Welcome! Need support, you got it. Or share your ideas and experiences.
Return to Planar Speaker Asylum
65.240.194.62
My 3.6Rs have a slight buzz on some bassy tracks, and I discovered that if I walk behind the speaker and press on the horizontal steel pieces under the socks it goes away (I'm pressing the steel pieces forward, toward the front of the speaker).
I assume that this means it's not the voicecoil pulling away from the mylar. Is that true? If so, what is actually causing this buzz and how do you fix it? Is it the bar vibrating against the perforated steel? If so, that seems like an easy fix. I can either put something between the bar and perforated plate to stop the motion or glue them together. Or could it be the bar rattling against the frame where it attaches? Could it have come loose?
Follow Ups:
"Did a double take on those fingernails."
And are those fingernails glued on?
3M fastbond 30 NF
This happened to my IIIAs, many years ago.
Given the glue failed once ... I didn't want it to fail again. So I drilled a hole through each end of each bar - and through the metal driver-surround - and used 4mm (5/32", in your language!) bolts with a spring-washer, to clamp the bars tight, permanently.
Mind you, if you do this, you need to tape A3 sheets of paper both sides of the driver, to stop drill-scarf from getting onto the mylar or into the holes.
Andy
Thanks! What glue are you talking about that failed?
Was it just the ends of your bars that became loose and screwing them back down corrected the problem?
The plant uses 3M fastbond 30 NF to glue the bars...do not use too much.
So if it fails after a number of years ... why would you simply want to use the same glue, to repair the failure?
Andy
Yes - and as there were no mechanical fixings that I could see, I assumed Magnepan must've used glue, originally.
Screwing the bars down ... stopped them vibrating. :-))
Andy
I have some humps in the response of my 3.6 (80-90 Hz). I have located it to the two buttons on top of the bass driver holding the Mylar to the backplate. These can come lose, it is just a screw. Mine are still not buzzing but I have a PEQ cutting out the resonances right now. I am too lazy stripping them down right now.
The crossbars on the perforated sheet steel are glued and can come lose. My old Tympanis (-76/77) have them glued and screwed.
Interesting, Roger - the 'tuning buttons' on my IIIa and 2.5 bass panels are riveted on ( not screwed).
Andy
This is what they do:
The early Tympanis were just glue no buttons.
Edits: 05/08/21
What is the red goop in the tube ???
The red goop is most likely Loctite for the screws.
couple different kinds of loctite. FOUR, to be exact.
The RED, I think is the 'hardening' type and will be a real Btch to remove.
the purple is a softer type and meant for smaller screw......I'd use THAT one....
Too much is never enough
"... will be a real Btch to remove." The cure being worse than disease?
I'm not a Loctite removal expert, BUT the hardening stuff is tough.......And I think the Loctite literature calls out fasteners above a certain size. NOT 1/4" or whatever, for sure.
The non-hardening is best for this applicaiton IF IT IS Necessary at all....
Too much is never enough
It looks like Loctite 268.
https://www.henkel-adhesives.com/us/en/product/threadlockers/loctite_268.html
panels don't vibrate right out of the frames given the way those picture frame "u" staples fasten them down. But I guess it works!
Did a double take on those fingernails.
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: