Amp Gain set up

[Teacher Denis 0]

Hello. I am setting up the gain on my Autotek M4000 amp. (used for 2 12'' subs in parallel)  I ran a 50 hz tone at 80% volume (Pioneer head  unit). The highest voltage reading I could get was 15 volts (output from amp). That is with the gain tuned all the way up (reading 0.2 Volts on the amp). I should set the gain to 44 AC volts.  ( V = the square root of (1000 rms x 2 ohms) ) The subs are disconnected. All levels on the head-unit and EQ are flat. My Clarion 7 band pre-amp EQ output is 8 volts. What am I doing wrong? What could be the problem that I can’t get the volts to 44? Thank you.

 

[1point21gigawatts 451]

The head unit is sending off a weak signal or the RCAs aren’t good or that external EQ is doing it. I’d take that external EQ out of the circuit to check that first. Then I would try another pair of RCAs. If that doesn’t work then most likely it is the head unit sending a weak signal. Any EQ, internal in your head unit or external, anything over flat would make it difficult to tune your setup because of distortion. I don’t use external EQs and I keep my head units EQs flat and it’s straight. You are suppose to tune an amp with the EQs flat then once the amp is tuned, the way to play with the EQs is to tune them in the negative or just leave it flat. Positive creates distortion.

Edited December 1, 2020 by 1point21gigawatts

[liteblue 3]

Check

1)RCA are plugged into the correct output from stereo to EQ and out put is active/turned on (some head units have "subwoofer off" by default)

2)does the EQ have a gain setting or require power? check to see if you are getting 8v out from the EQ to the amplifier

3)Bass knob unplugged, or turned to max

4) sub sonic all the way down

5) low pass all the way up

6) Bass boost all the way off