jwp@uwmacc.UUCP (Jeffrey W Percival) (02/27/86)
I complained about my car speaker buzzing with the low notes, and received a bunch of help and many requests to summarize (sorry for the delay in responding, but work got busy...) Problem: Car speaker (Pioneer ts-411) had a raspy noise, correlated with bass notes. Possibilities: 1. Bad radio. I swapped speakers; the problem followed the speaker, so the radio is OK. 2. Tear in the cone material. Visual inspection revealed no obvious flaw. 3. Cone separating from voice coil. I peered into the metal housing, to see if there was any gap developing between the voice coil and the cone base. Small gaps may be repaired by dabbing a bit of clear fingernail polish on the split. I thought I saw a gap, dabbed it, but the problem remained. 4. Warped cone, rubbing on the piston. Bingo. The cone material is a paper-like substance, and moisture from the trunk area plays havoc with speaker cones. There's no fixing this problem, so I'm shopping for new speakers. Some people recommended speakers with polypropylene cones. A membranous material that looks highly resistant to moisture. All the good manufacturers make some models with this material, and I think I'll go with that to avoid buying speakers every two years. Thanks! -- Jeff Percival ...!uwvax!uwmacc!jwp
tommie@psivax.UUCP (Tom Levin) (03/06/86)
In article <2003@uwmacc.UUCP> jwp@uwmacc.UUCP (Jeffrey W Percival) writes: >Problem: Car speaker (Pioneer ts-411) had a raspy noise, correlated >with bass notes. > >Possibilities: >4. Warped cone, rubbing on the piston. > Bingo. The cone material is a paper-like substance, and > moisture from the trunk area plays havoc with speaker cones. > >There's no fixing this problem, so I'm shopping for new speakers. >Some people recommended speakers with polypropylene cones. A >membranous material that looks highly resistant to moisture. >All the good manufacturers make some models with this material, >and I think I'll go with that to avoid buying speakers every >two years. Indeed, polypropylene is water proof as well as temperature proof. Thus, it is an ideal material for a car speaker. There is an alternative, though. For those of you who have paper speakers, why not make them water resistant by treating them? Go to your nearest art supply store and buy a small bottle of "Acrylic Mat Medium" along with a small paintbrush. Apply a THIN coat (you don't want to change the speaker's mass significantly) to the speaker. Not only will this make it water proof, but it will also "clean up" the mid-range quite a bit! This is an old trick in the speaker biz to make cheap drivers sound better. It works because you "stiffen-up" the driver without adding much to it's mass. Are you skeptical? Well, Polk audio does this with their loudspeakers. They buy cheap paper drivers and then treat them with "plastiflex". I have used Acrylic Mat Medium on more than one system I've built (both home and audio) with excellent results. Cheers! -- __________________________________________________________________________ Tom Levin {ttidca|sdcrdcf|logico|scgvaxd|bellcore}!psivax!tommie "Turn it up!!!"
ben@catnip.UUCP (Bennett Broder) (03/08/86)
In article <1049@psivax.UUCP>, tommie@psivax.UUCP (Tom Levin) writes: > In article <2003@uwmacc.UUCP> jwp@uwmacc.UUCP (Jeffrey W Percival) writes: > >Problem: Car speaker (Pioneer ts-411) had a raspy noise, correlated > >with bass notes. > > > >Possibilities: > >4. Warped cone, rubbing on the piston. > > Bingo. The cone material is a paper-like substance, and > > moisture from the trunk area plays havoc with speaker cones. > > > >There's no fixing this problem, so I'm shopping for new speakers. > >Some people recommended speakers with polypropylene cones. A > >membranous material that looks highly resistant to moisture. > >All the good manufacturers make some models with this material, > >and I think I'll go with that to avoid buying speakers every > >two years. > > Indeed, polypropylene is water proof as well as temperature proof. > Thus, it is an ideal material for a car speaker. > > There is an alternative, though. For those of you who have paper > speakers, why not make them water resistant by treating them? > Go to your nearest art supply store and buy a small bottle of > "Acrylic Mat Medium" along with a small paintbrush. Apply a THIN > coat (you don't want to change the speaker's mass significantly) > to the speaker. Not only will this make it water proof, but it will > also "clean up" the mid-range quite a bit! This is an old trick in > the speaker biz to make cheap drivers sound better. It works because > you "stiffen-up" the driver without adding much to it's mass. Are > you skeptical? Well, Polk audio does this with their loudspeakers. > They buy cheap paper drivers and then treat them with "plastiflex". > I have used Acrylic Mat Medium on more than one system I've built > (both home and audio) with excellent results. Be aware that there is a risk in this procedure. The acrylic mat medium can cause the cone to warp (in much the same way as the water would), and you can find yourself with a brand new speaker with a voice coil that rubs, and absolutely no recourse. Speaker manufacturers who produce doped cone speakers apply the dope and allow it to dry completely before the speaker is assembled. -- Ben Broder {ihnp4,decvax} !hjuxa!catnip!ben {houxm,topaz}/
eric@amc.UUCP (Eric McRae) (03/11/86)
Folks who have non-enclosed speakers mounted in the rear window deck should close their trunks very slowly. A slammed trunk creates high enough pressures to destroy speakers mounted in this fashion.
s0220@techsup (03/12/86)
Tom, do you want to treat the top, the bottom, or both? or is this magic elixer absorbed into the cone? perry@techsup
tommie@psivax.UUCP (Tom Levin) (03/19/86)
In article <-74821349@techsup> s0220@techsup writes: > > Tom, do you want to treat the top, the bottom, or both? or is this >magic elixer absorbed into the cone? > >perry@techsup Huh? I don't understand the question (But that won't stop me from replying! ;-)). Once again, to treat a paper speaker with acrylic mat medium, take a small paint brush and "paint" thin concentric circles on the *front* of the speaker. (i.e., the part that sticks out of the door or wherever it's mounted.) The inside will be protected from water by it's enclosure or a door jam. /| || | <-- Apply on the entire front of the speaker. || | \| -- __________________________________________________________________________ Tom Levin {ttidca|sdcrdcf|logico|scgvaxd|bellcore}!psivax!tommie "Turn it up!!!"