I'm revisiting the ICE on my 80s BM as I don't think anyone has done anything to the system since 1985!! I know its not VAG but no-one on the classic BMW sites really does ICE, they're more interested in dropping turbos in and such like so far I've replaced the stock speakers (one-way paper cone 6x4s) and fader system and wired 4 new 6x4s direct to a new head Sony HU. 6x4s are the only option on this car as the speaker mounts are so small and are also very shallow. It took some effort to get two-way 6x4s in to be fair. this gives a much improved result and I have improved it still further with a pair of dash mounted tweeters (with a cross-over built in) wired in parallel with the front speakers. I think this is ok as the cross-over means that the HU doesn't see 2 Ohm impedance but something closer to 4 Ohms?? The tweeters are cheapo maplin efforts bought as an experiment. I may upgrade these dependent on cost... I also renewed all of the speaker cable. Now I think I need more bass, I'm not looking to blow out my windows, I just need a bit more presence. The current set-up is missing something at the bottom end, I actually thought for a time that I must have a speaker out of phase (I have checked twice) but I now am sure its just the 6x4s not being up to the job due to their small size. I was thinking of something easy, like a bass tube with built in amp. My HU has 2v pre-amp outs so I can wire these to a bass tube in the boot. Is this a good option? Some other 635 drivers have put ported 9x6s under the rear seats but I would rather avoid this as that would involve slicing up the trim. Maybe a single twin voice coil sub and dedicated 2 channel amp? Any opinions and suggestions welcome
is your car quiet? if so, a simple 10 inch sub would be perfect IMO, you have too many speakers in there already, more 6x9s would be pap tbh add a sub and keep it simple
ta Matt, 4 6x4s and 2 tweeters too much? OK but its only really the two front 2-ways and the two front tweeters that you hear. hmm, something to think about. the system is not quiet, it'll go much louder than my ears can cope with, but lacks it bottom end as the 6x4s are not really big enough to deliver that bottom end. What variety of 10" sub would you recomend? dual voice coil or just a mono sub. Plus if I put it in the boot how powerful will it need to be? I've been looking at sub tubes on ebay as they're cheap and come with a built in amp. Are they cheap because they're crap? or is this a good way forward?
I'm really not an expert on this but my 6x4s didn't start working properly for the low-end frequencies until I amped them. Might be worth getting a seperate 4 channel bridgable amp that could drive the 6x4s and the 10" sub and then buy the sub later.
to be dead honest, small coned speakers like a 6x4 is never going to produce meaningful amounts of bass. you are best off letting them get on with producing non-bass frequencies as theyll do that better. the reason id say what you have is too much is that the 6x4s are 2 ways and then youve added another set of tweeters. i take it the additional tweeters are on top of the dashboard and the 6x4s in the doors? just seems there'll be too much trebble going on with trebble coming from two difference sources on each side.... too complicated! the ideal system is litterally just a set of nice components up front and a sub in the boot. sub wise, it depends on how loud your car is. if your car is very quiet, you can get away with a 10" sub. if its particularly loud, youll need a 12 as for what to get, it depends on your budget. id expect to pay 80-100 for a nice sub. when choosing an amp, aim to have about 15% more power than you really need for 'headroom' as for dual/single coil. much of a muchness, biggest effect is the flexibility on impedence (how many ohms the sub will present to the amp). dual 4 is good because you can wire it to 2ohms, most bass amps will make moer power at 2ohm
