LSi9 / LSi15 / LSi25 mid-woofer question

All three of these speaker models -- LSi9, LSi15, LSi25 -- use a pair of the mid-woofer drivers.

Question: is this driver identical in all three models? In other words, do they have the same Polk part number? Or is there an electrical difference (perhaps in nominal impedance) between them, if they are different?

Comments

  • [Deleted User]
    [Deleted User] Posts: 7,658
    The LSi25 and the LSi9 share the same 5.25" driver, part number RD5534-1, the LSi15 uses an RD5535-1 5.25" driver.
  • OK, different part numbers. Cool. That would likely mean there is some electrical difference. Seeing how these differ in the way they are connected in the schematics, it makes sense now.

    You filled in one of the pieces of my "puzzle." Thanks!
  • 11tsteve
    11tsteve Posts: 1,166
    my LSi9 are labeled MW5534-1 and MW5534-2. That "-1" and "-2" are for no reason?

    And these are still available from Polk, correct?
    Polk Lsi9
    N.E.W. A-20 class A 20W
    NAD 1020 completely refurbished
    Keces DA-131 mk.II
    Analysis Plus Copper Oval, Douglass, Morrow SUB3, Huffman Digital
    Paradigm DSP-3100 v.2
  • FranzDolas
    FranzDolas Posts: 5
    edited November 2016
    Have exactly the same dilemma. Can the RD5535-1 (LSi15) work properly starting from 80Hz instead of 150Hz as the RD5534-1 (LSi25) does?

    I'm asking because going to modify the LSi15 crossover and do the following:

    1 Remove the HP filter capacitor (130 uF) in the 5.25" woofers circuit and feed them along with the tweeter circuit from a separate amplifier (no. 1) thru the upper binding posts.

    2. Remove all RLC passive elements in the the sub-woofer circuit and feed it from a separate amplifier (no. 2) thru the bottom binding posts.

    3. The Fc is going to be set up at 80 Hz with 24db/oct Linkwitz–Riley active crossover. Why 80Hz and not 150Hz. I think, this selection is going to eliminate 'booming bass' issue of the 8" sub-woofer.

    4. Obviously, all remaining low quality RLC crossover components will be replaced with better ones.

    The above idea seems to be more quality/cost efficient than modifying the whole LSi15 crossover.
  • I have owned many Polk speakers and the driver numbers could include a source, revision or a different impedance rating. The LSi25's have a built in amp for the woofer and the LSi15 uses a passive woofer.

    Most people with LSi15 and LSi25 speakers also upgraded their side mounted woofer.
    AVR-Onkyo TX-NR808
    Front amp-Adcom GFA 555>Polk Audio LSi9's(Vr3 Castle Mods)
    Center amp-Adcom GFA 5400>Polk Audio LSi9 bi-wired(Vr3 Castle Mod)
    Surrounds-Polk Audio F/X500's<Onkyo TX-NR808
    Sub-Velodyne SPL-1000R