Help with Model 5

Stagerguy
Stagerguy Posts: 10
edited March 2012 in Vintage Speakers
I have an a pair of Monitor 5's that I purchased new in 1987, used them for years until my x-wife blew them up (at least I thought she blew them up). I tossed them into the garage (circa 2000) and have missed them ever since. I didn't think they were worth trying to fix, then I discovered this forum. I knew the tweeters were blown and just ordered and installed the RDO194's. It looks like I might have more problems, one speaker fired right up, the other not so much. The tweeter works fine, but nothing out of the driver. I am also trying to determine the absolute model, but I doubt I'll ever really get to the bottom of that, it appears there were quite a variety of Model 5's. The original tweeter is a SL2000, the driver is a MW6500. It has a fuse and shows a date of FEB 11, 1986. Cabinet size 22"H x 10 1/2"W x 8 1/2" deep. Some pictures:
Monitor 5a's, Monitor 4a's, CSi40
Post edited by Stagerguy on
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  • Stagerguy
    Stagerguy Posts: 10
    edited March 2012
    I'm wondering if crossovers fail? I'll try swapping the crossover from the working speaker to determine if it's the actual driver, but seems to me it would still make some noise. Where would you start troubleshooting? I'm quite handy with a soldering iron, but quite useless at figuring out my multi-meter, unless I'm under the hood of my car.
    Phil
    Monitor 5a's, Monitor 4a's, CSi40
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  • drumminman
    drumminman Posts: 3,396
    edited March 2012
    Not to be insulting, but have you checked the fuse on the binding post cup of the inoperable speaker? Before anything else I would swap fuses with the good one - occasionally the fine wire inside can be broken and difficult to see the break.

    After that I would swap the affected drivers rather than the Xover - easier. If it's the driver you can keep a lookout here on CP for a used replacement. Polk sells new replacements, but not sure if they have that particular one.

    And. . . . . .Welcome to the Forum!
    "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
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  • heiney9
    heiney9 Posts: 25,165
    edited March 2012
    That model should have MW6502's. It's an early 5B before the tweeter fuse delete by adding a polyswitch for tweeter protection.

    Are both drivers MW6500's? Unless this was a parts bin run all the models I've seen with that manufacture date use the MW6502.

    Here is the schematic for your model (which is the same model I have)

    http://www.polkaudio.com/forums/showthread.php?38755-POLK-AUDIO-Speaker-Wiring-Schematics-amp-More-ALL-MODELS-except-SDA

    Scroll down to Monitor 5B original

    If the driver isn't working it's probably toast.
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • Stagerguy
    Stagerguy Posts: 10
    edited March 2012
    drumminman wrote: »
    Not to be insulting, but have you checked the fuse on the binding post cup of the inoperable speaker? Before anything else I would swap fuses with the good one - occasionally the fine wire inside can be broken and difficult to see the break.

    After that I would swap the affected drivers rather than the Xover - easier. If it's the driver you can keep a lookout here on CP for a used replacement. Polk sells new replacements, but not sure if they have that particular one.

    And. . . . . .Welcome to the Forum!

    Thanks for the welcome!
    I did check the fuse, when I removed the fuse the tweeter stopped functioning so I figure it not a fuse.

    heiney9, thanks for the link. I'm with you on the driver #, seems strange. I have owned these since new and they have never been serviced (as far as I know). I don't remember if they were an "open box" when I purchased them... it was 25 years ago, yikes!
    I'll open the other one up, I'll need it to check the x-over as well.
    I'll keep you posted.
    Phil
    Monitor 5a's, Monitor 4a's, CSi40
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  • heiney9
    heiney9 Posts: 25,165
    edited March 2012
    Probably a parts bin build, in that they were using up older driver stock. If you are the only owner they probably came with those drivers. They are a little harder to find used, but if you call Polk I'm sure they have a new equivalent. If it were me and I was buying a new driver, I'd buy two new drivers and replace them both at the same time.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • heiney9
    heiney9 Posts: 25,165
    edited March 2012
    Here is a link to my 5B upgrade.

    http://www.polkaudio.com/forums/showthread.php?51420-Monitor-5b-s-x-over-upgrade-w-pics&highlight=upgrade
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • Stagerguy
    Stagerguy Posts: 10
    edited March 2012
    I just opened the other cabinet, lo and behold the driver is a 6502.
    I believe you nailed it heiney9, I'll do a quick search and see if I can find a replacement. I was looking at a thread earlier in the week and thought I saw a driver for sale.
    I'll swap the drivers around after work just to verify it's not a wiring/ x-over problem.
    Phil
    Monitor 5a's, Monitor 4a's, CSi40
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  • HTguru1982
    HTguru1982 Posts: 1,066
    edited March 2012
    There a few 6502's on Ebay right now.
    Display: Sony 42" LCD
    Sources: Harman Kardon DVD-27,
    Panasonic DMP-BDT110 blu ray player
    AVR: Sony STR-DA2400ES
    Amps: Sonance Sonamp 260(fronts),
    Kenwood KM-894(surrounds)
    Fronts: NHT 2.5
    Center: NHT VS-1.2A
    Surrounds: NHT Super One
    Subwoofer: SVS PB10-ISD
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  • skrol
    skrol Posts: 3,375
    edited March 2012
    I also agree that they are 5B and should have the MW6502. The capacitor and resistor values match my 5B's (1984) which use the MW6502 and the SL-2000 and have the single fuse.

    Do your mid-woofers move freely, no scraping, when you gently press them in?

    They should be fixable but would depend on how much you have invested in them already to determine if they are worth the while. Worst case, you could part them out and put the money toward another pair in better working condition. In working condition, they are a sweet speaker.
    Stan

    Main 2ch:
    Polk LSi15 (DB840 upgrade), Parasound: P/LD-1100, HCA-1000A; Denon: DVD-2910, DRM-800A; Benchmark DAC1, Monster HTS3600-MKII, Grado SR-225i; Technics SL-J2, Parasound PPH-100.

    HT:
    Marantz SR7010, Polk: RTA11TL (RDO198-1, XO and Damping Upgrades), S4, CS250, PSW110 , Marantz UD5005, Pioneer PL-530, Panasonic TC-P42S60

    Other stuff:
    Denon: DRA-835R, AVR-888, DCD-660, DRM-700A, DRR-780; Polk: S8, Monitor 5A, 5B, TSi100, RM7, PSW10 (DXi104 upgrade); Pioneer: CT-6R; Onkyo CP-1046F; Ortofon OM5E, Marantz: PM5004, CD5004, CDR-615; Parasound C/PT-600, HCA-800ii, Sony CDP-650ESD, Technics SA 5070, B&W DM601
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  • Stagerguy
    Stagerguy Posts: 10
    edited March 2012
    The mid-woofer (6500) moves freely, but not without making some scraping noises. The 6502 in the other cabinet moves freely and quietly, guess that will solve that. I will swap the mid's between boxes to verify.
    Monitor 5a's, Monitor 4a's, CSi40
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  • Stagerguy
    Stagerguy Posts: 10
    edited March 2012
    I swapped the 6502 between cabinets, yes indeed the 6500 is dead. Thanks to the lead from HTguru1982 I ordered up a 6502 replacement. YEE HAW!, the monitor 5's are back up and running. I had forgotten how much I missed their sweet sounds, can't wait for the tweeters to burn in... shouldn't take long :cheesygrin:
    Phil
    Monitor 5a's, Monitor 4a's, CSi40
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  • drumminman
    drumminman Posts: 3,396
    edited March 2012
    Pssssst! Do the Xover upgrade! You'll be pleased at how much better they can sound.
    "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
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  • cnh
    cnh Posts: 13,284
    edited March 2012
    If that is supposed to have a 6502, I have one that, unfortunately was a replacement (wrong mid for my 5As--so I replaced it with a 6500). The problem is that the 6502 has a 3/4" tear in the rubber surround which I've put a temp repair on by using rubber cement and tissue paper. It seems OK. But you might want to redo that! It plays fine. Seem to hold the air seal, etc. Nothing wrong with the driver. It's just that the A-HXXE who put this wrong driver in my 5As didn't cut away the rubber surround around the screw holes so he ripped the surround near one screw while he was tightening it (space cadet).

    If you're interested, I can try to pack this up and send it your way for $10 and the price of shipping! (Oh, I see you're in Canada! I've never shipped over the border before--have to check on that!).

    Get your post count up so you can PM me if you want!

    I'm sure there may be others who have a spare 6502 around here as well!

    cnh
    Currently orbiting Bowie's Blackstar.!

    Polk Lsi-7s, Def Tech 8" sub, HK 3490, HK HD 990 (CDP/DAC), AKG Q701s
    [sig. changed on a monthly basis as I rotate in and out of my stash]
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  • Stagerguy
    Stagerguy Posts: 10
    edited March 2012
    Apparently Polks are an addiction. Now that I have the Monitor 5's back up and running I find myself scanning CL to see what's out there. In the meantime, my piece of crap Infinity centre speaker disintegrated and I happened to find a CSi40 on... you guessed it CL. Seems to be a nice match for the 5's. I see now that joining this forum is going to cost me $$
    Is the 40 a vintage speaker?
    Phil
    Monitor 5a's, Monitor 4a's, CSi40
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