Rta 12b woofers not connected and barely working
Dr Rick
Posts: 3
These have been in my family since my brother bought them new. Their sound always seemed a little lacking. I decided to open them up and found that the left woofer on both speakers was disconnected. When I connected them there was barely any movement and no discernible sound. It made me wonder if they were never connected. How could I tell if it needs new crossovers? What else could explain this? Recommendations?
Comments
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Either that or the VCs are sticky or frozenSamsung 60" UN60ES6100 LED
Outlaw Audio 976 Pre/Pro
Samsung BDP, Dish Rcvr, Phillips CD chgr, various game consoles
Canare 14 ga - LCR tweeters inside* & CC outside
BJC 10 ga - LCR mids, inside* & out
8 ga Powerline - LR woofers, inside* & out
*soldered
LR: Tri-amped RTi A7 w/Rotels. Woofers - 980BX; Tweets & “Plugged” Mids - 981
CC: Rotel RB981 -> Bi-amped CSi A6
5 Subs: Sunfire True Sub Sig -> LFE & CC; 4 Audio Pro Evidence -> “Corners”
Surrounds: Rotel 981 -> AR 12 ga -> RTi A3
Power Conditioning & Distribution:
3 dedicated 20A feeds; APC H15; 4 Furman Miniport 20s -
If you press evenly on the said drivers do the scratch, rub, or make any noises?
Did you make sure you hooked them up right? I THINK in those speakers the black is positive. -
On the 12 B & C, the two woofers receive power differently. On the left speaker, the left/outside woofer receives its signal from the upper crossover section. The right/inner woofer receives its signal from the lower crossover section. The right speaker is the opposite/mirror image.
Home Theater/2 Channel:
Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
Center: Custom Built forum.polkaudio.com/discussion/150760/my-center-channel-project/p1
Surrounds & Rears: Custom Built forum.polkaudio.com/discussion/151647/my-surround-project/p1
Sonicaps, Mills, RDO-194s-198s, Dynamat, Hurricane Nuts, Blackhole5
Pioneer Elite VSX-72TXV, Carver PM-600, SVS PB2-Plus Subwoofer
Cables: Speaker: Furez 10/2 with GLS Locking Banana Plugs
Interconnect: Furez 10/2 with SpeakONs
ICs: Custom Furez by Douglas Connections
Den:
Bose 901 Series II Continentals Restored, Re-Built Equalizer with Elna Silmic IIs, Sonicaps, and Silver Mica Caps
Carver CT-3 Pre, Carver C-500
dhsspeakerservice.com/ -
The drivers are frozen. 😡. Still seems like it wouldn't be coincidence that the same drivers on both speakers froze. Something I should fix before I replace them, so it doesn't happen again? Also, where do I find a replacement? I searched polk for mw 6501 and found nothing. Some ebay options, but they are originals and I don't trust the longevity or quality.
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It's not unusual actually. The thing is you can also use the mw6600 driver as well. They pop up on ebay more often than mw6501. They are sonically the same. First thing to do is glue up the good drivers. Original JB weld or power grab express heavy duty.
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Well maybe the previous owner knew they weren't working and thought that it was best to disconnect them, perhaps out of a lack of knowledge of how a loudspeaker works or fear that there was a short circuit or something. We need Colombo (ahh one more thing.....) to question that guy.
You definitely want to go with the originals (6501 or 6600X). They really do hold up very well over time, except for the vulnerability to magnet/pole piece shift, probably due to adhesive that wasn't up to snuff. The surrounds seem to last a long long time, being of butyl rubber (maybe neoprene?), which doesn't deteriorate very easily unless the storage conditions are very bad.
Just ask any eBay sellers whether the voice coils are rubbing or not and ask them to make sure to pack them with lots of cushioning around them.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 -
The drivers are frozen. 😡. Still seems like it wouldn't be coincidence that the same drivers on both speakers froze. Something I should fix before I replace them, so it doesn't happen again? Also, where do I find a replacement? I searched polk for mw 6501 and found nothing. Some ebay options, but they are originals and I don't trust the longevity or quality.
You're not going to find new ones....lolPolitical 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 -
https://www.ebay.com/itm/154361801427?ul_noapp=true
Just popped up on fleabayHome Theater/2 Channel:
Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
Center: Custom Built forum.polkaudio.com/discussion/150760/my-center-channel-project/p1
Surrounds & Rears: Custom Built forum.polkaudio.com/discussion/151647/my-surround-project/p1
Sonicaps, Mills, RDO-194s-198s, Dynamat, Hurricane Nuts, Blackhole5
Pioneer Elite VSX-72TXV, Carver PM-600, SVS PB2-Plus Subwoofer
Cables: Speaker: Furez 10/2 with GLS Locking Banana Plugs
Interconnect: Furez 10/2 with SpeakONs
ICs: Custom Furez by Douglas Connections
Den:
Bose 901 Series II Continentals Restored, Re-Built Equalizer with Elna Silmic IIs, Sonicaps, and Silver Mica Caps
Carver CT-3 Pre, Carver C-500
dhsspeakerservice.com/ -
I contacted Polk. They, of course, don't make replacements. They suggested these: MW Audio MW-6503-8: 6.5 inch Polk Audio Copy Woofer | Midwest Speaker Repair.
Turns out the glue on the magnet completely failed on those speakers. Now I need to learn how to repair them. Looks like I would have to take off the cone to get them to line up perfectly.
Good idea on the JB Weld for the current speakers. Might as well keep them running as long as possible -
Good idea on the JB Weld for the current speakers. Might as well keep them running as long as possible
That is what we do. Though I have not heard these models, if they are cosmetically good the restoration process is very desirable and satisfying! You'd be surprised at how many really good sounding speakers are tossed because drivers fail, surrounds fail, crossover components fail or just sound like crap! I've restored several old Polks, Infinitys, Klipsch's and Boston Acoustics all of which turned out superb using the knowledge gained from this forum and it's great members!Gustard X26 Pro DAC
Belles 21A Pre modded with Mundorf Supreme caps
B&K M200 Sonata monoblocks refreshed and upgraded
Belles 350A Reference modded with Mundorf Supreme caps
Polk SDA 1C's modded / 1000Va Dreadnaught
Wireworld Silver Eclipse IC's and speaker cables
Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)
There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January.
by Dr. Sardonicus -
That eBay seller is accepting offers (only 3 left!) and the price ain't terrible. Your speakers are more than worth it! There are members here who have repaired them successfully but I would go with the eBay ones and keep yours to repair as spares. Keep us posted and good luck.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 -
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Looks like I would have to take off the cone to get them to line up perfectly.
No you do not remove the cone -
I contacted Polk. They, of course, don't make replacements. They suggested these: MW Audio MW-6503-8: 6.5 inch Polk Audio Copy Woofer | Midwest Speaker Repair.
Turns out the glue on the magnet completely failed on those speakers. Now I need to learn how to repair them. Looks like I would have to take off the cone to get them to line up perfectly.
Good idea on the JB Weld for the current speakers. Might as well keep them running as long as possible
Let me know if you'd like to know how to build a jig to re-center them. Or, if you'd like me to do it for you if you wanted to mail them to me, no charge.
my 3.1TLs
I will fix your shifted magnets for free.
