Upgrading front stage soon: questions
 

Hey guys, I'm going to be ditching the fosgate components I have in front soon and going with some XR650 CSi's possibly.

My questions are about the connections I'm looking at. Currently I have an eclipse 12" and amp in the back. My HU has only one set of RCA outs, so would I be running the rca's to the sub amp IN, then the sub amp PRE to the speaker amp IN? Would this change how I set up the crossovers and such on the sub amp?

Would it be better to run from the HU to the speaker's amp first then the sub?

Not sure if i'm moving in the right direction so if it seems like I'm guessing, it's because I am :D.

Thanks.

A rca splitter is one option. Run each set to an amp. Downside to that is your lowering the signal output.

The other option is a line driver. Phonenix gold has one. This is what I would do. You can take regular wire and convert it to rca and at the same time increase it's line-level output and it will take the one set of rca's and amplify it also.

Here:

http://www.phoenixgold.com/2004/linedrivers.html

SLD44, you can run your front and rear hi inputs to it and the one rca, and it will give you amplified rca outputs (3 sets).

There's a few others that do it too.

The last thing I would do is convert speaker levels -- depending on if your amps outs are filtered, that is the best route to go.

Splitting the RCA signal is the next best option -- you lose under 5% of the preout voltage -- so it wouldn't be noticeable with almost any HU.

Not sure how to find out if it's filtered or not but the sub amp is an eclipse 33240 and I haven't bought the speaker amp yet. It has RCA ins and preamp outs if that helps.

Chances are that one set of pre-outs are sub only and you know that is filtered. Even if it wasn't filtered. A splitter won't give you the front and rear fades that most music has today. It would just play in both left or right.

The phoenix gold sld44 would be the best solution or a compariable product.

What head unit does the OP have would be the thing to find out first. Like I said, most one set of pre-outs are usualy sub-outs.

HU is a JVC kameleon I picked up a year or two off of someone I worked with. Eventually this won't be a problem because I'll get a flip-out dvd HU.

The RCA output will work on that amp for what you need.

ChannelFlex Crossover Adjustable Low-Pass Crossover (12dB/octave, 50-200Hz) Adjustable Pre-Out High-Pass Crossover (12dB/octave, 50-200Hz)

So you have a High-pass cross-over on top of the extra pre-outs.

The only issue you will have is no independent fade/level control. Just have to set the gains right and call it a day. No control from the HU.

Yes, he'll lose the ability to adjust the fade on the HU... However, almost no music at all is recorded such that it will adjust the fade on its own (e.g. surround sound). Most music (almost all music?) is available in stereo only.

In addition, he will be able to adjust the fade level at the amp if the front and rear channel inputs have independent gains.

I agree with the other posts here: Using the RCA pre-outs as pass throughs should work fine.

Thanks very much guys.

I finally decided on what I'm going with and ordered a set of JL XR-650 CSi components for up front and a JL 300/4 amp to power them.

That being said, is there any preference over which amp I should run the RCAs to first or will it not matter?

As far as the crossovers, would I run both low and high on the first amp and then have them both off on the second amp or would it be better to run the low pass on the sub amp only and the high pass on speaker amp only?

Sorry I'm such a newb :D.

Again, this is temporary anyway until I pick up a new HU :).

If its temporary then just run y-splitters in the back of your HU. It'll make life 1000x's easier when it comes time to replacing your HU. Hell I'd even look into buying a new JVC unit if they have something you like. Most of the times the wire harness is shared across the entire line of headunits, so it would just be a plug and play type ordeal.

Sorry, just saw your post in this thread. I'll do the y splitters then and run the low pass on the bass amp and high pass on the component amp for now. At least one of the amps has its own gain control so that'll make it easy to even things out I would think.

Good point about re-using the harness, I actually do like at least one of the newer jvc models and I hear good things about it so I'll keep that in mind when the time comes.