brownrock

thanks for taking the time to answer my question Glenn. Much appreciate your input.

Thanks David

Many thanks for that detailed 'how to' Glenn. You mentioned in one of your posts (somewhere else) that you had tried the tone method with good results. I think it was for a sub though. Do you think the tone method works equally for mids or is the tolerance too tight (probably a stupid way of formulating my question!)? I am given to understand that the tone to use is 1675 Hz? What about the battery method? Any thoughts?

Thanks so much David. Turns out my surrounds are foam but posting the link to cloth surrounds might prove useful ... if not to me then to someone else with the challenge of finding them. So short answer: yes, please. And thanks for your support and help and contribution.

ra.ra... Thank you ever so much for taking the time to answer my questions and musings. What you say makes sense and so I think that maybe my starting point was correct and that would be to order some foam surrounds from AudioFriends. From my research (albeit still somewhat limited) these AudioFriends surrounds appear to be the correct size and configuration ie. 'inverted'. https://www.repairyourspeakers.com/en/foam-surrounds/other-manufactures/peerless/peerless-k040-mrf-821385-midrange-repair-foam-surround/a-2278-20000060 Hopefully they will confirm that that these are the surrounds I need. Now I'm left with the question of whether I have what it takes to 'take on' the challenge of positioning the cone correctly. I've read about using shims but this sounds arduous especially that the cones are enclosed. But I also did read Glenn's post re: using a tone to position the cone. This sounds somewhat arduous but in a different way. Both ways do not appear to be the subject of extensive 'how to's' and that maybe the real challenge. I'm happy to take on even complex tasks (like replacing head gaskets) provided I have good instructions. So I guess I'm off to look for good instructions on how to position a cone in an enclosed` unit. Hopefully I'll find something I can use. Thanks again

Thanks again ra.ra, Attached is a close up and I would have to say that these are foam. I cannot make out any fibers in the surround material. Which is consistent with what was said on the post you linked to (above). So if these are foam surrounds (and not fabric as I stated earlier) would there be any merit to giving Glenn's suggestion? or is the idea of mating a silk patch to a foam surface a nonsense idea? here's a close up pic of the surround.

Thanks so much Ra.Ra, Much appreciate your thoughts and comments. #1 - I actually didn't realize I was posting in any particular section. Is there any way this post can be moved to the correct section? #2 - To be perfectly honest I don't know for a fact that these are fabric. I was going by what I have read here and there. Any number of people suggest that these surrounds are fabric but that's no proof of anything (is it ever!). They may well be foam, but if they are they don't look like the kind of foam surrounds you see these days. I've avoided touching the surrounds for fear of damaging them further. Is there any way I can delicately test to see if they are foam or fabric. The Mission manual of the times doesn't say anything on that subject. Thanks so much for the link. I'm there now. Looks spot on so far!

Thanks Glenn, You are confirming what I was hoping might be possible. Also I appreciate how specific your answer is. May I ask what sealer you use on AR and KLH? In your opinion (or better still experience) would such a repair substantially restore the surrounds to their original functionality OR will the sound quality be significantly altered / impaired due to the addition of new materials (fabric and rubber / sealant)?

Thanks David, By the sounds of what different people say there's no one making cloth surrounds any more and no NOS. But, hey, I hope I'm wrong on that score. Finding new cloth surrounds would be great.

Many thanks David, Foe anyone looking for foam surrounds there are a few suppliers. The one that seems to stand out ahead of the others is one called AudioFriends out of Holland. Here's a link to the item - https://www.repairyourspeakers.com/en/foam-surrounds/other-manufactures/peerless/peerless-k040-mrf-821385-midrange-repair-foam-surround/a-2278-20000060. As far as the link you provided the seller claims to sell surrounds but when you follow the link they are just selling a pair of old Kenwoods. Not sure what their deal is. At this point and having ready a substantial number of posts / comments here (and elsewhere) I would really like to try to save the existing cloth surrounds by repairing them. Just not sure whether this is just wishful thinking on my part, Thanks again for taking the time to read and answer my post.

Hello to all, So far I've have been happy just reading all the knowledgeable things people here have to say but now I have a question of my own I would like answered (which may or may not already be answered elsewhere here - in which case hopefully someone will be kind enough to direct me accordingly). I have a pair of Mission 720s which I have owned from day 1 (I purchased them in 1980). I have used them more or less continuously all these years. The mid range surrounds (the mid range as I understand it are Peerless K040-MRF) are separating / coming apart in a couple of places on the outer edge (pic below with lines on either sides of the split surrounds). I have more pics I can post if anyone wants to see more of what I'm talking about. This is affecting the sound quality. I am considering replacing the existing surrounds which are fabic (silk???) with foam surrounds BUT after reading many of the comments on this site it occurs to me that there may be some way to repair the damage (Permatex on the split, maybe) and keep the original surrounds which 'appear' to be in otherwise reasonable condition. Your thoughts and suggestions would be very welcome. Many thanks to you for taking the time to read this post and possibly answer my question.