On the Bench Tonight...-group-therapy-thread/?action=dlattach;attach=1047318;image)
So... on the way back from taking a load to the storage unit, I spotted this just hanging out on the curb with somebody's recycles.
GLOMM!!! Along with a couple bundles of nice big cardboard boxes.
-group-therapy-thread/?action=dlattach;attach=1047322;image)
Got it home and after clearing off the bench... THIS is what I found broken.
This one little cut wire on one of the speakers. Patched that up, tested it... everything works, even the cassette deck has decent belts; not in the least bit marshmallowy.
Of course I went through and cleaned the CD and cassette decks, blew it all out with compressed air. The sound from this thing is actually pretty freaking awesome for a bookshelf unit; I'd guess a honest 15-20 watts per side. Bi-amped speakers make so much difference in the sound reproduction, even at this size.
-group-therapy-thread/?action=dlattach;attach=1047326;image)
Other than that, the only thing I found wrong at all was poked tweeter domes... which I know how to fix. Normally, my first line of attack for this would be a vacuum cleaner to pop them back out; however, the design of this speaker makes disassembly quite difficult without doing permanent damage. We're gonna have to get medieval on its arse.
-group-therapy-thread/?action=dlattach;attach=1047342;image)
First, we need a small hot air gun we can set on LOW. This one cycles between 250-325°F. Perfect.
-group-therapy-thread/?action=dlattach;attach=1047330;image)
Next we need to make a puller to do this; think auto body work, only smaller scale. You'll need something with a rounded end, approx the same diameter as the poke in the dome. Next, cut a piece of the black foam mounting tape used for car emblems and the like. It needs to be a little smaller than the poke in the dome.
Now we make our tool: first, wrap some masking tape with sticky side OUT across the end of your tool (I used a Sharpie here); then fold it over itself and use another bit of tape to fasten this sticky tube to the body of the tool, leaving the end 13mm or so as exposed masking tape stickum. The reason for doing this is we need to make sure this side sticks better to the foam tape than the side that will get stuck to the dome. When you're done applying the foam tape to the end of the tool, it will look like this.
-group-therapy-thread/?action=dlattach;attach=1047388;image)
Now to make the pull; you'll insert the tool such that the shank is as close to 90° from the center plane of the poke in the dome as you can manage. Place the end with foam tape against the dome and press gently; be very careful. You want to be centered in the poke as much as possible, and not press hard enough to make the poke in the dome any deeper. Twisting gently sometimes helps make a good bond.
Once you can feel that you have a good bond, pull out quickly in a straight line; again, at 90° to the centerplane of the poke. The curve of the end of the tool will force the dome to pull back out; the adhesive sortof rolls free of its surface.
Or, every once in a while, it pulls the dome clean off of the speaker.
Then it becomes just a matter of straightening it out from the back side and gluing it back it in place.
-group-therapy-thread/?action=dlattach;attach=1047338;image)
This is what a successful pull will look like. Not perfect, but we're not done yet. This is why we need the hot air gun. If it doesn't go the first time, you may need to apply a new bit of foam mounting tape; the first try gets rid of the dust & accumulated smoke, etc, leaving you a nice clean spot for the second attempt. Be patient, be brave!
-group-therapy-thread/?action=dlattach;attach=1047346;image)
This part requires care and finesse. You need to make sure you have really good lighting so you can see the instant the dome reforms and pull the heat away; usually a circular motion is best, starting from ~150mm away and working closer in steps 20-30mm per. But because this plastic is in the way and I really can't disassemble the speaker, I'm doing a little back & forth in this crescent slot, then the same action in the top slot.
-group-therapy-thread/?action=dlattach;attach=1047350;image)
The money shot - an almost PERFECTLY restored dome. This technique will also work on silvered/chromed mylar domes as well, however you do run a risk of peeling the shiny coating off. Even if you do it still looks better than a poked dome, however.
Now that this beast is 100%, I can give it to my wife to use at her new job at a local music school... after I finish modding it for her iPod. But that is a project which requires some 3DP, and I have some connectors on the way from Amazon for that part of the project.
See you in a bit when that all arrives!
mnem
Home
Help
Search
Login
Register
