Advice on repairing SL1000 tweeter
shnaggletooth
Posts: 5
Picked up a pair of Monitor 7C speakers today. These have SL1000 tweeters, not the SL2000 tweeters, and the Polk badge is directly on the front bottom of the wood cabinet, not on the grill itself.
Anyway, one of the tweeters is less bright than the other. Examined it, and the clear plastic half-spherical covering has come about halfway undone the main perimeter. The black fabric-y portion underneath it floats "loose" with the cover not securing it tightly.
Not sure if that is any cause of the slight dullness, but assuming it has to be repaired anyway -- what is best to seal the covering -- rubber cement, Elmer's? Does is really matter?
Toothpick to illustrate how the plastic cover has come undone:
Anyway, one of the tweeters is less bright than the other. Examined it, and the clear plastic half-spherical covering has come about halfway undone the main perimeter. The black fabric-y portion underneath it floats "loose" with the cover not securing it tightly.
Not sure if that is any cause of the slight dullness, but assuming it has to be repaired anyway -- what is best to seal the covering -- rubber cement, Elmer's? Does is really matter?
Toothpick to illustrate how the plastic cover has come undone:
Comments
-
Not worth repairing...
-
shnaggletooth wrote: »Picked up a pair of Monitor 7C speakers today. These have SL1000 tweeters, not the SL2000 tweeters, and the Polk badge is directly on the front bottom of the wood cabinet, not on the grill itself.
Anyway, one of the tweeters is less bright than the other. Examined it, and the clear plastic half-spherical covering has come about halfway undone the main perimeter. The black fabric-y portion underneath it floats "loose" with the cover not securing it tightly.
Not sure if that is any cause of the slight dullness, but assuming it has to be repaired anyway -- what is best to seal the covering -- rubber cement, Elmer's? Does is really matter?
Toothpick to illustrate how the plastic cover has come undone:
Not worth repairing and besides, it's a horrible sounding tweeter. Buy two of these, you'll thank me. https://reconingspeakers.com/product/polk-sl1000-sl2000-tweeter/
One thing, you'll have to slightly modify the opening on the bezel to make it fit.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
I know it isn't your question but are you sure they are 7C and not late model 7B? I had *thought* that the 7C marked the change to the SL2000 tweeters. Late model 7B went from Peerless to SL1000 and they did have the grill not extending all the way to the bottom with the badge on the enclosure as you say. Did your speakers originally have the SL2000's?
I've never understood how, apparently the SL1000 tweeter was Polk's attempt at making a better Peerless, and how when they made the switch in the 7B they saw no need to modify the crossover networks, yet people say that the RD0194 is a replacement for the SL1000 but not the Peerless. There is also the issue of how the SL1000 mounting holes and bezel size are the same as the Peerless but not the SL2000. There were some SL1000 that were purported to be NOS on eBay but I don't know if they are still there. Everybody seems to say they are harsh sounding. I haven't heard them; only Peerless.George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Crown D150 amp
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 -
Gardenstater wrote: »I know it isn't your question but are you sure they are 7C and not late model 7B? I had *thought* that the 7C marked the change to the SL2000 tweeters. Late model 7B went from Peerless to SL1000 and they did have the grill not extending all the way to the bottom with the badge on the enclosure as you say. Did your speakers originally have the SL2000's?
I've never understood how, apparently the SL1000 tweeter was Polk's attempt at making a better Peerless, and how when they made the switch in the 7B they saw no need to modify the crossover networks, yet people say that the RD0194 is a replacement for the SL1000 but not the Peerless. There is also the issue of how the SL1000 mounting holes and bezel size are the same as the Peerless but not the SL2000. There were some SL1000 that were purported to be NOS on eBay but I don't know if they are still there. Everybody seems to say they are harsh sounding. I haven't heard them; only Peerless.
They're 7C's, according to the labels on the back. Picked them up in Weehawkin for $50 yesterday, curbside, but I messed up yet another Polk buy -- didn't at least take the grills off to examine the drivers, as one of the midwoofers turned out to be a non-Polk (Pyle driver) that had no surround. There was some excuse for my carelessless -- Weehawkin traffic police van was making it's way up the street and I was double-parked, so I had to get out of there. Still, I should have had the seller send me pics of all the drivers before the sale. Fortunately, I have a midwoofer available from an earlier 5 Jr+ goof-up which needs an SL2500 to complete (and if anyone here has a good, working SL2500 tweeter available for a reasonable price, PM me
I think Polk back in the day was probably pretty sloppy with standardizing their Monitor and SDA releases across the entire spectrum. So the majority of 7C's might have SL2000's, but a significant minority being released were for some unknown reason equipped with SL1000's. Meanwhile, a majority of 7C cabinets had the Polk logo on the grills, but others (like mine) used the 7B cabinets, etc. I'm not even sure what impedance these speakers are because there's no mention of it on the rear, and there's no solid info on the Web. There's more reliable info and more back-in-the-day official literature for 60's AR speakers and other manufacturers than there is for late 70's-1980's Polk speakers.
Anyway, how to safely seal up this plastic half-dome for the tweeter...? -
Not worth repairing...shnaggletooth wrote: »Picked up a pair of Monitor 7C speakers today. These have SL1000 tweeters, not the SL2000 tweeters, and the Polk badge is directly on the front bottom of the wood cabinet, not on the grill itself.
Anyway, one of the tweeters is less bright than the other. Examined it, and the clear plastic half-spherical covering has come about halfway undone the main perimeter. The black fabric-y portion underneath it floats "loose" with the cover not securing it tightly.
Not sure if that is any cause of the slight dullness, but assuming it has to be repaired anyway -- what is best to seal the covering -- rubber cement, Elmer's? Does is really matter?
Toothpick to illustrate how the plastic cover has come undone:
Not worth repairing and besides, it's a horrible sounding tweeter. Buy two of these, you'll thank me. https://reconingspeakers.com/product/polk-sl1000-sl2000-tweeter/
One thing, you'll have to slightly modify the opening on the bezel to make it fit.
I wouldn't ask the question for someone just to respond that it's not worth repairing. I was hoping for actual advice on sealing up the plastic half-dome.
F1 Nut: I know your standard response for these questions is to tell people to open up their wallets and buy the latest Polk R-something-or-the-other tweeter replacement, but that's not possible for everyone. -
Gardenstater wrote: »I know it isn't your question but are you sure they are 7C and not late model 7B? I had *thought* that the 7C marked the change to the SL2000 tweeters. Late model 7B went from Peerless to SL1000 and they did have the grill not extending all the way to the bottom with the badge on the enclosure as you say. Did your speakers originally have the SL2000's?
I've never understood how, apparently the SL1000 tweeter was Polk's attempt at making a better Peerless, and how when they made the switch in the 7B they saw no need to modify the crossover networks, yet people say that the RD0194 is a replacement for the SL1000 but not the Peerless. There is also the issue of how the SL1000 mounting holes and bezel size are the same as the Peerless but not the SL2000. There were some SL1000 that were purported to be NOS on eBay but I don't know if they are still there. Everybody seems to say they are harsh sounding. I haven't heard them; only Peerless.
They are 7C's. Polk apparently was sloppy back in the day standardizing their releases. -
That is pretty strange. I'd be SUPER interested in knowing what else is inside your speakers. MW# and crossover components. I'm also confused surprised by that construction of an outer clear plastic dome over an inner darker material one with a significant air gap between. Are you sure that black stuff isn't the wool on the pole piece that was used for some absorption of back wave? I would think that one dome would be the key. I think the other stuff isn't moving but is fixed to the pole piece. What adhesive to use? I really would be just guessing but perhaps Ayleens Tacky Glue. Maybe Super Glue Gel? Gotta be very careful not to get any into the voice coil gap.George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Crown D150 amp
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 -
Let me put it another way, NO REPAIR POSSIBLE.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
It's a felt dot they used on the sl1000/sl2000 so the dome didn't collapse. It you really want to try to repair it try contact cement on both pieces. The trick would be holding it open for the contract cement to set up to stick to each other. There's more wrong than just that. Have you taking any readings with a multimeter to see if they both register the same? I'm betting they are off enough to cause your problem. I've experienced other problems and yours reminds me of it. The sl1000 can also have the glue holding the pole piece let loose. I've had it happen on more than one of mine. There's no saving it when that happens as it traps the voice coil.
Whether you want to or not the best course is to replace it with another or buy the RD0194 and make some adjustments to the cut out for the new RD0. The new RD0 will be larger but more importantly the tabs that you attach the wires to will be pinched into the magnet if you do not remove a bit of the cabinet to allow for their position.
Good luck.
