Multiple HT Speakers

[Zene]

Hi .. I have 30 - 6 1/2" 4 ohm FR (misnomer) speakers for 5.1 HT.
I am going to try to use as many as impedances will allow.
I've asked this before but forgot answers and maybe newer thinking will help.
All three fronts will be equal amounts, but would like to know
proportions of rear surround quantities to aim for. The less I need, say 2 each in rears vs. 4 for fronts the more can go up front.
Anyone care to comment? If not I can live with my 1980's RS speakers.
Zene

[Wayne A. Pflughaupt]

Anyone care to comment?

Love to Zene, but I didn’t understand any of that. Are you asking if you can use say, ten speakers for surround sound instead of the usual five or so?

Regards,
Wayne

[jackfish]

If you wire speakers in parallel you end up with half the impedence value, wire them in series and you double the impedence. The math is pretty simple even with multiples of speakers. Most HT amps should be run at 6 or 8 ohms, most do not like a load 4 ohms or lower. I'd shoot for 8 ohms for any given channel. Also, I think 4 for the rears, 6 for the center and 8 for the fronts would work.

So if you wire two 4 ohm speakers in series it will yield 8 ohms. If you take two speakers so wired and run them in series with another two so wired it will yield 16 ohms, in parallel it would be 4 ohms.

This explains it, including series/parallel wiring.
http://www.termpro.com/articles/spkrz.html

Stacking many speakers together could result in phase problems.

[Zene]

Thanks Jay ... Wiring is no problem but did see that 5 would yield 8 ohms with one in series. Never encountered that before. Is it acceptable to do that or do they have to be even quantity clusters, 2,3,4 etc.?
Also, why less for center channel, thought they should be same as fronts?
Plan to curve the arrays to help eliminate notch problems. Will that change your opinion on quantity per channel?
Zene

[jackfish]

They can be any multiple as long as the end result of parallel/series combinations is a 6 to 8 ohm load on the amplifier. The center channel should complement the front speakers, so that array could be equal to that of each front but doesn't have to.

[Zene]

Didn't come close to answering my question, but thanks for the input. Probably my inability to explain my question. Did learn though.
Zene

[jackfish]

Ok, let me try this. Most of your program material is going to come from your fronts, they should dominate. The center channel usually emphasizes voice and other material and while it can sometimes emit up to 50% of the program material it doesn't usually need to equal the size or capability of one of the front channel speakers. The surround speakers are often the closest to the listener and provide only enhancement and directional material.

Each front channel is 8 speakers with:
4 in series/parallel for 4 Ohms
wired in series with
4 in series/parallel for 4 Ohms
resulting in 8 Ohms

The center channel is 6 speakers with:
4 in parallel for 2 Ohms
wired in parallel with
2 in series for 16 Ohms
resulting in 8 Ohms

Each surround channel is 4 speakers with:
3 in series/parallel for 2.66667 Ohms (2 in series in parallel with one)
wired in series with
1 speaker for 4 Ohms
resulting in 6.66667 Ohms

If you are dead set on a dominant center channel you could go 6 for each front channel, 10 for the center channel and 4 for each surround channel. As such:

Each front channel is 6 speakers with:
4 in parallel for 2 Ohms
wired in parallel with
2 in series for 16 Ohms
resulting in 8 Ohms

The center channel is 10 speakers with:
4 in series for 32 Ohms
wired in parallel with
4 in series for 32 Ohms
resulting in 16 Ohms
wired in parallel with
2 wired in series for 16 Ohms
resulting in 8 Ohms

Each surround channel is 4 speakers with:
3 in series/parallel for 2.66667 Ohms (2 in series in parallel with one)
wired in series with
1 speaker for 4 Ohms
resulting in 6.66667 Ohms

Or even 8 for the fronts, 10 for the center, and two (in series for 8 Ohms) for the surrounds. Experiment and see which sounds best.

In some of these arrangements not all speakers will draw the same power, but this shouldn't make a big difference if one uses the receiver to balance or equalize the sound of the system.

[Zene]

Thanks Jackfish .. I did not mean you specifically in comments, sorry, but do appreciate your more detailed explanation. Glad I don't need huge amounts for the rears. That would eat into the total quantity quickly.
I will build in modules of two so I can experiment.
Would you come over for some many many days and help me build 15 panels? On my large map it's only about 16".
Zene

[Wayne A. Pflughaupt]

Just keep in mind that there’s no free lunch. You can wire a lot of speakers together so that the load is ultimately 8-ohms, or whatever your receiver needs, but you’re still driving the amplifier harder to power them all.

Regards,
Wayne

[Zene]

Wayne ... Heard that before, but never understood. If the efficiency is greater for multiples, increased by +3dB per doubling then they should take less power for the same output. 'splain, plz? Could make a big difference on my choices as I only have 50 watts per channel.
Zene