Help with sub levels?

Discussion in 'Archived Threads 2001-2004' started by JamesMart, Feb 5, 2002.

  1. JamesMart

    JamesMart Agent

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    Ok, I just got the BFD and am trying to configure my audiosource sub for practice, so that when my SVS 20-39pc gets here next week I know how to configure it. Here is the data I got from my sub. This was data passing through the Outlaw ICBM crossed over at 80 Hz. I'm going to set up two presets one for my dvd with the recievers bass management, and one for my dvd with the outlaw handling the bass management. What do you all think of the data, it looks to me like I have a lot of work to do in order to tame the wild peeks. Can anyone sugest where they would start, possibly give me some ideas as to what peaks to tame, and the badwidths to use. Thanks for the help.
    Thanks,
    Jim
     
  2. Bob Christensen

    Bob Christensen Stunt Coordinator

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    James: I'm not seeing the data....
     
  3. JamesMart

    JamesMart Agent

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    sorry, I left out the link, it is there now
     
  4. Bob Christensen

    Bob Christensen Stunt Coordinator

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    A couple serious nulls that are going to be the hardest to deal with. The best way to deal with nulls is to pull down the peaks with your EQ. But to do so with your numbers, you are going to lose some serious horsepower in your system. Have you tried moving the sub around the room and seeing if it is a room interaction?
     
  5. JamesMart

    JamesMart Agent

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    Thanks Bob, I was thinking about putting my sub behind my TV. You can see what i'm talking about in THIS picture. You can also see the room I'm dealing with Here. My sub is currently against the sliding glass door to the right of the TV. I thought my data looked ok, due to the fact that I had lots of peaks to pull down. Am I wrong to think that I should start my 20 Hz tone at 75 db take my measurements, and then try to equalize all the peaks down to 75 db? Thanks for the help.
     
  6. Bob Christensen

    Bob Christensen Stunt Coordinator

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    I suspect that if you place the sub behind the TV (in the corner), that you will see significant changes in your data. Corner loading is typically better for subs (IMHO). You may find it tough to fit it in the corner, however, depending on your setup.

    As far as pulling down the peaks, you are right, you could probably do it. But you will have to feed the sub considerably more power to compensate. Since both your current sub and the SVSpc have their amp "on-board", driving them with more watts is not an option.

    The glass door adjacent to your sub may be causing some weird reflections. Try leaning a piece of carpet, or even hanging a sleeping bag behind the sub (temporarily) to see if it helps.
     
  7. JamesMart

    JamesMart Agent

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    Thanks Bob,

    I will try the sub back in that corner. That is where I use to have it, but I thought it was really boomy back there. I'm sure that glass door is probably messing with the acousics of the room due to the fact that it is flexible and could act like a giant woofer itself. Well, I like the Idea of hanging the sleeping bag, but if it does improve the conditions, how does this help me, I don't think I want to have a permanent sleeping bag hanging from my sliding door.

     
  8. Bob Christensen

    Bob Christensen Stunt Coordinator

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    The sleeping bag is not so much a fix as it is an aid to diagnosis. That would lead me to seek an alternate location.
    The corner loaded location MAY sound boomy. But it will likely be a single peak at about 50-60 hz, which can be more easily pulled down. When you relocate the sub behind the TV, also play around with rotating the sub in 45 degree increments and see if that helps the boomy nature. Sometimes this can have a tremendous impact in a corner-loaded setup.
    Also, I wouldn't overthink it too much, since it is a temporary setup, pending the SVS. Whatever setup and EQ you use with your current sub will likley go out the window with the SVS, and you will probably have to start from scatch (which, judging from the data may not be so bad [​IMG] )
     
  9. JamesMart

    JamesMart Agent

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    Thanks Bob,
    Yeah, this is a temp solution, but I'm trying to get experience with this sub, so that when the SVS gets here I can enjoy it, and not spend days tweaking it. Oh the people that live below me are going to hate me!!! [​IMG] I wanted to keep away from corner loading because I think it makes it worse on the people that live under me, but I guess if I can tame the peeks it will help in reducing the noise a little...
     
  10. Bob Christensen

    Bob Christensen Stunt Coordinator

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    You are likely to see a few dB increase due to corner loading room gains. I experimented with my SVS in 3 different locations in the room and was astounded how much difference corner loading made (at least in my case). I do not have to EQ, and I have a relatively flat response at my primary listening position. This was not the case when the sub was not corner loaded.

    WRT your question, the only option you have is to pull down the peaks. EQ is not effective at boosting the nulls, since you are simply trying to boost into an environment which swallows up those particular frequencies. So pull down the highest peaks little by little until you are satisfied with the SOUND. Most folks think that a lazer-flat response curve is the holy grail. But I have found that simply eliminating the worst spikes while not "overprocessing" the rest of the signal can be much more satisfying.
     

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