JBL system

[Valandil]

Hi guys,

Had my 02 coupe with the JBL "upgrade" for a while now and I'm getting a bit fed up of the awful sound quality and I've got a few questions if anyone has any answers!

I'm wondering whether the volume control on everyone else's is as weird as mine...I get no sound at all on setting 1, though on setting 2 it's not THAT quiet. It's not loud by any means, but it's far too loud for it to be the minimum volume. Is anyone else's like that? Also on mine I've never had it above 10 out of 15 (I think) because even then its very loud but starting to struggle. At motorway speeds when it boosts the volume a bit it's pretty darn distorted. Got the loud on like the manual suggests and only have the bass +1. It just seems odd to me that it goes up to 15. When I change inputs the default volume is something like 8 which is waaaay to loud for that to be correctly set.

Getting to the real point, has anyone else ever changed the amp and kept the original head unit? I really don't want to lose how integrated it is with the rest of the car (cd changer, display on the MFD and satnav sound/muting) so I don't want to change the head unit, though I don't know what the sound quality would be like. I seem to remember reading a while ago that the JBL system doesn't use standard low-level input voltages but I can't seem to find anything about it now. Does anyone know anything about the wiring to the amp? Like which wire is which?

If anyone has any clue I'd love to know! Thanks

[GingerMagic]

Hi, mines the same. Volume one is very very quiet and volume 2 is surprisingly loud...

I guess you have a cassette player head unit too? I was chatting to Finchy on the Coupe forum and he was saying that you can't swap to a CD head unit as it has a built in amp and would not be compatible with a JBL system ( double amps ) unless you do some complicated rewiring, although I might try it to see what happens.

As for changing the amp only, could be tricky finding one with a suitable connection but I'm not a techie person, maybe someone on the coupe club has done it?

[mjb]

It sounds like your head unit is a normal one, not the one for the amplified setup

The amp expects to receive line level, which is gets through the iso connector at the head unit. This means that on amped cars, the head unit needs to be unamplified - it's a different oem part.

[Valandil]

GingerMagic yea I've got a cassette player head unit, as far as I'm aware it's the only one compatible with the JBL amp. As for matching the connections it shouldn't be difficult to either make adapters that fit onto the existing wiring blocks or just cut the blocks off and do each wire individually!

mjb I wondered that myself, but gingermagic says his is the same so I guess not. I'm not sure they actually made a D9 cassette deck that wasn't for the JBL amp though I could be wrong. I just don't know whether the sound problems come from the head unit, the amp or a combination of the two.

[GingerMagic]

My old 2002 Hdi90 had cassette but no JBL, so a swap with CD player was fine.
If you are happy with chopping the wiring block off and going in directly then yes, give it a go. You can always wire the JBL back in if it goes tits up!!

The problems and hiccups with the head unit doesn't bother me too much, normally turn mine off cos of all the sh1te on Radio one......

[V6Exec]

Have you tried the setting in PP2000 for line level output?

[mjb]

mjb I wondered that myself, but gingermagic says his is the same so I guess not. I'm not sure they actually made a D9 cassette deck that wasn't for the JBL amp though I could be wrong.

They did

Have you tried the setting in PP2000 for line level output?

Didn't realise there was such a setting?!? Mind you, the first thing I do with 406s is rip out the stock head unit and put something mp3-capable in My JVC was thankfully configurable enough to let you drop the speaker outputs to line level, which worked a treat, unlike my attempts at using the unit's preamp outputs

[Valandil]

mjb and GingerMagic sounds like I might as well check the model number!

V6Exec I didn't know about that option either, I'll have a look next week sometime. Maybe it will be manageable if there's a few options like that. It might also work quite well with the nicomod (if you've heard of it) but I think he charges £100 which I don't really want to spend.

My brother has a spare amp at the moment so I could give it a try but I still need to know something about the wiring! Hopefully the existing power wire is thick enough for the up-rated amp...which I doubt very much!

[V6Exec]

It might also work quite well with the nicomod (if you've heard of it)

I have a coupe - of course I have heard of the mod, but not actually heard it.

I swapped my cassette version for the CD version, which apparently is not as good sonically.

[Valandil]

I swapped my cassette version for the CD version, which apparently is not as good sonically.

How ironic

[8Jb9]

Getting to the real point, has anyone else ever changed the amp and kept the original head unit? I really don't want to lose how integrated it is with the rest of the car (cd changer, display on the MFD and satnav sound/muting) so I don't want to change the head unit, though I don't know what the sound quality would be like. I seem to remember reading a while ago that the JBL system doesn't use standard low-level input voltages but I can't seem to find anything about it now. Does anyone know anything about the wiring to the amp? Like which wire is which?

Nico den Haak does it, as is mentioned a few places on this forum and on the coupe-forum:

http://www.406coupeclub.org/phpBB3/view ... 30&t=41691

[Valandil]

Nico den Haak does it, as is mentioned a few places on this forum and on the coupe-forum:

http://www.406coupeclub.org/phpBB3/view ... 30&t=41691

You think he has changed the amp? Or do you just mean he does the Nico mod? Bloody search won't work so I can't find anything about it. Reading that thread though it might be worth getting the Nico mod and just sticking with the JBL amp (and upgrading the rear speakers) as it sounds like the problems come from the head unit and that the amp has enough power for it to sound decent. It would certainly be easier!

[8Jb9]

He explained what he does either in a mail or one of his thread. I'm not how to accurately describe it, but he works within the limits of the actual head unit, and fixes key audio-quality mistakes that in the end is supposed to make it sound great. Perhaps not in fact, but in effect the amp - the quality-relevant part of the amp - is replaced with something better.

I have not yet had mine converted, but after MOT and new shoes that's high on my list.

[Valandil]

He explained what he does either in a mail or one of his thread. I'm not how to accurately describe it, but he works within the limits of the actual head unit, and fixes key audio-quality mistakes that in the end is supposed to make it sound great. Perhaps not in fact, but in effect the amp - the quality-relevant part of the amp - is replaced with something better.

On cars with the JBL system the amp is in the boot, separate from the head unit- it takes the low level output from the head unit and amplifies it for the speakers. So yes, Nico works with the head unit, not the amp. My original question was whether changing just this amp an leaving the head unit unchanged would see any improvement, but yes I think I agree now that by the sounds of it the actual amp is fine, the problems come from the head unit.

[Captain Jack]

I ripped mine out after getting annoyed with the volume thing. First replaced the JBL amp keeping the head unit but wasn't happy either. Then replaced the HU with a nice Alpine.

Never looked back.