7C Beef Up help

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  • xschop
    xschop Posts: 4,707
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    Forum first right there. Great job.
    Don't take experimental gene therapies from known eugenicists.
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  • inanortherntown
    inanortherntown Posts: 27
    edited February 27
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    xschop wrote: »
    Forum first right there. Great job.

    Thanks—I had some help, natch. Currently giving John Prine at the Other End a listen, and the acoustic-ness of the recording is really showing me I did the right thing. VR3 xover is next…can’t wait.
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  • xschop
    xschop Posts: 4,707
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    On your model, where is the rear terminal cup positioned in relation to the midwoofer?
    Don't take experimental gene therapies from known eugenicists.
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  • inanortherntown
    inanortherntown Posts: 27
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    Not sure I’m tracking. The rear terminal cup that holds the xover is where I’d expect it to be…lower end of the cabinet, about 10” diagonally from the midwoofer
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  • odcics2
    odcics2 Posts: 309
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    pic?
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  • inanortherntown
    inanortherntown Posts: 27
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    First one is the terminal cup. It’s. 7c speaker so I’d say it’s about just below the halfway point on the speaker.

    3t8znospqoec.jpg

    8wb0r11aopbj.jpg

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  • Viking64
    Viking64 Posts: 6,695
    edited February 28
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    inanortherntown wrote: »
    First one is the terminal cup. It’s. 7c speaker so I’d say it’s about just below the halfway point on the speaker.
    If you're not going to eat that piece of pizza on the floor there, I wouldn't mind polishing it off before the dog comes inside.
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  • inanortherntown
    inanortherntown Posts: 27
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    Viking64 wrote: »
    inanortherntown wrote: »
    First one is the terminal cup. It’s. 7c speaker so I’d say it’s about just below the halfway point on the speaker.
    If you're not going to eat that piece of pizza on the floor there, I wouldn't mind polishing it off before the dog comes inside.

    Ha. That the corner of my rug runner thing. For when I obsessively pace back and forth before hacking into my speakers.

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  • xschop
    xschop Posts: 4,707
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    I was just curious if a dowel can be placed between the MW and PR extending straight to the back panel?
    Don't take experimental gene therapies from known eugenicists.
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  • inanortherntown
    inanortherntown Posts: 27
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    xschop wrote: »
    I was just curious if a dowel can be placed between the MW and PR extending straight to the back panel?


    What diameter dowel? I need to pull things to put the xovers in when they arrive so I'd be willing to try?
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  • xschop
    xschop Posts: 4,707
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    3/4 to 7/8" wood dowel should be plenty strong.
    Don't take experimental gene therapies from known eugenicists.
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  • inanortherntown
    inanortherntown Posts: 27
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    Wow ok. So like just a single dowel running between the space between the MW and PR? Tried to take a pic. Have to cut it to size and lightly tap it into place?qrmp11sis3x1.jpeg
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  • xschop
    xschop Posts: 4,707
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    Exactly. You can use Liquid Nails or PowerGrab and let dry overnight. That and hurricane nut fasteners will be your best solution for cleaning up the mid-bass on those.
    Don't take experimental gene therapies from known eugenicists.
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  • F1nut
    F1nut Posts: 49,806
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    No dowel needed.
    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

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  • xschop
    xschop Posts: 4,707
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    F1nut wrote: »
    No dowel needed.

    He asked for beef-up mods, not vegan soy-boy mods.
    Don't take experimental gene therapies from known eugenicists.
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  • joebass3
    joebass3 Posts: 252
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    xschop wrote: »
    I was just curious if a dowel can be placed between the MW and PR extending straight to the back panel?
    xschop wrote: »
    That and hurricane nut fasteners will be your best solution for cleaning up the mid-bass on those.

    Definitely consider this! I've done it on my Monitor 7's and 10's. Cheap and easy mod with very noticeable gains!
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  • bcwsrt
    bcwsrt Posts: 1,602
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    4uosvomqda8r.jpeg
    Brian

    One-owner Polk Audio RTA 15TL speakers refreshed w/ Sonicap, Vishay/Mills and Cardas components by "pitdogg2," "xschop" billet tweeter plates and BH5 | Stereo REL Acoustics T/5x subwoofers w/ Bassline Blue cables | Rogue Audio Cronus Magnum III integrated tube amp | Technics SL-1210G turntable w/ Ortofon 2M Black LVB 250 MM cart | Sony CDP-508ESD CD player (as a transport) | LampizatOr Baltic 4 tube DAC | Nordost & DH Labs cables/interconnects | APC H15 Power Conditioner | GIK Acoustics room treatments | Degritter RCM
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  • inanortherntown
    inanortherntown Posts: 27
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    Yep hurricane nuts forthcoming
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  • inanortherntown
    inanortherntown Posts: 27
    edited February 28
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    I did learn through my disassembly that my 7's have the same birth day (not year) as my wife, so that's something
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  • inanortherntown
    inanortherntown Posts: 27
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    Oh and check out what the fill in one of my speakers looked like. Cigar burn?

    egfqa7gmdewp.jpeg
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  • VR3
    VR3 Posts: 28,054
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    Burnt resistor
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • Gardenstater
    Gardenstater Posts: 4,190
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    I'd really be interested in your crossover if you could check the values and maybe post a picture or two. Also, what MW# (6502?). Late 7B and early 7C both had the SL1000 tweeter and both had recessed passive and not recessed MW. Maybe the only main difference was the MW was changed from MW6500 to MW6502 and crossover values.
    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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  • inanortherntown
    inanortherntown Posts: 27
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    Hi yes the MW are MW6502
    htgwinla8c6s.jpg

    Here are the crossovers.
    92dj9imz8cpl.jpg
    63qyxkqkftjf.jpg
    1bd30dmyqax8.jpg

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  • xschop
    xschop Posts: 4,707
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    6502's are better drivers.
    Don't take experimental gene therapies from known eugenicists.
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  • pitdogg2
    pitdogg2 Posts: 24,586
    edited February 29
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    There is your dacron burner... that sucker got HOT!!! Looking at the discoloration on the board I'd say it's toast.

    l67u355umavc.png


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  • inanortherntown
    inanortherntown Posts: 27
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    pitdogg2 wrote: »
    There is your dacron burner... that sucker got HOT!!! Looking at the discoloration on the board I'd say it's toast.

    l67u355umavc.png


    Yep. As luck would have it everythings getting swapped out
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  • Gardenstater
    Gardenstater Posts: 4,190
    edited February 29
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    Did you or previous owner have a shorted out tweeter? That resistor still works?

    This is close to your schematic only you have the previous one (that we don't have) with the 2.7ohm resistor and fuse instead of polyswitch:

    https://us.v-cdn.net/5021930/uploads/attachments/4/6/7/2/8/18772.pdf
    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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  • inanortherntown
    inanortherntown Posts: 27
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    Previous owner did, although he didn't tell me. Both tweeters were warranty repairs it looks like. I saw that when I pull them to replace them.
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  • inanortherntown
    inanortherntown Posts: 27
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    Rehab complete. XOvers arrived and they’re beauts, Clark
    rmiytpcjoe8a.jpeg
    bo55yqn7ak07.jpeg

    Hooked up everything
    4ipg4dcas5u0.jpeg
    m2wcyrte0cph.jpeg
    yfl40a1suptb.jpeg

    Mounted the xovers
    dozqvwkmxoax.jpeg

    Finally secured the drivers. That was kind of nerve wracking, and two of the hurricane nuts didn’t cooperate, but overall it was a 98% success, thanks entirely to you all.

    Already the soundstage is waaaay open and lower range is felt and really just experienced.

    Thanks again for all the input. Consider me a fan.


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  • inanortherntown
    inanortherntown Posts: 27
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    Oh and special shout out to Treynfor crafting a rainman-level awesome crossover set. Truly almost too pretty to put inside the cabinets.
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