Justin_Toronto

Hi, I have a 2002 330i with the Premium HK sound. I don't want to do any type of complete stereo overall, especially since I'll probably be selling the car in a few years and would rather keep it as stock as posible still. (only 56k on the car still.)

I've been told that all I'll need is a box, sub, amp, and line converter. Now I have no previous knowledge on using a line converter. How do I use one, and hook it up to an aftermarket amp?

I assume for the amp I'll tap 12+ into the battery, GND I'll ground to the chassis, and Remote I'll tap into the remote wire going to the stock HK amp from the factory head unit.

The line converters I've seen also have a 12+, GND, and Remote too... ? ... Note that the factory HK sound does have some crappy 6x9 subs mounted under the rear deck too.

Thanks,
Justin

MR2NR

iTrader: (66)

A good interface adaptor is going to make or break what happens down the line. Use a quality interface adaptor is the best advice I will give. If you ever sell the car and don't need it anymore, with the new vehicles on the road today it is a easy device to resell and have it hold it's value.

Justin_Toronto

I still need an interface adapter even though I'll be keeping my stock headunit / stock components / component amp?

MR2NR

iTrader: (66)

It is not a MUST have, it is a SHOULD have. If you want a basic unpowered LOC, expect the basic results. If you go to a better powered LOC, expect better results. If you go to a interface adaptor, expect the best results. It is all about where you want to be for the results you seek.

godzilla1978

There may be issues with this system. The reason is the speakers are individually amplified. Normally the basic converters can't handle all the power and it ends up sounding like poo.The problem with idividually amped speakers is that there is generally no accesable spot or not enough room to hook up speaker wires for the high level adapter. The low level going in is insufficient as well(not a normal low level in) with that system what you get is pretty much what your stuck with. The last one I did was that way anyways.(2003 bmw mini with PREMIUM Hk system)

Justin_Toronto

Individually amped speakers?... meaning a separate amp for each speaker? My HK system has a single amp for all the speakers. (this one here: http://www.realoem.com/bmw/showparts.do?model=EV53&mospid=47725&btnr=65_0476& hg=65&fg=25).

I also have two 6x9 subs in the rear shelf... can I use these inputs somehow? I think this is how they do with it the JL Audio Stealthbox, no?

BigRedGuy

iTrader: (11)

Right off the bat I'll admit I have not worked on one of these systems....

Having said that, in general, while a good interface adapter will clean up any factory EQ issues, if you are not planning on bypassing the factory amp and installing a full system, it might be over-kill for your needs. If it's possible to tap into an RCA level signal that would be ideal. Since the car already has a real sub signal it's feeding to those 6X9s, it would be simpler to use it to feed any add-ons.

While I am generally loath to amplify amplified signals, most 2 channel amps come with speaker level inputs and you could use them to feed a new amp.

If you are going to put a new sub box in the trunk, I would yank the factory ones out and install the new toys as you mentioned earlier. The openings will provide access for the bass from the trunk into the passenger cabin and with a little tweaking you should be good to go......

Don't forget you will need a fuse on that +12V line within 18" of the battery....

My $0.02 worth....feel free to correct me if need be.....

Justin_Toronto

Thank you, that's more along the lines of what I was thinking too... I'm no expert though. I also don't like to amplify pre-amplified signals. I think I should also mention that the BMW factory system does have 'advanced' settings in an easter egg menu. (hold down the M button for 10 seconds after powering the radio on, then hitting the treble/bass/fade/balance rotation button for 6 seconds and you can tweak the advanced settings.) One of which is the volume gain for the stock subs.... I think if I turn it down as much as possible and allow the aftermarket amp to do the work, it'll help a lot.

I was planning on removing the stock 6x9's to allow the bass from the trunk to filter into the cabin. (Note there's also a ski-bag pass through that is only fabric, so with the rear arm-rest down it'll also allow some bass to pass through). On my other BMW which I redid the entire system on, I removed the ski bag entirely to port the bass into the cabin, works well.

Would I still need a line output converter though?

BigRedGuy

iTrader: (11)

Not if you can find a line level signal for the sub output.......if you have to use the speaker leads you are better off with an amp with speaker level inputs, it saves another round of signal modification.....

godzilla1978

IT's good the one you have has one amp! That makes it much easier. As for using the rears for input you may have problems if they're low pass only. sometimes the 6x9's don't have a full pass signal and it tends to give the high level in's fits.