posted
Hi, I'm planning on adding a relay to each speaker out of each of my amps. (8 total for each + and - of each 2-channel amplifier.) The reason I want to do this is to quickly switch between "SQ mode" and "SPL mode". In "SQ mode" one amplifier is going to power a set of seperates and the other is going to power subwoofers. In "SPL mode", I'm thinking of bridging both amplifiers (with gains set correctly) into each coil of a large woofer which is strictly for SPL.
My questions are:
Can relays handle this type of power? (600 watts per amp)
Is there any noticeable signal degradation with the signal passing through relays? (for sq mode)
Thanks!
Posts: 1019 | From: Southern California | Registered: Jun 2000
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posted
yes a typical bosch relay will easily handle 600 watts no problem. they are rated at 30 amps usually, good for a couple thousand watts, depending on voltage and impedance..
there should not be any noticable sound quality difference.. if there is, a simple rectifier diode will take care of the back EMF accross the coil....
Posts: 1854 | From: freezing in FAIRBANKS ALASKA | Registered: Aug 2000
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posted
actually standard bosch relays will handle only about 300-400watts 12v*30A=360w (E*I=W)
I have done this type of a switch before, going from 1 ohm to 4 and such like your explaining, but when relays stay on, with their maximum allowable current running through them they get super hot. Everyone knows what heat does to electronics. After a period of time (granted that may be along while), the relay wil begin to fail and not live up to its original capacity.
Just think of it like this, how big is the switching wire in a relay? wayy smaller than the wire you are most likely running 600 watts through. So how long do you think that will last especially with other parts (85 & 86) keeping it on.
I suggest a manual switch. I used a DPDT on a 4ohm(300w) to 1ohm (roughly 1kw) switch. I dont remember now but I think it was a 120v 10 amp switch. NOT CHEAP.
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posted
I'm only going to be using the "600 watt" mode for a few seconds every few weeks... how do you think it would hold up for a situation like that?
Posts: 1019 | From: Southern California | Registered: Jun 2000
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quote:Originally posted by Soundrew: actually standard bosch relays will handle only about 300-400watts 12v*30A=360w (E*I=W)
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but with the relay being put on the amplifiers outputs, it is AC running thru it, and usualy at a higher voltage (of course its all impedance dependant) it wont always be 12volts... but yes, it will get hot and eventually may fail.
Posts: 1854 | From: freezing in FAIRBANKS ALASKA | Registered: Aug 2000
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