Rebuilding Polk Monitor 7C W/SL1000 To Accept Peerless Tweeter?

13

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  • Gardenstater
    Gardenstater Posts: 4,652
    Cold resistance of the 1A fast blow fuse is 190mOhms, so "technically" you'd want to increase the value of the tweeter resistor by 0.2 Ohms if eliminating the fuseblock.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    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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  • seagiant
    seagiant Posts: 51
    Hi,
    Yea, but it is there for a reason, so wondering what is the upgrade to the Crossover to get rid of it???
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  • pitdogg2
    pitdogg2 Posts: 26,808
    seagiant wrote: »
    Hi,
    Yea, but it is there for a reason, so wondering what is the upgrade to the Crossover to get rid of it???

    Good quality amplification.
    Look many of us have removed the fuse block or poly switch when upgrading our crossovers. The only reason it was ever used was to protect the Tweeter. Too many people used receivers or crappy amps and tried to run them at 15 on the dial and blew the tweeter. The fuse block is also notorious for being corroded in the wiring. That in itself is an issue, a bad issue.
    The upgrade is exactly what @Gardenstater suggested. You can never have too many watts or too much current. What you can have is an underpowered receiver or amplifier with a little or no current which results in blown drivers. Because as you increase the volume to what you feel is a suitable level you're also increasing the distortion at a magnitude destruction.
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  • seagiant
    seagiant Posts: 51
    Hi,
    Yes, I appreciate the info but already ordered Caps and Resistors, was going to keep the Fuse and Terminal Block but changed my mind.

    Had rusted out heads on the Screws holding the block and had to cut a slot to get them out so thinking now to just go with a new block and new binding post.

    Coil is wrapped around the OEM Terminal Block, I assume there is a way around that?

    I'm actually working on a pair of Klipsch KG-3's, but keep getting drawn to the Polks as they need more work, pretty rough shape.

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  • seagiant
    seagiant Posts: 51
    edited July 18
    Here is the Coil I speak of, trying to figure the best way to deal with it without to much pain?

    zjcpn1ier6s4.jpg

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  • pitdogg2
    pitdogg2 Posts: 26,808
    There is absolutely no reason to get rid of The binding post cup. Is it broke is it cracked?
    Honestly, I'm starting to believe you are in way over your head. The things you are asking about are some of the simplest things about that cup and that crossover. The first thing you do is you mark on the crossover board what color wire, what wire goes where, i.e. inductor, blk positive, wht negative etc. unscrew the actual crossover board, desolder the wires pull crossover board off.

    The thing you DO NOT want to do is unspool the inductor wire.

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  • seagiant
    seagiant Posts: 51
    Hi,
    LOL!

    No I'm not over my head, but learning about Speakers...

    The Screws that Polk used were cheap or these Speakers were owned by someone living at the beach, as both sets holding the Crossover board were rusted so bad that a screwdriver would not turn them.

    Had to cut a slot and use a flat blade to get them out of course that scarred the plastic...

    Was just going to go to a new after market terminal block but then there is an Inductor Coil wound around the OEM Block so not as easy as I first thought.

    Thanks for the help, hoping to keep this clean and not half **** it, but looking at the best way to go.

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  • pitdogg2
    pitdogg2 Posts: 26,808
    edited July 18
    Yes the Polk screws rusted just from humidity in the air it's a well-known thing. Scarred plastic, who cares it's in back, unless you stare at the back of your speakers..... If the original screw holes are stripped use hurricane nuts. Most do anyways.
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  • seagiant
    seagiant Posts: 51
    Hi,
    Thanks, I may have to they are not really bad I was as careful as I could be, but like things best I can make them.

    These Monitors seem built to a price point the MDF Board is flaking off.

    Will have to deal with that but seems people love these Speakers!

    I rebuilt a pair of Klipsch KG-4's, new Caps and Crite's Ti Tweeters.

    Used Leather Dye to get the color back into the Cabs and then some Howards Feed and Wax and looked pretty good.

    Found a pair of KG-3's and on them now, the Klipsch seem better built and easier to work on but there was probably a price difference and a different market with them...

    okazjriauun5.jpg
    7z0721t2uf8l.jpg
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  • seagiant
    seagiant Posts: 51
    Hi,
    Here are the Blocks, wiped them down not to bad I guess?

    cxizi1ybfard.jpg
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  • seagiant
    seagiant Posts: 51
    edited July 19
    Hi,
    Saw this, interesting!
    https://www.tnt-audio.com/intervis/polk_e.html
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  • F1nut
    F1nut Posts: 51,551
    I rebuilt a pair of KG4's. No, they are not built better. Double check the surround on the rear passive as it's prone to cracking. You won't find that problem on vintage Polk speakers.

    Those Polk cabinets are not MDF, it's basically chip board.

    Do NOT let the large inductor unwind.
    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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  • seagiant
    seagiant Posts: 51
    edited July 19
    Hi,
    No, the Klipsch are better built, but even Mr. Polk, in the article I posted admitted, he was building to a price point, and a certain Market, which was a good thing.

    The Polk Monitor Models, did not use the quality of materials, that the Klipsch KG Line did, but there was a price difference for that.

    You will never have to breakout the Die Grinder, to slot screw heads, so you can remove the Crossovers on a Klipsch Speaker!

    I've got some real Peerless Speakers, in the mail, and Caps, Resistors.

    I'm also going to try my hand at veneering the 7C's, hate vinyl, and hope to have a nice set of speakers when done.

    Saw your Monitor 7 Rebuild, excellent work, and well worth what you were asking for them.

    I'm sure somebody was happy!

    Thanks!
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  • Toolfan66
    Toolfan66 Posts: 17,944
    One of my favorite things I did when modifying my polk speakers, was building new binding post Plates/Cups, it is a shame they are hidden being on the backside, but I have no regrets, it made for a fun project.
    If you have the tools, skills, and or money, I say go for it..
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  • seagiant
    seagiant Posts: 51
    edited July 19
    Toolfan66 wrote: »
    One of my favorite things I did when modifying my polk speakers, was building new binding post Plates/Cups, it is a shame they are hidden being on the backside, but I have no regrets, it made for a fun project.
    If you have the tools, skills, and or money, I say go for it..

    Hi,
    Thanks, I'm over it, will use the OEM's not to bad after a wipe down.

    Stripped the vinyl, and used some DAP Wood Filler to try and re enforce the corners and stop the board from shedding...

    Long enough to get some veneer on it!!!

    nldt5vlo0t3f.jpg
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  • Gardenstater
    Gardenstater Posts: 4,652
    How thick is the particle board on the 7C? It seems like it may be thicker than in the 7B and previous, at least visually.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    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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  • seagiant
    seagiant Posts: 51
    Hi,
    One inch, and the back, has a rabbet, for about a half inch thick back...
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  • Gardenstater
    Gardenstater Posts: 4,652
    7B has "apparent" sides, top and bottom thickness at 3/4" at the front baffle and 3/8" at the rear panel, which is rabbeted also. 7C must have smaller internal enclosure volume.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    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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  • odcics2
    odcics2 Posts: 369
    Compare weights.
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  • Gardenstater
    Gardenstater Posts: 4,652
    Mine are no longer stock weight. Polk gave 36 lbs in 7B sales brochure and reported 35 lbs for 7B and 36 lbs for 7C to Audio magazine. Not as much difference as you would expect.

    1/4" particle board weighs 0.96 lb/sq. ft.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    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
    · Share on FacebookShare on Twitter
  • seagiant
    seagiant Posts: 51
    Hi,
    Is "10-32", the size Hurricane Nuts, you guys are using on these Speakers?
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  • pitdogg2
    pitdogg2 Posts: 26,808
    I'm thinking it is 8-32
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  • seagiant
    seagiant Posts: 51
    Hi,
    Thank you!
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  • Viking64
    Viking64 Posts: 7,476
    Hi,
    You're welcome!
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  • seagiant
    seagiant Posts: 51
    edited July 24
    Hi,
    So, I ordered some H Nuts, and some Allen Head screws to go with them along with new Binding Posts as the OEM'S were a pain to deal with.

    I like to just twist the end of the Speaker Wire and run it into the hole in the shaft.

    Aftermarket works better for that type of connecting, that I have seen!

    Not going full hog on these, but would like to make a few improvements...
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  • F1nut
    F1nut Posts: 51,551
    I like to just twist the end of the Speaker Wire and run it into the hole in the shaft.
    That's just stupid!
    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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  • seagiant
    seagiant Posts: 51
    edited July 24
    F1nut wrote: »
    I like to just twist the end of the Speaker Wire and run it into the hole in the shaft.
    That's just stupid!

    Hi,
    LOL!
    Please don't sweet talk me like that!
    My Wife will get jealous!!! B)
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  • pitdogg2
    pitdogg2 Posts: 26,808
    If you are buying new binding post, might as well use some decent banana plugs as well.
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  • seagiant
    seagiant Posts: 51
    edited July 24
    Hi,
    Thanks, I heard bad things about Banana Plugs, so never spent the money on them.
    Is that the way to go?
    What about the Spades?
    I guess at some point it comes down to opinion, AND...
    Why do almost every Speaker Maker, put those funny little holes in the Binding Posts???
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  • seagiant
    seagiant Posts: 51
    edited July 24
    Hi,
    Saw this!
    https://audiokarma.org/forums/index.php?threads/bananas-spades-bare.471512/
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