Help Make This Room Sound Right! (1 Viewer)

[Joe Greca]

I've tried figuring this all out myself, using the search a ton of times, but I just ended up confusing myself even more!

Anyway, I need to upgrade, badly. I am only keeping my 32" Sony Wega and my JBL PB10" sub. My currect receiver and speakers are an old Aiwa HTiB... Take a look at my current setup:

Now my questions:
1) What receiver would be good for a room like this? I was thinking Denon 2802 maybe? Would the 6th channel sound good in my setup?
2) Speakers??? This is where I am nearly lost. Since the couch is so close to the surround speakers, am I going to need dipoles? If I need them, I'll get them, but they are quite expensive. I was thinking maybe Mini-Monitors? Take 5.2s? Is there anywhere in New Jersey that I could maybe give the n0rh 4.0s a listen? I'm willing to listen to a lot of differernt suggestions...
3) Oh, also, where can I pick up some Aura Bass Shakers for the couch? I think those would be great since I'm in an apartment.
I really would appreciate any advice you guys can give on my currect situation. If you have been in a similar room, let me know what worked out! I just don't want to put too much or too little in this room. I don't want to match a powerful receiver with weak speakers or powerful speakers with a weak receiver. And I'm very worried about having the surrounds so close and direct... The surrounds I have up now don't really work anymore, so they're not a problem, but new ones might prove to be distracting, right?? Thanks again!
[Edited last by Joe Greca on October 23, 2001 at 05:29 PM]
[Edited last by Joe Greca on October 23, 2001 at 05:30 PM]

 

[Guy Kuo]

Let us know the dimensions down to the inch for
a. Room length (x), width (y), and height (z)
b. Exact position of your head x, y, z from front corner of room floor.
c. Height from floor of the center of your main speaker woofers for the front left, center, and right.
d. Distance from wall behind RPTV to front of center speaker.
If you get the distances in inches, I'll run the data through the RPG Room Optimizer and see what it comes up with as possible speaker positions to try.
NOTE: I cannot do this for everyone. That would take too long as the run times can take the computer a few hours.
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Guy Kuo
Link Removed
Ovation Software, the Home of AVIA DVD

 

[Bob_A]

What is your budget for receiver and speakers (+ external sub)?

 

[Joe Greca]

Guy: Thanks a lot:
a. x=160 y=140 z=95
b. x=100 y=74 z=45
c. L=39 C=56 R=39
d. 23
Bob: I'm looking to spend about $1000 or less on the speaker package. I'll spend a little more if I need to, but I'd rather not. I haven't really considered any prices for the receiver since I don't know what to buy, but no more than about $700. I actually only need 5 speakers, I'm keeping my current subwoofer, which is a JLB PB10.

 

[Guy Kuo]

It's running now. There looks to be a huge hole in the frequency response from 30 to 80 Hz in your room and seating position. I suspect you'll need to move the sub to fill that in, as it doesn't look thus far that the mains will be able to do it.
[Edited last by Guy Kuo on October 24, 2001 at 05:38 PM]

 

[Joe Greca]

Well I have a 10" 150watt sub right now that I'm going to keep, so hitting those low frequencies shouldn't really be a problem, as long as I can find a reasonable place to put the sub. Its really the surround speakers that I'm worried about. If someone is sitting on either end of the couch they are going to be very very close to one of the surrounds...

 

[Guy Kuo]

Things pretty obviously were converging on the same solutions so we have a suggested placement already. This is going to be pretty radically different from what you've diagramed. It's important to hit these positions to within an inch to get the benefit of the analysis. Remember this is only an estimate. The program does a pretty good job, but you'll have to listen and see. Once the speakers are repositioned be sure to reset the speaker distances in your receiver settings and also rebalance the channel levels with an SPL meter or else you'll have a tough time telling if the changes was the positioning or the altered volume.
I modeled the system without changes in elevations but did allow the program to move things about but still stay in reasonable stereo constraints.
The best positioning the RPG Room Optimizer predicts was....
Distances are length, width, height from front left room corner to center of woofer cone or head.
Listener position 8' 1.8", 5'10", 3'9"
Front Stereo Left 3'1", 3'6.5", 3'3"
Front Stereo Rt 3'1", 8'1.5", 3'3"
Center 2'7.7", 5'10", 4'8"
That pulls the Wega and center speaker into the room a bit, your listening pos a few inches closer, and puts the fronts well away from the walls. Looks like the program is suggesting something like a near field placement. The mid-bass still has a problem, but your sub should help that out.
Any way, give it a try and listen to a variety of material including stereo music. You probably find that the positioning makes a bigger difference than new speakers in the old position.
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Guy Kuo
Link Removed
Ovation Software, the Home of AVIA DVD

 

[Joe Greca]

Great thanks, I'll definately give that a try. I don't mind moving stuff around a bit, I was planning to anyway when I get new speakers and a new receiver.
So does anyone have any recommendations for a receiver and speakers in a room like this?

 

[Guy Kuo]

I've modeled the room for subwoofer only placement. That huge mid-bass hole can be filled in by moving your subwoofer to a rear corner of the room. Doing so will change that 15 dB hole to a much flatter response with a relatively small peak at about 43 Hz. This is of course only true for the listening position previously calculated.
The problem with a bass hole is that no matter how much power you pump into the system, you can never fill it in. Luckily, placement in the rear corners of the room will allow the hole to be very nicely solved. It's actually a little bit flatter at 10'4" from the front wall, but you'll give up some corner reinforcement. I'd just go one of the back corners.
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Guy Kuo
Link Removed
Ovation Software, the Home of AVIA DVD

 

[Joe Greca]

Alright sounds good. I'll move it back there when I get the new speakers and receiver. Still no recommendations??? Anyone??? I don't need the best speakers/receiver in the world, just what would be appropriate in a room like this.

 

[EugeneR]

Guy,
What the heck is an RPG Room Optimizer? A software program I take it? How does it work, or rather, how does it make its calculations?

 

[Guy Kuo]

Link Removed will take you to the web page for the RPG Room Optimizer. The demo won't let you customize the dimensions but will let you play around to see how the program works. The actual version gets e-mailed to you a few DAYS after you call and give them your credit card info. The program is pretty darned good at low frequencies and in rectangular rooms. Its predictions nicely mirror what I actually measure in the room using the ETF5 package (www.etfacoustic.com).
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Guy Kuo
Link Removed
Ovation Software, the Home of AVIA DVD

 

[Joe Greca]

Yeah I had never heard of the Room Optimizer either before I posted this topic. It sounds really great, I can't wait to try out Guy's settings when I get my new speakers. If only they made a computer program that would tell me which speakers to use in this room

 

[Guy Kuo]

Joe, go ahead and make the changes now. That way you can compare the positions using the SAME speakers. If you change both the speakers and positions at the same time, you won't be able to isolate how the room position affects things.
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Guy Kuo
Link Removed
Ovation Software, the Home of AVIA DVD

 

[Jack Lee]

Guy,
Other than aesthetic reasons, why is the optimal position still located along Y=70" (i.e. mid-width)? That seems to be right on the null of the of the horizontal fundamental mode near 44Hz.
I would have thought Y=W/3 or Y=W/5 would be better places than Y=W/2 for a smoother sub response since the acoustic room nulls don't occur until the third (132Hz) or fifth order horizontal room mode.
Is there some other trade off going on?
Just curious.

 

[Guy Kuo]

The trade off is stereo imaging vs absolute flatness of response. With the speakers and listener symmetrically placed, the left and right mains have identical effects of the room on their sound. That allows more precise imaging. You can tell RPG optimizer to try non-centered positions as well, but I opted to aim for maximal imaging as well as flatness of response. You are perfectly free to go with another set of priorities, but I went with a more common one for stereo tuning as I prefer the system to perform well for both HT and music.
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Guy Kuo
Link Removed
Ovation Software, the Home of AVIA DVD

 

[Jack Lee]

Thanks Guy.
The room in question is a bit on the small side - probably not alot of room to offset the mains and/or the listener from the center of the room before getting close to a wall.
Given a large enough room though, I'd tend to think any stereo-asymmetry introduced by centering the fronts and listener off of the room's mid-line as a small price to pay vs. a 15db null.
Anways, thanks again. You and your company are some of the very few who answer these questions with some understanding of acoustics rather than blind dogma.
Usually the answers I hear are like those from ancient Greek astronomers: "Orbits can't be elliptical. They can only be circular, since the circle is the perfect symmetric shape."

 

[Scott Page]

Joe,
You might want to consider Paradigm speakers. They are a good value, their dipoles are reasonably priced and sound very nice. Personally, I would use dipoles in your room unless you want very directional surrounds. But IMHO, with the seating that close only the sweet spot would sound very good using direct surrounds. Check out the reviews of the ADP-170 on audioreview.com. They might strain your budget a bit but you could go with the ADP-70 in a small room and then trade up latter if you can't afford the 170's. The 170's work great in my 3,000 sq foot room.

 

[Joe Greca]

Yeah I'm definately into the Paradigms, I just hope they're not a waste in this room... Guy, what do you think? Dipoles or directs for the surrounds in a room like this?
Actually, I guess I could try both out, right?

 

[Guy Kuo]

I'm inclined to go with dipolar surrounds given a relatively small room in which you will be very close to the surrounds. A direct radiator may be too easily localized especially for listeners on the end of the couch. Dipoles with their nulls pointed at you should be fairly diffuse despite the short distance. I'm assuming that you are primarily listening to movie soundtracks rather than multichannel music. If your balance of listening is more multichannel music than movies then perhaps there would be a stronger argument for direct radiating surrounds.
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Guy Kuo
Link Removed
Ovation Software, the Home of AVIA DVD