Setting gains with bridged amp?

[JaysonR 10+ year member]

OK so I'm still a little confused with setting the gains using these formulas. I have a JBL amp running 180x2 at 4 ohms but I have it bridged as a sub amp (2 dvc 4ohm subs) running 700 at 4 ohms (according to the birthsheet)

Now what the heck is my voltage supposed to be????

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[RandyJ 10+ year member]

Uhh, I cant rememebr but I believe there is an archived thread about this. Have you tried a search?

 

[JaysonR 10+ year member]

I did but I don't understand it with a bridged amp

 

[JaysonR 10+ year member]

nobody in a helpful mood today?

 

[Sythetic1 10+ year member]

Power = (Voltage)^2 / Resistance

Want to find the voltage ? Then reorganize the equation

Like this: Voltage = square root of (Power x resistance)

V = sqrt (700 Watts x 4 Ohm)

V= sqrt (2800 "units")

V = 52.915 Volts (Lets just say 60 Volts, it doesnt have to be precise)

Connect the AC multimeter to the bridged channel, Set your head unit to about 75% volume (If it goes to 20 then set it to 15, for instance) and turn up your gain until the meter reads 60 volts. Make sure you set the meter to read RMS voltage, not peak. Your gain has been set. Might want to play some test tones to make this setting.

As long as you stay within that 75% volume range you are almost assurred to get unclipped playback, should the subs be able to handle that RMS power. Obviously, beyond 75% volume you will be driving the amp out of spec and risk clipping the output signal.

Hope this helps

 

[Justinw303 10+ year member]

Setting gains for a bridged amp is the same as with a mono channel amp, IIRC.

Correct me if I'm wrong.

 

[JaysonR 10+ year member]

from 53 to 60 V, is that safe?

 

[Justinw303 10+ year member]

I wouldn't risk it.

 

[Sythetic1 10+ year member]

****, I meant 53 volts. I 'm retarded

 

[Sythetic1 10+ year member]

I must have been really high when writing that post. At least you questioned it before you took my advice. The math is right at least !