SDA CRS+ 4.1tl upgrade question??

Toolfan66
Toolfan66 Posts: 17,254
edited November 2010 in Vintage Speakers
Can the 1986 CRS+ take the 4.1tl upgrade?? also if so does one have to put in the MW6511 drivers to complete the upgrade?

The 1986 CRS+ take all MW6510 drivers..
The 1987 CRS+ take two MW6503 & two MW6511
The 1989 CRS+ take two MW6511 & two MW6510

So is the 1989 CRS+ the only set that can take the 4.1tl upgrade? as the Schematic's call for the MW6511 & MW6510's

And yes I have the 1986 CRS+ version..

Thanks!!!

Larry.
Post edited by Toolfan66 on
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Comments

  • gimpod
    gimpod Posts: 1,793
    edited November 2010
    Larry I think you could do it but you would have to re-do the tweeter circuit, You would need to remove the 2.7 ohm resistor that's in series with the 0.4mh inductor and jumper it them put a 5.8uF cap across the other 2.7 ohm resistor. Then all you have to do is slap a RDO-198 in. I don't think the drivers make a difference in doing the TL upgrade but I could be wrong too.:rolleyes: ~ gimpod
    “The two most important days in your life are the day you are born and the day you find out why.” ~ Mark Twain
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  • F1nut
    F1nut Posts: 50,569
    edited November 2010
    ^What he said^
    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: 17,254
    edited November 2010
    Thanks guys!!

    I figured as much and tried the search but it would not bring anything up.

    The only thing that had me ask was the drivers when I looked at the 4.1tl schematics.
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  • Face
    Face Posts: 14,340
    edited November 2010
    6510's may have a different roll-off, it's possible the shunt 2.7ohm resistor may be there to compensate. No way to tell without confirmation from Polk or if someone could measure a 2A or 1986 CRS+.
    "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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  • Toolfan66
    Toolfan66 Posts: 17,254
    edited November 2010
    Well the nice thing "if needed" I have MW6511's in stock :) two of them that I have came out of CRS+'s ;)
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  • Joe08867
    Joe08867 Posts: 3,919
    edited November 2010
    Keep the resistor. I tried removing it from my SDA2's and ended up having a mid-range loss that was weird. I think the Face hit the nail on the head. The 6510 has a big rolloff that the tweeter compensates for.

    They fixed it in later versions with the 6511's..
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  • brgman
    brgman Posts: 2,859
    edited November 2010
    Whats a 4.1Tl upgrade?
    Main Rig-Realistic AM/FM Record player 8 track boasting 4 WPC

    Backup Rig-2 CH-Rogue Audio Zeus w/Factory Special Dark Mods,Joule-Electra 300ME Platinum Preamp,OPPO-105 w/Modwright Tube Mod, Auralic Aries G2.1,Polk 2.3TL,3.1TL's,Dreadnought,RTA-15TL's,1C's All Fully Modded,2xRTA-12c's ,Benchmark DAC3 HGC,Synology NAS,VPI Scout w/Dynavector DV-20XH and Rogue Audio Ares Phono Preamp,Sony PCM-R500 DAT,HHB-850 Pro CDR,Tascam CC-222SLMKII Cassette/CDR,MIT S3.3 Shotgun Cables,Shunyata Hyra-8,Shunyata and Triode Labs Power Cords

    I’M OFFENDED!!!!
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  • Joe08867
    Joe08867 Posts: 3,919
    edited November 2010
    This schematic is what they are talking about.

    http://www.polkaudio.com/forums/attachment.php?attachmentid=26710&d=1186358580
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  • FTGV
    FTGV Posts: 3,649
    edited November 2010
    Since the component values in the 6511's filter section are exact multiples(inductance is halved,shunt capacitance doubled)might indicate it is a 4 ohm driver vs 8ohm for the 6510& 6503?
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