I am running in ceiling and bookshelf speakers - I have 2 Jamo speaker selectors (6 speakers each) being driven by a Yamaha RX-797 (100w per channel) and a Parasound 2250 (250 w per channel). the speaker selector being driven by the Yamaha runs HOT at semi-high volumes. So, I put a Phoenix Gold in and, it does the same thing. the selector being driven by the parasound is cool as cucumber.

Is my Yamaha just not stout enough for this task? I can understand if this is the case - but just thought that I would put this out there for suggestions and comments. Thanks in advance
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Is the speaker selector an 'active' (powered) unit or a passive unit?

Two different switchers act differently in this situation?

Passive, no power to it.

The Jamo speaker selector ran hot when pushed by the Yamaha, as did the Phoenix Gold speaker selector. The common denominator for both was being connected to the Yamaha.

Contact resistance is the only critter which will cause heating in this circumstance. It is possible that the parasound unit uses a higher rail voltage (higher voltage gain) and therefore requires less current output to the speakers causing less internal heating of the contacts at the switch.


Heating is caused by current, in watts this is I^2R heating

My guess is it has nothing to do with the amps running it.

Are the number of speakers, impedance of the speakers, and how many zones you have turned on at any given time the same between the two switches?

I'm thinking one or more of the speaker circuits has a problem. Any way for you to get hold of a mulitmeter and check the resistance of the speaker circuits?

Contact resistance is the only critter which will cause heating in this circumstance. It is possible that the parasound unit uses a higher rail voltage (higher voltage gain) and therefore requires less current output to the speakers causing less internal heating of the contacts at the switch.


Heating is caused by current, in watts this is I^2R heating

The current and voltage delivered by the amps will be the same according to Ohm's law for any given volume setting until the limit of the lesser powered one is reached.

Could clipping cause it? Hmmm.... I dunno, maybe? I'd think the receiver wouldn't be liking that either and be extremely hot running at that level.

As I mentioned before, I think it might be something in the speaker wiring.

My guess is it has nothing to do with the amps running it.

Are the number of speakers, impedance of the speakers, and how many zones you have turned on at any given time the same between the two switches?

I'm thinking one or more of the speaker circuits has a problem. Any way for you to get hold of a mulitmeter and check the resistance of the speaker circuits?


Yes, I should be able to do this. And, it occurred to me that one way to eliminate the possibility of it being the Yamaha would be to simply swap - that is have the Yamaha power the cool speaker selector and have the Parasound power the one that is running hot.

Also, some of the in ceiling speakers are Jamo and have 8 or 4 ohm settings. I am going to go back and make sure that they are all set to 8 ohm. However, with the impedence matching speaker selectors and im volume controls, should that make a difference?

My money is on a short on one of the speaker circuits.
Connect each speaker pair individually to identify which one is overheating the selector. Then examine the terminals for frayed wiring and lastly the runs themselves for damage like pinching from a staple.
good luck

Some switches have internal resistors to compensate for the low impedance presented when multiple speakers are driven. Depending upon the number of speakers and their impedances, these resistors may have to disapate several tens of Watts--enough to become quite warm.

Your amplifier is not the problem; attempting to drive a low total impedance at high gain is more likely the issue.