Problem with 7B Bookshelf Speakers

Lawrence Grand
Lawrence Grand Posts: 21
edited September 2008 in Speakers
Hi All. I'm new to the forum, and apologize if this issue has been covered in the past. I have Model 7B bookshelf speakers, which I've had since 1979 (no kidding!) I use them for 2 channel audio only. They've been great, but recently developed a problem. The left speaker is no longer powering the passive radiator woofer. I contacted Polk Audio, and spoke with a very knowledgeble technician. He said that the problem is a faulty midrange speaker, which is no longer powered sufficiently to drive the passive woofer...and recommends replacement. Sounds like a reasonable approach. Has anyone heard of, or experienced this problem? Thanks!
LG:confused:
Post edited by Lawrence Grand on
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  • fbm211
    fbm211 Posts: 1,488
    edited August 2008
    Sounds like you need to get a new driver.You should just replace the mids in both speakers.If you tell polk your a club member you will get a nice discount and free shipping.
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  • ben62670
    ben62670 Posts: 15,969
    edited August 2008
    First welcome to Club Polk.
    Now your problem. Is the midrange driver moving when you play music, or is it just the passive radiator that is not moving?
    Ben
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • nikolas812
    nikolas812 Posts: 2,915
    edited September 2008
    Welcome to the Club!


    Is the 7B a bookshelf speaker? If so you need a pretty damn big bookshelf.:eek:



    Carry on



    Nick
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  • joe.inom
    joe.inom Posts: 16
    edited September 2008
    Hey , i am not joking here , but you have used the speakers enough and u have absolutely had acheived full course money out of that product , now you seem to be a sound fan , if so , then keep the peice as an antique , and fetch a new one.
    I mean like i am not embaresing you but , i mean like the speaker might have destryed by now , fixing it woudnt give better sound quality.
    San Diego Life Insurance
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  • Face
    Face Posts: 14,340
    edited September 2008
    joe.inom wrote: »
    Hey , i am not joking here , but you have used the speakers enough and u have absolutely had acheived full course money out of that product , now you seem to be a sound fan , if so , then keep the peice as an antique , and fetch a new one.
    I mean like i am not embaresing you but , i mean like the speaker might have destryed by now , fixing it woudnt give better sound quality.
    Go away troll.



    Lawrence, the Monitor 7's are still a very well regarded speaker around here. I would call up Polk, tell them you're a member here for a discount, and order one or two new mids for your speakers.
    "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
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  • Lawrence Grand
    Lawrence Grand Posts: 21
    edited September 2008
    Thanks guys. No, I'm not ready to toss these babies yet! The midrange is moving, but less so than in the speaker that is working properly. LG
    PS. Joe, nope.
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  • george daniel
    george daniel Posts: 12,096
    edited September 2008
    joe.inom wrote: »
    Hey , i am not joking here , but you have used the speakers enough and u have absolutely had acheived full course money out of that product , now you seem to be a sound fan , if so , then keep the peice as an antique , and fetch a new one.
    I mean like i am not embaresing you but , i mean like the speaker might have destryed by now , fixing it woudnt give better sound quality.



    Wrong
    JC approves....he told me so. (F-1 nut)
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  • ben62670
    ben62670 Posts: 15,969
    edited September 2008
    Can you pull the driver, and give us a model number. It should be MW6502, or MW6500. A pic would be real helpful too. Let us know before you purchase a replacement.
    Ben
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • Lawrence Grand
    Lawrence Grand Posts: 21
    edited September 2008
    Ben, the number on the back of the driver is MW 6500. I was told this has been upgraded to MW 6502.
    LG
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  • ben62670
    ben62670 Posts: 15,969
    edited September 2008
    The 6500 is 8 ohms, and the 6502 is 4. I have some 6500's around. Do you have the paper ring on yours? I would get a used 6500. The replacement is the 6503. This is not a perfect match.
    Ben
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • George Grand
    George Grand Posts: 12,258
    edited September 2008
    How old are you, where were you born, and do you have a real moustache?

    George Grand (of the Jersey Grands)
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  • ben62670
    ben62670 Posts: 15,969
    edited September 2008
    I am 38, I was born in CT, and I haven't sported a stache since it started turning grey:(
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • CTTE
    CTTE Posts: 183
    edited September 2008
    I don't want to step on Lawrence G's post, but I also have Monitor 7's purchased in '79. I fried the voice coil on my last original 6500 a while back watching "Rust Never Sleeps". Hey, hey; My, my...

    Let me know (after you take care of LG) what you want for a pair of 6500's (with cardboard)
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  • ben62670
    ben62670 Posts: 15,969
    edited September 2008
    I have one with Paper surrounds. I have a few without. If you need to change both the non paper ones look cleaner. We'll see what Las wants to do first.
    Ben
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • Lawrence Grand
    Lawrence Grand Posts: 21
    edited September 2008
    Ben, now I'm really confused. The tech I spoke with at PA told me the 6502 is the current (upgraded) version of my 6500. But these are 4 vs 8 ohms and therefore not compatible? Thanks. LG:confused:
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  • Face
    Face Posts: 14,340
    edited September 2008
    6502 is the replacement to the 6500.
    "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
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  • ben62670
    ben62670 Posts: 15,969
    edited September 2008
    Face wrote: »
    6502 is the replacement to the 6500.

    No the 6503 is the replacement to the 6500
    6500 is 8ohms
    6502 is 4ohms
    Edit:
    DCR 6500 6.6 OHMS
    DCR 6502 3.8 OHMS
    DCR 6503 6.8 OHMS
    Just tested. 6502 not even close.
    Some of the newer monitors switched to 6502's from the 6500, and the less seen 6600's, but you can not run a 6502 in one, and a 6500 in the other.
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • Face
    Face Posts: 14,340
    edited September 2008
    Doh, thanks for the heads up. I assumed they were interchangeable since they were in the newer models.

    I wish I could edit my post... :rolleyes:
    "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
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  • ben62670
    ben62670 Posts: 15,969
    edited September 2008
    Face wrote: »
    Doh, thanks for the heads up. I assumed they were interchangeable since they were in the newer models.

    I wish I could edit my post... :rolleyes:
    I say we duct tape Justin at PF and write all over him with permanent marker:D
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • Lawrence Grand
    Lawrence Grand Posts: 21
    edited September 2008
    My hat is off to you, Ben (and Sal). After seeing your test results, I contacted PA and spoke with a technical manager. He confirmed that the 6503 is the replacement for the 6500...and not the 6502 as I had been told earlier by another tech. Go figure. So I ordered a pair. Many thanks for your help. One other question...do I attach the drivers with fastons? Size 205? My drivers are now soldered in. Thanks again!
    Larry

    PS...George, I'm in New Jersey, too. A transplant from NY.
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  • George Grand
    George Grand Posts: 12,258
    edited September 2008
    I'm not sure I like this at all. How long has your name been Grand? In years instead of a catchy "all my life".
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  • ben62670
    ben62670 Posts: 15,969
    edited September 2008
    Lawrence Grand wrote: »
    My hat is off to you, Ben (and Sal). After seeing your test results, I contacted PA and spoke with a technical manager. He confirmed that the 6503 is the replacement for the 6500...and not the 6502 as I had been told earlier by another tech. Go figure. So I ordered a pair. Many thanks for your help. One other question...do I attach the drivers with fastons? Size 205? My drivers are now soldered in. Thanks again!
    Larry

    PS...George, I'm in New Jersey, too. A transplant from NY.

    Polk CS is the bomb. People are human(I hope), and make mistakes. The fast on size is .187, but 205 works too. The .187's are tight to put on, and most .205's need a little squeeze to hold tight. YMMV
    Ben

    BTW put on some bass heavy music cranked pretty good for a while. The 6503's are pretty tight;)
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • ben62670
    ben62670 Posts: 15,969
    edited September 2008
    George Grand wrote: »
    I'm not sure I like this at all. How long has your name been Grand?

    Long lost brother:confused: You both dig audio:)
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • ben62670
    ben62670 Posts: 15,969
    edited September 2008
    Now there is an excellent tip!
    I EFed mine up too:(
    Thanks Sal
    Ben
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • ben62670
    ben62670 Posts: 15,969
    edited September 2008
    I figured I could tighten them, and back them off a hair. Not a good idea:(
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • George Grand
    George Grand Posts: 12,258
    edited September 2008
    ben62670 wrote: »
    Long lost brother:confused: You both dig audio:)

    I already have one of those and he stays lost just long enough to make life bearable.
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  • Lawrence Grand
    Lawrence Grand Posts: 21
    edited September 2008
    Thanks for the tip. But not to sound too dumb (again), what do you mean exactly by eliptical notches? I don't have the speakers here with me, so I can't check out what the 6500 drivers look like. I'm trying to imagine why elipitical.

    I live in Flemington, NJ. Born and raised in Yonkers, NY and lived in NJ since '92. Been Grand for all of my 53 years. Used to have a moustache, until my son reminded me that I grew it about the time I bought the Monitor 7s when I was starting out in my career, to look older. He asked me if I still wanted to look that way.

    Out came the razor.
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  • George Grand
    George Grand Posts: 12,258
    edited September 2008
    I have been up that way a couple times and it is a pretty part of Jersey. I left Brooklyn for Jersey in 1977, a black day.

    I have been Grand a tad longer than you, and actually qualify for Extra Fine. You should smoke if you want to look older and cool.
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  • Lawrence Grand
    Lawrence Grand Posts: 21
    edited September 2008
    Hey Sal. Can you describe those eliptical cut outs a little more? My replacement drivers are being shipped...and I want to take advantage of your recommendation and do it right. Thanks!
    LG
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