Advice needed on two-amp setup

[Nick Read]

I need a bit of advice on my ICE project Im going to start on soon. Im stripping everything out of my Clio so thought Id put it all into my old Scirocco instead. Ive got a load of JBL stuff that Ive accumulated, ready to fit. The front 6x4s and rear 6x9s are already in and I can hear that the existing head unit is struggling to power them (25w per channel RMS). So the plan is to put in the JBL 80.4 four channel amp to run the front and rear speakers, then use my JBL BP300.1 mono amp to run the sub, a sealed box JL 10-W0

Ive got a pretty good idea of how its all gonna go together, but just wondering about any latest thinking on these kind of two amp systems...Ive not really delved deeply into this sort of stuff since the mid 90s

is it ok to use simple Y-splitters to distribute my low-level signals to each of the amps or is there a better way? I do have the full 4 channels of output available, and back in the day it was definitely frowned upon to use high level inputs on amps unless absolutely necessary.

Whereabouts do I hook up a power cap? Ive got a 1.5 farad job that I got off ebay, I assume it cuts into the main positive feed before the distribution block? Do I fuse before or after the cap? Or both just to be on the safe side?

The max current drain from my amps according to JBL are 43A and 29A, so 72A altogether. Thats one hefty fuse in the main live feed. Is that gonna kill my battery or is it fairly normal to run 2 amps in a car?

What gauge cable will I need to run the main feed from the battery? Assuming say 80A current capacity just to be on the safe side.

 

[Nick Read]

Anyone? There must be someone on here on Christmas Day LOL

 

[JAMESSRICH]

how many pre outs does your headunit have???

[Edited by JAMESSRICH on 25 December 2004 at 9:28am]

my valver is all Alpine - head unit has 3 sets of pre-outs front rear and sub!

so i have two sets of rcas going to a alpine 4 channel amp for front and rear , then the sub output goes direct to the big class-D alpine 2 channel amp for the subs

it will be ok to use splitters if you only have limited rca outputs cause you can adjust you high and low passive filters to match your speakers (i.e low pass is bass (subs) and high pass is top and mid (6x9s etc))

 

[Fred@BTM]

i thought youd grown out of your chav days????

 

[MattyK]

f**k off calling everything chav

 

[Lunner]

http://www.bcae1.com/images/swfs/systemdesignassistant.swfhttp://www.bcae1.com/images/swfs/systemdesignassistant.swf

Might find this useful Nick, apart from that i havent got a clue

 

[derv]

this is how i would do it,

http://erc.qmuc.ac.uk/cliosport/gallery/full/1104056318__wirs.jpg

re- the power cable, get the thickest u can to be on the safe side, prob 0 guage. i have no idea about the power caps though! what ive read they are not really needed. a standard battery will cope but will prob die a slighty premeture death.

 

[MattyK]

Just another quick question about this 2 amp set up. Is it ok to put 2 power cables to the battery?

 

[derv]

yeah that should be fine, ive got a 4 guage and an 8 guage running to the batt.

 

[Nick Read]

Well I have got four lines of pre-out: front left, front right, rear left and rear right. I was just wondering really if splitting the signal and feeding all four channels to each of the amps would degrade the signal that they get?
BTW Fred you hit the nail on the head mate LOL...no its just that the Turbo is garaged most of the time at the moment while I do little bits and pieces on it and theres no point commuting to work in it, it barely gets warmed up. So I bought an old Scirocco a few months back, every weekend I do a bit of work on it, you know, just fixing electrical niggles etc. So now its a pretty good motor for its age (20 years!) so it wants a bloody great sound system. In the Clio I cant hear the stereo any more anyway, the exhaust is too loud, so Im stripping it out and using it in the VW.