Tuesday, August 25, 2009

E39 Front Woofer Replacement

Friday I was really Jone's-ing for a project, but it was late and I was poor. So I decided to finally tackle the front speakers. I wanted to find out if it was feasible to add 6.5" drivers up front. Why 6.5" drivers you say? Well, because they sound better than 5.25" and furthermore, they were the Infinity coaxial set that I had on my Chevy- so I was driven to make this pair fit.

I took the first step and pulled the door apart per the bmw tips.com instructions- easy enough. With the new, larger driver in hand I sized of the clearance and saw that there was not much to be had. BMW designed these panels very tight. I was going to get rid of the stock enclosure completely to make more room, but then I would lose the resonance of the sealed enclosure and have lots of issues with mounting the new drivers. So I removed the weak ol' 5" woofers and tried to make the 6.5" drivers fit.

Well, no surprise, as seen in the size difference, it wasn't just going to 'slip in.' I was going to grind down the high spots (of which there are many) of the enclosure with a Dremel so the new driver could seat flush. That would have been fine, but then there would be gaping holes to fill for proper sealed resonance, so I tried to think laterally.

I have used heat guns before and it so happened that I have access to a couple at the university, so I swung by there @ about 12:30 am Saturday morning and tried not to set off any alarms. The heat gun did the job. It took about an hour per enclosure, but I slowly MELTED and reformed the plastic, trying to make it as flush as possible. This was no simple task. I was tempted to put it in the oven to make the whole thing more ductile, but I didn't want to pull out a soft, sagging mass of ruined plastic. This wasn't pretty, but it made room for the bigger basket.

The Infinity sits pretty flush, so I'm happy. But there are still lots of air gaps, so I used lots of weather stripping to seal it off. Luckily, I was able to use the factory wiring w/o a hitch.

All bolted in and ready for action.

I was pretty worried after all this work that the driver was not going to allow the door panel to go back on properly. Since everything was larger and the unit protruded more than the old woofer, I thought I was going to have to modify the door panel also. Luckily though, everything went back together as before (I consider that a freebie :). I think the fact that the tweeter pokes out so much was actually a blessing in that is probably pushes the grill away so the woofer cone and rubber surround isn't slapping the grill during hard hits. As you can see it fits and I can tell you things aren't slapping together while driving :).

Now you KNOW I couldn't add these sweet drivers and just power them with that nasty old factory amp, right? NO WAY! I just spliced in the remaining 2 channels on my 4-channel 1000w (claimed) Profile California 1040 amp.

This system SCREAMS! I enjoyed it in my Chevy, but it just sounds so much better in the 540. I still have the factory amp, mids, and tweets going in tandem with the new system- making 16 working speakers. In reality, I don't know how much good the factory system is doing. I am still going to play around with it and see I can't balance the 2 systems and get some quality out of it, but I am skeptical given the low performance of the factory amp. This was a fun install and it was rewarding to see it work.

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