Low-Frequency Distortion Magnifi Subwoofer

I've been testing out soundbars and am currently trying to decide between a 6500BT and Magnifi. One of my tests is playing James Taylor's "Gaia" (from Hourglass). The bridge includes some very low frequencies that extend for several seconds. When I play this portion of the song on the Magnifi (medium volume, bass at full or -1, music or movie mode), there's a distinct flapping/farting sound as the sub is unable to reproduce the notes. If I lower the volume or bass level further, the problem goes away and the sound cleans up, but my testing is nowhere near full volume for the unit, so I would expect it to be able to keep up.

When I tested it with the Magnifi One, it was able to reproduce the note (I returned that unit, though, because overall performance was not on par with the 6500BT). When I play it with the 6500BT at the same volume (and with the sub at it's max setting) there is no distortion, but the bass is also not as present as it is with the Magnifi.

So... is this characteristic/expected and only addressed by reducing the volume or bass level, or does it seem likely to be a defect in my unit that may be resolved by exchanging it for another?

Answers

  • tonyb
    tonyb Posts: 32,902
    Probably best you call Polks customer service. As a rule of thumb, full volume on anything is bad. What size room to you have this in ? Could be your just over driving the unit.
    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
  • I'll give them a shout... I know I was not at full volume, but I don't know how far up I was (the downside of no analog dial!). It's in a large room and was playing at a good volume to fill the room, but I know when I tested the same song, same source, and same room with the Magnifi One it didn't show the same issue. I may just return it to the retailer to try another unit (still within my return period).

    I'm also hoping to snag a Klipsch R-10B during the boxing day sales in Canada for about the same price, so depending on how that sounds it may not matter. From what I've read it's a bit of a pain to not have a remote subwoofer adjustment with the Klipsch, but the overall clarity and balance is supposed to be very good for the price, and the sub is a bit larger, which may help to cope with those low frequencies.
  • tonyb
    tonyb Posts: 32,902
    If it's a large room, I can understand you pushing the volume to fill the room but in reality....soundbars aren't meant to bang it out in a big room. Could be just a matter of too small of a speaker in too large a room. I'd return it and try another just to be sure.
    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
  • That makes sense. It's close, but I think I do prefer the Magnifi to the 6500BT. I'll get another Magnifi to see if the distortion is just a defect with this particular sub, test it against the Klipsch R10B and see who earns the permanent spot in the living room...
  • Chucky
    Chucky Posts: 4
    Just wanted to close the loop on this... I exchanged the Magnifi and the second unit was better than the first - not completely clean in that portion of the song, but far less of the completely broken up distortion. In the end, I decided to keep the Klipsch R-10B, rather than the Magnifi.

    The bass isn't as powerful as it is in the Polk and the soundstage is a bit narrow, but there is far more clarity, space, and precision in the mids and high end with details like reverb around vocals and acoustic guitar. When comparing back and forth, listening to the Klipsch made the Polk sound like there was a blanket over it... it was just missing some sparkle, even though it has lots of presence. The sub on the Klipsch is a bit less powerful, but it is also cleaner with a lower crossover point, so it stays out of the way (less rumbling under dialog, for example) when it's not needed.

    The subwoofer kicking in where it shouldn't be bothered me from first listen, but other than that the only way I was dissatisfied with the Polk was to compare it to the Klipsch. If the Klipsch hadn't measured up I would have kept the Polk and been quite content - it's a good unit, just not quite as well-suited to my need and my ears.