factory amp bypass (my way - lots of pics)

[BMWDriver]

Huzzah for this thread Tim btw !

[tim eh?]

Thanks, glad to be of some use.

I see wires soldered to the crossover board, but what are they connected to at the other end ? I'm starting to guess the speaker terminals of the amp box. What gauge ?

And Tim, I see black and blue wires on Derek's pic, were they missing in yours or are they already there ?

I'll soon be opening my amp later this week or this weekend.

The soldered wires are the speaker level outs (black is +, green is -) from the head. You can solder the + to the plug input board or run the wires directly. The '-' is the real question mark. There is something I don't understand about how the factory system does the Front/Rear fade and it involves the way the speaker grounds are shared L and R. I would try splicing each side together first and using the factory wires but if that doesn't work you have to run new wires to the head for the speaker grounds.

I think 16 ga wire is good- use speaker wire, not power wire.

I believe the black and blue wires are part of that factory amp and mine is slightly different - I don't know what they do.

And now that I have tried it three times, I would suggest it might be easier soldering to the underside of the board, not at the pins.

Anyone else have this technicolour equalizer?







...this diagram comes in very handy...


good luck buddy!

[filmy540i/6]

I don't know, this kind of technology hasn't changed much since '95, and unless something breaks or you need to hook up an ipod or something I wouldn't mess with it... I never heard a stock e34 system actually, I imagine they sound pretty decent even with the feeble amp.

Again, great explanation and visuals, Tim.

In fact, I do want to upgrade to a BlueTooth- and iPod-capable HU, but I understand there's no way I'll be able to integrate my (factory) trunk-mounted 6-CD player. Which means I'll need a single-slot CD Head Unit. OTOH, I don't want to spend $500 on it so my choices (and options) are limited - especially if I'll have to get it all professionally installed by someone who is familiar with the E34 amp/crossover box.

[genphreak]

Front of the Touring and Sedan is the same for speaker placement, only difference is the rear where they put the speakers in the headliner.

My speakers werent driven by an amp, they were driven by the panasonic dvd in dash 50Wx4 and there's no way you can compare stock speakers to these. Espically at 250 a pair, you DO get what you pay for. Crisp sound, with the crossover box to an adjustible tweeter.

I disagree. My 535's 10 speaker stock setup sounds great with the OE crossover/gutted amp driven by 4x100W. I run it at nuetral (maybe +2db treble) and have 100W worth of sub cutting out at 90Hz. I don't cut the frequencies to the stock crossover at all.

It sounds great and can hurt anyone's ears, except perhaps the guy I saw throw up in a bass bin at the front of a Killing Joke concert where my ears were about to burst at the back. (I used to do PA work).

Seriously, with clean 20W of power x5 in a confined space, there is no need for anything more... the crumby car stuff marked 100W is (in reality) abut that in real terms as it is mostly 4 ohm, runing on crumby 12VDC supply... etc.

BTW; I like the total guttedness of that setup. Only problem is the hot glue, I know in Oz, the sun and a warm day would see the components all dribble off the board by the time u got back from buying ur girl an ice cream...

Whilst we're on this... Does anyone know... in a 525 touring, how hard is it to replace the rear speakers? Mine are blown as the PO fitted a Pioneer head unit which has far too much bass adjustment and causes the output to clip like hell. I reckon the rear is not going thru a crossover - and that's proly what saved the fronts.

Has anyone ever had to pull them before?

[tim eh?]

Again, great explanation and visuals, Tim.

In fact, I do want to upgrade to a BlueTooth- and iPod-capable HU, but I understand there's no way I'll be able to integrate my (factory) trunk-mounted 6-CD player. Which means I'll need a single-slot CD Head Unit. OTOH, I don't want to spend $500 on it so my choices (and options) are limited - especially if I'll have to get it all professionally installed by someone who is familiar with the E34 amp/crossover box.

You can upgrade the head for functionality pretty easily. You can get head units that control an external cd changer (sold seperately )and have all the options you mentioned. Just be sure to get one that has line level outs for all 4 channels and use those instead of the powered speaker outs. No amp gutting required, just your basic head install, I believe you can get a plug adapter too, someone will know here. You would have to alter the plug slightly to use the line level outs instead of the speaker outs. The sound quality won't change, although you'd probably get better radio reception. You wouldn't be using the the new head unit's superior amp (), so don't worry about watts.

this would work -> http://www.jvc.ca/en/consumer/produc...model=KD-ABT22

...just happened to have jvc bookmarked, any brand will sell heads like this.

[tim eh?]

It sounds great and can hurt anyone's ears, except perhaps the guy I saw throw up in a bass bin at the front of a Killing Joke concert where my ears were about to burst at the back. (I used to do PA work).

BTW; I like the total guttedness of that setup. Only problem is the hot glue, I know in Oz, the sun and a warm day would see the components all dribble off the board by the time u got back from buying ur girl an ice cream...

that is funny - you can't hurt those ears!

That is a really good tip, the car is black and can get pretty hot in the sun, although maybe not Oz hot. I think I'll eventually put my sub amp in that space actually, so I will need to redo that board anyway to move it somewhere else and also to add some more crossovers (I'm going to run another passive setup at 125hz for the sub now that I know how) so I will take that into account about the glue when I do that, maybe I'll build a box after all like bmwdriver says. Good to know it works though.

***-

I reckon the rear is not going thru a crossover - and that's proly what saved the fronts.

hey... you know... do you think this could maybe relate to the common speaker grounds and how the factory amp and head do the fading? Do you use the factory grounds or separate ones? Before I did this I had the speaker outs of the jvc wired into the factory amp using the factory grounds. The fading seemed disproportionate, with too much power going to the rear before. And the rear woofer also blew on me. Now with all 4 grounds running seperately it actually seems a little soft in the back (will soon change ), although I had a passenger ask me to move the music to the front yesterday... didn't like John Coltrane wtf? Anyone else blown a rear speaker with their aftermarket head?

[BMWDriver]

I fixed both of my rear speakers with glue. The big black rubber rim was partly loose, making bad bass quirks, so I made it entirely loose and glued the thing. Problem solved, no issues.

[BMWDriver]

Well... just opened my amp, and I've certainly got a bird of a different kind in there. There's still coils and capacitors, but I have no clue how to bypass that one. Looks like a custom PCB will be simpler for me. We shall see. First I'll have to figure out many things like the cirucuit's design.

Unless anyone here has pointers to bypass that particular amp to the crossover.

I'm charging up my camera's battery, so pics up later.

[genphreak]

I simply ran low level Canare shielded 3mm dual core and terminated the ends using RCAs. That way it was easy to go down the console, under the rear carpet and rear seat to the amp. I stuck the amp under my parcel shelf as it was too long to go in the quarter panel. Also, better for heat and tweaking the amp's tone controls. All dodgy amps need accessible tone controls

Speaker outputs goto the crossover and avoid that silly fader up front. It will only add distortion and noise into your system, so is best bypassed anyhow. It occupies a good place for a more interesting gadget anyhow.

I just use the fader on my (replaced) head unit. Couldn't bear the factory one... tho alright for its time and easy to use when driving. Dumb ass Asian units are just so horrible to use. Oh the price we pay to break out to an mp3, phone or iPod

Tip: If you have an antenna integrated in the rear window, the latest JVC head units seem to work quite well. Many others I've used seem to dislike that antenna... search about it (keyword: reception) and you'll SWIM...

[genphreak]

You'll need an older style amp- e34 535 ones are probaly ok (at least to '90 but maybe even to '93?)... the later ones like yours are no good for this as far as anyone has worked out (to date).

I think someone has retrofitted the old amp and done 'a gut-job' to get the ultimate setup in a later model e34, not sure who though. You should check the pin-outs are compatible- I think they are different, if so the positions might need to be changed around... BMW's privte catchcry must have once been; "Always making it different, ya! Because we can" LOL