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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 4.2%
  • I tried this and had imaging issues, without front wall acoustic treatment

    Votes: 13 18.1%
  • I tried this and had midrange tone issues, WITH front wall acoustic treatment

    Votes: 2 2.8%
  • I tried this and had midrange tone issues, without front wall acoustic treatment

    Votes: 2 2.8%
  • I tried this and had other issues (other than too much bass)

    Votes: 5 6.9%
  • I can't wait to try this

    Votes: 3 4.2%
  • It's great!

    Votes: 44 61.1%

  • Total voters
    72

bo_knows

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I don't even want perfect I want 80 to 200 to not just disappear. Plenty of others doing it with cheaper and smaller rooms so I guess. I just have bad luck with my room.
Don't kid yourself. EVERYONE has a problem(s) in the bass, upper bass, and sometimes midrange region in the small room. I've acoustically treaded my room more than most and still have dips in the bass and midrange region.
Whoever tells you that they don't, ask them to show you REW sweep from 20-300Hz without any smoothing and without EQ with the mic being positioned in the MLP using only their main speakers. ;)

Yes, very frustrating to deal with dip(s) if you rely only on passive acoustic treatments.
 

srrxr71

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So I moved into a new space and after GLM calibration I found that my left speaker has a sharp dip at 125hz and a slightly less sharp one at 250Hz. Both speakers are 6” from the front wall as moving them out causes more problems.

I’m not as worried about the 125hz as I think the subwoofer might be able to help it even crossed over at 100Hz.

For the 250Hz I’ve ordered today GIK 244 flat bass traps to place behind the speakers. They are 4” I believe but they claim to absorb from 100Hz-about 500Hz.

They are 4” but they seem to have fiberglass construction which they claim to make them perform down to 100Hz. I wonder if that’s true. I guess I’ll find out soon.
 

SDC

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Far from wall, easy fix with subs. Close to walls, room treatments a must.
fr compensation to fix allison effect such as w371 system, even better.
I have many systems, 40cm and 2m they all work just in different fashion.

But I agree far from walls are exceptionally easier….
 

Chromatischism

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I have not read the thread responses and will just respond with my experience moving speakers against the wall, out from the wall, narrower, wider, toe angle, you name it. This is in a perfectly rectangular room with ideal positions for seating based on avoiding room modes.

I have heard the advice that for best stereo image the speakers should be away from the front wall.

Is this "away from the front wall" advice because:

-For full range speakers there is so much bass boost that it "overpowers" the image? (activating room modes, which could be fixed with eq to reduce bass)
As you say, room correction takes care of this issue.

Or, perhaps "away from the front wall" is total nonsense?
It's definitely not, from my personal experience.

I would guess that a lot of people have their speakers in the 3-6ft AVOID! range. That cancellation/comb filtering doesn't seem fixable by EQ according to this note from Genelec "Equalization of the monitor output level does not help, as the same level change applies also to the reflected sound."
You are right. Most of us will end up in that range with little we can do about it.

However, even with upper bass/lower midrange SBIR, they still sound better away from the wall.

What I heard when 6" from the wall + room correction: perfect bass with no dips. I also heard a sort of congestion, hardness, lack of clarity from the midrange.

What I hear when 2' from the wall + room correction: much more open and clear sound. Better separation of detail. The bass is not perfect however to hear the issues you really need to focus and play sine waves.

There is more to consider, though. When the speakers are moved, there is another variable that is changing: your distance to the speakers. This can affect where you sit in the polar response, and how much reflected sound you are getting. If you move the speakers back a couple of feet, you move the first reflection points back as well. When you're sitting closer, you're hearing fewer reflections as a component of the sound and it will sound more clear and intimate. This is a sound I prefer.

So when you read people's experiences about moving speakers back and forth, keep in mind they are probably not moving their seats to match and their listening distance is changing, as are the reflection points and direct-to-reflected sound ratio. This affects clarity, imaging, and soundstage. Having speakers against the wall has its own effects and it is hard to separate them.
 

Chromatischism

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The optimal configuration in my opinion for medium to small rooms is to have the speakers more than a meter away from a boundary, and have Subwoofers crossed at 80Hz.

This way the null will be in the range where the subwoofer is playing
This has been my experience, however I can't afford a meter; mine are at about .75m. My nulls are very sharp and hardly heard, and they occur around the crossover, so the subs are picking up any slack.
 

Thomas_A

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Just a note and question. When you tell the distance from the wall the relevant distance SBIR-wise is the driver to wall distance. I have toed in and a midwoofer to damping panel distance of 25 cm and to the wall 32 cm. This gives if I calculated correctly a first cancelation at 268 Hz.
 

Tangband

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My conclusion of this is:

1. Loudspeakers within about 50 cm or less from the undamped frontwall muddles the spatial quality and the sound gets worse.
One can easy test this by letting someone walk near the wall and talk at the same time - very near the wall the sound from the voice will be very coloured because of early reflections coming from the wall. At about 50 cm from the wall , the voice starts to be clearer compared to very close to the wall.

2. SBIR measurement results looks much worse than they sound. Its much better to put the speakers out from the frontwall anyway , and best result is often more than 1 meter away. The sound will become increasingly clearer from about 50 cm or longer from the front wall, if one measures from the baffle / frontwall. Try it.:)

3. Exactly the same happens in reverse, in the beginning of the audio chain with microphones If you do recordings of voices. If you place the microphone less than 50 cm from a stonewall or the floor, the recorded sound will be very unclear. Optimal distance is more than 5 ms timespan ( 1,7 meter or more )
 
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srrxr71

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It really depends if guess. Both KEF and Genelec give you the same type of diagram.

However they make one major assumption that you will not be using a sub/crossing over at 80-100Hz.

If you are then you are better off moving the speakers away from the wall. Because you don’t have to optimize for both sub 100Hz and imaging.

This is why personally I don’t understand the point of a full range speaker. It forces you to compromise on positioning for best bass or imaging or clarity.

Now that changed when placing some GIK 244 absorbers behind the speakers. I was able to move the speakers closer to the wall.

However that creates a huge dip around 110Hz (5 feet). I guess I can place more absorbers at that point away from the speakers as well and test.

Otherwise I suspect I would need to move the speakers 6ft+ away from the wall and check. In order to keep any dips below 100Hz.
 

Chromatischism

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Now that changed when placing some GIK 244 absorbers behind the speakers. I was able to move the speakers closer to the wall.

However that creates a huge dip around 110Hz (5 feet). I guess I can place more absorbers at that point away from the speakers as well and test.
That could be the floor or ceiling bounce cancellation. It often occurs around there. It might even be overlapping with another which makes it even more severe.
 

curiouspeter

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My LS50 Meta's are 6 inches from the front wall. I benefit from the boundary effect and I do not even need a subwoofer.

I use RoomPerfect to fix acoustic issues. It is working quite well.

Unless you build your house around your listening room, you need DRC or at least PEQ.
 

Thomas_A

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It really depends if guess. Both KEF and Genelec give you the same type of diagram.

However they make one major assumption that you will not be using a sub/crossing over at 80-100Hz.

If you are then you are better off moving the speakers away from the wall. Because you don’t have to optimize for both sub 100Hz and imaging.

This is why personally I don’t understand the point of a full range speaker. It forces you to compromise on positioning for best bass or imaging or clarity.

Now that changed when placing some GIK 244 absorbers behind the speakers. I was able to move the speakers closer to the wall.

However that creates a huge dip around 110Hz (5 feet). I guess I can place more absorbers at that point away from the speakers as well and test.

Otherwise I suspect I would need to move the speakers 6ft+ away from the wall and check. In order to keep any dips below 100Hz.
Is that 110 Hz dip due to speaker wall? 110 Hz cancelation implies 78 cm distance from woofer to wall.
 

Thomas_A

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My conclusion of this is:

1. Loudspeakers within about 50 cm or less from the undamped frontwall muddles the spatial quality and the sound gets worse.
One can easy test this by letting someone walk near the wall and talk at the same time - very near the wall the sound from the voice will be very coloured because of early reflections coming from the wall. At about 50 cm from the wall , the voice starts to be clearer compared to very close to the wall.

2. SBIR measurement results looks much worse than they sound. Its much better to put the speakers out from the frontwall anyway , and best result is often more than 1 meter away. The sound will become increasingly clearer from about 50 cm or longer from the front wall, if one measures from the baffle / frontwall. Try it.:)

3. Exactly the same happens in reverse, in the beginning of the audio chain with microphones If you do recordings of voices. If you place the microphone less than 50 cm from a stonewall or the floor, the recorded sound will be very unclear.
1. The experiment has other implications. If you move the speaker out, you need to move your listening position the same distance. Otherwise you are changing the direct to reflected sound ratio.
2. When you are close to the wall, the SBIR moves up in frequency. Having damping on the wall will reduce this interference and at the same time the intensity drops due to increased directionality. Tweeter dispersion be damped having a sufficient broad baffle, waveguide/damping and damping on the wall.
3. There is one trick to measure speakers which includes placing the microphone in a corner of the room. Thereby you are moving the interfering frequency very high up. It works. As is ground plane measurements.
 

Frgirard

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My conclusion of this is:

1. Loudspeakers within about 50 cm or less from the undamped frontwall muddles the spatial quality and the sound gets worse.
One can easy test this by letting someone walk near the wall and talk at the same time - very near the wall the sound from the voice will be very coloured because of early reflections coming from the wall. At about 50 cm from the wall , the voice starts to be clearer compared to very close to the wall.

2. SBIR measurement results looks much worse than they sound. Its much better to put the speakers out from the frontwall anyway , and best result is often more than 1 meter away. The sound will become increasingly clearer from about 50 cm or longer from the front wall, if one measures from the baffle / frontwall. Try it.:)

3. Exactly the same happens in reverse, in the beginning of the audio chain with microphones If you do recordings of voices. If you place the microphone less than 50 cm from a stonewall or the floor, the recorded sound will be very unclear.
1. The directivity of a voice emited by a head is not the directivity of a speaker. a speaker is omni until 400 Hz
2. SBIR ou LBIR ? the listening position . My experience with the sbir : the speaker against the front wall .
3. A speaker is not a microphone and you do not understand what is a voice.
 

Tangband

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1. The experiment has other implications. If you move the speaker out, you need to move your listening position the same distance. Otherwise you are changing the direct to reflected sound ratio.
2. When you are close to the wall, the SBIR moves up in frequency. Having damping on the wall will reduce this interference and at the same time the intensity drops due to increased directionality. Tweeter dispersion be damped having a sufficient broad baffle, waveguide/damping and damping on the wall.
3. There is one trick to measure speakers which includes placing the microphone in a corner of the room. Thereby you are moving the interfering frequency very high up. It works. As is ground plane measurements.
Works with static signals but not music;)
 

Thomas_A

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Tangband

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Which one? Sine sweeps are not static signals...
The last one.
Putting a microphone in a corner to do recordings of a voice is a clear receit for bad sound, it will sound very unclear but the frequency response from the microphone gonna be rather flat . In this case- The soundqualityproblem is the early reflections from the walls in the corner. The same will happen with a loudspeaker placed in a corner without damping material on the nearby walls. The sound will be very unclear.

As I wrote before, and Linkwitz seems to agree - one should try to avoid everything less than 6 ms delayed reflections from the speaker . The recording sessions is no different with microphones - you should avoid early reflections from a wall to the microphone within the timespan of 5 ms .
If you think about it - Putting a loudspeaker in a corner to listen to music is as I wrote very bad for sound.
 
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Tangband

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…and another example as you mentioned ground plane measurements - they work, but only for measurements.

Music is frequencies ordered in a specific way- in the time domain . Measurements are not.

Try to listen to your speaker with music if you lay on your back with your ears near the undamped floor. How does it sound ? Not really good… then try to sit up, and the sound will gradually be clearer the longer distance your ears are from the floor.

You can also try putting your ear really near one of the walls while listening to music. It can be the wall behind you or a sidewall. Now slowly walk away from the wall, and you will hear that the sound gonna be clearer at about 50 cm from the wall, and more than a meter away much more clearer.:)

As you mentioned already - I you put damping material on the wall behind a loudspeaker , the loudspeaker can be placed much nearer the wall without sounddestructive reflections. It can look like this:
2D9A4D29-4F9A-4A51-82F8-F560D250839B.jpeg
 
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Thomas_A

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The last one.
Putting a microphone in a corner to do recordings of a voice is a clear receit for bad sound, it will sound very unclear but the frequency response from the microphone gonna be rather flat . In this case- The soundqualityproblem is the early reflections from the walls in the corner. The same will happen with a loudspeaker placed in a corner without damping material on the nearby walls. The sound will be very unclear.

As I wrote before, and Linkwitz seems to agree - one should try to avoid everything less than 6 ms delayed reflections from the speaker . The recording sessions is no different with microphones - you should avoid early reflections from a wall to the microphone within the timespan of 5 ms .
If you think about it - Putting a loudspeaker in a corner to listen to music is as I wrote very bad for sound.
The thing is that a speaker flush to the wall do not have those reflections that you refer to. A speaker with a baffle would sound catastrophic if that would be the case. Genelec is correct in this matter.
 

Tangband

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The thing is that a speaker flush to the wall do not have those reflections that you refer to. A speaker with a baffle would sound catastrophic if that would be the case.
This is one of the myths that people believe in - putting a driver on a very wide undamped baffle gonna make early reflections like If you throw a stone into the water - theres gonna be small waves and those waves ( the early reflections) gonna blur the sound making it sound very bad .

The same reversed thing happens If you put a microphone on a recording session directly on a big wall or on a big table and try to do a recording of an instrument In that room. It will sound very unclear .

To understand this, I believe you need to do your own recordings , just as Linkwitz or I.Ö did.
 
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Thomas_A

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This is one of the myths that people believe in - putting a driver on a very wide undamped baffle gonna make reflections like If you throw a stone into the water - theres gonna be small waves and those waves ( the early reflections) gonna blur the sound making it sound very bad .

The same reversed thing happens If you put a microphone on a recording session on a big wall and try to do a recording of an instrument In that room. It will sound very unclear .
Can you refer to that myth?
 
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