Multi-Speaker Distribution

Any help is appreciated with this problem.

Kooch54...

Fine. Which problem?

Marc - Thanks for your response. I obviously don't know alot about HT or home audio and seldomly listen to music for long periods of time. I'm really only putting this together for some background music during parties, etc.... I would agree that the Phoenix website blows. The ISM6 that I bought is the single source model. It does have what they call "Impedance protection"; but I have it turned off with the switch because I also have an Impedance Matching Volume control in the basement and was under the impression that I don't need both. The speakers in the basement are Onkyo 100 W and say 8ohm on the back which is also what the receiver says. I thought that as long as I had the IM volume controls I would be OK. My original problem was that the volume in the basement was extremely low regardless of what I did with the volume control down there. It did change as I turned it up but not that much. Today while I was playing around I found that if I put the receivers volume control at about midway then adjusted the volume from the control downstairs that it worked well. Is that how a speaker distribution model with independent volume controls work? The receivers volume is used as a starting point and the volume control in the other zones make adjustments from there. I thought the entire reason for the distribution and volume control was to completely bypass the receivers volume control for the additional zones. Thanks for any help and guidance.

Kooch54...

The info on the Phoenix Gold web site is useless.

Only three feature/specs are listed one of which is "Four color display packaging" which tells me a lot ...

This page also says that the IH ISM 6 is both "single source" and "dual source". Which is it ?

The page for downloading manuals is non-functional so we don't know what's actually inside the gizmo including whether it has impedance matching or is just a box with switches.

You apparently want to run 3 pairs of speakers from a single "Sony 100W AV receiver". Without specific info about what receiver you actually have, the best we can do is give the general observation that this will generally blow out the output devices in the receiver if played too long and(or) too hard with low-impedance speakers without impedance matching.

We also know nothing about your speakers. What do their manufacturers' claim to be their nominal impedances?

Marc Marc_F_Hult

I've done what you want to do a few hundred times. The solution is simple enough. Keep the selector's impedance "protection" switched off as you have it now. Install impedance matching volume controls for each pair of speakers -- not just the ones in the basement. If you have 3 pairs of speakers on the amp, set the jumpers on all three volume controls to the "X4" position.

If you need further help, give me a call after hours some time and I'll walk you through it.

Robert, Thanks for the info. I only have 1 set of additional speakers right now, so I'll only need the one volume control. As I add additional zones I'll also add IM volume controls. Thanks again.

Kooch54...

No problem. Just remember to adjust the IM settings on all the volume controls as you add more. If there are only two sets of speakers on the amp, a 2X setting is fine. At three sets, go to 4X. Beyond 4 sets use the

8X setting.

There's a way to give a bit more oomph to the speakers in a larger room if you wish. If you set one VC to 4X and the rest to 8X the 4X room will get twice the power (~40% louder output) of the other rooms. If you decide to do this, be sure to do a load calculation first. It's a simple math equation that's expressed like this: "The net resistance of a parallel circuit is equal to the inverse of the sum of the inverses of the component resistances." Someone more erudite than I would likely express that better. :^)

Example: Two rooms with 8-Ohm speakers set to 4X and one room with 8-Ohm speakers set to 2X.

Solution: 1/((1/(8x4))+(1/(8x4))+(1/(8x2))) = 8-Ohms.

In short, if you have three rooms with similar speakers and you want more sound in one of them, set that room for 2X and the others for 4X. The overall system will present the same load on the amp as a single pair of speakers.

If you need parts, I sell this stuff online (URL below). Have fun.

Thanks everyone for replying. I had everything wired correctly but misunderstood the use of volume controls. I thought they completly eliminated the amp's volume control in that zone. I thought I could turn the amp's volume all the way down but still turn it up nice and loud in the zone from the IMVC. Not the case I guess. You need to set the amp's volume at about midway and then adjust to taste in the zone you are listening to.

Thanks again.

Kooch54...

I think Robert answered your questions, right?

Happy listening ... Marc Marc_F_Hult

Frank, Thanks for the response. That is exactly what I was looking for. Since I'll only be using the system for background music I can live with the main volume control being at the amp and not in the room itself. I can still make adjustments from the IMVC or turn it off completely from there. I'll just put the amp's volume control at midway and adjust to preference from there at each room. Thanks again.

Kooch54...

You're using the speaker "out" terminals of the AMP, so the amp's volume control acts as a "master" to all the speakers in the system. This means that you won't have the kind of control at the room volume control that you're expecting. In order to bypass this, you're going to need an amp with pre-amp outputs you can bridge to another amp in the basement. This would, of course mean that your room volume control would be replaced with the volume on the separate amp. I've seen some stereo amps with 25VAC speaker transformer outputs. You could control the volume of each speaker independently with this kind of setup as well although the quality of the sound is greatly reduced.

You're welcome. I wish folks would actually *read* the question before responding with irrelevant information (which at least was interesting).

We have a similar set-up here. It works!!

No problem. Have fun!!

That's not necessarily the best method. Instead, select the room where you will want the highest _available_ volume. Turn the VC in that room all the way up and turn the VC's in all other rooms most of the way down (but not off). Now listen while someone else slowly ramps the master volume up until the sound is the loudest you might want without distorting.

Mark the master VC setting so you can duplicate it easily. Now turn the VC in the room down a few notches and test the other rooms to make sure everything works well. This procedure will give you the most sound with the least coloration.