What is the proper way to add a sub to my Shaker 500 (with aftermarket head unit)

[Synyster06Gates]

I finished up my Maestro RR/Kenwood install and the setup sounds decent. I want to add a subwoofer in the trunk to make it sounds more like the Shaker 1000 that was in my old 06. I'm not an audiophile. It doesn't have to be the best sub ever as long as it sounds decent. With that said, I'm not sure how/where to get signal. The Kenwood head unit has 3 RCA preouts. The installation of the Maestro and Mus01 dash kit required me to use the subwoofer preout to retain the door subs in the shaker. Since that preout is taken, where do I get signal for my sub?

The way I see it, my only options would be

1. Use two RCA Y-splitters and send signal to both the door subs and the trunk sub with the same preout. Problem here is that I would not be able to control them independently.

2. Move the Shaker 500 RCA to the rear preout and use the SW preout for the trunk sub. I'm not too sure how this would work.

3. Leave the head unit alone and tap into the rear speakers with a LOC and plug the amp in there.

What would be the best method for this?

 

[TheVikingRL]

Are you still using the factory 500 sub/amp setup? Typically you want the door subs to act more as a mid-bass speaker then a true sub. Assuming the HU allows you to independently set the high-pass and low-pass crossover frequencies (it should), then use your sub out for the trunk sub. To do this properly you will need separate amp channels for the satellite speakers, door subs and trunk subs with a crossover built into the amps. But if you are keeping the stock Shaker 500 amp/speaker setup then connect the rear RCA's as mentioned and set the high-pass filter to 50hz to start. Set the front channel high pass filter to 250hz to start for your satellite speakers(front/rear). The stock Shaker amp has it's own filtering so there isn't much you can do but tweak around it. If your amp has a built-in crossover then you can lower the front hi-pass setting and use the amp crossover to set the front and rear high-pass separately if desired. Download a spectrum analyzer for your phone and look for any serious peaks or valleys using pink/white noise through the HU, particularly in the crossover areas.

if you ever decide to replace the factory 500 amp/sub setup then you have some other configuration options available. There is an awful lot that goes into the tuning and much of it is subjective. So take any advice with discretion

 

[Synyster06Gates]

Yes - I am still using the factory subs and amp. So I should move that connection to the rear RCA when I get the sub and set the high/low filters, connect the sub to the SW RCA and I'll be all set aside from tuning?

Appreciate the advice!

EDIT : Thinking about the way my wiring harness was setup, I have soldered connections for the FR, FL, RR, RL speakers - the stock door and rear deck speakers. The subs have the RCA connection (currently in the SW RCA). If I move that RCA connection over, is that going to take away the signal from the rear deck speakers and send it to the subs only?

 

[TheVikingRL]

So you are using the HU power for FR, FL, RR, RL speakers and not amp'd separately? Typically the HU will output RCA and speaker level signals simultaneously. An audiophile type unit might provide the option of turning off the built in amp to reduce potential noise. But this wouldn't be disabled by default. Through just the RCA and speaker outputs the HU has no idea what's going on downstream or how it's connected. So you connecting one way or another should make no difference.

 

[Synyster06Gates]

Correct. I'm using the head unit power for the stock 5x7 (or 6x8, which ever they are) speakers in the door and the rear deck. The door subs are powered by the stock amps in the drivers kick panel. Interesting. I guess I'll just have to try it out and see how it sounds!

 

[Synyster06Gates]

So you are using the HU power for FR, FL, RR, RL speakers and not amp'd separately? Typically the HU will output RCA and speaker level signals simultaneously. An audiophile type unit might provide the option of turning off the built in amp to reduce potential noise. But this wouldn't be disabled by default. Through just the RCA and speaker outputs the HU has no idea what's going on downstream or how it's connected. So you connecting one way or another should make no difference.

So I went out and played with it some today. I moved the door subs to the rear RCA preout. The actual rear speakers were no longer putting out any sound, so I think this solution may be out. They were also putting out next to no bass.

I think I'm left with either the RCA splitters or line out converter.