room dimensions

[wsloup]

i have 2 k horns and working on a design for a rec room. all things being equal what size of room will best accomodate these speakers? 25 X 25 or 20 X 20? i am leaning towards 9 foot ceilings instead of 8 foot ceilings. i will eventually add a center channel, a sub woofer and and side/rear fill speakers. i already have a 5.1 capable receiver. what center channel, sub woofer and side/rear speakers would you recommend? i have a mid range budget to work with. any help would be appreciated.

wsloup

[Groomlakearea51]

Welcome to the Forum;

I am not in any way an expert on the acoustics and room size. Right now there are a number of members that have an absolutely outstanding level of knowledge. As a start point for you to consider is the "golden rule" ratio of 1.618 (I believe); thus a room with 9 foot ceilings should be 14.5 feet x 23.5. You should "google" this and read why this ratio is so important with music, harmonics, etc. Regardless of the size, however, a most important thing is to make sure the room is properly constructed or treated for audio. So, to help understand about the issues involved, use search option and look for acoustics, large room/small room, etc. In particular read the posts related to these topics by mas, DrWho, and a number of others.

Good luck, and I'm sure that alot of folks here will help you out much more!

[Islander]

One basic concept that's often been mentioned is that all three dimensions of the room should be different from each other, and should not be multiples of one another. Some examples follow. The worst shape would be a room that is literally cube-shaped. A square floor plan is not good, nor is a room that's twice as long (or half as tall) as it is wide. If you're designing from scratch, you might consider making the walls non-parallel.

I'll let the more knowledgeable take over from here.

Pat on the Island

[jdm56]

I'm no expert either, but I can offer a little advice from my own experience. I had k-horns in a basement music room that measured 8.67'x16'x18.5'. If you check these figures you will see there are no pile-ups of resonant modes, which I thought at the time was all that mattered. WRONG! Although my dimensions were far enough apart to not have pile-ups of room modes, they were too close together to evenly distribute the modes related to each dimension. The result was bass that measured poorly, being very uneven, and that subjectively, just sounded very thin --not what one wants with klipschorns! I could find no solution, and since this was the only room available for the big horns, I ended up selling them. (Actually, I was a bit cash-strapped too, which was a factor in selling.) It still pains me to look at pictures of my set-up then: a pair of oak/oil k-horns w/ a matching belle center and heresy II surrounds. But I digress... my advice would be similar to what's been said. Definitely try to avoid dimensions that are mathematically related (12x24, or 20x20 for example). If you can achieve the "golden ratio", then by all means do so, but don't feel like you must. Other dimensions can work very well too. A perfect cube would be the worst possible shape. Good luck!

[oldtimer]

These guys have good advice. Do some research, why are auditoriums shaped the way they are?

[WMcD]

Forum member mas is trying to drag us though an appreciation of modern small room design. Quite a complicated subject.

Most of this goes to room treatment. I like this approach because most of us don't have much freedom in placement of walls. In your case, you are really only able to increase dimensions by about 10%. That doesn't seem like very much to me in the search for bass boost.

I know you are saying, all other things being equal. But maybe this extra 10% can be used to make the front a little more symetric, freedom from doors or windows, the seating postion being a little farther away from the screen and speakers, or leaving room for room treatment (even on the ceiling).

Gil

[George Roland]

I'm sure no expert on this either, but so far no one has mentioned wall construction. I'm guessing you would do well to insure that the walls in the corners where your K-horns are going are solid. Those walls are part of the horn and you do not want them flexing while playing music. Perhaps somewhat closer-together studs or maybe a double layer of wall material would do well to make these walls more rigid.

Best,

George

[garyrc]

What everyone else said.

A perfectly square floor plan is bad with any speakers you might put in there. Vary the dimensions.

I like the Klipschorn corners to be rock solid -- studs 8" on center, double 3/4 plywood/veneer or double 5/8" sheetrock 5 or 6 feet out from the corner, or more -- beyond that distance, the walls can be normal, but solid -- no illsupported paneling! ,,, if you decide to make some walls non parallel, make sure the corners are 90 degrees for 6 or more feet out ....and the floor should be either braced underneath with an extra joist pressing up on the others, going the opposite direction, or a slab floor (with rug). With such a set-up, I had smooth bass response extended beyond specs.

The older audio review of the Khorns in AUDIO suggested a thick rug and high ceiling, and I believe it. The Khorns don't have to SIT on a rug (probably shouldn't, if it is spongy), just have a rug IN FRONT of them ... the idea is to keep the tweeter sound from bouncing off of floor and ceiling and the reflections reaching your ears too soon, in the case of the Khorn, before the bass wave gets there. A higher than 8 foot ceiling is therefore a good idea. Do it!

Before setting your dimentions, you may want to search for automatic room mode calculators online. I think Dr. Who, or someone, posted one. Put in some diffusion (just bookshelves with artifacts that don't rattle, books and spaces are better than nothing -- I like open ended bookshelves, rather than cases, so the sound can flow through, rather than being blocked by the end pieces -- and keep everything away from the first 6 feet of the Khorn corners). For more, you could put a few diffusers on the ceiling. Many audio rooms nowadays have too much absorption, so you may want to limit it to the rug, any soft furniture, and at the first reflection points (determined by having someone carry a mirror alongthe wall

In my view, nothing I've heard beats a pair of Khorns in an excellent room!

[JJkizak]

You might want to read some good acoustic books, most say to avoid any 17 ft. dimension. If you check the Bell Labs setup of K-horns with powered center channel they used a 25 x 25 ft room for testing, at least I think that was the dimension. It might have been 25 x 35 ft. depth. The high ceilings will give you a huge soundprint. I have had them in an "L" shaped room 24 ft. x 12 ft x 18 ft. with open roof ceiling, 17 ft x 17 ft x 8 ft ceiling, 20 ft x 20 ft x 12 ft ceiling, and lastly 24 ft x 12 ft x 7 ft ceiling. The best sounding was the 20 ft x 20 ft with 12 ft ceiings. The worst was the 17 ft x 17 ft x 8 ft ceilings which was really bad. In all cases the floors were wall to wall carpeting. The openings into the rooms will affect your glide tone balance a huge amount---high to low slowly changing single frequency which will change direction from one speaker to another if your acoustics are messed up as it changes from high to low. This test gives you an idea of how your room acoustics are affecting the spatial imprint. Open a window or door or change the position of a chair or put a new plant on the desk and everything gets fubar. That's why I gave up on acurate instrument placements. Umless of course you have a dedicated HT room without outside intervention if you know what I mean. All of these scenerios were with powered Cornwall center channel from 1965 thru 2006.

JJK

[meagain]

wsloup - I'm trying to figure out the same thing. My husband and I again had 'a meeting' about this last night. Tricky business. We have a starting point though. 28 foot wide room (tho now that I think about it, that's also arbitrary - but I'm sticking to 28' for now). Then I was figureing maybe 16-17 feet for the khorn wall. I think people will tell me this is too narrow for them.

After this room dimension issue, I have more problems.... what to do with the rears in a 5:1 MUSIC/DVD concert situation. Because I have khorns, I'm basically locked into having more big heritage. Khorns snug up nicely footprint wise and it might work to have another pair of khorns for rears. So then the 2nd pair of khorns would go 28 feet back from the mains. Husband says they should be equidistant. I question this by saying "why can't we just crank them louder to balance them?". IDK who's right. If he's right and they need to be equidistant, then - ewww. I'm going to have an aesthetic problem big time.