bolly said:sorry chrish I can't help ya...but good luck!
bolly said:question for ya chrish, do ya have the skills to repair an open voicecoil...halfways down? :scratch2:
probably notchrish said:whats a voice coil?
chrish said:yep, broken tensile lead. a DIY fix would be great!QUOTE]
Darn, I was hoping you wouldn't say that. Now I have to go and type it up. Back in a bit with the goods.
- JP
chrish said:It's a 2in. dome. Is there a suitable replacement? Also, any recommendations on a woofer surround source?
And don't reply to my post with "good luck"
Charivari said:It's in the mid-90s in here and I'm not thinking too clearly, so my writing abilities are suffering greatly. If I missed anything or wasn't clear enough, ask and I'll elaborate more.
Quantum Series Dome Midrange Repair
Patience, Perseverance, and a Sharp Knife
As you may have already seen, the tinsels for the dome midranges are incredibly fragile. They consist of a very fine copper wire wrapped with a cotton fiber all coated by a hard, orange resin. The very act of repair could easily break portions of the tinsel off by way of the need to remove the resin.
The resin coating the wire is many times thicker than the wire core and consequently stronger. It is resilient to most chemicals I’ve tried (lacquer thinner, acetone, isopropyl alcohol.) only concentrated Muriatic Acid (Hydrochloric acid) removed the coating, but dissolved the fine copper in the process. So, that option is out. My solution requires a pair of hemostats (“roach clips” to Californians) and a fine bladed knife with a particularly sharp edge. I used the short blade on a Swiss Army knife that I had sharpened to the point where I could and did shave with it, by way of experiment.
For the portion of the tinsel coming out of the dome, you’ll need to clamp the hemostat on it (be careful of the magnet as the field can force the tool where you don’t want it to go and possibly snap the tinsel locked within) just a little bit above the break. Then take your knife and very carefully and slowly scrape away the resin on just the top half until you see a nice linear copper glint about three millimeters long. Any attempts to uncover the wire wholly or to expose more will just result in either breaking the copper or scraping it away in the process. If you can, remove any scraps of the cotton fiber immediately adjacent to the wire. This step took my about 15 minutes of slow scraping, once I realized that going too fast meant having to start over again.
Now, as the tinsel tends to break at the face-plate, you’ll have to use the knife to scrape away the resin from the end portion of the wire in the groove. Typically, the wire has been pushed off to one side, so you’ll have to be careful exposing the copper until you again have several millimeters exposed. I kept scraping away the wire once I got close, so it took me on average three times to expose enough of the wire core.
Now that there are two exposed copper contact points, the hard part is out of the way and its time to solder a bridge. For this step, you’ll need some very finely stranded copper wire, a 15 watt soldering iron with the finest tip you can get, 0.015” silver solder, and a thing of soldering flux. Rosin core solder is too large to use and the rosin inside tends to float the solder over what copper there is to work with. The low wattage iron is a necessity as any hotter and the copper will vaporize when contacted with the tip (this is seriously fine wire we’re trying to solder) and will melt the resin back over the wire, preventing any soldering and necessitating a re-scraping.
First, take your flux brush and load it up with some flux. Then, lightly brush the exposed copper with it. We’re dealing with millimetric scales and a giant brush, so try creating a branch of flux hanging off the brush and just touch that to the copper. Then, melt a drop of silver solder onto the tip of the iron and just barely, barely touch the bottom of the drop onto the flux covered wire and pull away in short order. The heat of the solder should be enough to tin the wire without contacting the tip. If you touch the tip, you’ll either burn up the wire or need to re-scrape the resin. This is especially difficult in the groove, so multiple attempts may be required. Once tinned, on to the next step.
Here’ you will make the bridge between the broken, but now exposed and tinned tips. I used a scrap of 12 gauge Sound King speaker cable available at Parts Express. I removed the jacketing, exposing the wires, and removed three strands. The strands will become the jumper, so twist them together lightly and minimize contact as the oils from your fingers may hinder soldering. Then, measure the gap to be covered, hold the wire over the gap, and kink it at either tinsel end. The excess on the ends will give you something to hold onto with the hemostats. Tin these kinks with the silver solder and flux, but not the whole wire lest it become too stiff to flex. Then, clamp the hemostats onto the tag of the groove end and hold the kink to the exposed tinsel core. Using the iron while being very careful to not overheat the tinsels, lightly tap the tip to the kink just enough to solder the two wires together. Then, repeat the process at the dome end of the tinsel jumper (this is always easier than in the groove) while being careful not to flex the jumper too much and thus risk breaking the joint. Carefully snip the excess off while using both hands to stabilize the cutters near the magnet and you’re done.
Overall, the groove is the most difficult to do with the typical tinsel break being near the face plate. If the break is at the dome, as I had one like that, the same trick is used, but be careful on scraping because if you break that bit, you’ve nothing further back to work with.
I recommend using a magnifying glass during all these steps because with my 20/10 corrected vision, I was working with copper color glints at times. The first dome I repaired took me 1.5 hours to accomplish for all the times I broke the copper core and for the learning. The third took me only 20 minutes, as I got the hang of it. Thus far, the repairs have held to painful levels and over 200 watts, but I am uncertain if the repairs will break at higher levels. However, once done and learned, the fix becomes a simple matter and any new breaks can be fixed in short order.
- JP
MarkAnderson said::ntwrthy: :ntwrthy: :ntwrthy: :ntwrthy: :ntwrthy: Holy crap!! I'm impressed!! - Mark
SPL db said:Got a pic of what'cha need?
Scott
Charivari said:It's in the mid-90s in here and I'm not thinking too clearly, so my writing abilities are suffering greatly. If I missed anything or wasn't clear enough, ask and I'll elaborate more.
Quantum Series Dome Midrange Repair
Patience, Perseverance, and a Sharp Knife
As you may have already seen, the tinsels for the dome midranges are incredibly fragile. They consist of a very fine copper wire wrapped with a cotton fiber all coated by a hard, orange resin. The very act of repair could easily break portions of the tinsel off by way of the need to remove the resin.
The resin coating the wire is many times thicker than the wire core and consequently stronger. It is resilient to most chemicals I’ve tried (lacquer thinner, acetone, isopropyl alcohol.) only concentrated Muriatic Acid (Hydrochloric acid) removed the coating, but dissolved the fine copper in the process. So, that option is out. My solution requires a pair of hemostats (“roach clips” to Californians) and a fine bladed knife with a particularly sharp edge. I used the short blade on a Swiss Army knife that I had sharpened to the point where I could and did shave with it, by way of experiment.
For the portion of the tinsel coming out of the dome, you’ll need to clamp the hemostat on it (be careful of the magnet as the field can force the tool where you don’t want it to go and possibly snap the tinsel locked within) just a little bit above the break. Then take your knife and very carefully and slowly scrape away the resin on just the top half until you see a nice linear copper glint about three millimeters long. Any attempts to uncover the wire wholly or to expose more will just result in either breaking the copper or scraping it away in the process. If you can, remove any scraps of the cotton fiber immediately adjacent to the wire. This step took my about 15 minutes of slow scraping, once I realized that going too fast meant having to start over again.
Now, as the tinsel tends to break at the face-plate, you’ll have to use the knife to scrape away the resin from the end portion of the wire in the groove. Typically, the wire has been pushed off to one side, so you’ll have to be careful exposing the copper until you again have several millimeters exposed. I kept scraping away the wire once I got close, so it took me on average three times to expose enough of the wire core.
Now that there are two exposed copper contact points, the hard part is out of the way and its time to solder a bridge. For this step, you’ll need some very finely stranded copper wire, a 15 watt soldering iron with the finest tip you can get, 0.015” silver solder, and a thing of soldering flux. Rosin core solder is too large to use and the rosin inside tends to float the solder over what copper there is to work with. The low wattage iron is a necessity as any hotter and the copper will vaporize when contacted with the tip (this is seriously fine wire we’re trying to solder) and will melt the resin back over the wire, preventing any soldering and necessitating a re-scraping.
First, take your flux brush and load it up with some flux. Then, lightly brush the exposed copper with it. We’re dealing with millimetric scales and a giant brush, so try creating a branch of flux hanging off the brush and just touch that to the copper. Then, melt a drop of silver solder onto the tip of the iron and just barely, barely touch the bottom of the drop onto the flux covered wire and pull away in short order. The heat of the solder should be enough to tin the wire without contacting the tip. If you touch the tip, you’ll either burn up the wire or need to re-scrape the resin. This is especially difficult in the groove, so multiple attempts may be required. Once tinned, on to the next step.
Here’ you will make the bridge between the broken, but now exposed and tinned tips. I used a scrap of 12 gauge Sound King speaker cable available at Parts Express. I removed the jacketing, exposing the wires, and removed three strands. The strands will become the jumper, so twist them together lightly and minimize contact as the oils from your fingers may hinder soldering. Then, measure the gap to be covered, hold the wire over the gap, and kink it at either tinsel end. The excess on the ends will give you something to hold onto with the hemostats. Tin these kinks with the silver solder and flux, but not the whole wire lest it become too stiff to flex. Then, clamp the hemostats onto the tag of the groove end and hold the kink to the exposed tinsel core. Using the iron while being very careful to not overheat the tinsels, lightly tap the tip to the kink just enough to solder the two wires together. Then, repeat the process at the dome end of the tinsel jumper (this is always easier than in the groove) while being careful not to flex the jumper too much and thus risk breaking the joint. Carefully snip the excess off while using both hands to stabilize the cutters near the magnet and you’re done.
Overall, the groove is the most difficult to do with the typical tinsel break being near the face plate. If the break is at the dome, as I had one like that, the same trick is used, but be careful on scraping because if you break that bit, you’ve nothing further back to work with.
I recommend using a magnifying glass during all these steps because with my 20/10 corrected vision, I was working with copper color glints at times. The first dome I repaired took me 1.5 hours to accomplish for all the times I broke the copper core and for the learning. The third took me only 20 minutes, as I got the hang of it. Thus far, the repairs have held to painful levels and over 200 watts, but I am uncertain if the repairs will break at higher levels. However, once done and learned, the fix becomes a simple matter and any new breaks can be fixed in short order.
- JP
chrish said:WOW All I learned from that is to offer to pay you to fix mine! seriously...