Where to Place Mains

[Nordo]

Forget about toe-in and equilateral triangles for a second.

I have always been confused by the two schools of thought :-
1. Uncoupling the speakers from the walls (e.g. using WASP) i.e. keep them some distance from the walls, and
2. Locating them very close to the walls to minimise Speaker Boundary Interference Response (SBIR).

I hope I'm not going to start a war here, but need some learned opinions on what people have found from experience.
BTW, I have always followed the WASP approach, but have never been entirely happy with sound stage, etc.

I remember Sonnie testing several speakers in his own HT several years ago, and testing proved that in most cases, the tested speakers sounded better away from the walls.

We are moving to a new home and I'll be re-creating my home theatre/media room all over again.

 

[Sonnie Parker]

As I started reading your thread the first thought that came to my mind before I got to your part about our evaluations, was our evaluation results.

There are a few songs what all of us guys that have participated in our evals will listen to on a regular basis, as those songs are recorded with excellent depth acuity. When the speakers are against the wall, or what we consider too close, all of the imaging is on the same plane, and soundstage may not be as wide. Yet when we pull the speaker out from the wall, the soundstage widens and the depth acuity comes back to us. We can actually notice a horn player on the back part of the stage where the big bass is about middle, and the singer is front center stage. It is very evident on those songs. Pulling them out from the wall does cause most of them to lose any kind of extended bass, shy of a few speakers we've tested, however, it's nothing that either subs can't take care of... or filters from whatever source you choose.

Obviously I can't see this is true for every room as rooms are different from one place to the next. I don't think it is simply coincidence that of all the shows I've been to, Axpona, Rocky Mountain, Capital City, Lone Star, etc, most of those rooms have speakers pulled on out from the wall.

I've never been a fan of the equilateral triangle either. I prefer to be a bit forward in the triangle... closer to the speaker plane, although it's not by much, but I am closer to the speakers than they are from each other. It seems the guys that have been to my house prefer the same, and we've tried countless speaker placements. It really all boils down to your room, your acoustic treatments, the speakers you have, and ultimately and most importantly, what you like best.

 

[Nordo]

Thanks Sonnie, that's a great reply.
I've never placed any of my speakers in the corners, but the logic I have read on SBIR seemed to make sense, hence the enquiry.
However, the proof is in the listening.

BTW, my current setup has the equilateral triangle meeting a couple of feet behind my head. Which sounds similar to how you like it.
I'm excited to be applying my current knowledge to a new room.

 

[Sonnie Parker]

Yep... that's a much better way of stating it... the equilateral triangle meets behind my head. I'll have to check now... I'm curious what that distance is. I'm thinking about a foot or two.

Also consider the Cardas speaker setup information... this is where my placement all got started with pulling speakers out into the room, although granted I've never worried about bass since I have 4 subs to compensate.

Cardas Room Setup Guide

 

[ddude003]

I think that for a near field setup locating "smallish" speakers/monitors very close to the walls to minimise Speaker Boundary Interference Response makes sense... Post/Production Studios, Computer Office workspaces and bedrooms... For LivingRooms, Home Theatre and other Open Spaces, uncoupling the speakers from the walls by, up to, a wavelength, of your choosing, can create a larger, three dimensional soundscape/soundstage...

It also depends on the type of speaker design which determines where best placements may be... Look at some Spinorama charts to see some differences... For instance, DiPole speakers, like Martin Logan Electrostatic Hybrids, utilize the wall behind them in a direct/reflect way... They also radiate much less energy towards the side walls than conventional box speakers do...

By the way... What design are your DIY speakers?

 

[Nordo]

By the way... What design are your DIY speakers?

The mains are sealed two way using Vifa drivers. The Xovers are a 4th order Linkwitz-Riley.
The four surrounds are two way ported, again with Vifa drivers. From memory the Xovers were 2nd order.
I used an old DOS program called CalSod to design the Xovers (remember, this was 30+ years ago ).
The centre is an old Paradigm W-T-W, but I replaced the tweeter with a Vifa tweeter to get a tone similar to the rest of the setup (I didn't bother to check or modify the Xover).

 

[natty]

Forget about toe-in and equilateral triangles for a second.

I have always been confused by the two schools of thought :-
1. Uncoupling the speakers from the walls (e.g. using WASP) i.e. keep them some distance from the walls, and
2. Locating them very close to the walls to minimise Speaker Boundary Interference Response (SBIR).

I hope I'm not going to start a war here, but need some learned opinions on what people have found from experience.
BTW, I have always followed the WASP approach, but have never been entirely happy with sound stage, etc.

I remember Sonnie testing several speakers in his own HT several years ago, and testing proved that in most cases, the tested speakers sounded better away from the walls.

We are moving to a new home and I'll be re-creating my home theatre/media room all over again.

One of the most popular designs for recording studios monitoring and mixing rooms that also measures well (ie, not just tradition but science) places the speakers either in wall (baffle wall style) or directly on wall. They don't suffer from lack of depth and soundstage. Rather they benefit from controlling SBIR and predictable bass response.

Here is a fine article on the concept: http://arqen.com/acoustics-101/speaker-placement-boundary-interference/

Genelec has done some white papers on this, including studies in studios.

Digestible info from GIK: https://www.gikacoustics.com/speaker-boundary-interference-response-sbir/

And a video, if you prefer:

 

[Sonnie Parker]

I think if you plan on placing the speakers near that wall, on the wall, etc, you simply need to have speakers designed for this. Studio monitors are apparently designed for this... and for nearfield listening as well. As previously stated, we've done countless speaker evaluations in my listening room with traditional home audio speakers, and for the best sound stage, imaging and depth acuity we've always had to pull the speakers on out from the wall considerably. Which makes sense for traditional home speakers... and again... see the Cardas speaker/room setup guide link above. However, bass response will typically fall off as a result of achieving superb imaging, sound stage and depth acuity, so you need a subwoofer and/or speakers capable of equalization to reap the benefits. Of course even when we did test the speakers close to the wall, it caused a lot of boominess, so we still had to use EQ to make them sound their best. The question might be... are you at home with home speakers, or are you in a studio with studio monitors... two completely different applications I would think.

 

[wmlaven]

As I started reading your thread the first thought that came to my mind before I got to your part about our evaluations, was our evaluation results.

There are a few songs what all of us guys that have participated in our evals will listen to on a regular basis, as those songs are recorded with excellent depth acuity. When the speakers are against the wall, or what we consider too close, all of the imaging is on the same plane, and soundstage may not be as wide. Yet when we pull the speaker out from the wall, the soundstage widens and the depth acuity comes back to us. We can actually notice a horn player on the back part of the stage where the big bass is about middle, and the singer is front center stage. It is very evident on those songs. Pulling them out from the wall does cause most of them to lose any kind of extended bass, shy of a few speakers we've tested, however, it's nothing that either subs can't take care of... or filters from whatever source you choose.

Obviously I can't see this is true for every room as rooms are different from one place to the next. I don't think it is simply coincidence that of all the shows I've been to, Axpona, Rocky Mountain, Capital City, Lone Star, etc, most of those rooms have speakers pulled on out from the wall.

I've never been a fan of the equilateral triangle either. I prefer to be a bit forward in the triangle... closer to the speaker plane, although it's not by much, but I am closer to the speakers than they are from each other. It seems the guys that have been to my house prefer the same, and we've tried countless speaker placements. It really all boils down to your room, your acoustic treatments, the speakers you have, and ultimately and most importantly, what you like best.

How much away from the wall, in general, starts to make a difference. My room is such that the FR & FL speakers are against the wall because they're both by doors so on a "footpath." I could move them away from the wall maybe 2 inches before I start tripping over them, but would 2" really be worth it?

 

[Sonnie Parker]

Sounds like you have a challenging room for speakers... not sure there is an answer.

Here's the link again... a good recommended starting point: Cardas Room Setup Guide

But no... 2 inches is not going to help... and likely having them next to a doorway is not going to help.

 

[wmlaven]

Sounds like you have a challenging room for speakers... not sure there is an answer.

Here's the link again... a good recommended starting point: Cardas Room Setup Guide

But no... 2 inches is not going to help... and likely having them next to a doorway is not going to help.

Well, I'll just have to live with what I've got. Thanks.

 

[DanDan]

It all depends on everything...... Flush mounting delivers clear bass and low mid, without the comb filtering of near wall location. But.... pressure peaks at the boundary means the modes are maximally driven. Some speakers have wave guides to diminish HF and MF reflections from outside of the sweet zone. This and treatment creates a Zone Without Early Reflections. Incredible, even excessive clarity. Bass treatment allows the optimum drive of Flush mounting, great extended fast clear bass. In Control Rooms done well, we are essentially listening anechoically. Huge Headphones. Domestic listening spaces don't have the size or money to afford such treatment. LF decay can be ten times that of a CR. So placing speakers near the FW, driving all the modes more, diminishing the thinning out effect of LF comb filtering can result in excess bass which lasts way too long. Because SBIR is not just LF but a comb, moving away from the FW causes an overall tonal shift towards brighter, clearer. Stronger imaging effects.

 

[NBPK402]

I have usually found pulling the speakers out from the wall 2' or more has been the best, but with my current speakers I have found they do best in the corners. My current speakers have the front of the speaker 2' from the bass traps, and give me an excellent soundstage when aimed behind my head about 1'. Your mileage may vary, due to your speakers, and room.

 

[DanDan]

Open Mind, rooms are so complex....

 

[DanDan]

Open Mind I guess. Many people prefer to leave the Front Wall untreated. https://realtraps.com/art_front-wall.htm Manuals...... and guides....hmmm, I have seen two, by Yamaha and Harbeth, which are simply wrong. The Dirac Live manual too, until it got corrected. All types of speakers which radiate LF at the back will experience SBIR. I believe the room and circumstances prescribe the optimum locations.