Funny sound SVS subwoofer.

Discussion in 'Speakers & Subwoofers' started by JohnSmith, Oct 21, 2004.

  1. JohnSmith

    JohnSmith Supporting Actor

    Joined:
    Apr 8, 2003
    Messages:
    554
    Likes Received:
    0
    Trophy Points:
    0
    I've had my SVS PC Plus for a while now, and just recently it's lost that "impact" on low material. For example the plane planding that flies over the heads of Buzz and crew (Toy Story 2, end of film). I've double checked the processor settings, and output, settings on the subwoofer itself. Subwoofer is in the same place, so is mic. No new furniture. Sub has been next to main right (never moved) correct distance entered. Pahse has always been at 0. I'm stumped.

    See graph. In pink was the earlier graph, in blue is the most recent. I have no idea why this has changed so much.

    Settings are 80hz for all, sub sonic set to 20hz, no ports plugged. In a 750 cu foot room.

    I have no parametric equalizer. Lexicon MC-1 subwoofer out to input on the SVS.

    The MC-1 was repaired (faulty PSU) I reset the unit back to defaults then went back to my usual settings.

    http://nathansilly.012webpages.com/chart100.JPG

    cheers
     
  2. Mark Seaton

    Mark Seaton Supporting Actor

    Joined:
    Oct 10, 1999
    Messages:
    599
    Likes Received:
    0
    Trophy Points:
    110
    Real Name:
    Mark Seaton
    We can't see the graph as it is posted. It only makes sense that the changes are in the MC-1, especially if the measurements say so. If we saw the graph it would be easier to suggest possibilities. What were you using as test tones?
     
  3. Ilkka R

    Ilkka R Second Unit

    Joined:
    May 19, 2004
    Messages:
    270
    Likes Received:
    0
    Trophy Points:
    0
    Copy the link into another window, then you see it.
    I'd say there is something wrong with the xo. Seems like the xo-point has gone up to 160Hz.
     
  4. JohnSmith

    JohnSmith Supporting Actor

    Joined:
    Apr 8, 2003
    Messages:
    554
    Likes Received:
    0
    Trophy Points:
    0
    Correct, copy + paste into IE to view the jpeg.

    No, all currently at 80hz for L,C,R,RS,LS,RR,LR & subwoofer (and always have been all @ 80hz)
     
  5. Ilkka R

    Ilkka R Second Unit

    Joined:
    May 19, 2004
    Messages:
    270
    Likes Received:
    0
    Trophy Points:
    0
    Yes, but what if it's broken? Can you test it with a different processor?
     
  6. JohnSmith

    JohnSmith Supporting Actor

    Joined:
    Apr 8, 2003
    Messages:
    554
    Likes Received:
    0
    Trophy Points:
    0
    Yeah, a mate's got a Lexicon DC-2 V4. I'll ask him to bring it round, and will do a reponse graph.

    I've also got a Hi-Fi stereo system.

    Btw to get that "impact" bass I used to get I have to now calibrate subwoofer to +10dB over others (since low bass seems to have inverted (low bass=low spl, mid bass=higher spl)
     
  7. ScottCHI

    ScottCHI Screenwriter

    Joined:
    Feb 21, 2004
    Messages:
    1,292
    Likes Received:
    1
    Trophy Points:
    0
    phase didn't get flipped somewhere, somehow, did it?
     
  8. JohnSmith

    JohnSmith Supporting Actor

    Joined:
    Apr 8, 2003
    Messages:
    554
    Likes Received:
    0
    Trophy Points:
    0
    Doubt it.
    Digital audio from DVD player to Lexicon, Lexicon RCA output to subwoofer. Phase on sub to 0. Same cables as before. Correct distance entered.

    I've reset the MC-1, disabled loudness, and will re-calibrate the sub 85dB (which I did in the past) I'll redo the response graph, and also with loudness enabled.
     
  9. JohnSmith

    JohnSmith Supporting Actor

    Joined:
    Apr 8, 2003
    Messages:
    554
    Likes Received:
    0
    Trophy Points:
    0
    Right I tried the tones with my laptop USB to optical to DAC, then pre-amp to the SVS (crossover disabled) the graph looks similar to my old one (chart100) - pink line (peak at 22hz, then trailing down off to 64

    I've also plotted with the sub calibrated to 85dB, and with loudness on and off, it matches the blue line. So I'm sure it's the Lexicon MC-1.

    I'll try the DC-2 tomorrow. If that reports as a different response (same settings) then it must be the MC-1.
     
  10. JohnSmith

    JohnSmith Supporting Actor

    Joined:
    Apr 8, 2003
    Messages:
    554
    Likes Received:
    0
    Trophy Points:
    0
    OK I tried with the Lexicon DC-2, it shows the same graph (71hz area being much higher) so it's not the source at fault.

    Is the sub faulty? Tom/Ron?
     

Share This Page