POLK LS90 crossovers Two different ones?

geppy1
geppy1 Posts: 3,075
in Speakers
Can someone explain the why, when and what of Polk LS 90 crossovers? I understand there are two different ones? Thanks
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  • skrol
    skrol Posts: 3,387
    Falls falls under, "Specifications May Change Without Notice". I guess you are referring to the "Original" 1992 and the "Revised" 1993 schematics. Looks like they went from electolytic to mylar on the C1, increased R1 from 0.8 to 1.0 ohms and decreased L3 from 4 mH to 1 mH. I assume that the later is an improvement.
    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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  • geppy1
    geppy1 Posts: 3,075
    OK What would that do?
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  • geppy1
    geppy1 Posts: 3,075
    Looks like mine are 10/92 What did these changes do soundwise??
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  • Polkie2009
    Polkie2009 Posts: 3,834
    maybe smooth out the midrange to upper freq. response between driver and tweeter?
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  • skrol
    skrol Posts: 3,387
    Replacing the electrolytic for the mylar capacitor usually gives very nice improvements to the highs in terms of smoothness and sound stage. Increasing the resistance would tone down the tweeter slightly. The change in the inductor would shift the cut-off frequency of woofer 3&4 down a little.

    I would rest on the assumption that it is an improvement in the sound character of the speaker. Otherwise there would be no reason for the change as the replacement parts would cost slightly more.
    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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