Splitting speaker feed to run to amp?

[Cupra2505]

Hello everyone,

I posted this a few days ago on the ICE section of SCN but no one has replied, so I'm hoping I'll have a bit more luck here. Apologies if it isn't too relevant.

I'm hoping someone here will be able to help me to see if what I have planned is do-able.

I want to get a 10" active sub in the boot (something like a Vibe box) but continue to use my existing head unit. I've got to single slot CD player in the dash.

Now, I assuming the head unit has no pre-outs on the back, so therefore I need to use say the rear speaker feed to send the signal to the amp. Is it possible to split the signal to still run the speakers in the doors and the sub? I'm concerned there may be an inpendence/resistance problem and the head unit amp will have to work harder due to the lower resistance.

I'm also concerned how the amp would turn on. In my younger days, my Alpine head units all had a dedicated wire to switch the amp on whenever the head unit was on. How do I do this with a factory head unit?

Would it be better to use a high-low level converter, again from the split, to run to the amp?

Any advice on this matter would be greatly appreciated. I'd love some extra thump to my tunes, but do not want to go to the expense of a new head unit and CD changer.

Thanks again,
Mark

 

[The MoffMeister]

well head unit may not be powerful enough if its standard seat one

as far as i know the amp needs its own 12v supply speakers dont use 12v iirc?

someone will be along with better info

 

[Benny]

the amp does deffinatly need 12v.

What you would need to do is run a 12v feed from the battery

(not sure if this would work but it worked on my mates corsa (lol)) split the ariel wire and use that as the remote turn on

that will get your sub on, but i dont think running it off the split speaker wire will work at all.

 

[Cupra2505]

Guys,

Thanks for the replies, but I think I may have confused you.

Running a 12v feed from the battery to the amp is fine, I know how to do that, my problem is the signal from my tunes to the amp. Can I split the feed from the rear speakers to the amp on the sub box, without causing any damage to the internal amp on the original head unit? This will still be driving the fronts and the rears.

The signal into the sub box amp will then be used to 'pump' the bass!

Benny - thanks for the tip on the aerial to turn the sub on, something I'll be looking into.

 

[Benny]

Another little tip, get a proper sub and amp, my mate from work (also from briskoda) has got an active one in his VRS and its pants, no bass at all unless you turn it right up

 

[Benny]

After doing a bit of search on my ahm extended lunch hour i found this:

ISO to RCA Line in Adaptor

http://www.nexxia.co.uk/Car_Stereo_fitting_kits/ISO_Connectors.htm

But i think * that means you would have to run all the speakers off an amp.. someone else could possibly confirm this (or come up with a better idea )

 

[stuart86]

If your head unit has an "rca in" or sub output then you just need rca leads for the music signal

 

[Cupra2505]

Benny, thanks for 'your well spent time'. It's given me an idea!

Do I need the rear speakers on at all? Use the ISO RCA Line In adaptor on the rear feed only from the head unit to then send the signal to the sub amp.

That way, better quality signal going to the sub amp and I don't have to worry about killing the head unit!

Of course any ideas from anyone would be appreciated. Ideally I'd go for a complete amp'd up install with new head unit etc, but funds are tight and I need to do it on a relatively small budget.

 

[Benny]

funds are tight and I need to do it on a relatively small budget.

If thats the case, get a proper sub and amp as youl find 9times out of ten its cheaper than a active one. I think i spent about £250 on mine altogether.

Alpine headunit with ipod connector
JBL 480w amp
and a 1000W JBL sub

the wiring kit was about £25

ok so i got the headunit on a friend of a friends kinda deal but i think it was £150 new and i bought it for £100