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Hpm-100 Speaker Repairs

wiseguy

wiseguy

Active Member
I finally got my old HPM-100 "CLEAR DEMOS" back after a few years..
one of the woofers glue is coming apart.by the voice coil.(see pics), but What kinda Glue can i use to repair this area?.I have read various post on this,but would like to make sure...and my next step is to see if the plexi cabinets can be polished,my ex's brother did not take care of them,they Were mint when i gave them to him.also are the front casting of the woofers area on these painted? or polished,He used them in a indoor pool area for about 4 yrs..,so far i i found was 1 blown mid,1blown tweet,and 1 no working super tweet,those coupling transformers for the super tweets are all open..(open secondaries)...any suggestions?
thanks!
terry..(the wiseguy)
 
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Very cool speakers. To bad they were abused. I'm not sure about polishing plexi but surely there is information online. Good luck with them.

cubdog
 
Tap Plastics has a polishing compound for plexi that works really great that I've used for turntable dust covers. That and a little elbow grease does wonders.
 
I am working on the crossovers,but i noticed the round tweeters after the level controls are wired "out of phase" or in other words the striped wire is now negative going to the tweeters neg terminal..i am confused as i thought pos to all drivers are the same??
i also had one of the cabinets outside to wash it down..someone walking a dog asked me if it was a fish tank..HUMM..LOL..its been years since i had these back,so i cant remember how they were when i bought them..and is there a way of testing the "super tweeters"?,i know one of them is shot,but the other one i cant get much out of it,unless you put your ear up to it..so im not sure if it is shot or not,i replace that .15 mfd capacitor..(non polar),didnt make a difference..Gee this is the first time i have ever had to ask questions on speaker repairs..LOL
thanks
terry
 
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wiseguy said:
I am working on the crossovers,but i noticed the round tweeters after the level controls are wired "out of phase" or in other words the striped wire is now negative going to the tweeters neg terminal..i am confused as i thought pos to all drivers are the same??i also had one of the cabinets outside to wash it down..someone walking a dog asked me if it was a fish tank..HUMM..LOL..its been years since i had these back,so i cant remember how they were when i bought them..
thanks
terry
Click to expand...


This is normal in a multi-way crossover. It's a function of the crossover itself. You can reverse it but you'll notice a midrange suckout.
 
the things we do for love! your ex's brother? i guess your lucky you got them back at all must of been a amicabale split up your a lucky man !!!!
 
MicroMesh does a good job of polishing plastics:

http://www.rockler.com/product.cfm?page=6461&cookietest=1

Brasso works well on certain types of clear plastic as well. Take my advice as you would that of any random rube on the internet. ;) (But micromesh is amazing stuff! If it's any kind of endorsement, we use it for various purposes at my workplace, a violin shop.)

Sad to see that your ex-relative beat on those nifty speakers.
 
Very little sound comes out of the super tweeter. The plexiglass cabinets were made for the sales floor demonstration, and were never production units. HPM 200 in plexi can also be found. When the 100 was discontinued, the dealers sold 'em!. Soundwise, the plexis do not have the bass of the wood cabinet, because the thin plastic flexes too easily. With that many problems, you might do better parting them out. Coolness counts for something, though.
 
thats interesting as i was told by several that the plexi is "denser" than wood,and should have better bass response..but i have nothing to compare them to..so now i am not sure if i am waisting my time on these or not..LOL..
thanks for the info..the thickness is just about 1" on these.. all around..here is a thread that i started about these a few days ago..

http://audiokarma.org/forums/showthread.php?t=72454
terry
 
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For the voice coil, actually that is the spider to cone, use Aleene's Platinum Bond 7800. You'll have to squirt some out of the tube on something and use a model paint brush to apply it.

Polish the plexiglass, the Tapplastic polish, or what I use for plexiglass here in my shop, Kit Scratchout (made for plastics), available in automotivie stores, Wallyworld auto dept, yellow bottle. Soft cloth and elbow grease.

Tweeter wiring, put it back the way the manufacturer had it. With 12 db/oct crossover, adjacent drivers are "cross connected". I have to assume that the woofer to mid xover is 6 db/octave, and mid to tweeter is 12 db. Right at the xover point with a 12 db xover the two adjacent drivers are 180* out of phase. Switching the polarity on one fixes that problem without any other audible effects.

Plexi is denser than wood, but it transfers vibrations very well, whereas wood would damp, or absorb the vibrations.

No, you are not wasting your time with them, they are GREAT conversation pieces!

On the other hand, you could build some wood or mdf cabs for them. Apparently they sounded good enough for the manufacturer to use them for store demo.
 
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thank you.!!
at least one of my cat's like the cabinet..this is in the kitchen,er.. dining room..and notice the SX-1250 on the old sony with new filters awaiting to be installed..:)
terry
 

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Those clear HPM's are cool! :thmbsp:

....I think someone here once posted a picture of "see-through" Klipschorns. Can't remember who though. :dunno:


Russ
 
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I would never part those out! They are rare and a bit of Pioneer history. Do your best to restore them but take your time. Bringing the cabinets back is key. Have you contacted Pioneer? It's a longshot but someone there might be able to help.

cubdog
 
Everyone with clear speakers should post pictures of them. I saw a clear 901 on ebay not so long ago.
 
I agree with cubdog. Keep those things. You'll prolly never see anything like 'em again.
 
thank you all for the help on speaker repair,it all turned out great..!!solid woofers and no sloppy bass..
but not to confuse this thread..even though the "plexi" stuff can be related..
I had to post these pics..I added my custom built clock to one of the pioneer hpm-100's top..
this is a board inside that i purchased from david forbes a few years ago,i used my own parts,(but i used his preprogrammed processor)..I had the plexi cabinet built at a plastics shop here in wisconsin,it is not the usual 3" CRT.
I selected a prewar electrostatic tube, it is a 5" old new stock electrostatic scope tube.from the very early 40's...if you look closely you can see all of the elements/gun structure in this old tube,and it works great!!
i had to build the HV multiplier for this tube..it has been running for several years..non-stop..no burns..the cabinet cost me 325.00 to have built per my specs..
it just looks cool on top of these old pioneer plexis..:),i am not into "clear things",it just happen to be that way this week with my old speakers being back in my hands..
 
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Glad to hear the speakers came out good! They look great as does the clock, It's a great combination.
 
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