Hi All
My first post 🙂
I recently got a pair of Mission 765i Towers from a yard sale almost free. However on one one of them the Tweeter does not work. The part # is R76/78-HFU-D26. Please advise where I can buy it. If it's no longer made, is there an equivalent I can use?
Please let me know if you have any questions and/or need any additional information.
Thanks a lot!
My first post 🙂
I recently got a pair of Mission 765i Towers from a yard sale almost free. However on one one of them the Tweeter does not work. The part # is R76/78-HFU-D26. Please advise where I can buy it. If it's no longer made, is there an equivalent I can use?
Please let me know if you have any questions and/or need any additional information.
Thanks a lot!
Welcome aboard, my friend.
I think you may be in luck here. 😎
larryldspkr seems to have done this fix with a Vifa D27TG-35-06:
Mission 767 Tweeters Help
https://www.wilmslowaudio.co.uk/vifa-d27tg-35-06-diameter104Vifa D27TG-35-06mm-695-p.asp
Presumably the faceplate comes off this unit for fitting to the waveguide. If your units voicecoil looks like this, you are home and dry I'd think:
Scanspeak Voice Coil (600058) for D27TG35 or D27TG45 Mission
I think you may be in luck here. 😎
larryldspkr seems to have done this fix with a Vifa D27TG-35-06:
Mission 767 Tweeters Help
https://www.wilmslowaudio.co.uk/vifa-d27tg-35-06-diameter104Vifa D27TG-35-06mm-695-p.asp
Presumably the faceplate comes off this unit for fitting to the waveguide. If your units voicecoil looks like this, you are home and dry I'd think:
Scanspeak Voice Coil (600058) for D27TG35 or D27TG45 Mission
Hi Steve
Thank you for your response. I spent some time today evening to try to narrow down the issue with my Tweeter....it appears to be a faulty voicecoil. The voicecoil is exactly like the link you sent
I did take a look at Vifa D27TG-35-06 dimensions. This is around 104mm diameter with 4 screw holes. Whereas the Mission Twitter (R76/78-HFU-D26) has 3 screw holes -- approximately 30mm from the center. I took some pictures of the Twitter with a ruler.
May be I am missing something....could you/someone guide me how to use Vifa D27TG-35-06 as a replacement? Do I still fit it on the faceplate? Height of faceplate is ~90mm.
Thanks!
Thank you for your response. I spent some time today evening to try to narrow down the issue with my Tweeter....it appears to be a faulty voicecoil. The voicecoil is exactly like the link you sent
I did take a look at Vifa D27TG-35-06 dimensions. This is around 104mm diameter with 4 screw holes. Whereas the Mission Twitter (R76/78-HFU-D26) has 3 screw holes -- approximately 30mm from the center. I took some pictures of the Twitter with a ruler.
May be I am missing something....could you/someone guide me how to use Vifa D27TG-35-06 as a replacement? Do I still fit it on the faceplate? Height of faceplate is ~90mm.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Thanks!
It's all there in the Madisound voicecoil link.
You take the faceplate off an existing tweeter. Seems we are looking at three bolts on a diameter of 56mm for scanspeak and vifa tweeters here. The magnet is 70mm diameter. This is what bothered me initially, because it's not industry standard. It's not always clear if the faceplate is removable either. Often isn't with SEAS.
But I was guessing it was that Vifa anyway, because it was a very common tweeter back in the day.
Some work like this:
3D printed adapter plate | Waveguide - tweeter
That's because the Monacor WG-300 waveguide is designed for a Monacor DT-300 tweeter. Everybody else has to mess around with adapters.
Usual troubleshooting for tweeters is to measure the voicecoil resistance with a meter. Expect 4.7R, or it's open circuit if broken. If resistance is good, look at the state of the black or brown ferrofluid oil in the gap. Has it dried solid?
Simple test for tweeters is just to wire a 1.5V battery across it using a paperclip or wire. It should crackle if it works. Otherwise you might be cleaning out the fluid with blotting paper and WD40 and replacing: Blue Aran - The UK's no.1 Loudspeaker Component Stockist > Sonitus Audio > High Frequency Drivers > Ferrofluid
You can run a tweeter without ferrofluid, just keep the volume down.
You take the faceplate off an existing tweeter. Seems we are looking at three bolts on a diameter of 56mm for scanspeak and vifa tweeters here. The magnet is 70mm diameter. This is what bothered me initially, because it's not industry standard. It's not always clear if the faceplate is removable either. Often isn't with SEAS.
But I was guessing it was that Vifa anyway, because it was a very common tweeter back in the day.
Some work like this:
3D printed adapter plate | Waveguide - tweeter
That's because the Monacor WG-300 waveguide is designed for a Monacor DT-300 tweeter. Everybody else has to mess around with adapters.
Usual troubleshooting for tweeters is to measure the voicecoil resistance with a meter. Expect 4.7R, or it's open circuit if broken. If resistance is good, look at the state of the black or brown ferrofluid oil in the gap. Has it dried solid?
Simple test for tweeters is just to wire a 1.5V battery across it using a paperclip or wire. It should crackle if it works. Otherwise you might be cleaning out the fluid with blotting paper and WD40 and replacing: Blue Aran - The UK's no.1 Loudspeaker Component Stockist > Sonitus Audio > High Frequency Drivers > Ferrofluid
You can run a tweeter without ferrofluid, just keep the volume down.
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Just to close out the thread. I ordered a pair of Peerless D27TG-35-06 from digikey (I live in the US). It arrived couple of days back....I installed it today. The sound is absolutely is amazing from the towers! Much nicer from the old Mission bookshelves it replaced.
On a related note....I wanted to recommission the Mission bookshelves as rear surround speakers in my 5:1 setup (now with 5 Mission speakers)....However was a bit disappointed with the volume/spread from bookshelves. My previous rear surrounds from Cervin Vega 5.1 set produced much nicer rear surround. Is it not a good idea to use bookshelves as rear surrounds?
Thanks.
On a related note....I wanted to recommission the Mission bookshelves as rear surround speakers in my 5:1 setup (now with 5 Mission speakers)....However was a bit disappointed with the volume/spread from bookshelves. My previous rear surrounds from Cervin Vega 5.1 set produced much nicer rear surround. Is it not a good idea to use bookshelves as rear surrounds?
Thanks.
Thanks for getting back on this tweeter fix.
Glad it worked. Those seem like a mighty fine pair of MTM or TMM speakers. MTM is a good idea, IMO, because it delivers a good sound with less annoyance (-3dB quieter) to the neighbours. And is less dependent on room acoustics.
Most folks I know aren't greatly enamoured with Mission's cheaper efforts in bookshelves.
The best home Cinemas I ever hear use MTM all the way. With subwoofers.
Something to do with inverse square and inverse distance dispersion. But the main event is always the midrange, IMO. We want to hear the dialogue. 😀
Glad it worked. Those seem like a mighty fine pair of MTM or TMM speakers. MTM is a good idea, IMO, because it delivers a good sound with less annoyance (-3dB quieter) to the neighbours. And is less dependent on room acoustics.
Most folks I know aren't greatly enamoured with Mission's cheaper efforts in bookshelves.
The best home Cinemas I ever hear use MTM all the way. With subwoofers.
Something to do with inverse square and inverse distance dispersion. But the main event is always the midrange, IMO. We want to hear the dialogue. 😀