Wiring new sub amp ?? help ??

[Bigbopper]

Hey audio gurus....

I just picked up a Kenwood 10" sub and amp package that I will be installing in the near future.
I'm not really sure how to run a pre-out to the new amp though....
Currently my Kenwood head unit has both of the front/rear amp pre-outs running to a JBL 4 channel amp and driving 6 DB651s....
There are no more pre-outs on the head unit, but the JBL amp has an unused aux pre-out. Could this be used to run the sub amp?
I read the JBL owners manual, it's useless and doesn't even refer to the connections....
I guess my only other option is to split one of the pre-outs at the head unit.
Just looking for the best way to get a signal to the sub amp.

Thanks,
BB

[bzubke1]

On either your stock amp or tower speaker amp if you have one there will be a connection that looks like the rca inputs but will be labeled "output", "preouts" or something along those lines. What you will do is plug the rca's for your new sub amp into the preouts from either your cabin speaker amp or tower speaker amp instead of the head unit. What this does is just passes the audio signal from the head unit through the amp. I hooked the rca's for my sub amp to the preouts on my tower speaker amp that way when I have someone riding I can fade most of the sound to the tower speakers but still get full output from the subwoofer. Below is a diagram from a JL amp so you can see what I mean about the rca inputs and preouts.

[MLA]

I would run the head-unit's "FRONT" RCA to the in-boat JBL amp and the "REAR" RCA to the new sub amp. If your current JBL amp will not signal all 4 chnls with only a single set of RCA's, then split the "FRONT" set and occupy all 4 inputs.

[sandm]

get a krypt/wetsounds preamp. that will give you the outputs you need along with some fading control so you can turn the volume on the towers/boat up/down independent of each other without having to search the deck for the fading controls..

mla's idea will work nicely as well.

[EarmarkMarine]

Big,
It reads like you do not have tower speakers so I'll just assume that is the case. If that is the case then an EQ would have limited value as a zone control or RCA splitter.
You should be able to use the preout pass-throughs on the JBL amplifier to feed the RCA inputs of your new amplifier. This only requires a short RCA jumper from amplifier to amplifier. The advantages would be a) constant bass regardless of the fader position, and b) most amplifiers (not all) have an independent OP amp driving the preouts so there is no real division and no loss of preout voltage. This provides the advantage of having a bow to cockpit fader if occasionally you want to turn down the bow and use that as more of a quiet sanctuary for the little people.
Mike's (MLA) suggestion would also be great if you wanted to use the fader as an active bass level control. You can always do a fixed gain balance between the bow to cockpit speakers on the amplifier. Most amplifiers (not all) have a configuration switch that allows all four channels to be driven by just the two front RCA inputs. If your HU is on the port side then the value of this feature is a little diminshed because the control would not be readily accessable to the driver. But it sure would be handy if the HU is on the starboard side.

David
Earmark Marine