Setting gains on mono amp

[tmorales509 10+ year member]

Was wondering i have a hifonics brutus monoblock amp, it has 2 negatives and 2 positives. Im setting the gains with a dmm and trying to get 48.9V for 600watts @ 4ohms. Do i just connect the dmm to one of the neg and one of the positives on the amp and turn the gain up until it reaches the desired voltage or since it has 2 neg and 2 pos do i cut that voltage in half like 24.5V? The reason im asking is because i just turned it up until it reached 48.9 but i pretty much had to turn the gain up all the way like 95% to reach that voltage, thats why i was wondering if i had to half the voltage or is that normal.

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[quackhead 10+ year member]

No, you do not divide the voltage...Which amp is it?..and how do you know it will not be clipping? What is your input pre-amp max voltage?

 

[tmorales509 10+ year member]

It is a hifonics brutus bxi 2006d. 2000 watts @1ohm, 1300 watts @2ohms and 650watts @4ohms. Whats the preamp max voltage? Is that the head unit, if so it is 2V.

 

[quackhead 10+ year member]

well, it sounds about right then if the gain is set almost all the way up....I am guessing @ 3 o'clock position? The important question is how does it sound?

ps..what sub are you using?

 

[tmorales509 10+ year member]

two R.E. SRX 12s. I mean it does sound good i just wanted to be sure i didnt have the gain to high and mess up the subs or something. i also have the bass eq all the way off. im guessing thats the same thing as like a bass boost.

 

[quackhead 10+ year member]

two R.E. SRX 12s. I mean it does sound good i just wanted to be sure i didnt have the gain to high and mess up the subs or something. i also have the bass eq all the way off. im guessing thats the same thing as like a bass boost.

and you have them wired to a 4ohm load? The gain pot goes from 0.2v - 9v...your head is likely not putting out max voltage, except on musical peaks..maybe. This is especially true if you used the old 75% rule on the HU volume when you set the gain. Your subs should be fine. Sometimes you just have to use your gut feelings and your ears with such things.

 

[quackhead 10+ year member]

ps...you are one of the smart ones and yes, the Bass knob on your amp is an EQ boost. They are better left alone. if you start boosting the bass frequencies, then you will have to adjust the gain setting accordingly to prevent clipping. Normally, depending on the music, I may add a touch of boost or cut with my HU...and that is it.

 

[zako 10+ year member]

Do not forget that you need a 0dB tone. The other day I pulled some random "audio setup" CD with some test tones.. and got readings indicating that something is off. I loaded the tracks into foobar and opened the spectrum visualizer. Lo and behold, the test tones were -10dB or so. Also, for the test turn off all subwoofer filters, on the deck and on the amplifier.