A Real SL 2000 Hack. Replace stock (burnt voice coils) with "silk diaphragm dome ".
Comments
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Unfortunately my meter is missing, or gone from a coworker more likely. I believe they were aluminum, because I poked one of them with the knife during removal and it kinked just like aluminum would. If the pole is the center of the magnet, lol sorry not good with terms, I think you are seeing the ferrofluid that made a bit of a mess.
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Well, how do they sound?Don't take experimental gene therapies from known eugenicists.
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They sound fantastic! Couldn't be happier. I am not sure, but are they actually a better dome than was on there in the first place?
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Once fully broke in and a light sheen of Vit A oil applied, they sound just as good, if not better than RD0194s IMO.Don't take experimental gene therapies from known eugenicists.
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HA ! That is great to hear. We want to know everything because, well at least I think so far you are the only one who has done up a set of SL 2500's. If that Ferro fluid is all stickey due to the coils overheating then you probably do wanna replace it. If not that stuff should be ok to use as is. From what I know if anyhow. I will be corrected if that is not so and amended if the others know more. I have found that working with the fluid can be tricky but not at all hard.
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Cool! I will give that a try in a couple of days. My power went out at home so I can't use them now, lol. I think they say they are for all three of the RDO198, SL2500, and SL3000.
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HA ! That is great to hear. We want to know everything because, well at least I think so far you are the only one who has done up a set of SL 2500's. If that Ferro fluid is all stickey due to the coils overheating then you probably do wanna replace it. If not that stuff should be ok to use as is. From what I know if anyhow. I will be corrected if that is not so and amended if the others know more. I have found that working with the fluid can be tricky but not at all hard.
Yep, definitely sticky, I will order some, but I guess there is still a question of if I should put it in there with the new voice coils, not real sure, but they are different. I could just take the old fluid out as well as I can, and try them without it. -
Special Design Considerations
Material Compatibility: Adhesives
As previously mentioned, synthetic ester based ferrofluids may not be compatible with certain types of adhesives, particularly inexpensive, rubber-based materials. Ferrotec offers an adhesive compatibility testing service to test the compatibility of your candidate adhesive/ferrofluid system under a variety of conditions. Contact Ferrotec or your local agent for more details.
Material Compatibility: Voice Coil
The voice coil bobbin material selected for use with ferrofluid should be a non-absorbent material such as aluminum, Kapton or certain coated papers. If a reinforcing collar is to be used in the coil design, it must also be made of a non-absorbent material or care should be taken to ensure that the collar material does not come into direct contact with the ferrofluid.
Looks like Kapton is OK. Hopefully no incompatible adhesives were used.
https://ferrofluid.ferrotec.com/products/ferrofluid-audio/audioselect/
George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
Oh nice, so it won't damage it or anything, probably make it much better! Ok I will order it and try it. Thanks!
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Ordered the fluid, now am gonna put them back together, because the sound out of the tv speakers is really bad, lol.
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Now I want a set of 2500s to mod. See what you did lol.
Can't tell from DarkKnights thread, but yours surely look to have the copper sleeve.Don't take experimental gene therapies from known eugenicists. -
Just a suggestion, do as you please. I would clean the crap out of those tweeters both of them with masking tape down in there where the voice coil sits and re install them. No way I would leave that sticky fluid in there. The place I am talking about is between the pole piece and the magnet. I would clean that out really good. Then if I had another set of diaphragms I would give the ferro fluid a go just to see how things went. If the ferro fluid delaminated the first set then I would not use it again with the second set. But I guess that's obvious.
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Now I want a set of 2500s to mod. See what you did lol.
Can't tell from DarkKnights thread, but yours surely look to have the copper sleeve.
Here we go again !! HA !! -
They are doing great so far, a tree knocked my power out, but finally back on, it was 25 degrees today in northeast PA.
Now am trying them out watching star wars.
This is all new to me stuff that I have bought over the years, newest being a csia6 center channel, and an SVS pb12 ultra. I just have polk everything else besides the sub, M10's as surrounds... it is amazing. Oh the receiver is a yamaha rxa 1030. Not bad, just a little old, think its from 2013 or so. -
Just a suggestion, do as you please. I would clean the crap out of those tweeters both of them with masking tape down in there where the voice coil sits and re install them. No way I would leave that sticky fluid in there. The place I am talking about is between the pole piece and the magnet. I would clean that out really good. Then if I had another set of diaphragms I would give the ferro fluid a go just to see how things went. If the ferro fluid delaminated the first set then I would not use it again with the second set. But I guess that's obvious.
I will clean it out, will having no fluid in there be bad? And I should have ordered another pair of diaphragms, they are cheap enough. They took about 3 weeks to get here, lol. I may stop by an electronics shop that is local, and grab the fluid from there. Worth a shot. -
If it's gummy yep. I would clean it out and watch the volume knob. My take on it anyhow. I would not want that stuff (potentially) locking up my voice coil. The sound ain't so hot if that happens. If you got a local electronic store that has ferro fluid in stock you are one lucky human. Most have no local electronics stores anymore unless you count big box stores. Don't let anyone tell you that your ole Yamahahopper is a bad one. Lots of the older receivers work great and are a hidden gem price wise. Did you say Star Wars ? You gonna fit in nice around here.
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Went and looked at your Yamaha receiver shoot man this is what I call older as far as the receiver you have that would be like brand new to me. RXV-850
https://hub.yamaha.com/audio/a-history/cult-classics-part-3-vintage-yamaha-gear-of-the-1990s/ -
I am not "Certain", but when I first heard the SL-2000 back in the day, it sounded fairly decent. It seems almost as if their characteristics change over time, for the worse, as if some materials or glue break down or harden or what have you, or the domes "change" in some way........
I know they have that few db peak around 12,500 hertz, but it becomes worse sounding with the passage of time.
If this is common knowledge, forgive me for thinking it is anything newly discovered guys., -
Yes the polyamide dome does NOT age gracefully. Unlike silk or paper, the polyamide gets stiffer and more brittle as time goes on. Some start showing "wrinkles" with age as if it stretched from movement or shrinkage.
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Yes the polyamide dome does NOT age gracefully. Unlike silk or paper, the polyamide gets stiffer and more brittle as time goes on. Some start showing "wrinkles" with age as if it stretched from movement or shrinkage.
On mine, I observed a crinkling and a yellowing -
Went and looked at your Yamaha receiver shoot man this is what I call older as far as the receiver you have that would be like brand new to me. RXV-850
https://hub.yamaha.com/audio/a-history/cult-classics-part-3-vintage-yamaha-gear-of-the-1990s/
That is cool! I have an old Yamaha RXV660 that looks just like it. It is just here as a backup for now, eventually will go into the bar room. It has come in handy several times as it never dies, but various other onkyo's and others have died on me. -
Found the old SL2500 gaskets. You can see where air can leak through the perimeter edges.
Since the SL2500's are rebuildable as shown, a worthwhile mod would be to fill the endoskeleton voids with a solidifying polymer, perhaps Bondo even. This would add bezel mass and ensure positive sealing with new gaskets....
Don't take experimental gene therapies from known eugenicists. -
@Notenoughtaco
Thanks for the link! Just ordered some to repair a dead SL2500 in a pair of Series2 Monitor 7's.
Two questions. 1) How do you know which lead is positive? 2) Since the backing plate, hence dome coil, position is determined by the pins on the magnet, how did you ensure the dome was centered when you glued it to the square backing plate?
Thanks! -
@Notenoughtaco
Thanks for the link! Just ordered some to repair a dead SL2500 in a pair of Series2 Monitor 7's.
Two questions. 1) How do you know which lead is positive? 2) Since the backing plate, hence dome coil, position is determined by the pins on the magnet, how did you ensure the dome was centered when you glued it to the square backing plate?
Thanks!
The positive wire has a red dot on the side of the coil, that goes to the larger terminal. When you remove the old one you will see it is beveled. It is hard to center it in the bevel when it is slathered in your glue, (I used goop contact cement), so I flipped it upside down looking through the backing plate and centered it that way, you will see the hole on the plate is exactly the right size for this, just don't stick it down very much or you won't be able to move it. One one of mine the backing plate needed a little help to pry it off, the other one came right apart. -
Found the old SL2500 gaskets. You can see where air can leak through the perimeter edges.
Since the SL2500's are rebuildable as shown, a worthwhile mod would be to fill the endoskeleton voids with a solidifying polymer, perhaps Bondo even. This would add bezel mass and ensure positive sealing with new gaskets....
Dang, now I gotta look at mine, lol. -
Notenoughtaco wrote: »@Notenoughtaco
Thanks for the link! Just ordered some to repair a dead SL2500 in a pair of Series2 Monitor 7's.
Two questions. 1) How do you know which lead is positive? 2) Since the backing plate, hence dome coil, position is determined by the pins on the magnet, how did you ensure the dome was centered when you glued it to the square backing plate?
Thanks!
The positive wire has a red dot on the side of the coil, that goes to the larger terminal. When you remove the old one you will see it is beveled. It is hard to center it in the bevel when it is slathered in your glue, (I used goop contact cement), so I flipped it upside down looking through the backing plate and centered it that way, you will see the hole on the plate is exactly the right size for this, just don't stick it down very much or you won't be able to move it. One one of mine the backing plate needed a little help to pry it off, the other one came right apart.
Thanks! I wonder if I put the backing plate on the pins, then drop in the dome if the coil would self center itself in the gap. Only one way to find out I guess. Ordered 4 of them so I can afford to goof one up.
Anybody have an opinion on using Aileen's tacky glue instead? Used it for numerous woofer surrounds, but those have all been foam and paper cones. It's pretty forgiving for adjustments. -
You could play a 5kHz signal and adjust for best sound before whatever adhesive you use sets up. I did this with one of the Wuhan VCd Peerless that xschop sent me that got shifted by getting roughed up in the mail. There was no adhesive involved in that case, just tightening the magnet screws when it sounded loudest as shown by an sPL app on my phone.George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
Yep. I have yet to find an exact science to doing it. Multiple ways there are. Eilliens glue is fantastic Dave.
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Most people just listen to music and watch movies. I EXPERIENCE them.
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That sounds like a good plan, but yeah as soon as it touches the glue, it would take some force to move it, and that would scare me a bit. I like your thinking tho. Before you put any glue on and have removed and cleaned up the old ones, take a look at it upside down on the plate, it lines up nicely, and try them without glue with your idea, and see if they line up differently, cool idea Dave.
