Speaker placement the ultimate tweak!

[djwhog]

OK Bob Carver had a theory and there is something to it. The thickness of our heads and the time it takes the L sound to get to the right ear Vs the Left ear and the same on the R side sound to reach the R ear Vs the L ear. The recording design and the speaker placement and the impact on the sound time arrivals.

It can get pretty heavy in terms of math etc… Then when you read you will see familiar names and terms, with names like Doppler and then understand how it is used even in weather tools etc. to measure waves, times, effects etc.


The perceived frequency (f ´) is related to the actual frequency (f0) and the relative speeds of the source (vs), observer (vo), and the speed (v) of waves in the medium by http://paws.kettering.edu/~drussell/...r/doppler.html
Here is a part of that Bob Carver thought process and design and a link.

"SONIC HOLOGRAM Stereo Image Processor
"Sonic Holography" is a method of processing stereo signals so as to correct a basic imaging flaw which is inherent in two-channel stereophonic recording and reproduction via loudspeakers. What that flaw is and why it can't be corrected by any conventional recording technique are discussed later in "Stereo Recording and Playback". Briefly, the problem is that in stereo listening, both ears hear the outputs of both loudspeakers. When a sonic event such as a musical transient is reproduced by the Left-channel loudspeaker, the sound travels in a straight line from the speaker to your left ear. A tiny fraction of a second later the same Left-loudspeaker sound arrives at your right ear, somewhat filtered by the obstruction of your head. If the same sonic event was recorded in both stereo channels, as normally is the case, then some version of it will be reproduced in the Right-channel speaker, whose sound will arrive at your right ear and then, a tiny fraction of a second later, at your left ear. Thus the single original sonic event is represented by a total of four sound arrivals at your two ears. In real life a single sonic event can never cause more than two sonic arrivals: one at your left ear and one at your right ear. (Which ear gets the sound first depends on which direction you are facing, relative to where the sound is coming from. If you are facing the sound, it will arrive at both ears simultaneously.) The goal of the Carver Sonic Hologram Generator is to eliminate the "extra" two sonic arrivals that occur in stereophonic playback but do not occur in real life. With these eliminated, the ear/brain system of the listener will receive unambiguous timing and phase information about the original sounds as they struck the recording microphones. Without extra sonic arrivals to confuse it, the ear/brain system will be able to perceive the true location of each sound source in the stereo recording — not only from left to right but also from near to far. This is accomplished by canceling the unwanted second arrival of the sound from each speaker to the opposite side ear, so that each ear is free to concentrate its attention on the signal from the speaker on the same side; i.e., the left ear will hear mainly the Left speaker, and the right ear will hear mainly the Right speaker, without the confusing acoustic crosstalk which normally occurs in stereo playback. " Stereo Recording and Playback
SONIC HOLOGRAPHY: Canceling Acoustic Crosstalk
Sonic holography - Wikipedia, the free encyclopedia

Speed also plays a HUGE factor in how we hear. So placement room size, material, reflective surfaces etc all have a major impact in addition to the angles and positioning.

See Also see The Doppler effect (or Doppler shift http://en.wikipedia.org/wiki/Doppler_effect

General
In classical physics, where the speeds of source and the receiver relative to the medium are lower than the velocity of waves in the medium, the relationship between observed frequency f and emitted frequency f0 is given by:[3]
where is the velocity of waves in the medium is the velocity of the receiver relative to the medium; positive if the receiver is moving towards the source. is the velocity of the source relative to the medium; positive if the source is moving away from the receiver. The frequency is decreased if either is moving away from the other.
The above formula works for sound wave if and only if the speeds of the source and receiver relative to the medium are slower than the speed of sound


OK back to me and my vision of sound.

Picture a pond of water and tossing in a rock and visualize the waves in 360 degrees from the point of rock entry. Sound is kida like this. But then think about it like in terms of a 3d sphere leaving the speaker and points that would be like the shore or an object changes the path of the wave at that point, and then how the wave point being changes at that point affects and distorts the rest of the sphere.

Kinda heavy. Well that is sound.

A lot more than just the frequency of say 20-20k, the volume of each tone within the band width, there are many things to consider and speed and time is critical.

So there is much we can do in terms of placement to achieve and locate a prime listing seat in our rooms, but above and past that we should consider acoustics panels and the such.

My 2 cents is that even without sophisticated and high dollar tools you should be able to add and subtract acoustics with panels and sometimes even things like furniture and curtains etc to achieve the sound that one is trying to get.

Additional great source to view and read.
http://www.lenardaudio.com/education/06_x-over_4.html

[metaphacts]

Originally Posted by werd

Hello folks

Turn your speakers around and face them into the wall. This little nick of humor just demostrates how important the speaker placement is. Where your speakers are facing is so important and yet so political . Since you want them facing forward, how do you do this?

Well the answer is, do what ever way you want. Tape measures help ,but really there is nothing stopping you from putting your speaker in the most awkward, screwed up position that you like. The trick is - know what you like in your room and ad- lib.

Just look for an open space in soundstage, don't worry about frequency ups and downs and stuff. You will find the most enjoyable experiences in soundstage is if what you hear is uninterrupted by walls and tvs and furniture.

Interesting. This thread was started to discuss the way to grow beyond "throw a bunch of stuff at the wall and see what sticks" method of speaker set up.

[metaphacts]

Originally Posted by C220MC275

I did experience many positions, but still found it difficult to prefer one over the other. I like the sound with only 3 or 5 ° of toe in ( more air between instruments, more details, larger scene ) and I like it also indeed with much more toe in of about 15 to 20 ° ! ( more weight of the sound, more bass but some loss od details and air ).

So i prefer to wait for Bill to come to Paris !
( Bill, if one day you come to Paris between 20 july and 15 august, you can come with all your family : I will let you the whole house ! )

Another important tidbit: Toe in/ Toe out adjusts tonal balance as well as imaging. It's predictable and repeatable.

[metaphacts]

Originally Posted by djwhog

Picture a pond of water and tossing in a rock and visualize the waves in 360 degrees from the point of rock entry. Sound is kida like this. But then think about it like in terms of a 3d sphere leaving the speaker and points that would be like the shore or an object changes the path of the wave at that point, and then how the wave point being changes at that point affects and distorts the rest of the sphere.

Kinda heavy. Well that is sound.

A lot more than just the frequency of say 20-20k, the volume of each tone within the band width, there are many things to consider and speed and time is critical.

So there is much we can do in terms of placement to achieve and locate a prime listing seat in our rooms, but above and past that we should consider acoustics panels and the such.

My 2 cents is that even without sophisticated and high dollar tools you should be able to add and subtract acoustics with panels and sometimes even things like furniture and curtains etc to achieve the sound that one is trying to get.

Additional great source to view and read.
Lenard Audio - Education - X-overs. Time Alignment.

Great stuff here!!!!

[metaphacts]

Originally Posted by Alberto

2) Different recordings sound best with different positioning. E.g. thin sounding recordings can benefit from a bit of a bass boost by moving the speakers closer to the backwall, boomy recordings sound better with the speakers farther into the room.



Alberto

Going back toward the wall can increase or decrease bass. Coming out from the wall can do the same. The trick is to get your speaker to work with the room in the bass, not to try and fool it.

It's hard to get someone to listen to the bass only to begin positioning a speaker, but that allows you to build a proper foundation on which to build proper tonal balance and stage.

[Jerome W]

Originally Posted by metaphacts

Going back toward the wall can increase or decrease bass. Coming out from the wall can do the same. The trick is to get your speaker to work with the room in the bass, not to try and fool it.

It's hard to get someone to listen to the bass only to begin positioning a speaker, but that allows you to build a proper foundation on which to build proper tonal balance and stage.

Bill,
It seems to me that what Alberto is saying is that it depends also on the music played. When the bass in a recording is boomy, then, increasing the distance from speaker to back wall will help, as decreasing toe in.
Of course, we're not going to play with the position depending on the music we listen to, but we still go back to the main problem in audio : the quality of the music played.
The "absolute" best position of the speakers may not be the best one with some recordings.

[1KW]

Originally Posted by djwhog

OK Bob Carver had a theory and there is something to it. The thickness of our heads and the time it takes the L sound to get to the right ear Vs the Left ear and the same on the R side sound to reach the R ear Vs the L ear. The recording design and the speaker placement and the impact on the sound time arrivals.

It can get pretty heavy in terms of math etc… Then when you read you will see familiar names and terms, with names like Doppler and then understand how it is used even in weather tools etc. to measure waves, times, effects etc.


The perceived frequency (f ´) is related to the actual frequency (f0) and the relative speeds of the source (vs), observer (vo), and the speed (v) of waves in the medium by The Doppler Effect and Sonic Booms
Here is a part of that Bob Carver thought process and design and a link.

"SONIC HOLOGRAM Stereo Image Processor
"Sonic Holography" is a method of processing stereo signals so as to correct a basic imaging flaw which is inherent in two-channel stereophonic recording and reproduction via loudspeakers. What that flaw is and why it can't be corrected by any conventional recording technique are discussed later in "Stereo Recording and Playback". Briefly, the problem is that in stereo listening, both ears hear the outputs of both loudspeakers. When a sonic event such as a musical transient is reproduced by the Left-channel loudspeaker, the sound travels in a straight line from the speaker to your left ear. A tiny fraction of a second later the same Left-loudspeaker sound arrives at your right ear, somewhat filtered by the obstruction of your head. If the same sonic event was recorded in both stereo channels, as normally is the case, then some version of it will be reproduced in the Right-channel speaker, whose sound will arrive at your right ear and then, a tiny fraction of a second later, at your left ear. Thus the single original sonic event is represented by a total of four sound arrivals at your two ears. In real life a single sonic event can never cause more than two sonic arrivals: one at your left ear and one at your right ear. (Which ear gets the sound first depends on which direction you are facing, relative to where the sound is coming from. If you are facing the sound, it will arrive at both ears simultaneously.) The goal of the Carver Sonic Hologram Generator is to eliminate the "extra" two sonic arrivals that occur in stereophonic playback but do not occur in real life. With these eliminated, the ear/brain system of the listener will receive unambiguous timing and phase information about the original sounds as they struck the recording microphones. Without extra sonic arrivals to confuse it, the ear/brain system will be able to perceive the true location of each sound source in the stereo recording — not only from left to right but also from near to far. This is accomplished by canceling the unwanted second arrival of the sound from each speaker to the opposite side ear, so that each ear is free to concentrate its attention on the signal from the speaker on the same side; i.e., the left ear will hear mainly the Left speaker, and the right ear will hear mainly the Right speaker, without the confusing acoustic crosstalk which normally occurs in stereo playback. " Stereo Recording and Playback
SONIC HOLOGRAPHY: Canceling Acoustic Crosstalk
Sonic holography - Wikipedia, the free encyclopedia

Speed also plays a HUGE factor in how we hear. So placement room size, material, reflective surfaces etc all have a major impact in addition to the angles and positioning.

See Also see The Doppler effect (or Doppler shift http://en.wikipedia.org/wiki/Doppler_effect

General
In classical physics, where the speeds of source and the receiver relative to the medium are lower than the velocity of waves in the medium, the relationship between observed frequency f and emitted frequency f0 is given by:[3]
where is the velocity of waves in the medium is the velocity of the receiver relative to the medium; positive if the receiver is moving towards the source. is the velocity of the source relative to the medium; positive if the source is moving away from the receiver. The frequency is decreased if either is moving away from the other.
The above formula works for sound wave if and only if the speeds of the source and receiver relative to the medium are slower than the speed of sound


OK back to me and my vision of sound.

Picture a pond of water and tossing in a rock and visualize the waves in 360 degrees from the point of rock entry. Sound is kida like this. But then think about it like in terms of a 3d sphere leaving the speaker and points that would be like the shore or an object changes the path of the wave at that point, and then how the wave point being changes at that point affects and distorts the rest of the sphere.

Kinda heavy. Well that is sound.

A lot more than just the frequency of say 20-20k, the volume of each tone within the band width, there are many things to consider and speed and time is critical.

So there is much we can do in terms of placement to achieve and locate a prime listing seat in our rooms, but above and past that we should consider acoustics panels and the such.

My 2 cents is that even without sophisticated and high dollar tools you should be able to add and subtract acoustics with panels and sometimes even things like furniture and curtains etc to achieve the sound that one is trying to get.

Additional great source to view and read.
Lenard Audio - Education - X-overs. Time Alignment.

3 D audio with BACCH filter is here and it really works; I have heard for myself in my own house. 3D3A Lab at Princeton University
Edgar has met with people in Hollywood, Apple computer and the owner of Sonus Faber, so it will be coming to market , stay tuned.

[metaphacts]

Originally Posted by C220MC275

Bill,

The "absolute" best position of the speakers may not be the best one with some recordings.

Actually this is a quote we should archive and revisit after we have set up your speakers.

[Jerome W]

Originally Posted by metaphacts

Actually this is a quote we should archive and revisit after we have set up your speakers.

As you know Bill, I'm waiting.....
You will love Paris :

[metaphacts]

Originally Posted by 1KW

3 D audio with BACCH filter is here and it really works; I have heard for myself in my own house. 3D3A Lab at Princeton University
Edgar has met with people in Hollywood, Apple computer and the owner of Sonus Faber, so it will be coming to market , stay tuned.

David it is coming, but not to the high end. Look at the groups who are interested - Hollywood (whatever that means) thrives on the basis of HTiB and least common denominator, Apple, the recent hiring of Tomlinson Holman aside, has never been interested in high performance audio, and Fine Sounds (not Sonus faber) owns Wadia who make high quality compact lifestyle digital components. It's coming to your computer, to your HTiB, your headphones, to your in ceiling speakers, your soundbar under your plasma. Where it most assuredly is not coming is in high end, full range audio systems (as opposed to set to small with a sub).

In order for Sonic Holography (or 3D audio) to work, you must pretty much eliminate the room to a degree well beyond what normal speaker placement will allow. If you have an anechoic chamber, or in the real world, an overdamped to the point of dead room, it is much easier. But who has or wants one of those.

Years ago Noel Lee sold a passive approach to attaining the elimination of crosstalk. It was a panel that extended out between the speakers to insure that each ear heard the correct channel. It was interesting though never really had a chance - the implementation was something only the hardest core audiophiles would embrace.

So back to the placement issue. (And we do need to get together and do it at your place.) Where speakers end up for your room with SH/3D is based on eliminating the room and then adding back the coding to fool you into thinking you are someplace else. But should you play an analog disc, the speaker location has all kinds of sonic issues that keep it from being acceptable precisely because the speakers are in the wrong place in the room for them to interface to/decouple from the room properly. However set your Elipsas to cross over to a centrally placed single monoed sub at 80Hz and I would suggest that your SH/3D would be even more impressive.

A really cool way to test this in a more high end way would be with a speaker that wasn't really in the room, such as one of the high performance Wisdom in-wall systems. I suspect that the up side there would be far more effective without having to move speakers away from their ideal location at all.

But as long as we're using big, freestanding speakers in real rooms, we'll be putting them in the right place. Which brings us right back off the bypass and back up on the entrance ramp of speaker set up.