Amp Wiring - Do I Have This Right?

[Grsemky]

There are probably different variables. In my case, I have the amplifier in line with the speaker harness, ie, it goes head unit -> amp> - out to speakers. I then have the subwoofer wired in to the rear speakers. If I turn the fader on the amp "ON," ie, so it's processing both front and rear inputs, it completely cuts bass to the subwoofer. If I turn it OFF so it's only processing the front inputs, the subwoofer works fine. My thinking is that even having turned off all DSP/signal processing/etc via FORScan, there's some bass roll-off happening in the rear speakers.

So, I'm going to try tapping into the front speaker kick panels first, since that's only an extra 2-3 feet of wire, and if that doesn't work I'll just tap the subwoofer into the speaker wires going to the input of the amp, bypassing the amp's built-in DSP.

I went head>LOC rear only>amp>sub and have no issues, or bass roll-off at least with the kicker 10 I'm running

 

[XanRules]

Yeah, but I'm not running an LOC and am not looking forward to the prospect of yanking everything back out to wire one up. It's on the list as a possibility, though.

 

[Grsemky]

I don't blame you there

 

[Intuit]

Yeah I have my amp tapping the rear as well. No known issues.
I use the front/rear fade adjustment as an additional gain control for bass.
Otherwise the bass can be overpowering.

I transferred this from my prior car which had an aftermarket Alpine head unit.
The factory Sony head unit just doesn't compare; simply can't use all of that 600RMS power.
I too wish to avoid pulling everything apart to install an EQ + LOC + mini-Amp combination.

 

[XanRules]

Yeah I have my amp tapping the rear as well. No known issues.
I use the front/rear fade adjustment as an additional gain control for bass.
Otherwise the bass can be overpowering.

I transferred this from my prior car which had an aftermarket Alpine head unit.
The factory Sony head unit just doesn't compare; simply can't use all of that 600RMS power.
I too wish to avoid pulling everything apart to install an EQ + LOC + mini-Amp combination.

Yeah, so my setup - and forgive me if this is redundant - is two things in parallel.

I have the signal/DSP defeated on the stock head unit via FORScan, and then I custom-fabricated a t-harness for the speaker inputs and outputs. This is routed behind the head unit, through the center console, and connects to a Kicker KEY 200.4 amp under the driver's seat. The KEY has a built-in DSP that's pretty cool, you put a little microphone on the driver's side headrest, run some pink noise, and it calibrates the EQ curve, time delay, etc, to the car. Good enough for my purposes.

On a separate circuit, I have an NVX QBSTA spare tire subwoofer tapped into the rear speaker wires in the b-pillars. Power and ground for the amp and the sub are run off of fused distribution blocks but they are not connected to each other.

Doing it like this didn't really save me any time, but it saved me the $275 or so I'd have spent on a good LOC and prevented me from having to figure out where to put more equipment since interior space is at a premium anyway. I figured since I was tapping into the speakers and defeating the DSP anyway, the LOC would have been redundant. Knowing what I know now, I'd probably have installed one, but I'm not willing to take out the entire interior of the car again. When I say "entire interior," I mean everything except for the dashboard. I am talking every piece of plastic trim, the carpeted trim in the trunk, the carpet itself, the front and rear seats, the center console, the headliner, all of it. I am not doing that shit again to run a few wires, at least not for a good long while.

The KEY has a "Fader" function. When it's OFF it's getting signal from the front speakers as a single stereo signal, when it's ON it's getting two stereo signals, one front and one rear. When it's OFF, the subwoofer works fine. When it's ON, the volume on the subwoofer is reduced by about 90%. Even with the gain, low pass filter, and everything else maxed out, it's very quiet. Since the amp is before the speakers, I'm thinking that either the KEY's DSP processing is rolling off bass to the rear speakers, and/or there's already a built-in roll-off in the Sony HU even with the DSP and processing defeated.

So, that said, my first order of business is going to be to just taking the wires tapped into the rear speaker wires in the b-pillar and tapping them into the front speaker wires in the kick panels, since that's going to require an extra three feet of wire per side and removing three trim panels. If that doesn't give me the results I want, I'll tap them into the harness I fabricated for the amp, but before it reaches the amp - as Kicker's customer service has suggested - though this will require removing a lot more trim panels and the front seat again. Either way a pretty easy fix, I was very conscious of the fact that something could go wrong when I was wiring this and made all of the connections and taps pretty easily accessible.

Phew, lots of words. Spot the guy who finally got his ADD meds refilled.