Do I need to EQ too?

Discussion in 'Archived Threads 2001-2004' started by Jay C, Feb 3, 2002.

  1. Jay C

    Jay C Extra

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    Hello,

    I have been living with my SVS 25-31PC for a little over a week now, and the urge to tweak is getting worse. On a different thread I had posted that my sub sounded really boomy (day 1) so I enabled the crossover on the amp to tone it down. Today I bypassed the sub, and no boominess but I did get my mid range back (didn't really know it was gone, I guess the fronts were compensating.

    Anyway, here are my spl readings from 14' away from the sub, Styke disc, and only sub connected. Also, crossover set to 100Hz on receiver, and sound calibrated to 75dB at 1kHz (FWIW).

    Hz dB

    17.5 60

    20 70

    22 71

    25 78

    28 79.5

    32 81

    36 83

    40 76

    45 84

    50 78

    56 81

    63 71

    71 77

    80 75

    89 55

    100 63

    112 74

    3 valleys at 40, 50, and 89

    Thanks in advance, and if you are in the Memphis area and want to hear the SVS 25-31PC let me know.

    Jay
     
  2. Brian Fellmeth

    Brian Fellmeth Supporting Actor

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    A bfd would clean that up nicely. If you like to tweak, its a tweakers paradise.
     
  3. Rick Radford

    Rick Radford Supporting Actor

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    I notice that you have peaks: ~35, 45 and 55 Hz that I also found in my setup. My room is roughly 12 x 12 x 8.

    Is this a room dimension commonality? Or what might peaks at those freqs be related to?

    Just curious. For the record my BFD cleaned those up nicely too, Brian.
     
  4. JerryW

    JerryW Supporting Actor

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    Square rooms really play havok with acoustics. You might want to try repositioning the sub, maybe even away from the corner a couple feet, along one of the walls.

    To be honest though, your numbers are so bad. If repositioning doesn't clean it up as much as you'd like, the BFD would work wonders for you.
     
  5. Jay C

    Jay C Extra

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    Rick,
    My room is 16' x 27' x 8'.
    Jerry,
    Can I assume that you meant aren't so bad? the only one that really bothers me is the valley at 40Hz.
    I have seen an online store called Lentine,
    AllPro Sound, BSW. That carry the new DSP1124P for $129.
    Anyone have any dealings with any of these? Which is recommended?
    Thanks again,
    Jay
     
  6. Rick Radford

    Rick Radford Supporting Actor

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    Jay,
    Well, except for the 8' ceiling, your room is totally different than mine!
    I used Lentines. Another place I've heard recommended is: http://www.musiciansfriend.com/
    Or: this link to see how mine turned out with just my 2nd try. I sometimes have problems with GeoCities.. or else I am just inept in trying to post a graph here.
    Rats, I see neither works. Sorry! I do not know why I can't post a link to my freebie GeoCities site where I have this stuff loaded.
    How do you plan to collect the data? Manually or RTA software?
     
  7. JerryW

    JerryW Supporting Actor

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    Yes, I meant "aren't so bad". Oops. [​IMG]
     
  8. ling_w

    ling_w Second Unit

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    If you can change the crossover freq for the sub, maybe you could lower it to 80hz or lower and see how smooth the main speaker is in that region.

    You might be sitting too close to the center of the room, which might be causing the giant suckout at the room mode freq. You might try pulling your sub out 1/5 of the way from the corner, and place your seating position 2/5 the way from the back. This should minimize the peaks and nulls that you might be encountering.
     
  9. Jay C

    Jay C Extra

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    Rick, ok I will concentrate on the peaks then to bring them to the valleys. Not sure why your link didn't work in IE, but I was able to see the pics in Netscape. I had panned to do it by hand with Styke's disc and the RatShack SPL meter. There are only about 17 tracks to go through. I did notice in your pics you were using ETF. Is it fairly easy to use? Does it require purchase if all I want is a one shot tweak?
    JerryW, what is considered good enough? 3dB peaks/valleys from one band to the next? That one at 40 is -7 and -8 between 36 and 50.
    Ling_W, The crossover from my receiver has a low setting of 100Hz (Pioneer VSX-409) so I'm sort of stuck there. As for moving the room around, I share it with my wife and have made some sacrifices to accomdate both of us. That said, there is only one place the sub can go without ripping holes in the walls. It's by no means the ideal spot (perhapse the worst) as it is located front center wall (almost center of the room as you guessed). This wall has two openings to other areas, the worst being the 2-story entry foyer. I am happy with the bass content can can not go any loader than 105dB before I have to turn it down.
    I'm sure I could be happy with how it is, but like I said, there is that part of me that likes to tweak (thanks to all of you guys posting your tweaks). I need to find room for the BFD now, the AV cabinet is loaded to the gills. I appreciate all of the feedback. I will let you know if/when I get the BFD [​IMG] Also, when I get a free host, I will post pics of my room and let you see the SVS in a new light.
    Jay
     
  10. JerryW

    JerryW Supporting Actor

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    Try repositoning the sub, you should be able to get better numbers (with a little work). If worst comes to worst, then get a BFD. With it I'm sure you'd be able to get +/- 3dB from 25-100Hz because your unadjusted readings "aren't that bad". Trust me, I've seen worse... much worse.

    And yes, +/-3dB for the enitre band is the target.
     
  11. Jay C

    Jay C Extra

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    Ok guys, after about 10 minutes at Geocities, I have a site:
    [​IMG]
    I what the SVS looks like on it's side. Here is one (sorry for the lighting, I will take better ones and update soon) a bit further back so you can understand the asthetics part [​IMG]
    [​IMG]
    JerryW, thanks for the advice.
    My new site is at Couture's Home page
    Jay
    PS: That's the old Sony sub off to the right.
     
  12. JamesMart

    JamesMart Agent

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    Whoa!, I have never seen an SVS positioned that way? Where did you get that stand? Are there any problems with it in that position?

    Thanks,

    Jim
     
  13. Rick Radford

    Rick Radford Supporting Actor

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    Jay,
     
  14. Jay C

    Jay C Extra

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