Wide range surround speakers?

[Pashley]

One place where it looks to me like a full-range, or at least wide-range, speaker might work very well is in surround sound speakers, side or rear channels of a 5.1 or 7.1 home theater/music system. That is a much less demanding application than the main speakers, both the frequency range involved and the loudness required are lower. It should be relatively easy to find drivers, maybe even fairly cheap.

Linkwitz gives one design, 5.5 inch Vifa drivers mounted facing up atop a pipe which acts as a sealed box:
Surround loudspeaker
He says it is designed for music, and sub-optimal for home theater, but I can live with that.

Another possibility might be a transmission line, to get some low end extension out of some relatively small speaker. For bass, the line needs to be long, which is inconvenient. For surround sound, though, length might be OK. I wonder if some speakers might work well with a pipe acting as transmission line. Quarter wave tuning length for 100 Hz is 86 cm so you could get to an interesting tuning frequency without elevating the speakers too drastically.

Anyone tried something along these lines? Any drivers to suggest?

[planet10]

We haven't built the designs, but have built fronts that these are based on.

In the section under ML-TLs, the home theatre appendix. The splayed surround was designed based on Toole's suggestions for a wide dispersion surround.

dave

[zman01]

Dave,

The splayed surround is intended to be used as rear speakers in a 5.1 system?

[planet10]

Yes. Bsed on Toole's suggestions.

dave

[Michael Bean]

I've always thought it would make more sense that all the speakers in a surround system should be identical, especially for the front channels. If different speakers were used that have different drivers ,enclosures and crossovers, wouldn't all of the different phase shifts and frequency responses cause problems? Just wonderin'.

Mike

[planet10]

The dispersion characteristics required for surrounds require them to be different in most cases. And with no crossovers, you just need to insure a similar signature for the surrounds.

dave

[Bigun]

I'm learning that the issue with speaker matching is mostly associated with the front speakers, because this is where 99% of the time you'll hear human voices from, which we are more sensitive to. The surrounds tend to fill in the other noises and matching is more for aesthetics than anything else (IMHO).

I've been playing around with different speaker types for my HT. I built a set of full range single drivers. In the end I used my old hi-fi floorstanders for the front left and right. They are fairly big and reach down flat to 27Hz. I have learned that my preference is very clearly for large floorstanders for the front left and right. I find they are the most critical of the speakers in my system.

[sreten]

Hi,

Whilst it is true, it is not true of discrete multichannel.

For matrixed surround the rear has little bass and little extreme treble content.

You have to be specific for the context. But the fact is for 2.1 compatibility
for 4.1 or 5.1 encoding the older matrix systems are often emulated, or not,
and in those cases the 2.1 sound is extremely poor, with channels missing.

Linkwitz's design was for matrixed mutichannel, and makes sense for that.

rgds, sreten.

[18Hurts]

I use Tang Band 3" FRs as rear surrounds,

Built a triangle shaped sealed box, put four 3" full ranges in it, aimed the "point" of the speaker at the seated position of the person and it sounds very good. I was going for a sound field and did not want to hear it on axis, the rising response of FRs helped there. The main reason for using four of them (2 per side of the 90 degree angle) power handling, keep them at 8 ohms and improved output to match the LCR speakers.

All a matter of personal taste, some people like to "hear" the surrounds but I prefer a more diffused setup. The surrounda are about one meter from the back wall and one pair/one side of FRs bounce off the back wall--the other pair fire in front of you. The slight physical delay of the splayed speaker tends to mix is a bit better.

In theory, I figured I was making a mess--figured I could add tweeters between the 3" FRs at 3 KHz (D'Appolito) if it bothered me. So far, only good things have been said and my friends mentioned that they are leaning towards splayed or diffused surrounds.

My room is not optimum so the splayed approach works better for me--as always, YMMV.

The only downside of using FRs for surround arrays is you'll start reading the full range section and try to find justification for building another set of speakers.

[Bob Brines]

I have been using up-firing FE167E's for my surrounds. For most of that time, my mains were also FE167E's. I think that this has worked well. For movies, the surrounds are not intended to blend with the mains -- they are for effects that are off stage rear. 5.1 music may be different. I don't have any decent music DVD's.

With the demise of the FExx7E's. I have moved on. I now have Alpair 7's as mains, set as 'small'. The FE167E's still seem fine for the surrounds, but I will probably go to up-firing CHR-70's once they become available again. At least the boxes will be smaller. But then, I don't like center channel, so take this for what it is worth.

Bob