Anyone know the voltage for the sub output on the stock headunit? I just switched it out for an Alpine 9835, set the sub level on the headunit to 15, and with the same amp settings, my sub is hardly moving.

 

can you please clarify what you are attempting to do.. sounds to me like you wired up an aftermarket headunit and want your stock sub to work... if you used the metra harness then your stock sub is not going to work unless you do some modifications.. if this is not the case please be a little more specific and someone will steer you in the right direction..

 

Sorry...I originally had an aftermarket sub and amp wired to my stock headunit tapping into line level sub output. I switched out the headunit to an alpine 9835, and the subwoofer preouts didn't seem very strong. With the stock headunit, I would have to leave the my remote bass control at around 1/4 so it wouldn't overpower my stock speakers. With the Alpine, I had to turn my remote bass control all the way up to get similar output, plus turn up the gain on my amp. Anyways, I took a mulitmeter to the outputs and did some measuring, and did manage to get 4 volts at full volume which is 30 on the alpine. At 20, when my stock speakers would start distorting, the voltage was only around 1.7. I'm just suprised how stong the signal was from the stock headunit. Anyways, once I get my other amp and components installed, I should be able to tweak all the levels.

 

do you have a high/low input switch on your amp.. if so is it set to high.. try switching this to low and see if that changes anything..

 

I think everything is ok, I guess I was just used to turning up the stock headunit like 3/4 for normal listening levels, but the alpine is fairly high powered, so it would start distorting my speakers at under 1/2 volume, and I heard the alpine preouts, especially the sub outs need to be cranked to reach 4volts.