Building Floor Standing Speakers into a wall

[AcuDefTechGuy]

So I reached out to a home audio installation company. I got a quote from them, it's quite high.

How high?

 

[mazersteven]

R-5800-W II In-Wall Speaker | Klipsch

The Klipsch R-5800-W II in-wall speaker delivers quality sound in any location. Shop this speaker and more in wall home theater speakers at Klipsch today.

www.klipsch.com

 

[TLS Guy]

It sounds like there is some possible misunderstanding about the use of "Transition Frequency," here.

TLS will correct if I am wrong, but his usage of this is not about the Schroeder Frequency of the room (sometimes called transition frequency), rather it is the point where the soundwaves are not being reinforced by direct reflection from the baffle (as referred to in the article below as Baffle Step Response).

From his post above:


This is what, if I understand his usage correctly, he is calling the transition frequency.

From Elliott Sound Products:

Baffle Step Compensation

ESP - The Audio Pages. Baffle Step Compensation. How it works, and why you may need it. Includes details of how to build your own.

sound-au.com

You are absolutely correct. However, the baffle step loss and the room gain of the Schroeder frequency do interact. My current theater is substantially larger than the one at Benedict. This has resulted in the BSC signals having to be substantially increased.

So the OPs problem would be more noticeable in a small room than a large one.

I do note that this larger room sounds a lot better than the last one. This is because the room is not only larger, but because I could set optimal dimension ratios, and because the room is very rigid, with zero vibration on deep bass, like the ones that plagued me in the last room. The TLs in this room are incredible with a really natural bass all the way down. So rooms matter, but generally there is not much you can do about them. You have to work with what you have.

 

[shadyJ]

Another problem that I don't see being addressed about placing a free-standing speaker into a wall is diffraction which is certain to degrade the sound as well, even above bass frequencies.

 

[TLS Guy]

After reading all of the great comments - I realized that I have no idea what I'm doing!
So I reached out to a home audio installation company. I got a quote from them, it's quite high. I'm just not sure if the sales guy understands that I really need loud music to play in the family room! I tried to get the point across by telling him that currently I have Rockit6 speakers in my bedroom and Cerwin Vega D-9s in my living room.
What do you think about his proposed in wall solution?

1 Paradigm H55-LCR
2 Paradigm H65-IW
1 Paradigm RVC-12SQ

That system will be close to useless. As usual specs are minimal. However it is not a high powered system by any means. The speakers have no boxing or loading to the cones, which makes them next to useless. Then those LCR speakers have horizontal bass/mids, which will cause the dispersion to be 90 degrees rotated from what you want. The sub is not a sub with an F3 of only 35 Hz.

That system is absolutely typical of the in wall junk that is out there in the commercial market.

From what you are looking for, you will not be happy with that system.

I just don't know of an off the shelf system that will deliver what I think you are looking for. The system I linked you too, can be driven by 1000 watts at least for the four speakers. It plays loud and clean, with clear dialog and really good deep bass.

So I think you have to rethink if you really want an in wall system. As I said, I can arrange for the cabinet shop to cut you a set of flat packs, and ship them. The left right speakers will work equally well as the surrounds. If you think that you or someone else would be prepared to assemble them, I would agree to build you the crossovers. The file that I linked has the prices for all the drivers. However the tweeter for the center speaker is NLA, but there is a SEAS unit that can be substituted.

 

[TLS Guy]

Another problem that I don't see being addressed about placing a free-standing speaker into a wall is diffraction which is certain to degrade the sound as well, even above bass frequencies.

Strangely in my system diffraction of the upper frequencies did not turn out to be an issue that I can tell. The peaks and nulls from the flat wall were below 200 Hz.

As I said there is no good data on these systems, but there needs to be I feel. They are to all intents and purposes orphan products at this time.

That in wall system far exceeded my expectations, and I had far less problems than I expected. Certainly I regard it giving validity to the concept of high end and accurate in wall systems. If you heard my system blinded, you would never guess it was in wall.

 

[AcuDefTechGuy]

Another problem that I don't see being addressed about placing a free-standing speaker into a wall is diffraction which is certain to degrade the sound as well, even above bass frequencies.

All speaker baffles will have sound diffraction. Putting the speaker into the wall will increase the diffraction even more?

But a typical in-wall speaker will have less diffraction?

 

[AcuDefTechGuy]

Strangely in my system diffraction of the upper frequencies did not turn out to be an issue that I can tell.

This is what Linkwitz said regarding sound diffraction:

"Loudspeaker cabinet edge diffraction is a subject of never ending debate. I am not aware of any scientific study as to the audible effects of diffraction, but since it adds ripples to the steady-state frequency response of a loudspeaker, especially for symmetrical driver layouts, there are many claims to its detrimental effects."

So is the subject of Diffraction more "theory" than actual real life?

 

[Swerd]

It sounds like there is some possible misunderstanding about the use of "Transition Frequency," here.

TLS will correct if I am wrong, but his usage of this is not about the Schroeder Frequency of the room (sometimes called transition frequency), rather it is the point where the soundwaves are not being reinforced by direct reflection from the baffle (as referred to in the article below as Baffle Step Response).

When TLS Guy refers to "transition frequency", he means that frequency where a speaker's horizontal dispersion shifts from spherical (roughly 360°), to hemispherical (roughly 180°). If you use radian terms instead of degrees, the transition from 360° to 180° can be called the 4π to 2π transition. As he explained, the frequency at which the 4π to 2π transition occurs varies with the external width of the cabinet. Wide cabinets have a 4π to 2π transition at lower frequencies, and narrow cabinets at higher frequencies – right in the middle of the speech discrimination band.

This should not be confused with Schroeder Frequency of a room. Sometimes I've heard this called a transition frequency. Remember it this way:

• A room has a Schroeder frequency
• A speaker cabinet has a 4π to 2π transition frequency

 

[Swerd]

All speaker baffles will have sound diffraction. Putting the speaker into the wall will increase the diffraction even more?

But a typical in-wall speaker will have less diffraction?

All loudspeaker diffraction (that I know of) comes from the existence of edges on the front baffle. These mostly come at higher frequencies, and they vary with the distance between a driver and the baffles edge(s). Here is an example, a tweeter's unfiltered frequency response, as part of a 2-way speaker design, mounted in an 8" wide cabinet.

This is taken from https://www.salksound.com/blogtopic.php?id=5

To quote Dennis Murphy:

"Things are in pretty good shape from 3,000 Hz on up. But notice the dip and peak below that point. All tweeters will have a similar profile in this box. As the sound waves at those frequencies reach the edges of the baffle, some will be reflected back and either cancel or augment new waves just leaving the tweeter. These “diffraction effects” are also evident in the slight dips much further up. But what’s important is that even excellent tweeters will not have a smooth natural roll off in the types of cabinet baffles that are normally used."​

In-wall speakers won't have the typical diffraction problems that free-standing speakers have. In theory, they should have no diffraction effects because there are no cabinet edges. But in practice, I'm not sure if they have no diffraction effects at all.

 

[juseasy]

You keep mentioning "Loud". It's not about being loud it's about being clear and undistorted with all volumes

I should rephrase - I need it clear and undistorted at very high levels of volume!

 

[juseasy]

How high?

north of 15k!!

 

[juseasy]

That system will be close to useless. As usual specs are minimal. However it is not a high powered system by any means. The speakers have no boxing or loading to the cones, which makes them next to useless. Then those LCR speakers have horizontal bass/mids, which will cause the dispersion to be 90 degrees rotated from what you want. The sub is not a sub with an F3 of only 35 Hz.

That system is absolutely typical of the in wall junk that is out there in the commercial market.

From what you are looking for, you will not be happy with that system.

I just don't know of an off the shelf system that will deliver what I think you are looking for. The system I linked you too, can be driven by 1000 watts at least for the four speakers. It plays loud and clean, with clear dialog and really good deep bass.

So I think you have to rethink if you really want an in wall system. As I said, I can arrange for the cabinet shop to cut you a set of flat packs, and ship them. The left right speakers will work equally well as the surrounds. If you think that you or someone else would be prepared to assemble them, I would agree to build you the crossovers. The file that I linked has the prices for all the drivers. However the tweeter for the center speaker is NLA, but there is a SEAS unit that can be substituted.

My apologies, I completely missed your first post.
I live in Canada so I think there may be a problem getting your cabinets!


Beautiful home by the way!

 

[shadyJ]

This is what Linkwitz said regarding sound diffraction:

"Loudspeaker cabinet edge diffraction is a subject of never ending debate. I am not aware of any scientific study as to the audible effects of diffraction, but since it adds ripples to the steady-state frequency response of a loudspeaker, especially for symmetrical driver layouts, there are many claims to its detrimental effects."

So is the subject of Diffraction more "theory" than actual real life?

Earl Geddes studied diffraction in the sense of a slight group delay that can occur in the mouth of horn speakers. He showed that it is audible and that it resembles non-linear distortion to human perception. This type of diffraction would be present in all loudspeakers to some degree. Even a flat baffle is technically a waveguide. The wider you make that baffle, the more soundwaves reflect off of it. It's hard to say how much the diffraction that can be heard from suboptimal waveguides would translate to the infinite baffle of a wall, but it would only be a matter of degree, not of kind. It has always been thought that in-wall speakers benefit more from narrow dispersion designs rather than wide dispersion because of this.

 

[Pogre]

north of 15k!!

Phew!

And there's still some question of performance even at that price. If I were in your shoes I'd be getting to work on the wife. You know that kind of money can get you something really spectacular in traditional speakers. Some furniture grade and very aesthetically pleasing speakers that will perform at the level you're looking for.

 

[TLS Guy]

Earl Geddes studied diffraction in the sense of a slight group delay that can occur in the mouth of horn speakers. He showed that it is audible and that it resembles non-linear distortion to human perception. This type of diffraction would be present in all loudspeakers to some degree. Even a flat baffle is technically a waveguide. The wider you make that baffle, the more soundwaves reflect off of it. It's hard to say how much the diffraction that can be heard from suboptimal waveguides would translate to the infinite baffle of a wall, but it would only be a matter of degree, not of kind. It has always been thought that in-wall speakers benefit more from narrow dispersion designs rather than wide dispersion because of this.

Well as so often Geddes talks a lot of bunk. In a very live room there is probably a merit to wave guides. For most HF units I believe it is a detriment.

My in wall is wide dispersion by design. It has to be as it is a huge space, and I often listen right out in the kitchen and it has to sound fine everywhere.

You can see my in wall is very wide dispersion.

Above all it has good dispersion in the speech discrimination band, which is crucial, especially for a system that is only for music system a small percentage of the time. Good speech is essential over a wide listening area in a system like that.

 

[TLS Guy]

Phew!

And there's still some question of performance even at that price. If I were in your shoes I'd be getting to work on the wife. You know that kind of money can get you something really spectacular in traditional speakers. Some furniture grade and very aesthetically pleasing speakers that will perform at the level you're looking for.

That system as specked is not worth anything like that money. Mine did not cost anything close to that, and it would trounce that system and grind it in the dust.

 

[TLS Guy]

My apologies, I completely missed your first post.
I live in Canada so I think there may be a problem getting your cabinets!


Beautiful home by the way!

May be you could find someone to build it for you? I know my cabinet shop would Email the C & C details to another shop, if you stay set on an in wall system.

 

[Pogre]

That system as specked is not worth anything like that money. Mine did not cost anything close to that, and it would trounce that system and grind it in the dust.

You know I'm a long time admirer of your work. Unfortunately, your system is in limited quantity, and to complicate further op is in Canada.

That said is RBH an available option in Canada? I'm not positive on pricing for their in wall solutions but always hear good things about the company. I know @William Lemmerhirt has been looking at in walls too and might have some suggestions. @AcuDefTechGuy, you're a RBH guy right?

 

[Pogre]

May be you could find someone to build it for you? I know my cabinet shop would Email the C & C details to another shop, if you stay set on an in wall system.

This would be one way to do it!

If it's feasible and you can do it op, I don't think you could do much better without spending in multiples more.