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Does anyone have recommendations for tweeters which fit/can be made to fit the rear tweeter mounts in the 10 speaker system used on my MY91 S4?
I have excellent MB Quart component speakers to use in the 6.5" positions mounted to the original rings and driven by a separate Alpine amp, but I've discovered (12 years after buying car) that the original tweeters were disconnected part way through an install that was never finished!
The original tweeters were designed to be driven by the long-0since removed factory amp, so I don't know if they'll be man enough for the separate Alpine I recently installed. The Crutchfield site says that there are no suitable replacement tweeters for that position!
Photo shows the original rear tweeter removed from its mount. Note I didn't break the mount, it was like that after I removed the grille! The original tweeter diameter is 2 1/4" so anything same diameter will snap into the old mount.
Last edited by StratfordShark; 09-20-2021 at 09:12 AM.
When I replaced all 10 of my component speakers for my 1989 S4 back in 2019, I sourced all my parts from Crutchfield. In particular, I used the 1" silk dome tweeters from the Kicker 44KSS6704 Component Speaker system (https://www.crutchfield.com/p_206KSS...44KSS6704.html) to replace the OEM rear tweeters. My installer told me that they fit like a glove inside of the OEM speaker mounting ring. However, the trick might be driving the rear tweeters.
As you may be aware, Porsche used a connection point on the rear woofers to connect to the rear speakers. This is one of the ways that they were able to drive 10 speakers on a 4 channel amp. Since you're using the aftermarket MB Quarts, you don't have that jump-off point from the rear woofers to the rear mid-range or tweeter speakers. However, you're installer should be able to figure this out--e.g., connect to the woofers with the appropriate frequency cross-over.
Last edited by Instigator56; 09-20-2021 at 01:33 PM.
You will need a DSP to massively time align anything you put back there, and also fix lobe tilting from the cross over output...way back there. Just feeding everything 'at the same time'.
You will have a 2-3ms sound stage delivered in front just right to left, the rear seat sound will be 3-4ms late to you from the back seat drivers, and another 8-9ms delayed from the third set of "same signal time" speakers in the rear quarters.
It's audio mud. And just the beginning of the story on phase alignment for staging.
Anything that pulls the sound state from in FRONT of you, to behind you, is bad, bad, bad, and also really bad.
I mean, 9 milliseconds doesn't sound like a lot (pun intended), but to time align driver position in a car, the difference of 2ms hits you like a hammer, it's very discernible in "where" the sound is coming from.
I will also argue that "full" R/L output in just the rear speakers is far too much, and using a DSP and providing the R/L differences in the stereo signal are all that is important in the rear of the car, and adding in drivers 5 & 6 back there are worse than useless in either configuration...full rear stereo or DSP delivered differences.
You will need a DSP to massively time align anything you put back there, and also fix lobe tilting from the cross over output...way back there. Just feeding everything 'at the same time'.
You will have a 2-3ms sound stage delivered in front just right to left, the rear seat sound will be 3-4ms late to you from the back seat drivers, and another 8-9ms delayed from the third set of "same signal time" speakers in the rear quarters.
It's audio mud. And just the beginning of the story on phase alignment for staging.
Anything that pulls the sound state from in FRONT of you, to behind you, is bad, bad, bad, and also really bad.
I mean, 9 milliseconds doesn't sound like a lot (pun intended), but to time align driver position in a car, the difference of 2ms hits you like a hammer, it's very discernible in "where" the sound is coming from.
I will also argue that "full" R/L output in just the rear speakers is far too much, and using a DSP and providing the R/L differences in the stereo signal are all that is important in the rear of the car, and adding in drivers 5 & 6 back there are worse than useless in either configuration...full rear stereo or DSP delivered differences.
It's not 1980 anymore.
Thank you - you obviously know your stuff!
Was just concerned about feeding all the rear signal to the 6.5” drivers which won’t be happy with high frequencies, but sounds like I shouldn’t bother with rear? It’s just that PO had a rear amp (which I replaced recently when I couldn’t fix a fault on it cutting out) put under hatch cover feeding those 6.5” (nice MB Quarts), so would be shame not to use them at all.
Last edited by StratfordShark; 09-20-2021 at 04:10 PM.
When I replaced all 10 of my component speakers for my 1989 S4 back in 2019, I sourced all my parts from Crutchfield. In particular, I used the 1" silk dome tweeters from the Kicker 44KSS6704 Component Speaker system (https://www.crutchfield.com/p_206KSS...44KSS6704.html) to replace the OEM rear tweeters. My installer told me that they fit like a glove inside of the OEM speaker mounting ring. However, the trick might be driving the rear tweeters.
As you may be aware, Porsche used a connection point on the rear woofers to connect to the rear speakers. This is one of the ways that they were able to drive 10 speakers on a 4 channel amp. Since you're using the aftermarket MB Quarts, you don't have that jump-off point from the rear woofers to the rear mid-range or tweeter speakers. However, you're installer should be able to figure this out--e.g., connect to the woofers with the appropriate frequency cross-over.
Yes I was planning to connect to woofers via crossover, maybe in line with the leads to avoid mounting a crossover.
Was just concerned about feeding all the rear signal to the 6.5” drivers which won’t be happy with high frequencies, but sounds like I shouldn’t bother with rear? It’s just that PO had a rear amp (which I replaced recently when I couldn’t fix a fault on it cutting out) put under hatch cover feeding those 6.5” (nice MB Quarts), so would be shame not to use them at all.
Use a coaxial in the rear, and the problem's solved.
Idea..get a tweeter from MB that might be paired with that driver elsewhere, epoxy a bridge over the woofer cone for the tweeter that fits in the stock cover.
Drive it with a low pass feed from the amp, or a capacitor.
Check and see if your alpine amp is capable of running a bandpass crossover for the rear woofers.
Then you can actively run them without a separate crossover network of some sort. Those typically use up 20% of the power sent through them along with taking up space.
Use a coaxial in the rear, and the problem's solved.
Idea..get a tweeter from MB that might be paired with that driver elsewhere, epoxy a bridge over the woofer cone for the tweeter that fits in the stock cover.
Drive it with a low pass feed from the amp, or a capacitor.
Despite having the MBs, I’ve spent ages looking for decent co-axials which will a) fit the original 6.5” mount ring and b) has a tweeter that will fit under original cover. It’s ridiculously hard!
Despite having the MBs, I’ve spent ages looking for decent co-axials which will a) fit the original 6.5” mount ring and b) has a tweeter that will fit under original cover. It’s ridiculously hard!
Yup, remember the bridge you make, can lay the tweeters _deep_ in the cone, not way OVER it like most do.
You will need a DSP to massively time align anything you put back there, and also fix lobe tilting from the cross over output...way back there. Just feeding everything 'at the same time'.
You will have a 2-3ms sound stage delivered in front just right to left, the rear seat sound will be 3-4ms late to you from the back seat drivers, and another 8-9ms delayed from the third set of "same signal time" speakers in the rear quarters.
It's audio mud. And just the beginning of the story on phase alignment for staging.
Anything that pulls the sound state from in FRONT of you, to behind you, is bad, bad, bad, and also really bad.
I mean, 9 milliseconds doesn't sound like a lot (pun intended), but to time align driver position in a car, the difference of 2ms hits you like a hammer, it's very discernible in "where" the sound is coming from.
I will also argue that "full" R/L output in just the rear speakers is far too much, and using a DSP and providing the R/L differences in the stereo signal are all that is important in the rear of the car, and adding in drivers 5 & 6 back there are worse than useless in either configuration...full rear stereo or DSP delivered differences.
It's not 1980 anymore.
Uh - do you have all the O-scope waveform timings for this? I would really like to see your delays, and timing signals. I'm sure you are aware that the speed of electrical pulses from the head/amp to the speaker is running at nearly .8 speed of light, and the signals from the speaker to the ear are running at a microscopic fraction of that, basically the speed of sound(~1125Ft/Sec). Where is 9mS of delay coming from?
Uh - do you have all the O-scope waveform timings for this? I would really like to see your delays, and timing signals. I'm sure you are aware that the speed of electrical pulses from the head/amp to the speaker is running at nearly .8 speed of light, and the signals from the speaker to the ear are running at a microscopic fraction of that, basically the speed of sound(~1125Ft/Sec). Where is 9mS of delay coming from?
I use REW and work from where I want things to be aligned, right to left from that point, and then backwards from there. From there you can work with phasing to influence the depth of the soundstage. But there is no way to align it farther forward in time..than where the front speakers sit. Not correcting on the way back in the chassis, will only move it backwards.
Not concerned with DSP processing time, just the time from ONE point where sound is made, to all others. Sound moves roughly 1 foot per millisecond, and with the wedge in the rear, the speaker wont be firing directly, and adds some distance.
Hi Stratfordshark,
There were some rear tweeters for sale on Ebay - not sure if they are still available check out Schonerwolf's shop.
I have been going down the same rabbit hole with my 1991 S4 - trying to get the OEM system back up and running - I have everything except the rear 6.5 OEM speakers with the crossover mounted on the back - still trolling the Net for any recently discovered items!!
I have the 6 channel amp and Blaupunkt Symphony HU - all ready tio install.
The front angled tweeters are also hard to find in one piece - mine are chipped like your one - I can glue them back together with metal backing plates to get them repaired sufficiently to use - same for the grilles.
Speedtoys, question: did the old OEM system work with the 6 channel amp and the 2 OHM rears? Am I wasting my time in the quest for originality?
09-20-2021, 09:10 AM
Replacement rear tweeters?
