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This is a popular upgrade in the rest of Porsche-land but I have yet to see it done on the 955/957 platform (or at least no one has posted about it). The rear Burmester dome tweeters from the 958 are the exact same size and form factor as our factory dash Bose tweeters. I ordered a pair last year and finally got around to swapping them into the dash locations. It wasn't quite plug-n-play, but it wasn't difficult either and the end result is well worth it. The Burmester tweeter is much more natural sounding and smooth compared to the Bose tweeter, which sounds hollow, nasal and lower fidelity in comparison. They have the same impedance rating and the same high-pass cap values (more on that below).
I also looked into changing the center speaker out to the 958 Burmester center, but the 955 center speaker is 2.5" while the 958 center speaker is 3". There is no way to make the Burmester center fit without cutting into the plastic reinforcement in front of the speaker (below the grill). That being said, I did some experimenting with the Bose center speaker, the Burm center speaker, and no center speaker. The Bose was seriously bad. The Burmester was night and day better, however, the best sound was with no center channel at all. I'm guessing the center channel signal is an attenuated summation of the left and right stereo channels. While it provides a bit of fill, disconnecting it opened up the soundstage considerably and really let the smoothness of the Burmester tweeters shine through.
Burmester on the left and Bose on the right. The Burmester is noticeably heavier than the Bose, and built in Italy.
The backsides. Again, Burmester on the left and Bose on the right. Both have high-pass caps of equal specs, however the Burmester uses a Nichicon ES MUSE cap, which is pretty well regarded and of higher quality than the cap used in the Bose tweeter. Now, in every other install I've come across, there have been no caps included with the Burmester tweeters. Some people have run without (not at all recommended) and some have transferred the Bose cap to the Burmester tweeter. I would recommend the same caps that came with mine, which can be found here:
I'm not sure why mine came with caps when no one else's did, unless they were added by Rennspec before shipping.
So here's where it gets into "not exactly plug-n-play" territory. The factory connectors of the 955 don't quite match the connectors on the Burmester tweeters. The first thing is that the little notch on the side of the wiring plug is in the wrong place. Super common when doing something like this and easy enough to fix by simply cutting the notch off with a utility knife. The other difference is that the plug fits into the Burmester upside down from how it fits into the Bose due to where the pins are located on the vertical axis of the plug. So that means that your positive and negative wires would be reversed. So I just cut off the factory plug, flipped it, and connected it back to the opposite wires (red to brown and brown to red). That way when it plugged into the Burmester tweeter the signal and ground wiring would be correct with regards to the 955 wiring.
The factory 955 wiring to the Bose tweeter. As you can see, the red (positive) wire needs to attach to the side that has the capacitor.
The Burmester tweeter. As you can see, the factory plug fits into it the opposite way, where the brown (negative) wire is on the side where the capacitor is (positive). Cutting and flipping the wiring of the plug relative to the wiring of the car fixes the problem. I just used standard crimp connectors and then wrapped the splice in cloth tape.
The new Burmester tweeter. Looks like it came from the factory.
Given the big sound difference between the Bose and Burmester center speakers, not to mention how much better the Burmesters are constructed, my next step (one of these days) will be to change out the Bose midranges and midbass drivers in the front doors. The 3" Burmester center speaker looks like it will drop into the factory midrange mounting bracket (the Bose mids are also 3") and the Burmester door midbass units are the same size as the Bose speakers and also have a shallow form factor. The rear doors have the same tweeters as the front dash and a 6.5" midbass which is the same size as the Burmester driver, so I'll probably do the rear doors as well. The Burmester speakers all match the impedance of the Bose drivers. I doubt I'll bother with the rear mids in the D-pillar. They are the same 2.5" drivers as the center speaker so there's no real direct Burmester replacement for them, and the odds that you'd ever hear them from the driver's seat is probably exactly zero. Maybe I'll source some nicer 2.5" mids from Parts Express or something just so I have no more Bose speakers at all (except for the sub, but I may have an idea for that too).
Now, is this going to rival a dedicated Focal or Dynaudio system? Not a chance. However, it is going to be a very nice upgrade for not a lot of money and should be mostly drop-in. I'm also intrigued by just seeing if it will work the way I think it will.
So, if you aren't put off by some wire splicing, I would highly recommend the tweeter upgrade.
This has me very interested.
I wonder if I can find my old MB Quart tweeters that came with a component system I bought in the early 90s before the company changed hands. I think they might fit.
My thoughts are tweeters are the easiest to upgrade, since the way they fit isn't so important as far as any enclosure or related T/S parameters.
Then as long as the crossover frequency is maintained with that fancy cap you shared the only other thing to worry about is matching the level, which could be tweaked with my new Android radio's parametric EQ.
I'm also interested in the notion of deleting the center speaker. Or maybe adding a series pot to be able to dial it down as needed.
Of course the drop-in Burmesters are ideal... I could see myself splurging, but I usually don't pay full retail for things unless I have to.
Thanks for sharing.
This has me very interested.
I wonder if I can find my old MB Quart tweeters that came with a component system I bought in the early 90s before the company changed hands. I think they might fit.
My thoughts are tweeters are the easiest to upgrade, since the way they fit isn't so important as far as any enclosure or related T/S parameters.
Then as long as the crossover frequency is maintained with that fancy cap you shared the only other thing to worry about is matching the level, which could be tweaked with my new Android radio's parametric EQ.
I'm also interested in the notion of deleting the center speaker. Or maybe adding a series pot to be able to dial it down as needed.
Of course the drop-in Burmesters are ideal... I could see myself splurging, but I usually don't pay full retail for things unless I have to.
Thanks for sharing.
Levels can (and should) also be matched by keeping the same impedance rating as the Bose, which are 2-ohm (as are the Burmesters). The MB Quarts are probably 4 ohm, although if part of a component set with a passive crossover they may be different. A higher impedance rating translates to a lower volume output, although I'm not sure how much of a real-world difference that would make, especially with only a 2 ohm nominal impedance spread.
I hear you regarding paying retail prices for things. That's why I suggested Delaware Porsche Parts as they sell for below MSRP. The tweeters for instance have a 22% discount.
I bit the bullet and ordered the other speakers last night. I'm not sure when I'll have time to do the install given my current schedule and other obligations/projects, but hopefully not a year later like the tweeters.
Good point about the impedance.
I found my stash. I saved some stuff out of my old cars over the years... I also found a complete box (5.25 midranges, tweeters and x-overs) that I never installed. But those were much newer MB Quarts and less expensive... But they still say "hand made in Germany" for what that's worth.
Anyway, darn it, I only found one of the tweeters from the first set I bought in 92. They were pretty pricey back then... I did some googling and they were the "Q-series."
Well the newer ones have a nice sticker on the back of the tweeters and say 6 ohms. The older ones are stamped with illegible print.
Not that anyone cares, but the 6 ohm ones measure 7 (which I know is DC resistance, but can provide a clue) and the older ones measure 5. I'll keep looking for it's brother.
These are titanium dome tweeters which I remember some saying could be harsh. The included crossovers offered a choice of two outputs for your preference.
So I'm not so worried about them sounding muted but who knows... 2 ohms is super-low.
Thanks for re-sparking my interest in car audio. I got into home audio during the pandemic and amassed a nice collection of vintage speakers. Reminded me that newer isn't always better.
Especially when it comes to car audio. There probably will never be another era like the late 80s and 90s when it comes to sheer quality of the components. The market just isn't there anymore now that factory systems have gotten better and more integrated. I used to be really into car audio and put together a system in my first car in the late 90s with Focal speakers, an Xtant amp, a/d/s/ sub, and a Denon CD deck. Still one of the best sounding systems I have ever heard.
I actually prefer metal dome tweeters to soft domes as I love the detail they convey. I run Focals in my home systems for this very reason. Good titanium domes will be detailed but not overly harsh. Those Q-series tweeters should fall into that category. The Burmester tweeters are very musical, natural, and smooth but I do miss the "sparkle" of a good metal dome. It's a very good sound, just different than what I usually go for. But I knew that going in since they are soft domes.
If you cannot find your matching MB Quart tweeter and are interested in a metal dome alternative to the Burmester, the 958 guys found that Ferrari JBL tweeters are also a drop-in replacement for the Bose tweeters. This thread is what sparked my interest in doing the upgrade:
If the older tweeters measure 5 ohms on the multimeter they are probably 4-ohm nominal impedance. Yeah, 2 ohms is very low. The door midbass units are rated at 1 ohms nominal! Low impedance drivers are pretty standard fare for Bose systems. It lets them get away with lower output amplifier chips since the speakers have a higher resistance.
Sure, here are the part numbers and quantities to order:
- Front dash and rear door tweeter (4 total): 7PP-035-412-A
- Front door midrange (2 needed): 7PP-035-828-E
- Front door midbass (2 needed): 7PP-035-454-H
- Rear door midbass (2 needed): 7PP-035-453-B
I think I'm going to try another tweeter in the center channel location and see how that sounds. The center speaker appears to get a full range signal, and then the fronts will be timbre-matched. I may wire in an L-pad as suggested by thesteve and play around with the attenuation.
I don't know much about the sub except that it's a 5.25" driver and I believe it's 2 ohms. Not sure if it's a dual voicecoil driver or not. A lot of Bose systems use a dual voicecoil 4-ohm sub wired in parallel to provide 2 ohms of nominal impedance to the amp. I'll pull it out one day soon and check. The right way would be to have a shop fab up a custom enclosure that fits in the spare tire well for a new, larger, better sub and also replace the amp. The sub has a separate amp that is fed with speaker-level inputs from the main Bose amp, so it's not part of the fiber optic MOST bus and is easily replaceable. I would probably go with this AudioControl amp as a replacement: https://www.ebay.com/itm/353378951818. Before going the custom enclosure route, I'm going to try changing out the 5.25" woofer with this JL Audio unit: https://www.ebay.com/itm/165692742603. It's the same form factor as the Bose woofer and looks like it will drop right in. See here for a pic of the Bose enclosure and woofer: https://www.ebay.com/itm/265720110312. I'll run the AudioControl amp with the JL as well to give it the best chance at sounding good.
For the rear D-pillar mids I'm considering these Dayton Audio mids. The cone composition looks similar to the Burmester speakers and they are dirt cheap. Just will need a little MacGuyvering to fit them to the stock mounting assembly. https://www.parts-express.com/Dayton...Driver-295-150
Especially when it comes to car audio. There probably will never be another era like the late 80s and 90s when it comes to sheer quality of the components.
My first job while still in High School was at a pro car audio retailer / installation shop. I commuted on my bicycle toting a plastic fishing tackle box with my tools.
Before eventually hiring me to work there as an installer, the manager suggested the items I put in my first car, a 1978 Olds 98. .
A/d/s/ PH15.2 6 channel 300W amp ($600! that one I remember... still have it)
I put it all on my brandy new Amex card, and it was the first major purchase of my young life (besides the car that I paid $1100 cash for).
The years that followed with me as the designated drunk driver were memorable to say the least.
A lot of the friends I hung out with and drove around back then (a majority of them being rock musicians of course) remarked it was the best sound system they had ever heard.
Good times.
My first job while still in High School was at a pro car audio retailer / installation shop. I commuted on my bicycle toting a plastic fishing tackle box with my tools.
Before eventually hiring me to work there as an installer, the manager suggested the items I put in my first car, a 1978 Olds 98. .
Kenwood KDC-9000 head unit
...
Good times.
I too had a KDC-9000 in that era. Helluva deck. No idea what happened to mine.
Yup. Passive out only, with a remote and detachable face-plate.
I remember -20dB was the loudest I felt safely indulging for any period of time for fear of permanent hearing loss.
The new Burmester speakers showed up today. I checked the tweeters and they do not have the caps installed, so that must be something that Rennspec did before shipping them. I just ordered the caps from Amazon and I ordered the Dayton Audio mids referenced above for the D-pillars. Hopefully I'll have a chance to get all of this installed before the end of the month.
Ok, I'm game.
Found a pair used for $20 ea. and just bought them on eBay.
I was thinking... the impedance would influence the crossover frequency too... so that along with dropping them in and it's a no-brainer. They better be the best tweeters I've ever heard!!
j/k
Thanks for sharing. Just gotta order up those caps.
The speakers in your post look different than the Burmesters that I bought. Specifically the plastic “cage” is different. Four spokes vs six. Yours also include a cap and look smaller in diameter. Do you have the link to the eBay ad?
09-28-2022, 02:15 AM
Burmester Tweeter Upgrade
