plz suggest system configuration

[spazz]

Hi All-

I have been unable to achieve the sound I need for a specific application despite trying many different things, and need some help.

First off, the stereo image is not a critical factor, as the music is not meant to mimic live performances of any type. I need a uniform sound throughout the entire room. Every position in the room should resemble a near field placement characteristic, so that all the detail is audible even at a low volume (and with little distortion, phase/IMD/etc), and doesn’t significantly change as I move around.

Through trial and error I figured out that a pair of large floor standing 3-way speakers will not work at all, and I need a large number of speakers placed throughout the room (tried B&W 3-ways, as well as a 2.1 system).

My question is, do I need MANY smallish 2-way speakers throughout the room, and with subs? Do I need 4 or 6 larger 3-way floor standing speakers strategically spaced? Do I need to concentrate on units with the best possible dispersion? Please point me in the right direction here.

I should also mention that it is a large space with high ceilings, and very few absorbent object. Most surfaces are hard and reflective (wood floor with no rugs, bare walls for the most part, minimalistic furniture, etc).

[spazz]

It seems to me like the solution is to place about 6 near-field studio monitors throughout the room, backed up by a sub. Does this sound right? If so, what will be the difference between fewer units with larger drivers, vs more units with smaller ones (5 in vs 8 in midbass). Should these be placed on stands, or closer to the ceiling facing down? Thank you!

[spazz]

I have resorted to experimentation, and 2 acoustics textbooks , and need to know if I am on the right track here. The results seem to be positive so far, using single full range drivers instead of 2 or 3 way systems. This is what I have so far, but I know there must be an easier way, please point me in the right direction. Thanks.

1. The stereo image is mostly gone, but for this application this is fine.
2. Floor and walls need some sound treatment, no getting around this unfortunately.
3. Using the same type of a speaker will be much easier to tune than a mix of speakers, and each should have its own amp.
3. Symmetrically arrange 6 (or 8) speakers at the perimeter of the room.
4. Using an RTFA, find which frequencies interfere and where.
5. Separately equalize each unit to resolve interference.

So far I am very impressed with the resolution of detail at very low volumes. It sort of feels like wearing a pair of headphones while walking around, because the level remains so constant. At times it feels quite harsh because I have not played with eq at all, short of basic level matching on each unit and the subs. For the experiment, I strewed about Logitech single-driver speakers, as well as large 3-way B&W's, and subs, all level-matched..

[nac134]

First of all, achieving uniform deep bass will be next to impossible, unless the room is very large, even with 10 subwoofers. The key to getting a very fine level of detail in different parts of the room will be the damping used. You are going to want an excess of damping
You will also likely find that a symmetrical setup will not be ideal. You will want a staggered setup. Imagine two speakers on opposite walls, pointing directly at one another. There is going to be a great deal of phase variation as you move farther from one and closer to the other, with exact cancellation at the mid point. You may also want to be able to aim the speakers from side to side to fine tune things when you're done to eliminate any dead spots.

Basically - lots of damping, and staggered placement.

[nac134]

Also - smaller woofers are less directional due to beam effect.

[c2cthomas]

Would going with mono playback instead of stereo playback be worth consideration for your application?

[spazz]

Originally Posted by nac134

Imagine two speakers on opposite walls, pointing directly at one another. There is going to be a great deal of phase variation as you move farther from one and closer to the other, with exact cancellation at the mid point.

But isn't this an issue for any set of speakers set up to illuminate an entire room, such as line arrays or horns maybe? I keep thinking that this issue will be mediated by yet another speaker being in close proximity to the listener, where its energy will be more dominant than that of any other speaker. Assisted with some EQ, and as you mention, lots of damping. Seems like there is no way around some badly behaved spots, but overall it can be made to work.

I am also looking into a line array setup to minimize floor reflections, and would really like to know if this is a better way for me to go.

I am going through some great books on this, but there is just way too much theory, can't afford to read 1200 pages right now lol.

[spazz]

Originally Posted by c2cthomas

Would going with mono playback instead of stereo playback be worth consideration for your application?

This has been my exact question for a couple of weeks now. The type of material intended for this system is mostly recorded in such a way that stereo vs mono is not a huge issue, but certainly does have its moments. In my experiment earlier, playing "audiophile" test material with huge sound stages and very distinct instrument and vocal placement blew a major hole in the setup. As soon as I played the intended material, it sounded great again.

That said, I am really curious if mixing down stereo to mono using high quality components will cause a loss of any detail outside of removing the intended image, while introducing an artificial image from the speaker placement..