Aftermarket headunit destroyed my bass!

[Luuc]

Hi All,

After considering my options for being able to listen to CDs in my non-bose, concert stereo A3 I decided to use a sony mp3 player (mp40) I had lying around and get a connector cable (pc9-404) to use the rear pre-outs of the stereo to the standard amp.

At first I didn't think it was even working since there was no audible sound coming from the rear. However, after setting the fade almost completely to the back and pumping the volume up, I could hear it. However, since I've had to pump the volume up to hear it the sound is pretty shocking. There's pretty much no bass and unexciting mid or treble.

Is there something I am doing wrong? Is the amp/sub somehow not getting any power or is this kind of setup doomed from the start? Someone suggested that the stereo might not have a high voltage output to the audi amp?

Any advice apreciated /ubbthreads/images/graemlins/smile.gif

 

[RichA3Turbo]

[ QUOTE ]
Luuc said:
Hi All,

After considering my options for being able to listen to CDs in my non-bose, concert stereo A3 I decided to use a sony mp3 player (mp40) I had lying around and get a connector cable (pc9-404) to use the rear pre-outs of the stereo to the standard amp.

At first I didn't think it was even working since there was no audible sound coming from the rear. However, after setting the fade almost completely to the back and pumping the volume up, I could hear it. However, since I've had to pump the volume up to hear it the sound is pretty shocking. There's pretty much no bass and unexciting mid or treble.

Is there something I am doing wrong? Is the amp/sub somehow not getting any power or is this kind of setup doomed from the start? Someone suggested that the stereo might not have a high voltage output to the audi amp?

Any advice apreciated /ubbthreads/images/graemlins/smile.gif


[/ QUOTE ]
Have you connected up the remote power on for the rear amp? if you havent, there will be not much, if any sound coming from the back.

Rich

 

[Luuc]

As far as I'm aware I have just used whatever is supplied by the connector cable which just splits the rear RCA out to plug into the stereo rear pre-out. Is there something else that I need to do? Which cable is the remote power on? If it's the separate blue one then that's connected as well.

 

[RichA3Turbo]

Make sure there is a signal going to the remote power on. Also make sure there is actually power going TO the amp, and that it is earthed.

Rich

 

[Luuc]

Is there an easy way to check if power is going to the amp (i.e. a power light) or do I need to get hold of a circuit checker.

You also raise a good point about it being earthed. Due to the small amount of space and the large amount of wires I didn't plug the aerial in, which is probably used as the earth?

Finally is there a way to see if there is a signal going to the remote power on and is it the separate blue cable?

Thanks for the advice Rich, apologies for the newbie questions.

 

[Luuc]

Yeh, is that the one that doesn't have the pre-outs? (rca wires). I've got for the non-clunky (and a lot cheaper) connector because I was told the rear system could just use my pre-outs from my stereo.

It sounds like audio is getting to the amp but the amp just has no power to amplify it.

 

[RichA3Turbo]

I reckon youve got the wrong adaptor. I actually use the BOSE adaptor...sent to me by mistake but thought i may aswell just use it as its £40 and i paif £15 for it! Works fine, but i only use the rear outputs, and chopped the fronts off.

Rich

 

[RichA3Turbo]

Heres what i have

Heres what i think you have:

Here is what you need.

All available from www.caraudiodirect.co.uk

 

[Gambba]

That's the kiddy!

 

[Luuc]

You're right about the one I currently have, and could be right about the one I need.

Pretty annoying though as all the car audio places point to the one I currently have...

This Connector does look like it should work with this stereo since the max RCA output is 2V and the connector appears to be able to handle it /ubbthreads/images/graemlins/confused.gif

 

[Luuc]

Just spoken to the place I bought it from (www.ianbannings.com). It seems my stereo pre-out is too weak to power the audi-amp, but if I use the other adapter which sends an amplified signal then I could be sending too much power to the rear speakers and end up having to set the fader to the front /ubbthreads/images/graemlins/blush.gif . I guess out of the two I'd prefer better sound from the rear so I'm going to have a go with the adapter suggested above and see if it improves.

Thanks for the advice guys.

 

[RichA3Turbo]

[ QUOTE ]
Luuc said:
Just spoken to the place I bought it from (www.ianbannings.com). It seems my stereo pre-out is too weak to power the audi-amp, but if I use the other adapter which sends an amplified signal then I could be sending too much power to the rear speakers and end up having to set the fader to the front /ubbthreads/images/graemlins/blush.gif . I guess out of the two I'd prefer better sound from the rear so I'm going to have a go with the adapter suggested above and see if it improves.

Thanks for the advice guys.

[/ QUOTE ]

Smells like bullsh*t to me! The adaptor works fine!

 

[paul_brad]

butting here, Andymac gave me lots of advice on this, and ive still buy a radio, nevermind the leads. But he said to me get the RCA £15 one if your HU has preouts, and the £10 aeriel adaptor. Is that perhaps something youre missing that might make a difference? the aeriel adaptor?

I need to get all this cleared up so I know what to buy too!
(standard concert in oldstyle A3 at the mo - no bose)

 

[mramage]

So long as your running the pre-amp it should be fine. Mine was running that way for a (very short) while before I powered the rears directly off the head unit.

 

[Luuc]

Just a quick update. I changed to the connector advised by Rich and it works a lot better. Instantly there was a better balance between the front and rear speakers, and there was at least a little bass. Only problem is that when the ignition is on I can now hear interference coming from the rear speakers as if there is too much power being pushed through them. When I take the key out this goes and I can but the music volume stays the same. I'm thinking that my stereo may be powering the sub-woofer as well as amplifying it's own output, so I guess I need to disconnect the blue wire maybe (the one that i think powers the rear amp).

 

[AndyMac]

Luuc, you had the right adapter first time round, you just hadn't connected the remote on lead, to switch the rear amp on. The adapter you have now takes speaker output and reduces it down to pre-out level, which feeds the rear amp, so it is no surprise you are getting interference and additional noise as effectively you've got 2 amplifiers in series, which is bodgy to say the least.
Your Sony can't power the sub woofer as it has it's own amp inside the sub enclosure. What you need is pre-outs to feed the rear/sub amp, and then a switched 12v feed to turn the amp on with the HU (use the power antenna or remote on feed off the HU). The RCA levels will be higher on the Sony as the Concert RCA's are very very low level, s this shouldn't be causing any problems.

 

[paul_brad]

Tell us how you get on Luuc, cos Im waiting to buy a system myself! (Constant mind changing, but thinking of going for this now: Sony CDXF5500 MP3/CD)

 

[Luuc]

[ QUOTE ]
AndyMac said:
Luuc, you had the right adapter first time round, you just hadn't connected the remote on lead, to switch the rear amp on. The adapter you have now takes speaker output and reduces it down to pre-out level, which feeds the rear amp, so it is no surprise you are getting interference and additional noise as effectively you've got 2 amplifiers in series, which is bodgy to say the least.
Your Sony can't power the sub woofer as it has it's own amp inside the sub enclosure. What you need is pre-outs to feed the rear/sub amp, and then a switched 12v feed to turn the amp on with the HU (use the power antenna or remote on feed off the HU). The RCA levels will be higher on the Sony as the Concert RCA's are very very low level, s this shouldn't be causing any problems.

[/ QUOTE ]

Thanks for the reply AndyMac. I admit the current adapter seems a bit like a bodge to me as well. I am sure the rear audi amp isn't used to an amped signal.

I agree that the previous adapter (with pre-outs) in theory seems the best solution. The problem is that I thought I connected everything up including the remote power (a separate blue 3amp wire?), and still had the problem. Is there something I am missing? Is there an idiots guide to making sure I have the remote power connected to the amp? /ubbthreads/images/graemlins/confused.gif

 

[Luuc]

[ QUOTE ]
paul_brad said:
Tell us how you get on Luuc, cos Im waiting to buy a system myself! (Constant mind changing, but thinking of going for this now: Sony CDXF5500 MP3/CD)

[/ QUOTE ]

I'll keep you updated. I will say this though - take a good look at the head unit you're buying as I'm not impressed with the Sony MP40. I know my headunit isn't the most expensive but compared to similar priced units such as some of the baupunkt offerings, the quality just isn't there. There's also no rotary volume control which annoys me no end!!

 

[Gambba]

[ QUOTE ]
paul_brad said:

I do have another type of problem, which is that my radio is losing its memory when the ignition is off (clock, presets etc). I realise that is to do with the red and yellow wires probably being the wrong way round, but I would have thought the ISO blocks would have taken of everything for me??


[/ QUOTE ]

Paul,

I had the same problem when I first got my car and found that it was a matter of swapping bullet connectors around as described in the instructions I got with the stereo I think....anyway basically that cured that but now the rear amp is constantly powered /ubbthreads/images/graemlins/frown.gif

 

[Luuc]

Yep, I just put the red wire into the socket that has space for 2 and it remembered.

I've given up on those leads and am now looking for a Concert CD or changer. The RCA pre-out adapter was way too quiet in the rear and the other adaptor had way too much interference noise due to amplifying the sound twice. Guess my stereo just isn't compatible /ubbthreads/images/graemlins/burningmad.gif

 

[paul_brad]

Luuc, mine is a Sony also though (cdxf5500) so you would think we'd be both the same! anyway, good luck with getting a working setup....

 

[AndyMac]

[ QUOTE ]
paul_brad said:
Oh, and Andymac, Ive bought the aeriel adaptor you told me to get, but it isnt needed! The audi one just slots nicely on the end of the Sony adaptor you get with the radio! doh!!

[/ QUOTE ]

Paul the adapter isn't an aerial adapter, it provides a break out for the 12v signal that the Audi HU feeds to the aerial amp via the core of the aerial lead. Without this connected you have no aerial amp. You need to fit this and connect the flying lead to the power antenna lead or remote on lead from the HU.

 

[paul_brad]

apologies Andy.
What does it actually do then? If its supposed to be there, then I'll attach it as you described, but I can't see what the end result is, as the aeriel works fine, the sounds fine, and all the speakers are fine!

 

[AndyMac]

As the bee-sting aerial is mounted at the back of the car, the signal needs a boost in areas where reception is weak. Thus it is fitted with a booster which needs power in order to do its job. Audi in their quest to make stright forward wiring a thing of the past, decided against the traditional 12v feed from the HU via a separate cable, and chose to save tuppence by feeding the 12v down the core of the aerial lead. As no one else does this, aftermarket HU's will not have the 12v fed in this ridiculous way, therefore you need the adapter which breaks out the feed to the more conventional flying lead which can be connected in the normal way. You're right, on FM you will only notice a difference in areas with extremely weak signals, but I think it's more noticeable on AM.