help to install a sub and amp

[charris]

Can anyone point me to a form on how people have installed a Sub and amp on there standard Head unit and can it be done before I decide to buy.

This would help me out a lot

Thanks

[ryan-re]

Yes it can be done and there are a number of different options depending on budget.

Cheapest is the use a speaker to rca converter. You tap into one of your rear speaker cables and it gives you an rca output for the amp.

Second is to buy one of the many digital processors such as the audison bit 1, bit 10, mosconi 6 to 8, jl clean sweep etc

These give you a huge amount of control.

Remember the first option does mean you wont have much control at all over the sub. You wont be able tonturn it up and down from the headunit for example unless you fit a remote gain controller

[charris]

ok mate sound I'll look into, any advice on cable routing earth points and is it safe enough to come straight off the battery with the power cable as I'm sure I read some where it's not advisable to do that ??

[Paulbrown]

Think there's a thread some where about fitting a Bose sub in boot :-/

[JonBRapid]

I've just fitted an amp under my drivers seat of a skoda rapid...

My learning points have been...

1. Amp fitted perfect under the seat but hard to adjust levels once in place.

2. Although the amp has hi-level inputs (I was able to clip the speaker wires and extend the output to the amp then take the output from the amp back to the original speaker wires) they pick up lots of interference which means I get an engine whine/noise that is audible at low volume.

3. Make sure the Fader is set to the middle when you unplug the quad connector at the back of the stereo.

4. Skodas are very clever bits of kit and do a speaker test when you turn them on and so will register a fault on the computer system!

5. I think it's worth investing in a sound processor if you want quality and control of the sound - which is my next investment!

Having said that it makes a huge improvement to the sound quality - the tweeters are a little harsh on the ear!

[ryan-re]

ok mate sound I'll look into, any advice on cable routing earth points and is it safe enough to come straight off the battery with the power cable as I'm sure I read some where it's not advisable to do that ??

Running from the battery to amp is fine. Where ever you read that is totaly wrong. You MUST fuse that cable though.

Earth, depends on amp location. But you must sand the down the bare metal, earthing through paint is a big no no

Remove the battery and you will find a huge gromit behind it. I have fitted 4 runs of 0awg cable through it so plenty of space for what you will need

Edited 13 June, 2015 by ryan-re

[dave_l]

Easiest option use a rockford fosgate pbr400 with high in puts and use American 9 wire for ease that way it can go under the seat and you can run the 9 wire under the carpets and chip straight into the normal speaker wiring. If you haven't added the bluetooth loom, I'd buy one so you don't have to touch the factory wiring.

Also if you bullet connector the speaker wires you can pull out the amp and reconnect the speakers easily

[charris]

Thanks for the help lads, iv installed subs in most my cars but wasnt sure if this would be a pain from what the foams have been saying I know what I'm looking at now cheers

[JonBRapid]

Running from the battery to amp is fine. Where ever you read that is totaly wrong. You MUST fuse that cable though

I think you'll find that the battery on vwag cars goes to a fuse bar (not sure of the correct terminology but basically you'll see a few red wires going in to a plastic cover which is fuse rated) I connected mine to the 30amp one that was not being used and hey presto... No need for a separate fuse holder

[JonBRapid]

Easiest option use a rockford fosgate pbr400 with high in puts and use American 9 wire for ease that way it can go under the seat and you can run the 9 wire under the carpets and chip straight into the normal speaker wiring. If you haven't added the bluetooth loom, I'd buy one so you don't have to touch the factory wiring.

Also if you bullet connector the speaker wires you can pull out the amp and reconnect the speakers easily

I'd use hi-level inputs with caution. Despite running power and signal cable separately I am getting lots of interference :(

I will be buying an audison bit ten which will give me three sets (pairs) of rca outputs (which will be shielded thus lowering the chance of interference) front hi, front mid and sub. I happen to have a few old amps lying around so my alpine MRV-F340 will run tweeters from channel 1&2, mids from channel 3 & 4 and I have a rockfordfozgate punch a120.2 that will be bridged to run my little alpine 8" sub in the boot.

Currently the alpine amp is powering the speakers and the sub (ch1&2 speakers, 3&4 bridged for the sub).

[dave_l]

I don't get any interference at all, is your grounding alright

[JonBRapid]

that was my thought...I think I'll double check. How did you route your cables?

[ryan-re]

Cable location rarely makes a difference.

I have 4 runs of 0awg, 2 runs of rca, remote cable and 2 pairs of speaker cables down the passenger side with no interference

John, how big is your power cable? Must be tiny if you are safely using a 30amp fuse.

I personaly would never use that kind of fuse for car audio.

Edited 15 June, 2015 by ryan-re

[dave_l]

that was my thought...I think I'll double check. How did you route your cables?

Speaker input and output ran together down the left hand side of the transmission tunnel with the remote, live and earth are left hand side of car.

[JonBRapid]

Cable location rarely makes a difference.

I have 4 runs of 0awg, 2 runs of rca, remote cable and 2 pairs of speaker cables down the passenger side with no interference

John, how big is your power cable? Must be tiny if you are safely using a 30amp fuse.

I personaly would never use that kind of fuse for car audio.

why would the cable be tiny... surely the idea is the fuse blows before the cable burns? its 8awg, and not very long as its going to the drivers seat, to answer the question and the amp's fuse is 30 amps as well. The amp won't be drawing that much power as its rated at 55w RMS @ 4 ohms x4 channels (its an old amp so very underrated in terms of what it can produce).... 

 

cable location will make a difference if signal is run next to power then you're likely to get electrical interference. 

 

I did get an auto-lec to install the amp and stuff...

[BO60BYS]

Once its up and running you will have to make us a video demo

[ryan-re]

Years ago when cables had poor sheilding maybe. Not now, its a common misconception.

Id use a seperate fuse and not tap into the cars fuse box keeping it seperate but thats my personal choise

[JonBRapid]

Years ago when cables had poor sheilding maybe. Not now, its a common misconception.

Id use a seperate fuse and not tap into the cars fuse box keeping it seperate but thats my personal choise

I think you might be on to something regards poor shielded cables... 

[ryan-re]

Another reason people get interference and is over looked is faulty rca leads. People think they never get damaged but its a cheap way to test for interfetence by buyibg some new rca's

[JonBRapid]

not using rca's cause i'm going from speaker (hi level) inputs...

[ryan-re]

How is the amp getting audio signal or does it have a high level input?

[JonBRapid]

How is the amp getting audio signal or does it have a high level input?

 

yep hi-level input.. I checked today and it was installed with the power running next to the signal :( can't imagine that has helped it!

[ryan-re]

You can try moving it but it shouldnt make any difference