Crossovers

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TLOC
TLOC Posts: 14
in Vintage Speakers
New to the forum but not Polk. I was just looking to find out if there is a member or members that rebuild M7A and M10 crossovers. Both sets of speakers are in very nice shape and the 7's still have the registration tags stapled to the back. Please let me know and thank you in advance...Tony in NC
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Answers

  • pitdogg2
    pitdogg2 Posts: 27,741
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    @VR3
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  • VR3
    VR3 Posts: 29,684
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    Would be glad to help, please send a pm

    Thanks!
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • TLOC
    TLOC Posts: 14
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    Anyone else have any more info on crossover help for these vintage speakers? Both sets are in very nice shape, all original and actually sound really good. I can see where they created such a following but wondering how much better they can sound...thanks again and no worries either way, I always figure it out in the end... 012xt7b0lvho.jpg
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    b6bvyzdrbzid.jpg
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  • Gardenstater
    Gardenstater Posts: 4,873
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    Kinda vague. Whadya wanna know exactly? Many have rebuilt by following what is there and replacing components.
    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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  • bcwsrt
    bcwsrt Posts: 2,635
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    Gardenstater wrote: »
    Kinda vague. Whadya wanna know exactly …

    … that @VR3 could not answer?!

    Brian

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  • VR3
    VR3 Posts: 29,684
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    I spoke to TLOC. I showed him some of the options I have for the monitor series and he simply didn't see the value in my offerings, nothing personal for sure.

    I am sure there is someone who will be able to assist or he may decide to do DIY?

    All the best :)

    Thanks
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • SCompRacer
    SCompRacer Posts: 9,254
    edited August 2
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    VR3 is the guru for xover rebuilds.

    Anyway, as Gardenstater said Many have rebuilt by following what is there and replacing components. Pop the xover out, note values of components needed. Sometimes you'll find a 34uf capacitor and can only get a 33uf. That is well within the tolerance range. It tweeter cap isn't marked, there are schematics here that can help. Extreme builds will replace inductors, wiring and binding posts. Dynamat driver and passive radiator baskets.

    You can spend a little or a lot on capacitor upgrades. It's worth it to improve quality over what you are removing. You use Bipolar (non-polarized) capacitors. There are plenty of threads here in the DIY section and capacitor comparisons done on web sites to help one choose. Mills or better 1% tolerance resistors are typically used to replace the old ones. When purchasing capacitors/resistors, spend the extra buck or two per pair for matching. That way the values used in each speaker are closely matched.

    Folks will typically remove the tweeter protection poly-switch and increase resistor value by .5 ohm to compensate for its removal. Tweeter upgrades are commonly done to replace SL2000 and other tweeters. Keep the Peerless tweeters. Some will remove fuses, just jumper with a soldered wire, or bypass them.

    If you DIY take pics before disassembling noting wire colors, polarity. For example, you find only black and white wires will be connected to both the tweeter and driver. Wrap a piece of tape around wires and note what it connects to. You can also figure it out by where wires attach to xover/capacitor value. Drivers will typically have a color dot on basket for positive. You'll want to connect all wires properly upon reassembly.
    Post edited by SCompRacer on
    Salk SoundScape 8's * Audio Research Reference 3 * Bottlehead Eros Phono * Park's Audio Budgie SUT * Krell KSA-250 * Harmonic Technology Pro 9+ * Signature Series Sonore Music Server w/Deux PS * Roon * Gustard R26 DAC / Singxer SU-6 DDC * Heavy Plinth Lenco L75 Idler Drive * AA MG-1 Linear Air Bearing Arm * AT33PTG/II & Denon 103R * Richard Gray 600S * NHT B-12d subs * GIK Acoustic Treatments * Sennheiser HD650 *
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  • Striker2237
    Striker2237 Posts: 128
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    I and my friend have stuff from VR3 and it's fantastic, I also had a diy style sonic/mills rebuilt pair of speakers and there is a noticeable gap between that and the VR3 stuff.

    Anything is a huge improvement over stock components though as these speakers are all so old they aren't operating within even base factory specs anymore
    2 channel: MXN10, Anthem MRX740, Anthem MCA5, SDA1c recap/RDO, JL Fathom F112V2, Tributaries series 8A, Tara labs RSC

    Theater: Above plus Paradigm reference studio 100, Polk FX300i

    Projects: SRS1.2TL, SRS 2, M5Jr+

    Party/1st floor: iPad, Marantz SR5005, Paradigm reference S100v2, monster bulk cable

    B&O H9 Gen3
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  • TLOC
    TLOC Posts: 14
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    SCompRacer wrote: »
    VR3 is the guru for xover rebuilds.

    Anyway, as Gardenstater said Many have rebuilt by following what is there and replacing components. Pop the xover out, note values of components needed. Sometimes you'll find a 34uf capacitor and can only get a 33uf. That is well within the tolerance range. It tweeter cap isn't marked, there are schematics here that can help. Extreme builds will replace inductors, wiring and binding posts. Dynamat driver and passive radiator baskets.

    You can spend a little or a lot on capacitor upgrades. It's worth it to improve quality over what you are removing. You use Bipolar (non-polarized) capacitors. There are plenty of threads here in the DIY section and capacitor comparisons done on web sites to help one choose. Mills or better 1% tolerance resistors are typically used to replace the old ones. When purchasing capacitors/resistors, spend the extra buck or two per pair for matching. That way the values used in each speaker are closely matched.

    Folks will typically remove the tweeter protection poly-switch and increase resistor value by .5 ohm to compensate for its removal. Tweeter upgrades are commonly done to replace SL2000 and other tweeters. Keep the Peerless tweeters. Some will remove fuses, just jumper with a soldered wire, or bypass them.

    If you DIY take pics before disassembling noting wire colors, polarity. For example, you find only black and white wires will be connected to both the tweeter and driver. Wrap a piece of tape around wires and note what it connects to. You can also figure it out by where wires attach to xover/capacitor value. Drivers will typically have a color dot on basket for positive. You'll want to connect all wires properly upon reassembly.

    This was the info I was looking for, thanks SCompRacer. VR3, Trey, sounds like a nice guy and I'm sure his xovers are amazing. But can't justify his pricing, up to twice what the speaker sold for new. And these speakers created a cult following with the 40-50 yr old xover. Personally I can't have more in the XO than the speaker's worth and they're not worth much. I paid $650 for Chorus II Crites gold and over $300 for my KG5.5 and $150 for my ADS L710 II's (by Richard So, ADS engineer) since these speakers still have value. I'm sure opinions vary and money is not the problem, it's value...I'll end up using the info provided by this thread and site and do it myself...Thanks for all the info...
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  • VR3
    VR3 Posts: 29,684
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    I can always appreciate someone doing diy.

    As far as pricing and value, etc. Everyone has a different perspective but a house when these speakers came out was about 75,000 dollars average. My neighbor paid 30k for their house in the early 80s. That's about the cost of a full kitchen overhaul in some areas.

    Just saying, comparing prices from many decades ago doesn't really work.

    The monitor series is a great line up from Polk, should perform once you have rebuilt them!
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • F1nut
    F1nut Posts: 52,273
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    There are 2 types of folks when it comes to upgrading audio gear. One looks at the cost of the upgrades verses the value/ROI of the item. The other simply wants the best sonic result for the money spent. The former isn't a true audio enthusiast.
    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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  • Toolfan66
    Toolfan66 Posts: 18,351
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    It cost money to paint the right picture..
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  • billbillw
    billbillw Posts: 8,078
    edited August 10
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    F1nut wrote: »
    There are 2 types of folks when it comes to upgrading audio gear. One looks at the cost of the upgrades verses the value/ROI of the item. The other simply wants the best sonic result for the money spent. The former isn't a true audio enthusiast.

    "For the money spent" sometimes means not throwing a ton of money on one upgrade, that would be better spent improving other parts of the playback chain. It's not really the value/ROI that I consider, but just getting the best overall bang for my buck, which has always been limited in this hobby. I understand the OP has some vintage Polks that he wants to refresh. I would encourage him to read up and ask questions here and eventually attempt a DIY upgrade/refresh. It is definitely worth the effort to get rid of the old (sometimes low quality) parts in the original 40+ year old crossovers.
    See profile for rigs. Nothing else here.
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  • pitdogg2
    pitdogg2 Posts: 27,741
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    It is definitely worth the effort to get rid of the old (sometimes low quality) parts in the original 40+ year old crossovers.
    Agreed. Especially when most were +/- 10% to 20% from stated value, new is much closer like 3% to right on the stated value.
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  • Gardenstater
    Gardenstater Posts: 4,873
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    @TLOC "And these speakers created a cult following with the 40-50 yr old xover." But would they be as highly reviewed if they didn't test them out when they were new? Nope.

    Keep in mind that even DIY is going to cost way more than you seem to be willing to spend since you are talking about $ value and not <3 Value, if you get my drift. What will they be worth to you when you hear the way they could've sounded with higher end parts?
    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
  • TLOC
    TLOC Posts: 14
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    VR3 wrote: »
    I can always appreciate someone doing diy.

    As far as pricing and value, etc. Everyone has a different perspective but a house when these speakers came out was about 75,000 dollars average. My neighbor paid 30k for their house in the early 80s. That's about the cost of a full kitchen overhaul in some areas.

    Just saying, comparing prices from many decades ago doesn't really work.

    The monitor series is a great line up from Polk, should perform once you have rebuilt them!

    Hey Trey, don't take it personally please. But I don't think I'm comparing prices of many decades ago, comparing what the value of the speakers as is today and then with a XO upgrade. I'll have 3-4 times in them compared what I can sell them for. Agreed? At this point I'm stuck with them rather than having the option to allow another end user to enjoy without being completely upside down on them. I don't mind losing "some" money and typically do but this would be substantial. To me one of the best things about audio in general is experiencing, listening, buying selling all kinds of various equipment, finding out what's available, what you think sounds good, what doesn't and repeating the cycle. Then maybe one day settling on what one finds subjectively the best...again opinions may vary...like to know what the Polk enthusiast value these speakers at, as is...listening to them both right now through my 2275...
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  • Striker2237
    Striker2237 Posts: 128
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    The value is absolutely there when VR3 crossovers and full modifications to the cabs etc allow them to beat speakers that retail for over $25k head to head. At least that how I heard it when comparing them vs a set of VSA VR5 SRs
    2 channel: MXN10, Anthem MRX740, Anthem MCA5, SDA1c recap/RDO, JL Fathom F112V2, Tributaries series 8A, Tara labs RSC

    Theater: Above plus Paradigm reference studio 100, Polk FX300i

    Projects: SRS1.2TL, SRS 2, M5Jr+

    Party/1st floor: iPad, Marantz SR5005, Paradigm reference S100v2, monster bulk cable

    B&O H9 Gen3
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  • Conradicles
    Conradicles Posts: 6,412
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    If you want the best overall experience, hard to beat Mr. VR3.
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  • ptrooper
    ptrooper Posts: 533
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    I wouldn’t spend to much on a set of old moldy polks. >:)

    I’d pimp the chit out of em via Vr3 all day long .
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  • skipshot12
    skipshot12 Posts: 2,124
    edited August 13
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    If not wanting to spend the money on upgrading to film caps and the resistors just replace your caps with the same value electrolytics.
    That’s the cheapest way, not an upgrade but cheap.

    Definitely get rid of the poly switch, if these have them, and install the correct value resistor.

    Then do the DIY with the drivers and the cabinets.
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  • xschop
    xschop Posts: 5,724
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    Send them to @Toolfan66. We'd love to see EVH-10's😁
    Don't take experimental gene therapies from known eugenicists.
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