A4 install

[slight_problem]

iv installed my dbaudio sub into my a4 iv used the high level input into the amp, by using scotch locks to get feeds from the right hand rear speaker.

now the sub and amp worked fine in my old car but i had phono leads from the stero.

i want to try and use the standard stero which is a sympthy cd\tape deck,

sorry for babbling on ill get to the point when setting the sub up i got it sounding really nice and was chuffed, but when i turned off the engine there was the was a really loud rumble that came from the sub. the same when i turned it back on. now if i turn the gain down on the amp it goes,iv checked all the earthin points and thats fine. what could it be???

 

[AndyMac]

What are you using as the remote on for the amp? i.e. the 12v signal to turn the amp on/off with the HU.
All Audi HU's have front & rear pre-outs, you can pick them up from the stock rear amp, along with the remote on depending on what year A4 and whether you have Bose or not. You can then use the RCA input on the amp.

 

[slight_problem]

its a 2000 A4, and non bose, remote iv got comin from the leads from the cdc.

 

[slight_problem]

right iv had a mouch on the forum and found if i want mp3 i need to buy a phatnoise. as for the amp poping if i was to but the blankput connectors i could run 2 amps( front/rear), really stupid question if i was use the rear pre out will i lose my rear speakers.

sorry not called slight_problem for nothing lol
thanks for ur time

 

[AndyMac]

Yes the rears run off the amp bolted to the left rear speaker which is fed by the rear pre-outs coming from the HU. So if you run new RCA's directly from the HU then you'll lose the feed to the stock rear amp.
If it's just the feed to the sub then I'd splice it from the stock rear amp. Both left & right pre-outs are there and a proper remote on feed. But it does involve taking the amp apart to get to the connector and then soldering some RCA's on to it.
With your popping problem, what happens if you just wire the remote on feed directly to the perm live going to the amp?
Does it still pop? Need to ascertain if it's the remote on causing it or the speaker input. What amp is it?
If the problem is still there, then maybe worth trying a proper high low converter (rather than the speaker input on the amp), but I'd always try and run the amp from proper pre-outs as the speaker level input from the Audi rear amp is crap before you even start.
Also have you selecte the amp to run in mono mode since you are only feeding it a mono signal from the right speaker?

 

[slight_problem]

thats where iv bodged it slighty. iv got the 2 + feeds comin from the high level input to the + feed of the right speaker and the same for the -. ill have to try the permernent remote thing when im at home 2night. its some 1000w watt kenwood jobby. when you say take take the amp apart u mean totally dismantle or drop from the speaker i did try at first get a conection from the left and right speaker connections. if i can remember im sure i set the amp to mono but its also bridged to peak power so wouldnt that make it mono anyway

 

[AndyMac]

You don't need 2 feeds into the amp for a sub, and this could be the route of the problem. Just set the amp to mono and use a single feed.
Bridging the amp provides a mono output, but you still have to select the right input mode.
The amp on the speaker is enclosed so it's not easy to get a feed from it, it's very easy to dismantle just a couple of screws. Removing the speaker is the hardest part.

 

[slight_problem]

right then got the "poping noise sorted it was the remote line to the amp wich was causing it cheers andy for the advice. the only other thing i would like to do is get a clearer bass tone into the cabin, the bass sounds good but is muffeled and slighty un clear due to bein in an enclosed boot i thought about porting the box into the cabin, the only other thing i can think to do is a free air build this is what i did with my mini but really dont wanna be choppin the audi up. any ideas????

 

[AndyMac]

I'd be tempted to just remove the rear speakers, a free air build will be a nightmare. I'd also try and use the pre-outs going to the rear amp rather than the speaker outs, as you are currently using a signal that's already amplified & thus distorted by the crappy stock rear amp. A cleaner signal in will provide a cleaner signal out.

 

[slight_problem]

iv already done all off that i took apart the rear amp a did what you said, i think the muffeled sound is mainly because of the rear pannels vibrating thus makin the sound, sound distorted. iv ready got some sound proffing comining just wonderd if there was any alternative way of gettin the bass into the cabin. i think i will take the rear speakers out like you said.

cheers for the help