Setting gain on bridged amplifier..

[kingsxman 10+ year member]

Is there something special you need to do to set the gain on a bridged amp? I have a Profile AP1040 (4 channel) amp that I wanted to drive a set of rainbow comps off. Its 80x4 @ 4 ohms in its "normal" state. I bridged it and went to set the gains. According to profiles web site its 255w x 2 @ 4 ohms bridged. So on a 4 ohm load ...using the normal gain setting equation... I come up with a voltage of approximately 32 volts.

When I set my head unit volume @ 3/4 I can only get about 18 volts at full gain on one of the channels. I didnt check the other channel...

When I set the gains in normal 4 channel mode I didnt have any issues. Of course the voltage was only 18 volts then....

any ideas? Is a 4 channel amp different? I was measing from the positive of one terminal (channel 1) to the negative of the other set of terminals on channel 2.

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[squeak9798 5,000+ posts]

You wouldn't measure the voltage of just one channel. You would measure at the terminals you would use to bridge the amplifier. So you take the (+) from one channel, and the (-) of the other channel and then measure the voltage.

 

[kingsxman 10+ year member]

That is what I did. I measure + from channel 1 to - on channel 2. So the leads are basically spanning 2 channels.

I did just realize that I had my equalizer on......which could cause an issue. I would have thought I would have to turn the gains way DOWN for that kind of pwer.....but so far not the case....