Imaging/Soundstaging - Does room size matter?


Hi guys,

I have a great little system in a pretty small room, 17 x 13 x 10. The center image is perfect. On vocals, the speakers totally dissappear, and all I hear is the singer chillin' in between the two channels. But most things that aren't supposed to be completely centered don't image very well. Instead of simply coming from one side or the other, they always seem to come directly from the drivers. Is there something that room acoustics or speaker position can do about that, or is it just going to be that way because of the size of the room?

Thanks!
omains
The speakers are set up according to the Cardas Golden Triangle system. The room has been treated with foam and such, but it's not acoustically perfect.
I had two systems in two different rooms. The system in the larger room, with the speakers out into the room and wide apart, has a wide and deep(!) stage. But the width of the stage stops at the speakers.
The smaller room only allowed for the speakers to be maybe two feet from the outside walls. The imaging in this case was realistically beyond the boundaries of the speakers, width and height too. Although overall the soundstage was smaller, the music did not appear to be coming from the drivers.
I think maybe the "acoustic support" of the side walls can actually improved imaging.
But I could be wrong! They were different systems. I would be interested in what others have to say.
I am inclined to think that off-center images being localized at the speakers may well be a loudspeaker issue rather than a room one. Maybe a driver breakup mode, or a diffraction artifact, or a crossover phase anomaly, or a box resonance (either internal or panel). In my experience, sidewall reflection issues skew the image to one side or the other (and often will pull the sibilants to one side of a center vocalsit's voice), but I don't think they tend to consistently localize the sound images at the drivers. You said the center vocalist images very well, which makes me think it's more likely the speakers than the room.

You might try some felt rings around your tweeters in case it's diffraction. Two bucks each from Madisound.

Best of luck to you!

Duke
HEIGHT as far a soundstage? that's a first. well maybe second, but quite impossible.
The cardas triangle doesn't take into account such things as large pieces of furniture, windows and doors etc. It's a good starting point. Start by playing around with toe in. Try no toe in, then slowly increase it to see if it helps. The most toe in that you want to try is when the axis of the tweeters cross right in front of your listening position. Also, the tweeters should be at about ear level when sitting. Next you need to move the speakers around a little. Move them forward or backward a few inches at a time. Also, you might have to move them farther apart or closer together. Remember that when you move them you will have to re-adjust the toe in.

When you get them into position where you have the best soundstage you need to damp the first and second points of reflection. Sit in you listening position and have a friend move a small mirror along the left wall, at ear level, until you can see the left speaker. That's the first reflection point. Now, have him move the mirror until you can see the right speaker. That's the second reflection point. Repeat this procedure on the right wall. Now, damp those four spots with some accoustic foam. Next you want to damp directly behind the speakers. Also, damp the midpoint between the speakers on the front wall and the spot on the wall directly behind your listening position. This will greatly improve the width of you soundstage. And yes, with proper setup, it is possible to get height also. Remember a tweeter radiates in a 360 degree pattern. Also, if there are any objects between the speakers, such as a tv or a cabinet, the front baffle of the speaker needs to be at least 12" in front of the object.

It usually takes me about a week to "dial in" a pair of speakers. When I get a new pair of speakers in my listening room, I place them according to the Cardas recommendation. I take a quick listen then I put on some cable radio, shut the door and let them burn in for about 3 weeks. Then I start playing with positioning. Sometimes I get a speaker that's a little harder to "dial in" and it might take me two weeks. I've had all kinds of speakers in my system ranging in price from $229 a pair up to $16000. It's possible to get them all to image; some better than others, but it is possible. My room measures 18 x 20 (almost a square - not easy to setup) with a vaulted ceiling. I have 48 custom accoustic panels on the walls. However, being married, I had to "incorperate" the panels into the decor of the room. I've had friends over and the swear that the surround system is on because they can hear sounds coming from the sides as well as behind them. I love the look on their face when I show them that they are only listening to two channels.

I have not got around to posting my system yet because it's constantly in a state of flux and I'm too lazy to keep updating it. The speakers in the system in the last year are B&W N805's, B&W N805sigs, B&W N802's, Paradigm Titans, VSA VR4jr's, Totem dreamcatchers, Totem rain makers, Totem hawks and Soliloquy 5.3i's.

Also, I see a lot of mega-buck system here on the Gon. Very few of them are setup properly. But, I do realize that most people have to set their system up in the living room or family room and don't have a dedicated listening room.

Check out the rives oudio site at www.rives.com. They have a wealth of info on proper room setup.

Good luck,
Wow, thanks for the help you guys! So it seems like a bit more tinkering is in order, and maybe a bit more dampening on the side walls.

Thanks, Duke, for the felt reccomendations. I'll give that a try.
And yes indeed, the system is in phase, according to the second track of stereophile test cd 3.
good post Rolf. My wife factor and the general layout of my room negates acoustic tweaks on the walls. My soundstage, however, is still, quite amazing. Has more to do with the speaker positioning and system, itself. I wonderwhat it would be like in an acoustic paradise? The tweeter deal, 360 degrees? Still haven't heard a soundstage like you're talking 'bout. Not in any system. go figure. peace, warren
Looking at the photo of your system setup your speaker positioning seems like it should give you pretty good imaging. It might be time to look at your gear also, though speaker placement is the number one factor in imaging I think some gear just images better than others. So it may just be that your ss integrated just doesn't do the imaging thing that well. Also keep in mind that some recordings, especialy vintage jazz, is often recorded with a hard left-right pan that keeps the sounds stuck to your drivers. So keep experimenting, but try some different recordings and see if maybe a buddy had another amp he could bring over, particularly one that is tubed.
Height? I ain't gonna argue wit cha...so you hear your cymbals, violins, brushes on cymbals, etc., on the ceiling? Since those tweeter of yours are 360 degrees: ya hear the same coming from the floor? beats me...
A tweeter radiate 360 degrees in the plane of the front baffle of the speaker unless there is some kind of damping or impediment. Yes, I hear sounds coming from above the speakers. Remember, there is a reflection point on the ceiling also. However, because I have carpet, I don't hear HF sounds coming from the floor.
I agree with Jond. Speaker placement and of course recordings. And I think just swapping components to get it right is the ultimate answer. My experience is limited so I am in part sharing it to also get an answer to the imaging question. So take the following in that context:
I have had two amps an Adcom and now a CJ11. When I switched to to the CJ the soundstage depth greatly increased. You seem to hear more "atmosphere" or venue. However this did seem to reduce the width of the stage-though on most recordings it was more realistic. It is more like actually being in the club as opposed to having the musicians playing in your room.
To clarify- I guess you can say it is like sitting close or sitting far. The further you are... the smaller the image.
Make sense?
specific example...
Spica tc-60 with Adcom. Paul Simon, "Negotiations and Lovesongs". In the room eerie band size imaging. About two feet beyond the outsides of the speakers and a foot or two above. Cymbals high, snare drum middle, bass drum low. Vocals forward of middle. That specific.
AP Virgo with CJ11a, nearfield set up. Speakers really wide apart, really far into room. "Jazz in the Pawnshop" Image starts at speaker plane and goes way back. Real deep. Layered. You can hear the people in the lounge at each table. Big layered. But not much beyond the outsides of the spaekers.