MacFever

Hi all,
I was able to buy some used Burmester tweeters to replace the crappy Bose dash tweeters
I have read all the threads here about upgrading but one thing still is not clear : can I swap the Burmester for the Bose or do I need to solder a resistance onto the Burmesters before connecting them ?
Thanks a lot for your help

Stealth 993

"resistance" I think you are taking about a "cap" to filter out the lower bass to the tweeters. Not you do not have to do that. You will need to clip the plastic tabs on the connector to get them to plug into the new tweeters.

Also you NEED the Burmester tweeter grills.
R 991 552 576 01 5q0
L 991 552 575 01 5Q0

The last digits are the color codes, these are for the black ones.

MacFever

Yes I meant the cap, some solder a 4.7or 6.7µF bipolar cap to the tweeter
http://www.carstereo.com/help/Articles.cfm?id=1
If not necessary this would mean that the Bose amp separates the frequencies that are going to the separate speakers, is the Bose amp doing that ?(I know the Burmester does)
Are the Bose and the Burmester the same resistance ?
I have read that the Bose is 4 and the Burm 6 Ohm

Stealth 993

I'm not sure if it's separate or not. I did this to my 991 8, months ago, and did not use any caps. It has been fine.
No, they are not the same resistance, but I would not worry about that. You will need to turn down the treble with the new tweeters, they are so much louder!
Also disconnect the center speaker, it will really help.

On my car, after doing the tweeters, the rest of the car sounded even worse! So I upgraded all my speakers to Burmester, and did some sound deading in the doors and in back. It's so much nicer now!

MacFever

I already disconnected the center speaker and sound is already better now ;-)
So you changed all the speakers to Burm and kept the Bose amp ?
Since I have a GT3 I think I dont have the sub but I have the rear medium speakers
Can I just swap out the 4 speakers in the doors and replace with Burm ?
No caps ?

Stealth 993

Same, GT3, but I have the crap lower end stereo.
Yes, just swapped out all the speakers. only had to do some plastic clipping on the connectors to get them to fit.

MacFever

After a lot of reading I think I finally get it : the Burmester tweeter needs a crossover around 4000 Hz (vs 8500 Hz for the Bose)
So to get a 4000 Hz highpass filter I will need to solder a 6.67 UF cap to the positive of the Burmester tweeters (Burmester are 6 Ohm vs 4 Ohm Bose)

asellus

This is assuming the tweeter is currently getting full spectrum..

MacFever

12V Nick of musicar tested that and indeed the Bose tweeter is getting full spectrum
This is why there is a 4.7uF cap on the Bose tweeter
On the Burmester there is none because the Burmester amp does the filtering where the Bose does not

asellus

Ah, perfect. Just wanted to make sure you weren't doing it all for naught.