Problem With SRT Subs

Gatecrasher
Gatecrasher Posts: 1,550
edited August 2014 in Troubleshooting
Well, I think I have a problem with my SRTs. I have a very noticeable "rattle" coming from both subs when they hit a low tone hard. Sounds like crap. I wanted to make sure it was the speakers so I pressed my ear against the cabinets and it sounds like the rattle is coming from inside the cabinets.

It sounds kind of coincidental that both would have the same identical problem but they do.

What do you think? Blown drivers? I find it hard to believe if it was something loose inside that they would both have the issue.

Everything else works good. The top satellites sound OK.
Post edited by Gatecrasher on
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Comments

  • [Deleted User]
    [Deleted User] Posts: 7,658
    edited February 2014
    Hello,
    It is possible the spiders have come loose from the baskets. This might be something Polk can repair for you, give them a call on Monday.
    Regards, Ken
  • Gatecrasher
    Gatecrasher Posts: 1,550
    edited February 2014
    I haven't taken them apart or anything yet but I hope it's something that can be repaired because they are awesome.

    Even screwed-up they're awesome.
  • Gatecrasher
    Gatecrasher Posts: 1,550
    edited February 2014
    Has anyone on here ever worked on these subs?

    I've taken the RT3000p subs apart before. I imagine these are pretty-much the same (except bigger)?

    If the drivers are still good, I'll probably have the amps serviced while I have these apart. Might as well but I don't want to put any more money into them if it's a lost cause.
  • Gatecrasher
    Gatecrasher Posts: 1,550
    edited February 2014
    I see that all the schematics for the SRT are in the forum archives except for the amplifier. Does anyone have the amp schematics they could either post or email to me?

    You help would be greatly appreciated.
  • [Deleted User]
    [Deleted User] Posts: 7,658
    edited February 2014
    Polk CS should be able to send you that.
  • Gatecrasher
    Gatecrasher Posts: 1,550
    edited February 2014
    Polk CS should be able to send you that.

    Well I just got off the phone with Polk customer service and they couldn’t find the amplifier schematics but they say they will keep looking. I also asked about the driver repair and they are checking on that too. I still may try to fix them myself but it’s always nice to know all the options out there. We'll see what they come up with.

    Thanks for the help.
  • Face
    Face Posts: 14,340
    edited February 2014
    What are the dimensions of the amplifier? You might be able to find a plate amp that would fit. If not, and you're good at woodworking, you could make something work. Worse case scenario, you could use a pro audio amp that has an adjustable crossover.
    "He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
  • Gatecrasher
    Gatecrasher Posts: 1,550
    edited February 2014
    That would be a last resort and I think I would probably sell them before doing that. The amps work, they just have a hum. The same things you have to contend with the RT3000p amps. I'm hopeful that it won't be impossible to overcome as long as the drivers are salvageable.
  • Face
    Face Posts: 14,340
    edited February 2014
    If Polk isn't up to repairing them, check this place out: http://reconingspeakers.com/
    "He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
  • Gatecrasher
    Gatecrasher Posts: 1,550
    edited March 2014
    Well I just took one apart. It had some white insulation stuffed in it.

    x2m4j5.jpg

    I guess the next thing to do is to remove the drivers?

    Any ideas how best to accomplish that? It looks like they are riveted to the wood or something.

    2rz9umh.jpg
  • Gatecrasher
    Gatecrasher Posts: 1,550
    edited March 2014
    Where are these "spiders" at?
  • [Deleted User]
    [Deleted User] Posts: 7,658
    edited March 2014
    Hello,
    This link will have an illustration that shows where the spider is on a woofer:

    http://en.wikipedia.org/wiki/Woofer

    Regards, Ken
  • Gatecrasher
    Gatecrasher Posts: 1,550
    edited March 2014
    Well I hooked the disassembled sub up and played it with the bass turned up and the "rattle" sounds like it is coming from the bottom driver.

    I pressed my finger on the cone of the bottom driver and the rattle quieted down and when I did the same to the top driver it didn't quiet down at all.

    Then I played just the assembled one and it has the exact same rattle so I'm wondering if the bottom one in it is causing the noise too?

    Are the drivers both the same? The top one looks like it has some different shielding on it or something.
  • Gatecrasher
    Gatecrasher Posts: 1,550
    edited March 2014
    Well I just looked and the bottom driver is MW1080 and the top is MW1082.

    I guess I have to drill these rivets or whatever the hell they are to remove them. I just hope I can find something wrong with them because I don't know if I have any other option other than to try and re-glue them myself (if the "spiders" are detached).

    Polk customer service is about as worthless as **** on a bull.
  • Face
    Face Posts: 14,340
    edited March 2014
    "He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
  • [Deleted User]
    [Deleted User] Posts: 7,658
    edited March 2014
    Hello,
    The two woofers are very similar, except for the lower woofer has a second magnet on the rear to reduce stray magnetic fields. Usually the woofers are attached to the baffle with a type of wood screw. Is there any way to take a closeup of whatever is holding the woofer to the cabinet?
    I'll forward this to Polk's CS manager and head of engineering for you. Don't do any drilling before they check this out.
    Regards, Ken
  • [Deleted User]
    [Deleted User] Posts: 7,658
    edited March 2014
    Hello,
    I talked with Kim at Polk CS and he recommends that you remove all four of the woofers and send them to: Polk Customer Service, 5601 Metro Drive, Baltimore, MD. 21215-3208 attn: Kim Jasper. This way they can repair the spiders on all of them and avoid any future issues. This will be at no charge.
    The woofers should be held in place with 9/64th hex head bolts that go into "T" nuts, just remove them and the woofers pull out of the cabinets. Turn around time will be as brief as possible and Polk will ship them back.
    Cheers, Ken
  • Polkie2009
    Polkie2009 Posts: 3,834
    edited March 2014
    Thank you Ken for your work and effort on going above and beyond on this . Solid customer service like this speaks volumes to me as a consumer and the integrity of the company.
  • Gatecrasher
    Gatecrasher Posts: 1,550
    edited March 2014
    Thanks Kenneth. I called Polk over a week ago on this and the guy I spoke with had no answers but he took my contact info and said he would get back to me in a day or two but never did. I guess you must have more "pull" than us normal peons do or something? I still haven't received anything on the schematic for the amp either.

    When I firrst looked at the speakers up close, I thought they were attached with very small socket head screws but after looking closer they appeared to be riviets or something. I didn't think Polk would use such tiny screws to hold them in but when I get home tonight I will try to put an Allen wrench in one.

    Polkie2009 wrote: »
    Thank you Ken for your work and effort on going above and beyond on this . Solid customer service like this speaks volumes to me as a consumer and the integrity of the company.

    Huh? Do you have some blown SRT subs too Polkie2009? How are you getting yours out? Did they just unscrew?
  • [Deleted User]
    [Deleted User] Posts: 7,658
    edited March 2014
    Hello,
    I'll check on the bass amplifier schematic.
    Regards, Ken
  • Polkie2009
    Polkie2009 Posts: 3,834
    edited March 2014
    Hi Gatecrasher, congrats on the SRT's, I don't own any, have admired the SRT line from afar for decades, never could afford anything like that though. I just wanted to show Ken & the Polk Audio CS crew some appreciation for helping out on this, I think it's commendable.
  • [Deleted User]
    [Deleted User] Posts: 7,658
    edited March 2014
    Hello,
    If you'll send me your email address via a PM I can send the amp's schematic.
    Regards, Ken
  • Gatecrasher
    Gatecrasher Posts: 1,550
    edited March 2014
    Well I just got home and removed the drivers from the 1st speaker. They were 7/64" socket head cap screws (small buggers) holding them in. Low and behold, the "spiders" are loose in both of them. Almost completely loose on the bottom driver and about half loose on the top one.

    I'm a happy man now!

    Thanks Ken!

    You too Face.

    I'm going to remove the drivers from the other speaker and get them all packed-up to ship to Polk.

    I'd like to send Polk the amps too and have them freshen them up with new capacitors or whatever they think they might need. Think they can do that too Ken? I'm willing to pay them.

    In the meantime, I might refinish the cabinets while they are apart. They are in decent shape but have the usual scratches and nicks. That's why I prefer the black ones. I wouldn't mind re-doing the grilles too even though they aren't totally-trashed.

    The cabinets are built very solid and inside they are stamped with:

    de652q.jpg

    When I removed the drivers this was how the insulation was. Seems kind of weird. Looks like it was just kind of thrown in there. I didn't notice any signs of these having ever been apart before.

    suvdyq.jpg
  • [Deleted User]
    [Deleted User] Posts: 7,658
    edited March 2014
    Hello,
    I've forwarded you the information on the bass amp and the controller. I'll check with Polk to see if they have the ability to perform any service on the bass amps.
    Sorry about having the wrong size hex head, should have known they were smaller.
    Cheers, Ken
  • Gatecrasher
    Gatecrasher Posts: 1,550
    edited March 2014
    Thanks for the info Ken. You're a life-saver!

    Here's the amp: alg9wl.jpg
  • drumminman
    drumminman Posts: 3,396
    edited March 2014
    Hello,
    I talked with Kim at Polk CS and he recommends that you remove all four of the woofers and send them to: Polk Customer Service, 5601 Metro Drive, Baltimore, MD. 21215-3208 attn: Kim Jasper. This way they can repair the spiders on all of them and avoid any future issues. This will be at no charge.
    The woofers should be held in place with 9/64th hex head bolts that go into "T" nuts, just remove them and the woofers pull out of the cabinets. Turn around time will be as brief as possible and Polk will ship them back.
    Cheers, Ken

    Impressive CS.
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
  • Gatecrasher
    Gatecrasher Posts: 1,550
    edited March 2014
    I removed the drivers from the other cabinet and the spiders are loose in both of them too.

    of7r15.jpg
  • Gatecrasher
    Gatecrasher Posts: 1,550
    edited March 2014
    nbrowser wrote: »
    Ok, time to put the camera away, go to a box place and get a stiff heavy duty box and materials to protect those woofers, package them up nicely and get em to Kim, seriously Polk is gonna take care of them for you. They took care of me when something went awry with my speakers in short short order.

    I've been collecting ultra-duty boxes from work for free to ship these out in this weekend. The best ones I've found are the boxes we receive Baldor electric motors in.

    And I have dealt with Polk customer service before over the years with mixed results (usually positive though). Communication (or lack there of) has always been an issue with me though.

    This time they were totally unresponsive until Ken got involved so I think most of the sucking-up I've seen on here should be directed towards Ken up to this point on this particular issue. I'll be congratulating Polk CS after the mission is accomplished because I still haven't heard back from them on my original inquiry that was made weeks ago.

    But things are looking a lot better now that Ken got the ball rolling for me.

    That's one of the nice things about this forum. People are here who really help when you need it.
  • Gatecrasher
    Gatecrasher Posts: 1,550
    edited March 2014
    I got the drivers all packed-up and ready to ship out via Fed Ex ground. I put them in 4 individual boxes all packed nice and put the boxes inside a larger heavy-duty box filled with even more packing material.

    While I'm down I decided to connect a pair of RT3000p subs to the SRT control center with the SRT satellites still connected.

    They sound a whole lot better than the SRT subs with the loose spiders did.

    Music especially is much better. The sound is amazing!

    I hope the SRTs come back as good as new but I still want to have the amps looked at too to get rid of the hum and to PM them for the next several years.

    What do you think Ken? Should I just go ahead and replace every electrolytic capacitor on board and pray it gets rid of the hum or should I try to get Polk to take a look at them? I'm willing to pay to have them professionally serviced. I was willing to pay to have the drivers repaired too but am glad Polk offered to fix them for free.

    I have a Fed Ex account and enclosed a note for Polk telling them to use my account number for the return shipping.
  • Gatecrasher
    Gatecrasher Posts: 1,550
    edited March 2014
    The drivers are shipped and I'm waiting to hear back from Polk.

    In the meantime, since I really don't have many other options, I've decided to replace the 4 big capacitors on each amp board to see if that will get rid of the hum. A few of the capacitors are slightly bulged plus they are 18 years old. I found replacements on eBay for a decent price (10 for $37.99)