Listening Room Acoustics

[enigzenig]

The listening room:

The ceiling is 10' high. I would like to use this game room as a home theatre setup. Currently have have two '86 industrial La Scalas as front speakers (in the bottom corners). Eventually, I would like to get a pair of Klipschorns and use the La Scalas as rear speakers. The two bottom corners of the room would be perfect corners for Klipschorn placement.

The reverb and standing waves in this room are irritating to say the least. It is bad enough that I can't listen to the speakers. I like to have a pretty dead room so subtle detail is clear. There isn't any furniture currently in this room and the "Open to Below" feels like it makes the first floor an echo chamber. I would really like to use this room due to the size though I do not know what techniques I can use to control the reverb from "Open to Below". Does anybody have any suggestions? I was going to look at the software CARA but I am not sure if it will be able to assist in this situation. If I can control the "Open to Below", I feel confident that I can control the rest of the room with furniture, acoustic treatments and other objects/techniques. I don't want to spend time and money on trying to control acoustics that may be impossible due to the floorplan.

Thanks,
Shawn

[colterphoto1]

The Dimensions look ok. That open space is killing you. Is this kind of a loft type room? Are the stairwell walls open also?

[WMcD]

I wonder if the passage to below is the problem. Of course you know best . . . but.

Do you have a slap echo? If you stand at your listening position and clap your hands, once, loudly, do you hear a booiinnggg?

If so, I would think it is the close by walls that are the problem rather than the passage below.

Gil

[enigzenig]

The white walls that surround "open to below" are maybe 4 feet tall (half-wall used as a railing).

When I performed the clap test, it went booiinggg... and the reverb sound like it was bouncing off the walls on the second floor, not from below. I don't want to spend time and money unless I know the I can treat the room properly to my taste. Are there any other tests to determine how much of an issue the "open to below" can cause even with good acoustics in this room?

[enigzenig]

The room is actually a full 2nd floor with 3 bedrooms. I believe the room was more intended for a pool table and a open atmosphere rather than a theater... but I opt for a theater (mostly 2ch listening).

[Chris A]

I'd think about using JubScalas (or
Jubilees) for your fronts - since the 402 horn can keep the ceiling and floor
bounce issues down to a minimum. Is the floor carpeted? Is the ceiling flat?

Actually, I would say that a major issue may be the long dimension - I would be nice if if were longer to support lower Fo in that dimension. The open space is like an open door - and should actually reduce many "clap test" issues, unless the floor below is not carpeted (such as tile). Asymmetric damping of the open space may be a problem, but I bet its the ceiling that may be more of a factor, even though it is 10' high.

Chris A

[enigzenig]

I would really like to get Jubilees! I am not sure if I am ready to fork over that much money ($????). I haven't heard them in person, wonder if anybody has a pair in the Orlando area that I could audition...

The floor of the room is carpeted and the ceiling is flat. The open space below is tile so it does create some slap back from what I can tell. What can I do about the asymmetric dampening? Any other recommendations on acoustic control?

I do have another room that I may give up for a good acoustic properties. The room is 16'8" by 14'4" though diagonally the corners have doors (not good for khorns).

Shawn

[Chris A]

You could use reflector/diffusor panel(s) along the low wall, about halfway to your main listening position--see photo here: http://www.realtraps.com/cust_ht5.jpg

I'm not real big on absorption devices since this really sucks the life out of the room. I recommend just concentrating of balancing left-right asymmetries and selecting speakers that don't radiate more than about 60 degrees vertically and 90 degrees horizontally, like the 402 horn does above about 450 Hz. If you want to control some room modes, I would put corner traps behind your listening position to control ~100-500 Hz room modes. I'd also think about putting an area rug on the first bounce position on the downstairs floor to control some of that delayed reflection area.

Other than that, I'd say get a fairly good subwoofer (i.e., large driver area) or two for reinforcing the frequences that are below the fo of the longest dimension of the room--length in your case. I'd say you will start to have trouble reproducing frequencies much below about 40-45 Hz without resorting to a good amount of subwoofer driver area. For movies, you'll want to go down to as low a subwoofer fc as you can get into the room . For two-channel, I find that 30-35 Hz is probably sufficient for most sources unless you're into hip-hop, etc.

[jamesV]

Just an ideal, but have you thought about putting drapes in the area? You would have to mount them from the ceiling but it would work a double purpose. 1. It should cancel out the sound waves from going into the "open to below " area. 2. Will give you the added darkness that a HT should have. Plus you would be able to open up the curtains when not in use.

James

[Coytee]

I haven't heard them in person, wonder if anybody has a pair in the Orlando area that I could audition...

Eric (6foot8) has a pair of 3-way Jubilees (as displayed here http://www.klipsch.com/products/details/kpt-jubilee-535.aspx )

So... a couple thoughts...

1. No one else has the 3-way version, it's not necessarily the first pick for home use, also PWK originally intended on taking the Khorn back to a 2-way.

2. Eric isn't too active on the forum

3. He has had some folks over to hear them but might not love me doing the inviting!

4. Though I do not know where he lives, he either lives in the Orlando area or close enough that someone who heard them, lives in the Orlando area and went on a day trip.

[enigzenig]

Well, I won't bother anyone until I am ready! [] Do you know the MSRP for the 2 way?

I have been listening to the La Scalas in the large room and the room just doesn't seem intimate. I am not sure if it is because the acoustics suck (haven't treated the room yet) or because I am not use to having them in a large room.

I am thinking about using this room instead:

I am not sure if the dimensions are closer to the "perfect" size or not (height = 10'). If I put the La Scalas in this room, it should be large enough though. Now if I decide [in the future] to get the Jubilees and use the La Scala's as rear speakers, this room may be too small.

I can't seem to win with this! Maybe I am making this decision more complicated than what it is but I am trying to strive for the most accurate listening environment so I can hearing what is coming out of the speakers rather than just hearing the room. [8o|]

[psg]

I would suggest using the game room, but putting Klipschorns on the long wall, one in the bottom right corner (close to the bathroom) and the other in the corner of the staircase (possibly with a false corner). That would put yor KHorns about 20 feet apart, which is very good, and you seated 10 feet back from the stari railing, so with 4 feet behind you. Of course you would need to put the display next to the staitcase railing, which isn`t ideal asthetically.

KHorns on the 14 foot wall will be close together.

[michael hurd]

How much work and how much money outlay are you willing to partake in getting the area ( can't really call it an enclosed room ) to sound good without slap echo and resonances? The sky is really the limit, but having such a large space to energize might make the bass a bit thin.

If you plan on using K-horns, the long wall would be preferable, with the listening position near the railing. False corners or well reinforced wall construction is preferable. ( think plywood ) If you have the option to re-frame and drywall. consider splaying the ceiling some, as this will add in diffusion. Another problem in this space is the lack of "stuff", as soon as you start to add items such as carpet, couches, bookcases, etc, it will aid in absorption and diffusion.

Your best bet would to be to consult a professional that is well versed in acoustical design, for a consultation that I would consider a good investment. ( obviously this is dependant on travel time, your distance from a major center, etc )

[colterphoto1]

I like the alternate room MUCH better. You have control there without changeing the structure of the home too much.

With Khorns (if that's what you're thinking) on the 16.66 foot wall, you should be about 11-12 feet away to listening position, which puts you two feet from the back wall. Excellent positioning IMHO.

2387ft3 is a very nice sized room, not too big (a very common problem in today's homes). THX standard is 3000ft3

[enigzenig]

I think the alternate room would be better myself as I can apply more control over the environment. The issue is the place in which two doors reside. One door swings in from one corner, and from the adjacent corner, there is another door that swings out. I don't know the best way to position the speakers and listening position that will not block the doors...[:@] The only option I can see it to put the speakers on the left short wall.

[artto]

Just an ideal, but have you thought about putting drapes in the area? It should cancel out the sound waves from going into the "open to below " area.

James

The curtains will NOT "cancel" anything!!!! They may slightly reduce reflections. And they may slightly block/absorb some sound, mostly at treble frequencies (6887Hz wavelength is two inches). They may block slightly less sound at middle frequencies (2500Hz = 6 inches). And do absolutely nothing for the entire bass range (one-half of the entire audile range).

I like the idea though - the "theater" look, and conrolling the light.

[DrWho]

For what it's worth, letting the sound go into the open area isn't exactly a bad thing. In fact, it could even be used to your advantagte.

I would also wager that most of the echo you're hearing is the result of all the parallel walls in the room - not necessarily the open space (though the open space has parallel walls too). Adding furniture or anything else that would behave like a diffusor could get rid of it entirely if you were careful about it.

And while I agree with Artto that the drapes will have effectively no absorbtive effect, drapes that hang with folds and whatnot will work as diffusors - if nothing else, the acoustical impedance change through the material will bend the sound a bit (moreso when you've got a lot of folds happening). Diffusion is what you want anyway because it helps the room sound larger while getting rid of the specular reflections.

The other nice thing about drapes is that you can put acoustical treatments behind them and then you don't have to worry about the aesthetics...

[michael hurd]

As far as the door position in the wall, don't let that stop you, it is only a few 2x4's and a couple of sheets of drywall away from moving them out of the way!