LSiM 705 have arrived

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Comments

  • ClipdatClipdat Posts: 4,959
    Ah, I see what you mean now. Thanks for the clarification! :)
  • shsshs Posts: 13
    edited July 31
    As to the original 705 that I needed to replace, there was very obvious harmonic distortion coming from the mid-bass driver that would stop if you touched it. See attached jpgs for the good right and bad left 705s. Polk replaced the driver, but the distortion was still there. Polk decided that it was likely a leak in the mid-bass driver compartment that spoiled the acoustic suspension loading of the driver, hence allowing it to move outside of its linear range. Polk chose to replace the whole speaker, which I greatly appreciated. e9qlhc7kxsy6.jpg
    5wr3qbyfuu9k.jpg
    SONY VPL-VW385ES, Da-Lite 92" 0.9 HD progressive 16x9 screen, Apple TV 4K, Oppo UDP 203, Anthem AVM 60, D-Sonic 4000 (800x3, 400x4) for bed layer, 2 Crown XLS 1002 (225x4) for Atmos; Speakers: Polk LSiM 705s, 703 front, 4 702F/X surround, 4 Polk TL3 (Atmos), Velodyne DD15 Subwoofer.
  • ClipdatClipdat Posts: 4,959
    Excuse my ignorance, which graph is for which speaker?
  • shsshs Posts: 13
    The top graph is the "bad" left speaker and with a ~250 Hz signal, you can see the harmonics at 500 and 750 Hz are only 20-30 dB down and there is lots of hash at higher frequencies. With the "good" right speaker, bottom, you don't see any obvious harmonics. This was all done with my phone and used to show Polk the nature of the distortions.
    SONY VPL-VW385ES, Da-Lite 92" 0.9 HD progressive 16x9 screen, Apple TV 4K, Oppo UDP 203, Anthem AVM 60, D-Sonic 4000 (800x3, 400x4) for bed layer, 2 Crown XLS 1002 (225x4) for Atmos; Speakers: Polk LSiM 705s, 703 front, 4 702F/X surround, 4 Polk TL3 (Atmos), Velodyne DD15 Subwoofer.
  • ClipdatClipdat Posts: 4,959
    Thanks again for the clarification, I sincerely appreciate it.

    What did that distortion sound like when you were playing music? Was it obvious?
  • shsshs Posts: 13
    The answer to your last question is, yes and no. With music, it depends and only happened when there was fairly strong content in the mid-bass frequency range. Also, this type of harmonic distortion is often done on purpose, e.g. “fuzz” with electric guitars, and in the colloquial, sort of sounds like farting. When I first heard it watching TV, I wasn’t sure whether it was part of the soundtrack, e.g intentional fuzz, or a problem with the speaker. However, I was hearing it more than I thought I should, so checked with a frequency sweep, and it was very obvious as distortion when played through the left channel but not the right. The fact that I could stop the distortion by lightly touching the driver’s surround told me that the mid-bass driver was being driven outside its linear range. I snapped an FFT analysis to get some idea as to the magnitude of the distortion, as can be seen above.
    SONY VPL-VW385ES, Da-Lite 92" 0.9 HD progressive 16x9 screen, Apple TV 4K, Oppo UDP 203, Anthem AVM 60, D-Sonic 4000 (800x3, 400x4) for bed layer, 2 Crown XLS 1002 (225x4) for Atmos; Speakers: Polk LSiM 705s, 703 front, 4 702F/X surround, 4 Polk TL3 (Atmos), Velodyne DD15 Subwoofer.
  • halohalo Posts: 4,479
    shs wrote: »
    The answer to your last question is, yes and no. With music, it depends and only happened when there was fairly strong content in the mid-bass frequency range. Also, this type of harmonic distortion is often done on purpose, e.g. “fuzz” with electric guitars, and in the colloquial, sort of sounds like farting. When I first heard it watching TV, I wasn’t sure whether it was part of the soundtrack, e.g intentional fuzz, or a problem with the speaker. However, I was hearing it more than I thought I should, so checked with a frequency sweep, and it was very obvious as distortion when played through the left channel but not the right. The fact that I could stop the distortion by lightly touching the driver’s surround told me that the mid-bass driver was being driven outside its linear range. I snapped an FFT analysis to get some idea as to the magnitude of the distortion, as can be seen above.

    Great job on recognizing and diagnosing the issue!

    Now I have to be über diligent when listening for any issues.

    Thank you for posting this information.
  • joecoulsonjoecoulson Posts: 942
    In my opinion, the mid bass driver (which I have already replaced one in my 705’s) are the weak links of these speakers. Otherwise very stellar.
  • halohalo Posts: 4,479
    joecoulson wrote: »
    In my opinion, the mid bass driver (which I have already replaced one in my 705’s) are the weak links of these speakers. Otherwise very stellar.

    Hmmm. Design flaw?
  • joecoulsonjoecoulson Posts: 942
    Not sure. They seem to move more than the subwoofers when driven hard. Could be a design flaw in the power distribution between the drivers but I’m not sure.
  • halohalo Posts: 4,479
    Ok. I don’t drive them that hard. Even when I played the soundtrack to Blade Runner 2049 the only drivers visibly moving were the Cassini woofers / subs
  • SCompRacerSCompRacer Posts: 6,949
    halo wrote: »
    I don’t drive them that hard.

    Crank 'em up to 11..... B)
    Make yourself necessary to someone. Ralph Waldo Emerson

    Salk SoundScape 8's * Audio Research Reference 3 * Bottlehead Eros Phono * Park's Audio Budgie SUT * Krell KSA-250 * Harmonic Technology Pro 9+ & Pro 11+ * Signature Series Sonore Music Server w/Deux PS* Twisted Pear Buffalo III Dual Mono ESS Sabre32 DAC * 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 *

  • DaveHoDaveHo Posts: 2,019
    Crossover to the cassinis is too low IMHO. That said, they sound spectacular withn the limits.
  • joecoulsonjoecoulson Posts: 942
    DaveHo wrote: »
    Crossover to the cassinis is too low IMHO. That said, they sound spectacular withn the limits.
    I agree
  • halohalo Posts: 4,479
    DaveHo wrote: »
    Crossover to the cassinis is too low IMHO. That said, they sound spectacular withn the limits.
    joecoulson wrote: »
    I agree

    Would’ve been nice to know this before I bought them :#
  • joecoulsonjoecoulson Posts: 942
    Not saying I don’t love them, I do. But even great products have their flaws. You will not regret buying them.
  • DaveHoDaveHo Posts: 2,019
    While they are not SPL monsters, you don't need to baby them. I have never bottomed out the mid-woof. That said, when running them full range, the 5 1/4 driver really moves. Play Pink Floyd, Mother & crank it up some. You'll see what I mean.
  • txcoastal1txcoastal1 Posts: 9,966
    Agree with Dave ^^^^ above

    Right after the 705's were born and Russman still was a Polk rep we jammed these babies at LSAF for their debut...and you know how we do it at LSAF ;) B)

    From 12watts to 200+ watt amps these babies can play....do a search here on the forum :)
    2-channel: Modwright KWI-200 Integrated, Dynaudio C1-II Signatures
    Desktop rig: LSi7, Polk 110sub, Dayens Ampino amp, W4S DAC/pre, Sonos, JRiver
    Gear on standby: Melody 101 tube pre, Unison Research Simply Italy Integrated
    Gone to new homes: (Matt Polk's)Threshold Stasis SA12e monoblocks, Pass XA30.5 amp, Usher MD2 speakers, Dynaudio C4 platinum speakers, Modwright LS100 (voltz), Simaudio 780D DAC
  • halohalo Posts: 4,479
    DaveHo wrote: »
    While they are not SPL monsters, you don't need to baby them. I have never bottomed out the mid-woof. That said, when running them full range, the 5 1/4 driver really moves. Play Pink Floyd, Mother & crank it up some. You'll see what I mean.

    Performed this "test" with no major cone movement visible. This is probably because I live in an apartment & the "loudest" listening levels I get to here aren't very loud (perhaps by forum standards?). lol.
  • shsshs Posts: 13
    edited August 1
    The 705s certainly play loud enough for my purposes, and I live in a large house some distance from the neighbors with a dedicated home theater. Let's see if my signature block now has info. Tried several times, but no luck.
    SONY VPL-VW385ES, Da-Lite 92" 0.9 HD progressive 16x9 screen, Apple TV 4K, Oppo UDP 203, Anthem AVM 60, D-Sonic 4000 (800x3, 400x4) for bed layer, 2 Crown XLS 1002 (225x4) for Atmos; Speakers: Polk LSiM 705s, 703 front, 4 702F/X surround, 4 Polk TL3 (Atmos), Velodyne DD15 Subwoofer.
  • jayu969jayu969 Posts: 105
    Nice reviews...considering getting a pair of 705's myself.
  • mhardy6647mhardy6647 Posts: 19,568
    lightman1 wrote: »
    Manticore wrote: »
    lightman1 wrote: »
    Manticore wrote: »
    lightman1 wrote: »
    I don't have a home....

    Yeah but is any of your equipment located close by? :)

    Where you at?

    I was just funnin with you since you seem to have equipment in many,many states. B)
    Southern NH, about an hour S SE of @mhardy6647

    You're in luck.... There is a big amplifier of mine floating around near you. Call Doc.

    It is true, but the amplifier in question is still in rehab.
    We wanted it to go to rehab, and we said, yes, yes, yes.
  • verbverb Posts: 4,001
    halo wrote: »
    F1nut wrote: »
    Victor, if you call Conrad-Johnson they will tell you that Steve McCormack is no longer there.........just saying ya know.

    Yes, I caught that thread. ;)

    Thankfully, SMC is up and running in California!

    That Conrad Johnson amp @verb has looks like a beast

    Hey Vic just caught this. Yes it is! I've got it paired with the VTL pre and SRS's with new tweeters. Still breaking em in, but so far sounds fantastic! Was playing the new Bill Idol album rather loud last night and the CJ didn't break a sweat! :smile:
    Basement: Polk SDA SRS, Micro Seiki MB14 TT, VTL 2.5 Preamplifier, Marantz CD6006 CDP, Conrad Johnson MF2300A Amp, Furman 15PFi Power Conditioner, AQ Diamondback (version 1) RCA IC's, MIT Terminator2 Bi-Wire speaker cables
    Office: PC, Marantz CD-1, Marantz AMP-1, Acoustic Technologies Classic Speakers, Polk PSWi225 wireless sub, MIT AVt2 speaker cables, IFI Purifier2, AQ Cinnamon USB cable
    Spare Room: Dayens Ampino Integrated, Project BoxE, Polk TSi200's
    Living Room: Pioneer SX-N30 Network Receiver, Pioneer PD10AE CD Player, Furman M8-LX Power Conditioner, Polk RT265 In Wall Speakers, Polk DSW Pro 660wi Subwoofer
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