Master Set - Loudspeaker Alignment

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stvnharr

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Re: Master Set - Loudspeaker Alignment
« Reply #140 on: 17 Apr 2009, 01:18 am »

Hi Andy,
No, I don't have Hell Freezes Over.
I think I tried to answer some of your concerns in the longish post I just wrote.  I think if you can find a "decoupled zone" with your speakers you can do MS. It's likely farther out into the room that that of a box speaker.  You'd just have to try it by experimentation if you really wanted to know, and I realize that that might not be the most practical thing to do because to the size of the speakers.

Steve

PSP

Master Set - first sign of a new frontier?
« Reply #141 on: 18 Apr 2009, 04:56 pm »
From my position on the sidelines (I'm on a 9-month assignment 300 miles from home, so I haven't tried MS yet), I'm coming to the view that MS may be strong evidence that our current views of how "audio works in living spaces and in people's heads" might be in need of major revision.

MS is reported to dramatically improve the audio experience in a way that is unexpected and unpredicted based on the current paradigm.

The MS effect has been reproduced by a number of independent people, many with very high credibility.

Given the surprising claims that have been reproduced by numerous credible people in a variety of listening rooms with a variety of equipment, it won't do to keep arguing based on the old paradigm.  The old paradigm must be at least partially wrong since it apparently can't predict the MS effect.

When this happens in a scientific discipline, things get very exciting.  I'm going to give MS a good workout when I return home in the fall.

Take care,
Peter


DSK

Re: Master Set - first sign of a new frontier?
« Reply #142 on: 19 Apr 2009, 01:37 pm »
...Given the surprising claims that have been reproduced by numerous credible people in a variety of listening rooms with a variety of equipment, it won't do to keep arguing based on the old paradigm.  The old paradigm must be at least partially wrong since it apparently can't predict the MS effect.......

Actually, having now viewed and listened to Hugh's "Master Set" setup, I don't think that is the case.

Hugh's setup now looks like this ...



You can see that the right speaker is set slightly closer to the front wall than the left. This is where Steve and Hugh observed the most even bass response in the room during the MS procedure. I had not noticed any bass problems on my previous visits but that doesn't mean much and I'm not implying that there weren't any or that the bass isn't more even now than it was before. In my previous posts I stated that I could envisage how the MS setup could indeed lead to more even bass throughout a room, especially an asymmetrical one. For this reason alone I will still try MS in my room at some point.

However, the key point of my earlier posts was that the room's capacity/dimensions/materials/etc will only have a "pressurisation" effect on frequencies below approx 200Hz (causing peaks and nulls in this range), not those above it. However, room boundary "reflections" will have an affect on this higher frequency range. The longer paths to our ears off the walls (than the direct path from the speakers) causes "time smear" and is a form of distortion of the playback. This is why we use absorption and diffusion to treat the primary reflection areas and minimise the coherent reflections.

As the amplitude of one speaker rises in relation to the other, it starts to dominate the other speaker and this is why the vocalist/instrument sounds like it is coming from the loudest speaker (this was the reason for balance controls). When both speakers play a vocalist at the same amplitude, that vocalist will appear to be standing in the middle between the speakers (assuming that is where they stood during the recorded performance). This is one of the basics of how "stereo" works. When both speakers play the vocalist at the same amplitude, but one speaker is closer to you, the nearest speaker will have less energy loss due to the shorter path to your ears, and will thus sound louder. This causes the vocalist to move toward the nearest/loudest speaker. The only way I know of to offset this effect is to toe-in the speakers such that they cross in front of the listener. This means that as the listener moves toward the right speaker (thus hearing lower amplitude from the left speaker due to losses over the greater distance) he becomes more off-axis from the right speaker and more on-axis from the left speaker. You may have experimented with toe-in and found some speakers to sound too "hot" in the high frequencies when on-axis (ie. pointed at the listener) and needed to toe them out a little to reduce the energy. This is the same thing. We are moving more off-axis but to the other side of the axis. Therefore, the drop in energy from the nearest speaker (more off-axis) compensates for the higher amplitude caused by that speaker being closer to the listener. The end result is that the vocalist remains in the centre off the soundstage. This is why I was asking Steve whether he felt that this might be the reason that MS did not upset the imaging.

Crossing speakers in front of the listener has an additional benefit. The side walls become much more off-axis from the speakers and thus side wall reflections are greatly reduced in energy. This reduces the time smear distortive effect mentioned earlier and provides a sense of calmness or purity to the presentation. It helps focus the imaging and can enhance low level detail. Initially, this loss of energy from the side walls can be perceived as a lessening of the envelopment effect from the speakers, but as you listen further you become used to it and notice the benefits. For simplicity, I'm just talking about dynamic cone speakers here as dipolars and other speaker types have different radiation patterns etc. Bear in mind that although MS may require crossing the speakers,  crossing the speakers does not require MS. Many people, including myself have had their speakers crossed in a standard symmetrical setup and observed the benefits I just described.

As soon as I walked into Hugh's room and saw the speakers crossed in front of the listener, I could see that I was right about how MS overcomes the amplitude/imaging problems caused by unequal distances from the listener to each speaker. This is what I was trying to coax from Steve. When I listened from the single chair (point A in the diagram) I immediately noticed the reduced sidewall reflections and the same improvements I have heard previously from crossing speakers. The imaging (at this seat) stayed fairly well central as a result, despite the seat being closer to the right speaker. Moving to listening position C, the lead vocal did tend to move toward the left speaker (just as it does in a typical non-crossed symmetrical speaker setup) though perhaps to a lesser degree. I did not listen from point B although Hugh indicated that he heard the vocalist closer to the centre than I did from point C.

To clarify, I agree with Steve that MS can help even out the bass around the room by avoiding positions where particular bass frequencies (under 200Hz) suffer peaks or nulls as a result of interaction with the room. However, the improved mids and highs are a result of crossing the speakers in front of the listening position rather than the actual speaker locations, and crossing the speakers is necessary to overcome the problems that would otherwise occur from an MS setup due to the speakers being at different distances from the listener.

So, if you acknowledge crossing the speakers as an MS concept (rather than something that can be done independently), then yes, I agree that MS can provide benefits in the bass, mids and highs!





gerado

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Re: Master Set - Loudspeaker Alignment
« Reply #143 on: 19 Apr 2009, 04:07 pm »
Steve,
or anyone else for that matter.
Can MS be done using a single tone? If so what bass tone frequency do you suggest is best.

stvnharr

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Re: Master Set - Loudspeaker Alignment
« Reply #144 on: 19 Apr 2009, 11:27 pm »
Steve,
or anyone else for that matter.
Can MS be done using a single tone? If so what bass tone frequency do you suggest is best.

Geraldo,
At present, I don't know of a way to properly use a single tone to do MS.
In smoothing the bass, every speaker/room interface acts differently.  While the bass line in Ballad of a Runaway Horse doesn't include all that many bass notes you do seem to get a different emphasis with each room/speaker interface, and all you are trying to do is smooth this out as best as possible.  Afterall it's the speaker sound in YOUR room that matters.
I've often thought that a single tone for matching sound pressure levels would work.  However there would have to be a way to have this single tone inserted into the equipment.
Remember, MS is a way to do things without having to buy ANYTHING, other than a song.

Steve

gerado

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Re: Master Set - Loudspeaker Alignment
« Reply #145 on: 19 Apr 2009, 11:40 pm »
Thanks Steve,
I was thinking about my situation where I do not have the song(got the old album which does not include the Ballad of the Runnaway Horse, and the new release I have not seen in stalls) but I do have an easy way to get what ever tone I want into my system. I suspect the way the whole thing is set up and the fact that it works without a scientific explanation how it does so, that there may be an advantage in having an instrument note rather than a pure tone?

T

stvnharr

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Re: Master Set - Loudspeaker Alignment
« Reply #146 on: 19 Apr 2009, 11:51 pm »
Thanks Steve,
I was thinking about my situation where I do not have the song(got the old album which does not include the Ballad of the Runnaway Horse, and the new release I have not seen in stalls) but I do have an easy way to get what ever tone I want into my system. I suspect the way the whole thing is set up and the fact that it works without a scientific explanation how it does so, that there may be an advantage in having an instrument note rather than a pure tone?

T

Understand about not having the song.  In my first try at MS, in 2007, I didn't have the song.  I used a jazz cut that had the player playing nearly a full scale and repeating it.  I just set the player on repeat for these 20 seconds.  In my later attempts I also tried this same cut.  I found BotRH song to be easier to do MS with.  Although, with the jazz cut it was easy to hear the sound all move to one speaker.

stvnharr

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Re: Master Set - first sign of a new frontier?
« Reply #147 on: 20 Apr 2009, 12:47 am »
...Given the surprising claims that have been reproduced by numerous credible people in a variety of listening rooms with a variety of equipment, it won't do to keep arguing based on the old paradigm.  The old paradigm must be at least partially wrong since it apparently can't predict the MS effect.......

Actually, having now viewed and listened to Hugh's "Master Set" setup, I don't think that is the case.

Hugh's setup now looks like this ...



You can see that the right speaker is set slightly closer to the front wall than the left. This is where Steve and Hugh observed the most even bass response in the room during the MS procedure. I had not noticed any bass problems on my previous visits but that doesn't mean much and I'm not implying that there weren't any or that the bass isn't more even now than it was before. In my previous posts I stated that I could envisage how the MS setup could indeed lead to more even bass throughout a room, especially an asymmetrical one. For this reason alone I will still try MS in my room at some point.

However, the key point of my earlier posts was that the room's capacity/dimensions/materials/etc will only have a "pressurisation" effect on frequencies below approx 200Hz (causing peaks and nulls in this range), not those above it. However, room boundary "reflections" will have an affect on this higher frequency range. The longer paths to our ears off the walls (than the direct path from the speakers) causes "time smear" and is a form of distortion of the playback. This is why we use absorption and diffusion to treat the primary reflection areas and minimise the coherent reflections.

As the amplitude of one speaker rises in relation to the other, it starts to dominate the other speaker and this is why the vocalist/instrument sounds like it is coming from the loudest speaker (this was the reason for balance controls). When both speakers play a vocalist at the same amplitude, that vocalist will appear to be standing in the middle between the speakers (assuming that is where they stood during the recorded performance). This is one of the basics of how "stereo" works. When both speakers play the vocalist at the same amplitude, but one speaker is closer to you, the nearest speaker will have less energy loss due to the shorter path to your ears, and will thus sound louder. This causes the vocalist to move toward the nearest/loudest speaker. The only way I know of to offset this effect is to toe-in the speakers such that they cross in front of the listener. This means that as the listener moves toward the right speaker (thus hearing lower amplitude from the left speaker due to losses over the greater distance) he becomes more off-axis from the right speaker and more on-axis from the left speaker. You may have experimented with toe-in and found some speakers to sound too "hot" in the high frequencies when on-axis (ie. pointed at the listener) and needed to toe them out a little to reduce the energy. This is the same thing. We are moving more off-axis but to the other side of the axis. Therefore, the drop in energy from the nearest speaker (more off-axis) compensates for the higher amplitude caused by that speaker being closer to the listener. The end result is that the vocalist remains in the centre off the soundstage. This is why I was asking Steve whether he felt that this might be the reason that MS did not upset the imaging.

Crossing speakers in front of the listener has an additional benefit. The side walls become much more off-axis from the speakers and thus side wall reflections are greatly reduced in energy. This reduces the time smear distortive effect mentioned earlier and provides a sense of calmness or purity to the presentation. It helps focus the imaging and can enhance low level detail. Initially, this loss of energy from the side walls can be perceived as a lessening of the envelopment effect from the speakers, but as you listen further you become used to it and notice the benefits. For simplicity, I'm just talking about dynamic cone speakers here as dipolars and other speaker types have different radiation patterns etc. Bear in mind that although MS may require crossing the speakers,  crossing the speakers does not require MS. Many people, including myself have had their speakers crossed in a standard symmetrical setup and observed the benefits I just described.

As soon as I walked into Hugh's room and saw the speakers crossed in front of the listener, I could see that I was right about how MS overcomes the amplitude/imaging problems caused by unequal distances from the listener to each speaker. This is what I was trying to coax from Steve. When I listened from the single chair (point A in the diagram) I immediately noticed the reduced sidewall reflections and the same improvements I have heard previously from crossing speakers. The imaging (at this seat) stayed fairly well central as a result, despite the seat being closer to the right speaker. Moving to listening position C, the lead vocal did tend to move toward the left speaker (just as it does in a typical non-crossed symmetrical speaker setup) though perhaps to a lesser degree. I did not listen from point B although Hugh indicated that he heard the vocalist closer to the centre than I did from point C.

To clarify, I agree with Steve that MS can help even out the bass around the room by avoiding positions where particular bass frequencies (under 200Hz) suffer peaks or nulls as a result of interaction with the room. However, the improved mids and highs are a result of crossing the speakers in front of the listening position rather than the actual speaker locations, and crossing the speakers is necessary to overcome the problems that would otherwise occur from an MS setup due to the speakers being at different distances from the listener.

So, if you acknowledge crossing the speakers as an MS concept (rather than something that can be done independently), then yes, I agree that MS can provide benefits in the bass, mids and highs!


Hello,
Just a few points here. It's nice to have some feedback from another listener on how things sound.  It is very valuable to me as I try to tweak Hugh's setup. With an unfamiliar system and room, it's hard to get it right the first time, especially after an afternoon room cleanup on a hot sweaty day.  My MS experience is limited, for sure, and will likely always remain so.

First off, the above drawing is incorrect in the placement of the speakers!  The right speaker is about 5 inches farther out into the room than the left speaker. The right speaker was the "anchor" speaker, and the left speaker was moved out only until it matched the sound pressure of the right speaker.  There is a huge imbalance in Hugh's room with the half wall separating the office space from the main room. This makes the left side of the room much much larger than the right side, and makes the left speaker input a lot more sound pressure to fill the office space.  In short, it's a lot more difficult.
The drawing does have the listening spots about as I remember them, although I remember the single chair as being in the middle of the two speakers, not off to the side as in the drawing.  The spot over to the left, the B spot, is next to the half wall of the office. I've never sat there to listen.  I think this is a crummy spot as the sound will bounce off that wall into the ear quite noticeably. It's preferable to sit a couple feet away from any wall or reflecting surface.
I think the relative spacing of the speakers and the set up spot is correct as I think that's about how I had things when I did the setup.  Both speakers are about 3 feet in from sidewalls of the room.

The set up is done along the short wall in Hugh's room.  However the short wall is not much shorter than the long wall, so I thought it would be quite doable.  The long wall would have been better, but was not possible. Short walls make things more difficult as you can get some reflections off the sidewalls that can muck things up a bit.

Lastly, NO, "crossing" the speakers is not an explicit MS concept. The MS concepts are to set the speakers in the small "decoupled" zone, and equal sound pressure into the room from each speaker. However, in order to do the procedure, the speakers are toed in a lot during the listening process, and then left that way. If you wish to consider this as part of the concept, okay.  But, you can't just do an extreme toe-in and think you've done part of Master Set.

Steve


richidoo

Re: Master Set - Loudspeaker Alignment
« Reply #148 on: 20 Apr 2009, 02:20 am »
No you can't use a single tone. You need to play all the bass tones so you can dial the speaker position to avoid exciting room modes. I think that the Cowgirl track doesn't have enough bass tones, but the recording is so good that it is still very useful. I want to make a recording of sampled acoustic bass specifically for the purpose of tuning the speaker position, with precisely matched dynamics and a chromatic scale from 40-200Hz, plus tonal patterns and some two note chords. In time....

Most common bass instruments only play down to 40Hz. Top of bass range is considered to be 300Hz, but rare for serious modes to occur above 200Hz. Acoustic bass recording has a lot of texture that helps to hear the quality of the tone, not just the boominess. Only the first two choruses of the song are useful, after that the background vocals start singing in stereo so the illusion of music coming from one speaker is lessened. The bass playing is very steady and flat dynamically. You will hear loud notes that sound like he is accenting a note, but he is not, it is your room interpreting the music incorrectly for you. It is a useful track, but annoying after 300 times.

I found a used copy of the song on Amazon.com for a few bucks. It arrived scratched to hell and would not rip to my hard drive without dropouts. I found that I can play it in my CDP with minimal glitches. It is on a CD by Rob Wasserman called Duets.


I am moving my speakers back to the short wall tomorrow. Will do the MS again during the week. I also hope to measure the room response.

andyr

Re: Master Set - first sign of a new frontier?
« Reply #149 on: 20 Apr 2009, 02:30 am »

But, you can't just do an extreme toe-in and think you've done part of Master Set.

Steve


But can you do Master Set and without having the speakers toed in further than the baffles being perpendicular to your ears?  From being at Hugh's place Saturday morning, the toe-in Hugh has, relative to his chair(s) would IMO make MS unsuitable for my Maggies.

Regards,

Andy

gerado

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Re: Master Set - Loudspeaker Alignment
« Reply #150 on: 20 Apr 2009, 02:53 am »
Hi Andy,
From what I gather if I understand various comments there is no prescribed position that MS dictates, its where the speakers end up sounding best and decoupled to the room after using the procedure of MS.
If your speakers do not sound good toed in I suspect you will not end up in that position if the set up of MS is followed. There is no pre determined position or angling, its where it ends up sounds best IF you want to use this set up method.

I know in Hughs room it sounds better when I also heard it, maybe the top end gets a little compromised but nothing is going to be perfect.

Do the more experienced  ones think this sounds right?

stvnharr

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Re: Master Set - Loudspeaker Alignment
« Reply #151 on: 20 Apr 2009, 02:57 am »
Hi Andy,
From what I gather if I understand various comments there is no prescribed position that MS dictates, its where the speakers end up sounding best and decoupled to the room after using the procedure of MS.
If your speakers do not sound good toed in I suspect you will not end up in that position if the set up of MS is followed. There is no pre determined position or angling, its where it ends up sounds best IF you want to use this set up method.

I know in Hughs room it sounds better when I also heard it, maybe the top end gets a little compromised but nothing is going to be perfect.

Do the more experienced  ones think this sounds right?

Yes, pretty much.

stvnharr

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Re: Master Set - Loudspeaker Alignment
« Reply #152 on: 20 Apr 2009, 03:03 am »
No you can't use a single tone. You need to play all the bass tones so you can dial the speaker position to avoid exciting room modes. I think that the Cowgirl track doesn't have enough bass tones, but the recording is so good that it is still very useful. I want to make a recording of sampled acoustic bass specifically for the purpose of tuning the speaker position, with precisely matched dynamics and a chromatic scale from 40-200Hz, plus tonal patterns and some two note chords. In time....

Most common bass instruments only play down to 40Hz. Top of bass range is considered to be 300Hz, but rare for serious modes to occur above 200Hz. Acoustic bass recording has a lot of texture that helps to hear the quality of the tone, not just the boominess. Only the first two choruses of the song are useful, after that the background vocals start singing in stereo so the illusion of music coming from one speaker is lessened. The bass playing is very steady and flat dynamically. You will hear loud notes that sound like he is accenting a note, but he is not, it is your room interpreting the music incorrectly for you. It is a useful track, but annoying after 300 times.

I found a used copy of the song on Amazon.com for a few bucks. It arrived scratched to hell and would not rip to my hard drive without dropouts. I found that I can play it in my CDP with minimal glitches. It is on a CD by Rob Wasserman called Duets.


I am moving my speakers back to the short wall tomorrow. Will do the MS again during the week. I also hope to measure the room response.

Rich,
You sure are ambitious!!!!  Your comments on the bass line in Ballad are correct. I found it easiest to hear the bass line in the first two verses, and then it got harder so I just either set the player on repeat or just go back to the start.  After listening to this short bit of music you can get tone deaf after awhile and you just have to stop.

The Duets cd is the other disc besides Famous Blue Raincoat 20th Anniversary to have Ballad of a Runaway Horse.  The disc Trios does not, although it has been said incorrectly that it does.

Good luck with your next Master Set.  Actually by doing it so many times you do get a bit more familiar with what you need to listen to/for.  It's hard to pick up a couple years of experience by doing something once, and not really knowing if you got it right.

Steve

stvnharr

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Re: Master Set - first sign of a new frontier?
« Reply #153 on: 20 Apr 2009, 03:08 am »

But, you can't just do an extreme toe-in and think you've done part of Master Set.

Steve


But can you do Master Set and without having the speakers toed in further than the baffles being perpendicular to your ears?  From being at Hugh's place Saturday morning, the toe-in Hugh has, relative to his chair(s) would IMO make MS unsuitable for my Maggies.

Regards,

Andy

Hi Andy,
You can do MS if you can find the de-coupled zone, and thus with both speakers playing only hear the sound of one speaker.  I don't know if there is a minimum/mazimum toe in needed to do this.  I do not know if Master Set has ever been attempted with Magneplanars.
Next chance I have to speak with Rod Tomsen I will ask him about this.  But that will be awhile.

Steve

DSK

Re: Master Set - first sign of a new frontier?
« Reply #154 on: 20 Apr 2009, 04:17 am »
... the above drawing is incorrect in the placement of the speakers!  The right speaker is about 5 inches farther out into the room than the left speaker.
Sorry Steve, when I got home I couldn't remember which speaker was the one further forward ... 50/50 odds and I still got it wrong, good thing I'm not a gambler.  :D

...
The drawing does have the listening spots about as I remember them, although I remember the single chair as being in the middle of the two speakers, not off to the side as in the drawing....
From memory, the left arm of the chair was central between the speakers, placing the listener's head a little to the right of centre.

...
Lastly, NO, "crossing" the speakers is not an explicit MS concept.... However, in order to do the procedure, the speakers are toed in a lot during the listening process, and then left that way.....
Yep, if the listener leaves the listening seat at the apex of the triangle where the speakers were toed in to point at during setup, then the speakers will be pointed at the listener rather than crossed in front of the listener. In Hugh's case, the listening seat is further back than this which causes the speakers to be crossed in front of him, thus producing a more off-axis setup with even less side wall reflections etc etc.

... But, you can't just do an extreme toe-in and think you've done part of Master Set.
Exactly! My room is an example of this. The speakers are toed-in to point directly at the listener, and therefore I get the benefits of reduced sidewall reflections, etc etc. But, I have not done MS yet and doing so may potentially improve bass response in the room due to the MS derived speaker locations.


In a nutshell:

MS speaker locations => more even and efficient loading of bass in the room.
Aggressive toe-in => reduced sidewall reflections (less time smear distortion, better focus and inner detail etc etc)

This is why I keep highlighting the fact that MS can improve response below 200Hz ONLY as these are the only frequencies that are affected by a rooms dimensions. It is the aggressive toe-in that has the potential to improve mids and highs, and this is the reason that I said that "MS can improve bass, mids and highs IF you assume aggressive toe-in to be an integrated component of MS (rather than a separate procedure)".

Note that the toe-in benefits will be largely room and speaker dependent.






AKSA

Re: Master Set - Loudspeaker Alignment
« Reply #155 on: 20 Apr 2009, 04:51 am »
Steve, Darren,

Do you consider that with some sound absorbent material on the walls - such as heavy curtains, or a large woven rug - we could then less aggressively toe in the speakers for the same benefits?

It seems to me that the principle drawback with most listening rooms is the flat, highly reflective wall left and right......

Cheers,

Hugh

andyr

Re: Master Set - Loudspeaker Alignment
« Reply #156 on: 20 Apr 2009, 10:16 am »
Steve, Darren,

Do you consider that with some sound absorbent material on the walls - such as heavy curtains, or a large woven rug - we could then less aggressively toe in the speakers for the same benefits?

It seems to me that the principle drawback with most listening rooms is the flat, highly reflective wall left and right......

Cheers,

Hugh

If you contemplate my room, Hugh, you'll recall that, although I have solid masonry walls, I have a large-dimension 1" thick cork "sculpture" on one long wall and some wall hangings on the other.  These removed the "flutter echo" that I experienced previously but they also damp the "first reflection points" on the side walls.  :thumb:

IMO, this is all you need to do - ie. you may not have to cover the whole of each side wall.  :D

Then again, having attended my first concert at the spectacular Melbourne Recital Centre on Sunday evening (with its amazing sculpted plywood surfaces), maybe "bagged" masonry walls is in fact a good wall material, sonic-wise ... as it is not smooth like plasterboard?  :o

Regards,

Andy

stvnharr

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Re: Master Set - Loudspeaker Alignment
« Reply #157 on: 20 Apr 2009, 10:23 am »
Steve, Darren,

Do you consider that with some sound absorbent material on the walls - such as heavy curtains, or a large woven rug - we could then less aggressively toe in the speakers for the same benefits?

It seems to me that the principle drawback with most listening rooms is the flat, highly reflective wall left and right......

Cheers,

Hugh

Hugh,
I don't think you have any sidewall reflection issues.  The speakers are 3 feet from the nearest sidewall. The office wall is a half wall with a couch in front of most of it.  The other wall has a cabinet and 2 doors in it, then there is just stuff stacked against the clothes cabinet.  If you think you have a sidewall issue just open one or both doors (the ones that open into the bedrooms) and listen for any difference. You will always get some bounce back off the wall when sitting on the couch unless the couch is moved out from the wall. You won't notice this unless you move your head while listening. And if you have music on and the door to your office open, it will bounce the sound quite a bit, so serious listening needs that door closed.
Darren's description of what sidewall reflections do to the sound image is correct. In a decent MS, which you now have, you shouldn't hear any of that. And I've not heard anything to make me think you have any sidewall issues.

But one reason MS is best when set up on the long wall is that it is easier to get away from sidewall reflections. Even when they exist they arrive at the ear too late for the brain to recognize them.  This is much more of an issue if speakers are on short wall and listener sits faraway.  In fact there is no way to not have them affect sound without serious treatments on those walls. But it's a tricky issue as absorptive materials usually just suck out the upper frequencies as the bass wavelengths are just too long to be affected.  The result is the "dead room" syndrome.

Hugh, in your room the area of most reflection is the bare wood floor where the speakers sit.

Darren,
I figured you just couldn't quite remember which speaker was more out into the room.
Perhaps the easy chair has been slightly moved to allow for side by side listening in the metal chair. Doesn't matter.
It was a nice drawing.

Break

Oh, and just one more thing. The area of brain recognition of reflected sounds is interesting.  Earlier I referred to the AES 1984 study about sounds arriving 5 ms after the initial sound being recognized as direct sounds by the brain.  I am not aware of any study that has been made about how long a time delay the brain will recognize a reflected sound while listening to music. Master Set is designed to minimize as much sidewall reflections as possible.

Steve

PS. I just read the post Andy wrote while I wrote.  Well, you can't really cover the bedroom doors unless you put on some hanging thing, which might not be a bad idea. And there isn't all that much area above the couch.

DSK

Re: Master Set - Loudspeaker Alignment
« Reply #158 on: 20 Apr 2009, 09:48 pm »
Hugh,
Andy has pretty well summed it up in the post above (I believe that it is generally considered that a reflection delayed by 20ms+ is considered by the brain to be an echo whereas those under 20ms are interpreted as part of the same sound but spread over time...ie. the time smear I referred to in posts above).
The speakers are crossed so far in front of the listener that the side walls are significantly off-axis from the speaker and any reflections will be much weaker as a result. Typically, we are concerned with reflections from the right speaker off the right wall and from the left speaker off the left wall. However, in your setup, the aggressive toe-in actually reverses this and you may hear reflections off each wall from the opposing speaker. The couch doesn't extend as high as your ears when seated so it will not be doing too much to absorb the primary reflection. For this reason it may be worth experimenting with something absorptive at ear height on each side wall. Rest a mirror panel against the side wall, or have someone move it along the side wall until you see the speaker in the mirror (when seated in your listening seat). This is the primary side wall reflection point that you need to treat. As a temporary test you could use a heavy rug draped over your office counter top that covers the wall between the counter top and the couch. On the other side, if the bedroom door happens to be where the first reflection point is, simply open the door as Steve suggested to remove this reflection. You may then get a delayed reflection that has bounced around the bedrrom walls before coming back out but this will be reduced in strength as a result and will be delayed beyond the 20ms and simply add to the reverberant field rather than smear the direct signal from the speaker.

The speakers were sounding nicely focussed so I don't think I would play around with the toe-in after treating the side wall reflections.

DSK

Re: Master Set - Loudspeaker Alignment
« Reply #159 on: 20 Apr 2009, 09:49 pm »
Duplicate post deleted