LSiM 707s: 2.5-3 dB difference

alucididea
alucididea Posts: 113
edited June 2018 in Speakers
So I hooked up my new preamp and as I was listening and setting up, I’m hearing a solid difference in output between the 707s. When the balance is even, I’m clearly hearing the right channel higher. And even when I I shove the balance over 2.5-3 dB, they sound sort of even, but even the right still pushes more high frequencies. It’s driving me pretty crazy, truth be told.

I’m going to hook up a couple other sets to speakers to troubleshoot before I contact Polk. I’d rather not have to try and send one/either of them in, especially since both the boxes got relatively destroyed in shipping.

Is this sort of thing normal in production to have such a difference between units?

Comments

  • FestYboy
    FestYboy Posts: 3,861
    No, I'd be checking the bias on the preamp before condemning any speakers.
  • alucididea
    alucididea Posts: 113
    edited June 2018
    FestYboy wrote: »
    No, I'd be checking the bias on the preamp before condemning any speakers.
    No bias switches on either amp or preamp. NAD M22/M12
  • FestYboy
    FestYboy Posts: 3,861
    Reading the first post (to me) indicates that this issue only presented itself after the preamp was installed. If this is wrong, please clarify.
  • tonyb
    tonyb Posts: 32,902
    edited June 2018
    FestYboy wrote: »
    Reading the first post (to me) indicates that this issue only presented itself after the preamp was installed. If this is wrong, please clarify.

    That's my take also.

    If the new pre is of substantial improvement over what you had been using, what your hearing may be just simply a better separation of instruments and imaging. Also placement of the speakers in relation to your listening position and room reflections can also give the illusion of one speaker being louder. I highly doubt it's the speakers.

    Check all your wire connections also.
    HT SYSTEM-
    Sony 850c 4k
    Pioneer elite vhx 21
    Sony 4k BRP
    SVS SB-2000
    Polk Sig. 20's
    Polk FX500 surrounds

    Cables-
    Acoustic zen Satori speaker cables
    Acoustic zen Matrix 2 IC's
    Wireworld eclipse 7 ic's
    Audio metallurgy ga-o digital cable

    Kitchen

    Sonos zp90
    Grant Fidelity tube dac
    B&k 1420
    lsi 9's
  • Clipdat
    Clipdat Posts: 12,559
  • alucididea
    alucididea Posts: 113
    Clipdat wrote: »
    Any updates?
    Sorry, none yet. I’ve been a little too busy to do a full troubleshooting with it all.
  • GospelTruth
    GospelTruth Posts: 403
    Sounds obvious, but did you switch the speakers and move the right one to the left and the left to the right? If the one speaker is still lower when moved, then you've isolated it to the speaker. If it's still the right channel, then it's your pre or room. Best way to see if it's the speaker though.
    Speakers
    Energy RC-70 Mains, Energy RC-LRC Center, Energy RC-R (x4) Rear Channels, Energy RC-R (x2) Front Effects
    Polk 5jr+
    Polk SDA 2B
    Polk SDS 3.1TL

    Equipment
    Panamax 5510 Re-generator Power Conditioner
    Yamaha RX-V3800 Receiver
    Digital Sources: Sony CDP-X339ES CD Player, HHB CDR830 BurnIt Professional CD Recorder, Sony PS3, Oppo DV-983H DVD Player
    Analog Sources: Sony TC-K890ES Cassette, Nakamichi DR-1 Cassette, Technics SL-7 Turntable
  • alucididea
    alucididea Posts: 113
    edited June 2018
    Sounds obvious, but did you switch the speakers and move the right one to the left and the left to the right? If the one speaker is still lower when moved, then you've isolated it to the speaker. If it's still the right channel, then it's your pre or room. Best way to see if it's the speaker though.
    So I tried switching the channels at the input, no help. I just switched the speakers a few minutes ago. In both cases it still leans to the right, so it’s not the speaker.

    If it’s not the speakers or the pre, it’s either the cables or room. Obviously I’m trying the cables next.
  • joecoulson
    joecoulson Posts: 4,943
    Room dynamics for me always changes the perceived output of each side. I have windows/Wall left and open right so it always sounds louder from the left side. I’m sure that’s obvious but...
  • alucididea
    alucididea Posts: 113
    I’m not positive, but I think I may just have some hearing loss in my left ear. Maybe one too many loud concerts or something. Guess I’m going in to get my hearing checked...
  • Airplay355
    Airplay355 Posts: 4,298
    Can you use a db meter app or db meter to test individual channels? Or, unplug a speaker and do it the old fashioned way :)
  • alucididea
    alucididea Posts: 113
    edited July 2018
    Airplay355 wrote: »
    Can you use a db meter app or db meter to test individual channels? Or, unplug a speaker and do it the old fashioned way :)
    Maybe. I didn’t even think to check for an app. I’ll have to look into that.
  • Airplay355
    Airplay355 Posts: 4,298
    I have a free db meter app just called db meter. Seems to do the job well enough. It's not something I would use to setup room correction software but maybe it will help you figure out if one speaker is a few db lower than the other. It's an iOS app but maybe there's an android version as well.