Wiring Suggestions? Please help!

[FrankRoss]

I am installing a pair of ceiling speakers in each of 3 rooms (totalling 6 speakers in all). Each room will have an impedance-matching volume control (3 volumes controls in all). I'm using 16/4 wire - I'll most likely pair the wires up to make 8-guage leads.

I will use the LEFT and RIGHT outputs on the amp to drive all pairs of speakers, so my question is this:

Should I run individual wire runs from the back of the amp to each volume control? Or am I better off daisy-chaining in parallel from one volume control to the other. I only have 1 set of outputs on the back of the amp.

I have plenty of wire to accomplish either method - my aim is for best sound quality.

What I'm worried about with the daisy-chain method is that the single wire pair from the back of the amp supplying 3 pairs of speakers (extending out to a 50' run) won't be sufficient to handle the load? Or is this not a concern due to the fact that I'm using impedance-matching volume controls? However, daisy-chaining will substantially REDUCE the amount of wire used as opposed to running separate lines...

Thanks for any help!

 

[AudioFreak]

Generally, shorter cable runs will be better.... so i would do point to point from the amp to each volume control. I am assuming your setup is stereo? Use a heavy gauge wire from the amp into 4 distribution blocks (one for each terminal of the amp so only 2 if it is mono) then wire a seperate cable run to each volume control.

 

[FrankRoss]

(Reply to AudioFreak)

Thanks for replying!

Just so I understand correctly, you're recommending to use the distribution blocks so that all pairs of wires will "fit" because the posts on the amp won't support multiple pairs of wires - and the heavier guage wire from the amp to the blocks will better feed the multiple wires after the blocks - that all makes perfect sense.

But say I start at the amp, run a 12' wire to Volume Control #1, then run another 15' wire from VC #1 to VC #2, and finally a 10' wire from VC #2 to VC #3. That is a total of 37'.

But if I run separate wires from each block to a VC, the sum of all cable lengths will by far be longer than 37' - more like 76'. So are the separate runs still prefered over the daisy-chain method (and why)?

Still a little confused...

 

[AudioFreak]

Yes, because each cable run will have only a small effect on the other cable runs whereas with 37' of cable prior to the last speaker the effects will be dramatic.

Just a word of warning ... cable losses may become a big problem @ these lengths and also capacitance/inductance .... in this case i would prefer a cable that is almost purely resistive.

 

[FrankRoss]

How does one know if wire is resistive? I purchased Beldin 16/4 CL2 CL3 stranded wire - does it fall into this category (BTW - I'm doubling up the pairs to make 8/2 wire)?

Thanks again for all the help!

 

[griff]

wire is resistive, it is the quality of the wire that determines resistivity, the higher the quality, the less resistive

 

[AudioFreak]

Yes but wire is also inductive and capacitive.... these qualities can also have a huge importance when selecting speaker cabling...

All cable has these properties to some extent... but if the cable is thick, it will generally be quite capacitive.... if it is stranded, it will generally be quite inductive ..... cables are a science and can make a big different particularly on long runs or when used with commercial 'hifi' amps.... having said that, alot of what is said about cables today by PR people is not science, it is marketing .... and it's not always easy to tell the difference if you are uneducated in the area.

 

[leroy]

I'm wondering if the amplifier will survive 3 speakers in parallel. The impedance will be very low and most amplifiers respond with some smoke.

 

[AudioFreak]

Well yes it could be a problem running 3 speakers in parallel especially during the low frequency passages where the phase and impedance of the speakers is likely to become an extremely challenging load to the amp.

 

[paulb]

FrankRoss, what is the impedance of the speakers you are using? And what is the lowest rated impedance that your amplifier can drive? It may not be possible to do this with one amp unless you wire the speakers in a series-parallel arrangement, and then one speaker pair will get more power than the others (which you could reduce with its volume control, I guess). Most amps aren't happy with less than 4 ohms; 3 speakers of 8 ohms in parallel would be 2.7 ohms.
I like separate amps for each speaker, because this helps feed my DIY frenzies.
BTW, in the commercial world this is done with higher impedances and a matching transformer at each speaker; higher impedance means less current so less voltage drop in the wiring. "70-volt" is a typical standard for this. Not what you are looking for, but I thought I'd bring it up.