Schu Posted March 21, 2017 Share Posted March 21, 2017 Diaphragm... is this gap normal for a k55 phenolic? I picked up a reoccurring "buzz" at certain frequencies in one speaker and decided to break apart the 55x driver to see if I could see any damage. nothing across the dome itself, and everything looked fairly clean except this gap I have never taken apart a driver like this before so I really did not know what to look for other than OBVIOUS damage. I really did not expect to find anything traumatic because the "buzz" only happens on certain songs and at certain frequencies and the buzz is exactly repeatable every time i play those songs. for a time I though maybe it was distortion on the recording itself but it seemed to have gained in regularity and widened it's occurrence to some other recorded material. I cleaned the gap, inspected the diaphragm and carefully reassembled the driver... now, no "buzz" at all (after already ordering 55g's from bob)... the driver sounds perfect. the question is... is that gap normal? what causes "buzz"... is it physical contact between the magnet and the diaphragm? could simple misalignment of the diaphragm within the magnet assembly cause "buzz"? Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted March 21, 2017 Share Posted March 21, 2017 The buzz is common. I've read several times about it. I believe the back comes loose. When you tightened everything back up during reassembly, you repaired the issue. Normally you can press on the back of the driver to make it stop. Quote Link to comment Share on other sites More sharing options...
Schu Posted March 21, 2017 Author Share Posted March 21, 2017 That's for the other drivers where the plastic cap loosens... these are the atlas pd 5vh (k55x). Unless the issue is the same for both driver types. One thing I have noticed is overall imagining and clarity are better since doing the dis-assembly/re-assembly. There may have been something else going on... Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted March 21, 2017 Share Posted March 21, 2017 Other posters have stated that the connections to the drivers were the issues as well. I've never heard it out of mine but seems semi common. Quote Link to comment Share on other sites More sharing options...
Schu Posted March 21, 2017 Author Share Posted March 21, 2017 That makes sense... but if were connection seating, why would it only take place at certain frequencies and on some songs exactly in the same spots in this songs and not in other songs at all... Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted March 21, 2017 Share Posted March 21, 2017 5 minutes ago, Schu said: That makes sense... but if were connection seating, why would it only take place at certain frequencies and on some songs exactly in the same spots in this songs and not in other songs at all... Maybe it was at the frequencies where the impedance dips and the driver needed more current. I'm honestly just guessing. Quote Link to comment Share on other sites More sharing options...
ricktate Posted March 21, 2017 Share Posted March 21, 2017 I'm confused as to what gap you are talking about in pic. But others have just re-glued that black plastic cover down and stopped some noises. Looks like you fixed it any way..lol Quote Link to comment Share on other sites More sharing options...
Schu Posted March 21, 2017 Author Share Posted March 21, 2017 You can't see gap? Quote Link to comment Share on other sites More sharing options...
djk Posted March 21, 2017 Share Posted March 21, 2017 Are you talking about the split in the Kapton former? Crap-in-the-gap makes noise, cleaning it quiets it down. Never use compressed air. 1 Quote Link to comment Share on other sites More sharing options...
Schu Posted March 21, 2017 Author Share Posted March 21, 2017 Thanks... I used a folded piece of paper. Quote Link to comment Share on other sites More sharing options...
djk Posted March 21, 2017 Share Posted March 21, 2017 Masking tape folded into a triangle, sticky-side-out. Quote Link to comment Share on other sites More sharing options...
pzannucci Posted March 22, 2017 Share Posted March 22, 2017 Yes, folded tape, post-it, anything sticky that can pull stuff out of the gap because it will stick to the tape or post-it. Particularly good when cleaning metal that may stick to the magnet or ferrofluid (not in the k-55). Years ago I did actually have a k-55 in a k-horn where I could hear the screen rattle. Removed the screens and the rattle was gone. Quote Link to comment Share on other sites More sharing options...
ricktate Posted March 22, 2017 Share Posted March 22, 2017 If your talking about the tiny gap in the [ voice coil ] part at top of pic . I think that's there for thermal expansion. When you cleaned the magnet gap it probably got some dirt out didn't it? Quote Link to comment Share on other sites More sharing options...
Schu Posted March 22, 2017 Author Share Posted March 22, 2017 Probably.... I didn't really notice any. One thing is for ceretain, it made a world of difference. Quote Link to comment Share on other sites More sharing options...
djk Posted March 22, 2017 Share Posted March 22, 2017 I've had to spent hours cleaning just one driver (before they quit buzzing). 1 Quote Link to comment Share on other sites More sharing options...
Schu Posted March 23, 2017 Author Share Posted March 23, 2017 Really... was material coming out the entire time? I made a couple passes, didn't see any debris, and reassembled. Quote Link to comment Share on other sites More sharing options...
pzannucci Posted March 23, 2017 Share Posted March 23, 2017 Sometimes just resetting the driver positions is a good thing. Quote Link to comment Share on other sites More sharing options...
djk Posted March 23, 2017 Share Posted March 23, 2017 "Really... was material coming out the entire time?" No, I quit when it seems clean, re-assemble, then listen. Sometimes there is debris under the top plate (especially if someone used compressed air and blew it back away from the gap), and it works its way back to the gap. "I made a couple passes, didn't see any debris, and reassembled." That's what I do too. 1 Quote Link to comment Share on other sites More sharing options...
Schu Posted March 24, 2017 Author Share Posted March 24, 2017 The problem is, and perhaps its a good problem, my new squawkers just arrived today... 55G's. These things are super beefy... will be doing an AB session all weekend. Quote Link to comment Share on other sites More sharing options...
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