

 

[microstrip]

I agree with this as IMO there is no particular listening position that I look for or ever looked for. There is however IMO a proper/correct/excellent/great/and any other word one chooses for a pair of speakers in an individual room. The entire sound locks in place, the sensation of speakers is dramatical decreased and the sense of effortlessness and space is dramatically increased. As I have said before , a quote from Mozart and Debussy, that the music is in the spaces between the notes. When you can experience this then IMO you are on your way.

A very reasonable and sensible approach. However, it also applies particularly to Cage, but there the music is in the spaces between the noises ...

A practical question that only experience can answer - can we expect to have several such speaker positioning points in one listening room, or just one or two?

 

[Elliot G.]

A very reasonable and sensible approach. However, it also applies particularly to Cage, but there the music is in the spaces between the noises ...

A practical question that only experience can answer - can we expect to have several such speaker positioning points in one listening room, or just one or two?

I am only looking for one. That is sometimes determined by the set up in the room in advance and hopefully that can be made to work.
Layout, door placement, windows, dimensions all play a part of course and sometimes in non dedicated or not thought out space for sound or have other issues ( wife, decorator whatever) this becomes much more difficult.
If you are asking could there be more than one location I would say yes and no. Yes in that you can try anywhere , no because I think there is correct way to do it and then there is the have to do it this way. I don't think they are equivalent and the end result reinforces that opinion.

 

[sbnx]

Hi @sbnx

Would you elaborate about the order of magnitude regarding spatial hearing that the Audiologists are unaware of?
Thanks!

Let's suppose you have the left speaker in a perfect position and you are working on matching the right speaker. The time differential between the left and right speaker is what gives us stereophonic sound (phantom images). Summing localization occurs when signals arrive with less than 1 milliscond of difference. For example, panning curves used in mixing show the sound engineer how much to delay a sound or boost a sound to position it withing the soundstage. a delay of 1 milliscond will pan the signal hard left (or right). Most audiologists are speaking in terms of milliseconds or 100's of microseconds.

If we calculate how much time difference a 1mm movement to one speaker creates we come away with about 3 microseconds. (This is to first order). A tenth of a millimeter movement would then be 0.3 microseconds. This is what I mean when I say that I am at least 1 order of magnitude (more like two or three) different than the experiments that audiologists are reporting data from.

The bottom line is I know what I hear. And it is not just placebo or expectation bias. Other people hear the same things. And, I have a specific trajectory to the sound in mind. bump, bump, tap, tap, rotate spike etc, etc until the sound is perfect.

 

[sbnx]

Of course, having a science and math background, I think of a room as something like a surface plot. The Z-axis would be sound quality and the X and Y axes are the X,Y co-ordinates of the room. Not every postion within a room will give good sound. Few actually work. Some will be horrible. But there are local maxima where we can find excellent sound within that zone. But if you have the entire room to explore you can find the global maxima that is the best sound that room is capable of producing. I hope this makes sense. The pic below might help.

 

[microstrip]

Let's suppose you have the left speaker in a perfect position and you are working on matching the right speaker. The time differential between the left and right speaker is what gives us stereophonic sound (phantom images). Summing localization occurs when signals arrive with less than 1 milliscond of difference. For example, panning curves used in mixing show the sound engineer how much to delay a sound or boost a sound to position it withing the soundstage. a delay of 1 milliscond will pan the signal hard left (or right). Most audiologists are speaking in terms of milliseconds or 100's of microseconds.

If we calculate how much time difference a 1mm movement to one speaker creates we come away with about 3 microseconds. (This is to first order). A tenth of a millimeter movement would then be 0.3 microseconds. This is what I mean when I say that I am at least 1 order of magnitude (more like two or three) different than the experiments that audiologists are reporting data from.

Exactly - we can't get hope that science will help us to understand such sub-millimetric approaches. Not

The bottom line is I know what I hear. And it is not just placebo or expectation bias. Other people hear the same things.

I believe you, as I said. But once we bring others in the discussion you are opening a Pandora box. Do you want to go such path?

And, I have a specific trajectory to the sound in mind. bump, bump, tap, tap, rotate spike etc, etc until the sound is perfect.

Is it different from tap, tap, bump, bump?