21 TRD Pro JBL Upgrade

Perfect. Its usually one of them. Gain issues will cause hiss and white noise that you are experiencing. If it is alternator whine that varies by speed of the engine that is usually a ground or power location issue. Glad you got that resolved.
Also, if you lose volume this way you can usually add back some on the output side. It is truly a balancing act. Glad you got it figured out.
I had some amps that you could hear the noise your referring to when I cut the truck off and before I opened the door there was hiss or white noise. Minor irritant but then I changed amps and took the truck to a friend to tune and he told me
I was probably fine with the amps I had but I had not adjusted the gains correctly. The new amps are silent but he also did an entire tune and we adjusted all the gains again.
Now I have three amplifiers sitting in a box that are only 6 months old and I thought they had noise but turns out they don't. Ill stash them away for another build.

 

How is that amp installed? did you leave it under the seat? and are you still running the DSP4086?

 

Yes, I’m still running the dsp. It’s still under the passenger seat next to the factory jbl amp. The Sony amp is attached to James’ amp mount and is under the driver seat.

 

What’s the specs of the amp? I just installed the sub today to go with the JBL dsp. But I may want a little more bump in the future.

 

Do you mind take a photo? I like the sound of that, I have James set up as well, except I have 2 10s in the back, wouldn't mind bit more air.

 

I posted the amp model in a previous response

Not sure what you want a photo of? I forgot to take a pic while i installing the amp, so the only photo’s have is the one i posted a few replies ago

 

So seems like a 500-600w mono amp would suffice to really get the sub bumping.

 

Was hoping to see what the mount looks like, I'll probably just build one around the floor vent.

 

What amp are you going with?

And I assume for wiring we can just take the sub channel output from the DSP / wiring to the sub and feed that to the high level input on the mono amp and then send that to the sub?