Pre amp question

PimpinD2 · Posted: May 02, 2011 7:03 am Post subject: Pre amp question

So... my headunit has 3 sets of pre amps, sub front and rear. I have the 2channel tower speaker amp currently plugged into the front... If i was to move it to the sub (i wanna installa 4channel amp on the in boat speakers) would it be any different?

Okie Boarder · Ladies Man Joined: 03 Mar 2008 Posts: 10056 City: Edmond

I would think you would want to put it on the rear. The sub out on most decks is designed to give the output for the sub and allow some of the deck settings to help with levels and frequency cut off.

browneye253 · Outlaw Joined: 07 Jul 2008 Posts: 115 City: Tulsa

I would plug it off the Rear or Front and if you need just split it again so you can hook up the 4 channel amp and the 2 channel.

jjaszkow · Posted: May 02, 2011 6:18 pm Post subject:

I'd leave the sub on the sub output, connect the tower to either front or rear output, and attach the remaining output to the 4 channel amp.

PimpinD2 · Posted: May 03, 2011 8:27 am Post subject:

i think im gonna daisy chain the amps, they both have the output rcas for that purpose it seems.

Okie Boarder · Ladies Man Joined: 03 Mar 2008 Posts: 10056 City: Edmond

PimpinD2, that might not be a bad way to go. Another option is to put in a pre amp EQ like the Clarion, Wet Sounds or Krypt like many people have done.

A danger in splitting is reducing the signal level, right? Does the output from the amp bring it back up to the level the stereo would normally put out?

PimpinD2 · Posted: May 03, 2011 9:37 am Post subject:

Im not sure... this is the tower speaker amp
http://mobile.jlaudio.com/products_amps.php?amp_id=559

and this is the 4 channel amp for the JL M770 in the boat:
http://www.amazon.com/gp/product/B0032GGTJ0

From the JL Audio manual:
"PreAM P OUT PUTS
The J2-360.2 incorporates a pass-through
preamp output section, so that additional
amplifiers can be easily added to the system. This
pass-through pre-amp output delivers the same
signals that are fed into the amplifier's inputs."

"The preamp output signal is not affected by the
“Bass Boost” processing selected for the amplifier
or by any crossover filter selected (if the input
signal is full-range, the preamp output will be
full-range).
Note: The signal level of the “Preamp Output” is
always line-level (low voltage)."

So i think that route will work nicely.

PimpinD2 · Posted: May 03, 2011 9:44 am Post subject:

and this is from the JL 320.4 amp manual...

Pre-OUTSOUTSOUTSOUTS
The J2-320.4 incorporates a pass-through preamp output section, so that additional amplifiers can be easily added to the system.
This pass-through pre-amp output delivers a summed stereo signal , combining the Ch 1 and 3 signals into a Left Preamp Output Signal and the Ch. 2 and 4 signals into a Right Channel Preamp Output signal.

So i think im good!

mseller · Outlaw Joined: 05 May 2010 Posts: 220 City: Charleston

I've never daisy chained an amp. I'm sure it works just can't confirm. My suggestion would be to connect the in-boat speakers to the front channel and tower speakers to the rear channel...use 2 of these http://www.amazon.com/RiteAV-RCA-Splitter-Female-Male/dp/B000V1PB3O to feed your 4-channel amp on the front channel...then you can use your radio's fade function to put more volume to the front(inboat) or the rear(tower) channels...just my 2 cents Mr. Green

PimpinD2 · Posted: May 03, 2011 11:14 am Post subject:

ehh, i wanna avoid using splitters as much as possible. The sound quality suffers when you do. Not that a boat has the best acoustics but stil Wink

...

It looks like these amps were designed exactly for this purpose. If that dosent work ill try the y splitters

Okie Boarder · Ladies Man Joined: 03 Mar 2008 Posts: 10056 City: Edmond

I'm with Pimpin...I would try the pass-through before the splitters. Aren't the splitters going to take the ~2V signal coming out of the head unit and split the voltage output, resulting in less overall amplitude of signal going into the amp?

jjaszkow · Posted: May 03, 2011 1:21 pm Post subject:

Daisy chain if possible, but I don't think I'd chain the tower and in boats. I like to keep the tower and in boat on separate channels, since this way I can adjust volume of each by fading front to rear. That way the passengers don't get blasted if your rider wants a bit more sound.

Brit Rider · Posted: May 03, 2011 1:24 pm Post subject:

PimpinD2, Simply plug the tower amp into the rear RCA outs and the boat amp in to the front RCA outs. Simple!

The jl amp can take a 2 ch input and will still power all 4 in boat speakers.

This topic is being way over thought Laughing

Hope this helps,

Mike

PimpinD2 · Posted: May 04, 2011 4:44 am Post subject:

haha, its not that its being over thought, is that the amp hasnt arrived yet, so i got nothing to do but read and post about it haha...

Do i have to change any settings on the 4 ch JL amp to output to all 4 channels via 2 rcas?

PimpinD2 · Posted: May 04, 2011 4:48 am Post subject:

If you wish to feed all four channels by using only two channels of input, set the “CH 3&4 Input From” switch to “1&2” and use only the inputs to channels 1 & 2.

LOVELY!

Brit Rider · Posted: May 04, 2011 6:30 am Post subject:

PimpinD2, That'd be it Laughing

Hey I don't blame you, I'm the same whenever a new toy is on the way... I want to know everything about it before it comes... have a new company vehicle coming next week and I'm constantly reading up online to find out details etc..

jjaszkow · Posted: May 04, 2011 6:31 am Post subject:

PimpinD2, that's exactly correct for that amp. Really simple.