Soffit-mounting advantages?

[DavidShe]

Soffit-mounted speakers are often preferred in critical listening environments, such as recording studios, where precise sound reproduction is crucial [ChatGPT]. How significant of an improvement does soffit mounting provide? Specifically, I am wondering about soffit-mounting, for example, a pair of ATC 100 or Neumann KH420 in a small treated room.

 

[MaxwellsEq]

Soffit-mounted speakers are often preferred in critical listening environments, such as recording studios, where precise sound reproduction is crucial [ChatGPT]. How significant of an improvement does soffit mounting provide? Specifically, I am wondering about soffit-mounting, for example, a pair of ATC 100 or Neumann KH420 in a small treated room.

The chief benefit is to reduce baffle edge/step artefacts. For some speakers this may be a significant benefit, so the size of the benefit depends on how the speaker is designed.

 

[tw99]

The chief benefit is to reduce baffle edge/step artefacts. For some speakers this may be a significant benefit, so the size of the benefit depends on how the speaker is designed.

Surely removing SBIR effects from the front wall is also a major consideration ?

 

[MaxwellsEq]

Surely removing SBIR effects from the front wall is also a major consideration ?

Yes, it does. I didn't mention it because the OP was asking about specific speakers rather than room artefacts.

 

[Duke]

Imo flush-mounting speakers has definite advantages. In addition to eliminating baffle step and SBIR effects, edge diffraction is eliminated, as is the reflection off the wall behind the speakers. Edge diffraction degrades imaging precision and can be a source of coloration, and the reflection off the wall behind the speakers can likewise be a source of coloration and is often a strong "small room signature" cue that tends to constrain the depth of the soundstage.

So not only is the lower midrange and bass response improved, coloration is reduced, along with the "you're listening to speakers... in a small room" cues. So you hear more of the spatial information on the recording.

You may end up with too much lower midrange and bass energy if the speaker was "voiced" for normal free-standing use.

And make sure you get the toe-in angle right before you build the walls!

Here's a thread that shows a flush-mounted system I made for a customer (he did the actual installation); the main monitors' axes cross a little bit behind the mix position:

Studio monitor collaboration with Jeff Hedback of Hedback Designed Acoustics

Multi-award-winning studio designer Jeff Hedback offered me the opportunity to bid on providing custom main monitors for a recording studio he designed, and his client accepted my bid. Jeff specified the tweeter height, outer dimensions, and look-down angle. The installation is in-wall, so the...

www.audiosciencereview.com

 

[Flaesh]

And make sure you get the toe-in angle right before you build the walls!

How did you make sure the toe angle is correct?))

 

[Duke]

How did you make sure the toe angle is correct?))

You could set the speakers where you expect them to end up and sit in your intended main listening position and adjust the toe-in by ear, giving consideration to off-axis listening positions if applicable.

You could use the manufacturer's recommendations and calculate a toe-in angle that is within the recommended range at the sweet spot and still gives good coverage for off-axis listeners, if applicable.

You could ask your dealer and/or hire an acoustician to advise you.

The issue of course is that once the walls have been built, the toe-in angle is not easy to change.

 

[Matt_Holland]

Imo flush-mounting speakers has definite advantages. In addition to eliminating baffle step and SBIR effects, edge diffraction is eliminated, as is the reflection off the wall behind the speakers. Edge diffraction degrades imaging precision and can be a source of coloration, and the reflection off the wall behind the speakers can likewise be a source of coloration and is often a strong "small room signature" cue that tends to constrain the depth of the soundstage.

So not only is the lower midrange and bass response improved, coloration is reduced, along with the "you're listening to speakers... in a small room" cues. So you hear more of the spatial information on the recording.

You may end up with too much lower midrange and bass energy if the speaker was "voiced" for normal free-standing use.

And make sure you get the toe-in angle right before you build the walls!

Here's a thread that shows a flush-mounted system I made for a customer (he did the actual installation); the main monitors' axes cross a little bit behind the mix position:

Studio monitor collaboration with Jeff Hedback of Hedback Designed Acoustics

Multi-award-winning studio designer Jeff Hedback offered me the opportunity to bid on providing custom main monitors for a recording studio he designed, and his client accepted my bid. Jeff specified the tweeter height, outer dimensions, and look-down angle. The installation is in-wall, so the...

www.audiosciencereview.com

Wow, I bet they move some air!

The only downside I think is you lose the illusion of the singer/instruments being in the room. I realise that this is partly created by the front and side wall reflections, but it’s a very pleasant effect for those with space to have their speakers positioned well out into the room. I also think that there is a psycho-acoustic effect at work where because we can see the empty space around and behind the speakers, we can easily believe the sound images can be located there.

Flush mounted speakers can image well of course and should, in theory, provide a more accurate sound, but in my experience the illusion of soundstage depth requires more concentration or to close your eyes.

 

[Flaesh]

You could set the speakers where you expect them to end up and sit in your intended main listening position and adjust the toe-in by ear, giving consideration to off-axis listening positions if applicable.

Yes, I can)). Usually my speakers (15"+SEOS24) are in the corners, toed in 45º, sometimes less. Unfortunately, there are windows and doors everywhere in the room; otherwise I would have already built the soffits
Thanks for the answer.

 

[Duke]

Wow, I bet they move some air!

I think they do.

The only downside I think is you lose the illusion of the singer/instruments being in the room.

Spatial cues can be dominated by the reflections in the room, and if that is the goal, then you want as much distance between speakers and walls as you can reasonably get for the sake of getting a convincing soundstage.

OR, the spatial cues can be dominated by the venue acoustic cues on the recording, and if that is the goal, then you want to minimize the "small room signature" cues of the playback room so they do not mask the venue acoustic cues on the recording.

Flush mounting done well eliminates some of those "small room signature" cues, particularly those which inhibit the depth-of-soundstage cues on the recording. Flush-mounted speakers should have sufficient radiation pattern control that they do not "illuminate" the wall they are flush-mounted in. In my opinion.

Flush mounted speakers can image well of course and should, in theory, provide a more accurate sound, but in my experience the illusion of soundstage depth requires more concentration or to close your eyes.

If the visual cues of flush-mounted speakers dominate your spatial perception, then just close your eyes.

Usually my speakers (15"+SEOS24) are in the corners, toed in 45º, sometimes less.

YESSS!!! That's a killer woofer/horn combination with a killer set of attributes, and imo your aggressive toe-in is the right set-up geometry to get the best from that type of loudspeaker system.

 

[DavidShe]

OR, the spatial cues can be dominated by the venue acoustic cues on the recording, and if that is the goal, then you want to minimize the "small room signature" cues of the playback room so they do not mask the venue acoustic cues on the recording.

I think i would prefer to have early reflections (<15ms) absorbed, so that "spatial cues" mostly come from the recording. (LEDE room championed by Thomas Hidley)

 

[Duke]

I think i would prefer to have early reflections (<15ms) absorbed, so that "spatial cues" mostly come from the recording. (LEDE room championed by Thomas Hidley)

Note that spectrally-correct late-arrival (after 15 milliseconds) reflections are in effect the "carriers" for the reverberation tails on the recording, so we want some reflection energy to survive intact long enough to deliver those reverberation tails from many different directions.

(In practice that 15 millisecond target can be difficult to attain in a modest-size home audio room; ime avoiding significant horizontal-plane reflections within the first 10 milliseconds is still worthwhile.)

 

[DavidShe]

Note that spectrally-correct late-arrival (after 15 milliseconds) reflections are in effect the "carriers" for the reverberation tails on the recording, so we want some reflection energy to survive intact long enough to deliver those reverberation tails from many different directions.

(In practice that 15 millisecond target can be difficult to attain in a modest-size home audio room; ime avoiding significant horizontal-plane reflections within the first 10 milliseconds is still worthwhile.)

That would seem to suggest absorbers on the side walls and ceiling, and diffusion on the back wall? The distance to the back wall would determine when the reverb "effect" (late reflections) starts. It's getting complicated!

 

[Duke]

That would seem to suggest absorbers on the side walls and ceiling, and diffusion on the back wall? The distance to the back wall would determine when the reverb "effect" (late reflections) starts. It's getting complicated!

View attachment 338417

I like the geometrical avoidance of early lateral reflections in your diagram.

 

[DavidShe]

 

[DavidShe]