A Sad Story About Accoustics..........

Discussion in 'Archived Threads 2001-2004' started by Jon D, Jul 1, 2002.

  1. Jon D

    Jon D Stunt Coordinator

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    Well, the unthinkable has happened, my SVS let me down. Not that it's the SVS's fault, but rather the room that it's in. The first room I placed it in was flexed and battered by the mighty tube, and I really liked that. Then I moved to a basement room, and after some tweaking, got the tube sounding pretty much like it did upstairs, aside from a noticeable drop in the really low bass (it only went to about 25 Hz before dropping, as opposed to 18 Hz upstairs). But it was a larger room, so I just accepted it. It still sounded great, just missing that extra subterranean boom. Now I've moved to a completely different house with a smaller room (only about 2/3rds the size of the old one), and despite having the exact same volume settings, the SVS sounds absolutely horrid. It's thin, tinny and almost completely lacking in any bass under 30 Hz. Yes, I calibrated again, and the volume level just didn't change. When I stand over the SVS, I hear all that glorious thunder that I've grown accustomed to (and feel the breeze), but when I move three feet back and sit on a couch, the bass all but dissapears. The SVS is in a corner and the couch is about a foot from the opposite wall. HELP! It boggles my mind that a *small* room makes the SVS sound worse than a *large* room. I know it's because of accoustics, but this just doesn't make sense. Somebody reassure my shattered nerves, because as it stands right now, my SVS sounds no better than my old 'consumer grade' sub.
     
  2. Jason Bell

    Jason Bell Stunt Coordinator

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    Sorry to hear that. I've read on this and other forums that the lower the bass wave the more distance it needs to really get going. I'm not speaking from experience though. I've only had one sub in one room[​IMG].
     
  3. Jeffrey Forner

    Jeffrey Forner Screenwriter

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    Hmm... Sounds like you and I need to do some trouble shooting when we see each other this weekend. There's no reason that subwoofer should sound "horrid."

    I'm not sure how big this new room of yours is, or if you can manage to place it in another spot, but you might want to look into finding a new location for it if you haven't already. I can tell you with a great deal of certainty that location does affect how a sub sounds.

    Recently I did some frequency sweeps on my system and found that the speakers on the right side of the room pumped out much deeper, louder bass than the speakers on the left. That should tell you why I put my SVS on the right side of the room. :wink:

    And if you need further reaffirmation that the 16-46PC is "good," stop by and I'll play your favorite scene from The Haunting DTS. That should do it.
     
  4. Jon D

    Jon D Stunt Coordinator

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    Jeff, I have fond memories of what my 16-46 can do, and I know that it's a good little cannon. I'm not blaming the sub, rather the absolutely hosed accoustics of this room. Like I said, it gives me a headache when I put my face over the top grille [​IMG]. It's just depressing that it sounds so anemic in the new room. I moved it behind my couch, and it sounds much better, but still far short of it's performance in the 'glory room'. I made a joke that my old house was ancient and the entire house frame was probably vibrating in sympathy to the SVS. The new house is more sturdy, but I will try the tried and true "stick it in your listening location and walk around the room" approach tomorrow. Hopefully, I'll find somewhere better (the room is only about 12x10 with a lot of annoying furniture)
     
  5. Jeffrey Forner

    Jeffrey Forner Screenwriter

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    Well, Jon, you have to remember that the room in which you originally placed the SVS was, for lack of a better word, tiny. I'm guessing the dimensions were something like 10' to 12' long, 7' wide, and with a 7' ceiling, leaving you with a room of 588 cubic feet at most. Not only did you have the benefit of a rickety old house that trembled at the might of the SVS, but you had a ton of cabin gain on your side.
    Perhaps you need to upgrade to the new driver for added "oomph!" Or better yet, bite the bullet and pre-order the forthcoming PC Plus line. Please do, because I'd like to hear one without having to purchase it myself! [​IMG]
     
  6. John Garcia

    John Garcia Executive Producer

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    Have you experimented with specific placement? Room size is a factor, but placement is also. You may just have a room shape that causes a lot of cancellation. "Listening position/walking around the room" should help identify this, but sticking it in a corner and taking some readings through the room may help also. My room is an odd shape, and I had to move my sub around to avoid cancellation at the listening position.
     
  7. Greg_R

    Greg_R Screenwriter

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    Sitting that close to a wall (1 ft) is going to cause a lot of problems. Figure out a way to sit away from the wall or try placing the sub in the nearest corner. Corner placement isn't always the best in every situation (but it's a good starting point). I would recommend taking some measurements of test tones with a RS SPL meter to see what is really going on (i.e. large dip a X Hz, etc.).
     
  8. Craig Woodhall

    Craig Woodhall Supporting Actor

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    It sounds like your sitting position is in a null, i think you are gonna have to move where you sit, or move where the sub is.. You need an SPL meter to *really* see what's going on.

    Craig
     
  9. Jon D

    Jon D Stunt Coordinator

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    I found a different corner that helped the bass a lot. It's still not as impressive as it used to be, but it's the best I can do with the circumstances. Placing the sub in your seat and walking around the room really helps. I found out that the original position of my sub was the worst place in the entire room, what're the odds?
     
  10. Wayne A. Pflughaupt

    Moderator

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    Jon,

    Smaller rooms can exhibit modes in the range of 60-70Hz. If they are bad enough they could overwhelm the lower frequencies, which would result in the lack of low bass you describe. Remember, when you set the sub to the “same level” as it was in another room, the SPL meter is merely reacting to whatever frequency is being generated at the highest level.

    I would to get a test disc and take some 1/6-octave response readings, as Greg suggested. This way you can know exactly what is happening instead of relying on subjective “seat of the pants” evaluations. I’m betting this, coupled with a parametric EQ, will restore the performance you are used to getting from your SVS.

    Regards,
    Wayne A. Pflughaupt
     
  11. Jon D

    Jon D Stunt Coordinator

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    Wayne, you're completely accurate. There are indeed large spikes around 70 Hz and 50 Hz, and every room I've used the SVS in has the same characteristic bump. The fact that the test tone on the Avia disc is mainly centered in those accentuated regions doesn't help. I could turn it up, but then the upper bass would be overbearing. I've known that I need to get a parametric EQ for a while, but the fact that I'm fresh out of college (re: broke as hell) kinda prohibits that right now. Maybe I should've splurged on the EQ instead of the laserdisc player[​IMG] .
     

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