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Speakers against front wall - can this be settled?

Speakers within 1m of front wall

  • I tried this and had imaging issues, WITH front wall acoustic treatment

    Votes: 3 7.0%
  • I tried this and had imaging issues, without front wall acoustic treatment

    Votes: 9 20.9%
  • I tried this and had midrange tone issues, WITH front wall acoustic treatment

    Votes: 0 0.0%
  • I tried this and had midrange tone issues, without front wall acoustic treatment

    Votes: 2 4.7%
  • I tried this and had other issues (other than too much bass)

    Votes: 2 4.7%
  • I can't wait to try this

    Votes: 2 4.7%
  • It's great!

    Votes: 25 58.1%

  • Total voters
    43

DjBonoBobo

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My report back is only subjective and almost useless so I hestiate to post, but wanted to follow up.

Trying with LS50 Meta, 6ft from any wall (reflective walls), the imaging/depth is amazing.

Putting them 6" from the front wall, no treatment, I have lost the depth. Distance from side walls not changed.

Same setup, 6" from the front wall, adding 3" foam absorbers directly behind the speakers, maybe a foot coverage on either side, and above and below, behind each speaker, (probably not nearly physically wide enough to cover the 360 degree radiation at 400hz and down) this did not bring the imaging back.

I really wanted to ignore the subjective reports of loss of imaging, but I felt it too. Yes yes yes, not double blind etc.

It occurred to me that Genelec might be expecting more nearfield users. If the extra "imaging/depth" would not be found in a treated room anyway at distances where direct sound dominates (assuming the depth perception is due to reflections), then nothing is really lost.

If I ever get around to treating a much larger area or an entire wall I will try this again.

Out of curiosity, how did you test this out, meaning did you have a test track where you paid attention to certain positions of instruments, or how did you check for differences? With which tracks exactly?
I'm not asking because I want to question your experience, but because I myself always have trouble detecting "depth" clearly anywhere at all. However, I've also had a near-field setup with the speakers on the front wall for a long time. Maybe I'm missing something. So I'd be interested to read what you hear so I can try it out myself when I get a chance.
 

abdo123

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My report back is only subjective and almost useless so I hestiate to post, but wanted to follow up.

Trying with LS50 Meta, 6ft from any wall (reflective walls), the imaging/depth is amazing.

Putting them 6" from the front wall, no treatment, I have lost the depth. Distance from side walls not changed.

Same setup, 6" from the front wall, adding 3" foam absorbers directly behind the speakers, maybe a foot coverage on either side, and above and below, behind each speaker, (probably not nearly physically wide enough to cover the 360 degree radiation at 400hz and down) this did not bring the imaging back.

I really wanted to ignore the subjective reports of loss of imaging, but I felt it too. Yes yes yes, not double blind etc.

It occurred to me that Genelec might be expecting more nearfield users. If the extra "imaging/depth" would not be found in a treated room anyway at distances where direct sound dominates (assuming the depth perception is due to reflections), then nothing is really lost.

If I ever get around to treating a much larger area or an entire wall I will try this again.
3” really does nothing to the frequencies that are radiated on the rear of the speaker, that’s why.
 
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73hadd

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3” really does nothing to the frequencies that are radiated on the rear of the speaker, that’s why.
Yes, performance is .87 NRC at 400hz and gets worse from there, but it still doing something at lower frequencies.

Are you stating that the "imaging" is actually in the lower frequencies, so if we absorbed all the way down to 80hz or so we could clean it up?

Or that the early reflections are causing some other interference in the higher frequencies?

I do wonder at what frequencies we are most/least sensitive to delay.
 
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OP
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73hadd

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Out of curiosity, how did you test this out, meaning did you have a test track where you paid attention to certain positions of instruments, or how did you check for differences? With which tracks exactly?
I'm not asking because I want to question your experience, but because I myself always have trouble detecting "depth" clearly anywhere at all. However, I've also had a near-field setup with the speakers on the front wall for a long time. Maybe I'm missing something. So I'd be interested to read what you hear so I can try it out myself when I get a chance.
One track. And one reason why I hesitated to post. If I said which track, someone might say it's a terrible test track so I won't say. It's soooo subjective. LOL I am going to start using terms like holographic. Do let us know if you hear anything interesting/better when moved away from walls.
 

DjBonoBobo

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One track. And one reason why I hesitated to post. If I said which track, someone might say it's a terrible test track so I won't say. It's soooo subjective. LOL I am going to start using terms like holographic. Do let us know if you hear anything interesting/better when moved away from walls.
I think you have made it very clear that you are not claiming to describe objective findings, but that you are talking about subjective experience. If someone still wanted to lecture you that you did something wrong, that would be very unfair.
Personally, I am not interested in clarifying whether your perception is right or wrong or whether there is a generalizable rule that speakers close to the wall are bad for spatial imaging.
I would simply have liked to try it out for myself how I perceive a track that someone perceives as - in certain positions - having spatial depth. I would have been interested to see if I could reproduce that for myself.
 
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73hadd

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I think you have made it very clear that you are not claiming to describe objective findings, but that you are talking about subjective experience. If someone still wanted to lecture you that you did something wrong, that would be very unfair.
Personally, I am not interested in clarifying whether your perception is right or wrong or whether there is a generalizable rule that speakers close to the wall are bad for spatial imaging.
I would simply have liked to try it out for myself how I perceive a track that someone perceives as - in certain positions - having spatial depth. I would have been interested to see if I could reproduce that for myself.

That makes sense. If I repeat the experiment I will take better notes. I think this was the album, don't recall which track

 
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Thanks for going through the effort of doing that listening comparison, but I'm just going to say that foam-type sound treatments are kinda useless. They mostly only absorb high frequency, which is often counterproductive.
 

Kvalsvoll

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Yes, performance is .87 NRC at 400hz and gets worse from there, but it still doing something at lower frequencies.

Are you stating that the "imaging" is actually in the lower frequencies, so if we absorbed all the way down to 80hz or so we could clean it up?

Or that the early reflections are causing some other interference in the higher frequencies?

I do wonder at what frequencies we are most/least sensitive to delay.
The frequency range that is important for this is around 200hz-1khz. It is likely the absorption you placed is insufficient because not enough surface area is covered, and the material itself does not provide enough absorption down to 200hz.

This collapse of the depth dimension is a speaker-placement-room issue. It is caused by early reflections from the front wall behind the speakers, in the 200-1k range. Then this should go away, if the speakers have more controlled directivity - and it does. Some speakers can be placed close to the wall, and still provide a deep soundstage, some speakers improve when moved out from the wall, some speakers have more depth than others.
 

ebslo

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Trying with LS50 Meta, 6ft from any wall (reflective walls), the imaging/depth is amazing.

Putting them 6" from the front wall, no treatment, I have lost the depth. Distance from side walls not changed.

Same setup, 6" from the front wall, adding 3" foam absorbers directly behind the speakers, maybe a foot coverage on either side, and above and below, behind each speaker, (probably not nearly physically wide enough to cover the 360 degree radiation at 400hz and down) this did not bring the imaging back.

I really wanted to ignore the subjective reports of loss of imaging, but I felt it too. Yes yes yes, not double blind etc.
Did you move the listening position to preserve the same angle to the speakers? If the angle was significantly reduced then stereo illusions will suffer just from that.

Also, it sounds as if the acoustic treatment was directly behind the speakers, not at the first reflection point. When I set up my system, measurements showed more effect from the treatment if is was at the reflection point vs directly behind.

I found the LEDR tests helpful for evaluation and they really highlight certain issues. But use real music too, because they don't tell the whole story.
 

Thomas_A

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My report back is only subjective and almost useless so I hestiate to post, but wanted to follow up.

Trying with LS50 Meta, 6ft from any wall (reflective walls), the imaging/depth is amazing.

Putting them 6" from the front wall, no treatment, I have lost the depth. Distance from side walls not changed.

Same setup, 6" from the front wall, adding 3" foam absorbers directly behind the speakers, maybe a foot coverage on either side, and above and below, behind each speaker, (probably not nearly physically wide enough to cover the 360 degree radiation at 400hz and down) this did not bring the imaging back.

I really wanted to ignore the subjective reports of loss of imaging, but I felt it too. Yes yes yes, not double blind etc.

It occurred to me that Genelec might be expecting more nearfield users. If the extra "imaging/depth" would not be found in a treated room anyway at distances where direct sound dominates (assuming the depth perception is due to reflections), then nothing is really lost.

If I ever get around to treating a much larger area or an entire wall I will try this again.

One obvious control is to maintain the angle and listening distance. Also for the hardcore to evaluate the ”imaging/depth” without walls, e.g. outside. My take is that hearing details such as reverb/reflections from the recording venue is the key. Which means reducing background noise and early room reflections arriving in the direction from the speaker side is important. Of course also reducing room- related peaks which may mask low-level details.
 

markus

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This collapse of the depth dimension is a speaker-placement-room issue. It is caused by early reflections from the front wall behind the speakers, in the 200-1k range.

Source? Or just anecdotal evidence?
 
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Zaireeka

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Just switched my 8350s from 120cm (2,40m triangle) to 24cm (2,20m triangle) separation from the front wall. I also moved my listening position to 38% of the room length... Everything is better, bass are tighter, imaging is more precise with a larger sweetspot. As a bonus I only need a -1dB @3500Hz high shelf now.

I just need to seriously treat my room now...

38%_2.png
 

krabapple

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What if the front 'wall' is...a floor to ceiling window?

How does that affect SBIR considerations, EQ, subs?
 

dshreter

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What if the front 'wall' is...a floor to ceiling window?

How does that affect SBIR considerations, EQ, subs?
It makes the SBIR considerations even more relevant because the reflections and effect will be more pronounced.
 

Inner Space

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What if the front 'wall' is...a floor to ceiling window?

How does that affect SBIR considerations, EQ, subs?
Interesting issue, and not necessarily as bad as it seems, intuitively. Glass itself is about as reflective as concrete, but heavy lined drapes will take care of upper-mid and high frequencies - which people worry about, because of spectral imbalance. But windows are also often very tympanic and diaphragmatic, and can act as really good bass absorbers. A draped window can be a pretty good broadband aid for SBIR and modal problems, overall.
 

dlaloum

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Interesting issue, and not necessarily as bad as it seems, intuitively. Glass itself is about as reflective as concrete, but heavy lined drapes will take care of upper-mid and high frequencies - which people worry about, because of spectral imbalance. But windows are also often very tympanic and diaphragmatic, and can act as really good bass absorbers. A draped window can be a pretty good broadband aid for SBIR and modal problems, overall.
Hmm interesting - had never considered this - also how does laminated glass, or double/triple glazing react sonically ... and double / triple glazing can also include laminated glass...
 

Inner Space

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... how does laminated glass, or double/triple glazing react sonically ... and double / triple glazing can also include laminated glass...
Triple is better than double, and double is better than single, and laminated is better than plain. The more layers the better, basically. That said, there isn't much definitive research on the subject. I made in-room measurements in a couple of places - one was a double-height room with wall-to-wall glass at first floor level, with a 11' x 11' window above, and with heavy drapes it was one of the best rooms I've had. With the drapes open and the sun in the right direction, I could see the glass moving, just like you would want a membrane absorber to perform. Counterintuitive, I know, but overall I considered it a benefit.
 

youngho

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Out of curiosity, how did you test this out, meaning did you have a test track where you paid attention to certain positions of instruments, or how did you check for differences? With which tracks exactly?
I'm not asking because I want to question your experience, but because I myself always have trouble detecting "depth" clearly anywhere at all. However, I've also had a near-field setup with the speakers on the front wall for a long time. Maybe I'm missing something. So I'd be interested to read what you hear so I can try it out myself when I get a chance.
I had posted this to another thread, in case you might find it helpful to consider: https://www.audiosciencereview.com/...ct-imaging-and-soundstage.13526/#post-1024067

This post (https://www.audiosciencereview.com/...al-music-pros-using.12225/page-26#post-955171) referenced an interesting report in an anechoic chamber where the speakers were positioned nearer and further away from the highly absorptive (broadband) boundaries, though some of the overall experiences varied with others' experiences (https://www.audiosciencereview.com/...al-music-pros-using.12225/page-26#post-950095)

I couldn't find anything definitely relevant from Blauert (author of Spatial Hearing), only tangential like: https://webcache.googleusercontent.com/search?q=cache:9rRIg90gVnAJ:https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.85.9082&rep=rep1&type=pdf+&cd=10&hl=en&ct=clnk&gl=us. He does discuss the spatial effect of a single reflection, though emphasizes delay of >=10 ms (as opposed to >6 as Linkwitz does)
 
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dc655321

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But windows are also often very tympanic and diaphragmatic

Holy crap, yes!
And when the glazing in old-home, single-pane starts to give out, once luscious sub-bass can become a rattle prone mess.
Please don't ask how I know... :confused:
 

JanRSmit

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Source? Or just anecdotal evidence?
Out of curiosity, can you point me to research on the influence of the distance to front-wall on perception of depth and width (dimensionality of sound-stage)? I am trying to find it but not yet found papers i understand. Over the years i have been playing with loudspeaker positioning, my observations are that close to the front-wall has a detrimental effect on dimensionality. Also when having some significant furniture (cupboard) in between. This invariably improved when using distances of more than a meter or so. (in living rooms i mean)
 
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