B&W Tweeter Repair

[AudioHTIT]

I wrote this looking for help on another board, but persisted and fixed it while I was waiting for someone to respond. I thought I’d post here if anyone else needed to do something similar. 
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Long time B&W owner, first time in this thread. I have a B&W HTM3S that I believe has a bad tweeter, connecting to either bi-wire connection with pink noise yields no tweeter sound (could also be the crossover). I have found that B&W sells a replacement tweeter for $135 or so, but I also have an HTM4S which I’m not using and found it uses the same tweeter. I’ve gotten as far as removing the tweeter grill and three small screws holding the tweeter in place, but it doesn’t budge.

Has anyone seen a service procedure for replacing the physical tweeter (not the entire assembly), on a speaker in this series (HTM3S, HTM4S, 805S, etc)? I have found the page below which implies I need to take the mid-range driver apart, remove it with a special tool, and then remove the entire assembly from inside; but I remain optimistic that the tweeter itself can be replaced (feel free to burst my bubble if required).

B&W 800D_Series_FST_Midrange_Replacement.pdf

B&W Parts Store

Here’s my current state:



1st Edit: I got brave and used a screwdriver to pry the tweeter free (see second photo), now something is holding it from behind, though I have unscrewed the wave guide in the back.



2nd Edit: I got braver and with more light saw that with needle nose pliers I could disconnect the tweeter leads and remove the unit, troubleshooting continues.



3rd Edit: First eliminated crossover problems with voltmeter on tweeter leads, pink noise produces a voltage. Then found no continuity on tweeter. Then into uncharted territory, it appears the tweeter coil / dome assembly is held in place magnetically, I carefully removed it from the magnet assembly and tested further, the leads are good, but the coil itself fails continuity. I believe what you see in the 4th picture is the part that needs to be replaced, what they refer to as ‘the tweeter’ ($145 part # ZZ14359) though it doesn’t include the magnet and housing.



4th Edit: Fixed! Took the tweeter out of my HTM4S and replaced this one. The hardest part is reattaching the leads, especially because they’re very short and you have little room to work, coupled with the strong magnets pulling the needle nose off the mark (aluminum pliers?). One mistake I made was removing the three screws first, that should be the last thing you do before removing the tweeter dome & lead assembly, and the first thing to put back when the new one’s in place. The screw in aluminum wave guide in the back (along with the leads) are what actually hold the tweeter assembly into the outer black cone.

This isn’t an easy fix, but probably saved at least $100 (minimum bench charge at my local dealer), I also didn’t have to lug a heavy speaker down to the shop and wait until they got to it. If you’re patient and careful it can be done, took me about two hours including figuring this all out, testing, and removing the tweeter from the other speaker. If you had the part before hand, it would take about 20 - 30 minutes.

One last thing, if you’ve looked at or owned B&Ws (especially 800 series) you know they’re built well, I gained a whole new appreciation of their parts quality and precision machining.

[Deleted]

Love these kinda articles/posts. Question, what stopped you from upgrading the tweeters? Was it the crossovers that stopped you? How do you think a tweeter upgrade might fare with the stock crossovers? Reason I ask is that I recently performed a tweeter transplant in my LCR speakers. At this point I'm just breaking in the new tweeters. They've really opened up after a few hours of play and today I began for the first time using the EQ to tame them down a bit. 

[AudioHTIT]

Jun 21, 2020 0:33:02 GMT -5 @shimei said:

Love these kinda articles/posts. Question, what stopped you from upgrading the tweeters? Was it the crossovers that stopped you? How do you think a tweeter upgrade might fare with the stock crossovers? Reason I ask is that I recently performed a tweeter transplant in my LCR speakers. At this point I'm just breaking in the new tweeters. They've really opened up after a few hours of play and today I began for the first time using the EQ to tame them down a bit. 

Well, my first goal was getting the important center channel working properly as quickly as possible, and I had a spare (identical) replacement part. But to your question, I find B&W’s to be very well designed and engineered (especially the 800 series), I can’t imagine what type of device I’d use that could improve the overall response, without essentially building a new speaker (which is outside of my current skill set and motivation). Certainly it would be difficult to mount a different device in their rather unique tweeter enclosure. I was surprised (and pleased), that I could actually remove and replace the diaphragm / voice ribbon so easily, essentially re-coning a tweeter.

I would probably feel similarly about the Tektons, and would doubt I could improve them, but being more conventional they’re probably easier to modify (and maybe restore if necessary). Though you’re obviously up for the challenge, and that’s what this hobby is all about, I hope you enjoy your mods. I’m more likely to play with the Maggies, as they’re my music speaker, but still probably with amps (maybe crossover), not drivers. Happy modding!

[Deleted]

Jun 21, 2020 5:38:53 GMT -5 AudioHTIT said:

Jun 21, 2020 0:33:02 GMT -5 @shimei said:

Love these kinda articles/posts. Question, what stopped you from upgrading the tweeters? Was it the crossovers that stopped you? How do you think a tweeter upgrade might fare with the stock crossovers? Reason I ask is that I recently performed a tweeter transplant in my LCR speakers. At this point I'm just breaking in the new tweeters. They've really opened up after a few hours of play and today I began for the first time using the EQ to tame them down a bit. 

Well, my first goal was getting the important center channel working properly as quickly as possible, and I had a spare (identical) replacement part. But to your question, I find B&W’s to be very well designed and engineered (especially the 800 series), I can’t imagine what type of device I’d use that could improve the overall response, without essentially building a new speaker (which is outside of my current skill set and motivation). Certainly it would be difficult to mount a different device in their rather unique tweeter enclosure. I was surprised (and pleased), that I could actually remove and replace the diaphragm / voice ribbon so easily, essentially re-coning a tweeter.

I would probably feel similarly about the Tektons, and would doubt I could improve them, but being more conventional they’re probably easier to modify (and maybe restore if necessary). Though you’re obviously up for the challenge, and that’s what this hobby is all about, I hope you enjoy your mods. I’m more likely to play with the Maggies, as they’re my music speaker, but still probably with amps (maybe crossover), not drivers. Happy modding!

Makes sense, that is in consideration of the tweeter enclosure. I didn't know whether B&W offered various models with different speakers. Seeing some DIY peeps performing similar upgrades themselves and upgrading crossovers in some occassions led me to the question. Always curious about anothers motivation.

Tekton offers Beryllium upgrades and I recently performed them myself. In case you're interested: www.disqus.social/2020/06/tekton-design-ulfberht-from-softdome-to.html?m=1

Enjoy,
William

[DavidR]

B&W have very nice sounding tweeters (to my ears). Clear, fluid and precise. Why would he want to change them?

[AudioHTIT]

Jun 21, 2020 9:10:22 GMT -5 @shimei said:

Jun 21, 2020 5:38:53 GMT -5 AudioHTIT said:

Well, my first goal was getting the important center channel working properly as quickly as possible, and I had a spare (identical) replacement part. But to your question, I find B&W’s to be very well designed and engineered (especially the 800 series), I can’t imagine what type of device I’d use that could improve the overall response, without essentially building a new speaker (which is outside of my current skill set and motivation). Certainly it would be difficult to mount a different device in their rather unique tweeter enclosure. I was surprised (and pleased), that I could actually remove and replace the diaphragm / voice ribbon so easily, essentially re-coning a tweeter.

I would probably feel similarly about the Tektons, and would doubt I could improve them, but being more conventional they’re probably easier to modify (and maybe restore if necessary). Though you’re obviously up for the challenge, and that’s what this hobby is all about, I hope you enjoy your mods. I’m more likely to play with the Maggies, as they’re my music speaker, but still probably with amps (maybe crossover), not drivers. Happy modding!

Makes sense, that is in consideration of the tweeter enclosure. I didn't know whether B&W offered various models with different speakers. Seeing some DIY peeps performing similar upgrades themselves and upgrading crossovers in some occassions led me to the question. Always curious about anothers motivation.

Tekton offers Beryllium upgrades and I recently performed them myself. In case you're interested: www.disqus.social/2020/06/tekton-design-ulfberht-from-softdome-to.html?m=1

Enjoy,
William

Ah, that makes sense too, an upgrade from Tekton, and I would expect Beryllium to be a little hotter as you’ve noticed, but also less distortion.

Now that you mention it, I suppose it’s possible the Diamond tweeter from the HTM1D (in this series) might also work in this enclosure, possibly just as a dome swap as I made. I’m probably more inclined to look for a used HTM1D or HTM2D and go for a bigger upgrade (as I once did from the HTM4S to 3S), but you don’t often see natural cherry up for sale. Interesting thought though as I still need to buy a replacement tweeter to fix the HTM4S I pilfered.