LSiM 707 bi-amp question

LSiM 707 bi-amp question.

I am assuming the bonding wire couples the mid-woofer, mid-driver and tweeter (basically 703 top half) from the two oval subwoofers correct? If so I'm looking to setup an active crossover for the subs and the top half set at 100Hz. Do I have to remove the passive crossovers? Is 100Hz appropriate? I'm trying to prevent too much roll off in the crossover region but also trying to prevent wasted energy from going to where they shouldn't.

I am breaking in a new pair of 707 and was playing different test tones, 20Hz and 30Hz at 10-80 watts and surprisingly the mid-woofer and mid-driver was trying to rattle of those frequencies?!? I felt active driver movement as I varied the volume. That can't be good?
Shouldn't the HPF even a passive crossover prevent those frequencies from reaching the smaller drivers?


  • mrbigbluelightmrbigbluelight Posts: 7,039
    edited June 2
    Almost gave the wrong advice. Rechecking my info.

  • mpitogompitogo Posts: 61
    i also did not see a wiring guide in the other section. short of opening it up, someone must know..?
  • K_MK_M Posts: 797
    edited June 2
    From manual.....

    "the upper set of binding posts are for the high frequency drivers"

    It does not specify, if it is only the tweeter, but the older Lsi series, the binding posts (upper) were just the tweeter, and the lower were the other drivers.
  • K_MK_M Posts: 797
    Bi-Wiring (see Figure 1)
    Bi-wiring can provide noticeable improvements in the overall
    transparency of your loudspeakers. Run separate speaker wires
    to the low and high frequency drivers from a single amplifier
    (the upper set of binding posts are for the high frequency drivers,
    the lower set of binding posts are for the low frequency drivers):
    after removing the jumpers, connect one set of speaker wires
    to the upper terminals on each speaker and one set of wires
    to the lower terminals. Connect the other ends of both wire
    sets to the same amplifier outputs.
    Bi-Amping (see Figure 2)
    Bi-amping allows you to use separate amplifiers for the high and
    low frequency sections of your loudspeaker for greater dynamic
    range and lower distortion. We recommend that your separate
    amplifiers have identical gain to preserve the speaker’s voicing
    balance. After removing the jumpers, connect the speaker wires
    from the high frequency amplifier outputs to the upper set of
    terminal posts on each speaker. Follow the same procedure
    for connecting the low frequency amplifier outputs to the
    lower set of terminals. Remember to maintain correct wiring
    polarity (+ to +, – to –) in all connections.
  • KennethSwaugerKennethSwauger Moderator Posts: 5,800
    The lower set of binding posts connect to the lower three bass components, the two woofers and the 6.5" mid-bass driver. The upper set of binding posts connect to the tweeter and mid-range components. I wouldn't recommend removing any of the internal crossover components.
    Cheers, Ken
  • mpitogompitogo Posts: 61
    really? what is the x/over point between the 6.5 and the 3" mid. I would have thought it could be a 703 split. I was looking to run a higher power amp for the two 6x9 with an active x-over at around 100hz and room correction such as the miniDSP 2x4HD.
  • afterburntafterburnt Posts: 2,929
    I am waiting with baited breath to see what you find. I like mine for HT but I have chosen a different tac with music.
  • F1nutF1nut Posts: 37,360
  • mpitogompitogo Posts: 61
    Well duh, just uncouple them... the 3" mid and tweeter are as @KennethSwauger pointed out connected to the upper binding posts. I'll have to figure out the rest.

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