gain setting help

[blackMTXgold 10+ year member]

well i know that i should post in the Gain tutorial thread, but honestly i would like to get this answered, well im trying to set my gain to 55V on my rockford 1501bd but when i play the 50 hz tone, and hook up the volt meter i notice that i can turn the gain all the way up and it only gets up to 42 V, thats with all my eq, loud, crossover settings set down, well crossover is at 50 hz on the deck, and my amp crossover at 70, car running, why am i only getting 42V

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[SVTLightning01 10+ year member]

is there a input voltage selector switch? If so, try switching to the other setting.

 

[blackMTXgold 10+ year member]

no there is not, thats what im thinking is the input voltage is low, my cd player is a PIONEER DEH-P47DH it came with the car so i left it in there, my other deck is a pioneer deh-p3700

 

[SVTLightning01 10+ year member]

without researching, your deck probably doesnt have high enough pre-outs to reach the voltage your looking for. Then again, im no pro, but thats my guess.

Good Luck.

 

[blackMTXgold 10+ year member]

well any help was appreciated, and ure the only help so far, so greatly appreciated

 

[squeak9798 5,000+ posts]

For starters turn off the lowpass crossover on the HU or set the frequency as high as it'll possibly go. If the HU's lowpass crossover is set to 50hz, then that means the 50hz tone you are playing is being attenuated by -3db.

2nd, where is the volume level set at when you are setting the gain?

3rd, set all of the settings (EQ, level settings, etc) to where they will normally be when you are listening to music. Don't turn them all the way down if that's not where they will typically be when listening to music. This excludes the Xover. Either turn the xover off, or set the frequency as high as possible so that it won't affect the tone you are playing (like it currently is).

Lastly...yes, you can measure the preout voltage from the HU with your DMM. The downside of using the DMM is that you won't be able to tell if the signal is being clipped or not at a given volume setting. But it'll give you an idea of what HU is capable of outputting voltage wise. Stick the red lead of the DMM onto the center of the RCA cable, and the black lead from the DMM to the outter shield of the RCA cable.

 

[squeak9798 5,000+ posts]

without researching, your deck probably doesnt have high enough pre-outs to reach the voltage your looking for. Then again, im no pro, but thats my guess.
Good Luck.

Most amps need as little as .2V to reach full power output. I'm sure his deck is capable of atleast that voltage output.

 

[SVTLightning01 10+ year member]

good call, i didnt even think of that,

 

[noob with an RS 10+ year member]

because you have the crossover all the way down on the amp. turn it all the way up and then set it accordingly after you set the gain.

 

[wilzyx 5,000+ posts]

also if your deck has sub control you gotta make sure thats turned up a little bit