I got these in a plastic cinema speaker (JBL 8340A). Unfortunately (and as expected), the foam surrounds have disappeared. The 127H-3 looks like a speaker worth refoaming - anyone any experience with this model? And these could serve as party boxes that could be permanently installed in my second garage with their nice wall holders.
I wonder how critical is the foam/rubber to be used - will a generic one do if having correct dimensions?
I wonder how critical is the foam/rubber to be used - will a generic one do if having correct dimensions?
Well, I will answer myself🙂 I used generic foam surrounds with not so suitable glue. Originals had the surrounds glued from the back of the cone. I succeeded to glue one surround like that. Second try was not as good, there was lots of distortion. So I glued the next one from the top. Not as original, but works fine. For garage speakers, that will work. I will try to measure the speakers for distortion - and might actually redo the first one of I find it necessary. This has been a fun (and at times, frustrating) project. Definitely worth it🙂
Somebody might be interested in a 3D printed adapter for standard 1.4" speaker pole mount - for the 8340a speaker (and other models using the same bracket mounting).
I've found that most urethane foam direct replacement surrounds are very light weight/mass and similar in compliance to original surrounds being replaced. This doesn't apply to the "one size fits all" surrounds that are physically different (mainly in thickness and also in the half roll radius, thus increasing Mms). As long as the physical dimensions are correct, there shouldn't be any appreciable change in performance based on some older JBLs I've reformed over the years. Just be sure you aren't dealing with a foamed rubber surround, which is significantly different than the traditional poly-urethane foam surround. Foamed rubber wasn't used until maybe 10 years ago by Seas and Scan Speak. Its much more stable than the traditional urethane that usually crumbles after several years in harsh environments.
I did not know what the originals were, but the replacements I got looked pretty fine and seem to work well so far. My biggest lesson was that you need to glue to the cone first🙂 The speakers are in use and sound surprisingly good. Definitely better than anything I could buy for the money I invested into them.
Glad you got them fixed and I'll remember to glue the cone first
How did you support the joint while it dried?
Brian
How did you support the joint while it dried?
Brian
I usef flexible rubber contact cement (not the proper stuff, I know) and that fixed it immediately. On the cone just the weight of the surround and on the frame a little weight on the cone just to move ot slightly in. Just watch a few YouTube videos as I did🙂