Subwoofer Help?

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  • 09-17-2004, 05:54 PM
    Marc B.
    Subwoofer Help?
    I have a Velodyne CHT-12 sub. which I run at almost half volume.
    My mains are Polk RT55i
    Rear Polk RT15i
    Center Polk CS400i
    Amp Onkyo 484
    55 watts per channel
    Any input on correct Velodyne sub volume?
    My other speakers are set with a sound level meter.
    I tried to set the sub with it and it did not sound loud enough.
    I was told by a few audio pros the sub needs to be set by ear.
    Any input on sub volume?

    Thanks'
    Marc
  • 09-17-2004, 06:12 PM
    cam
    Quote:

    Originally Posted by Marc B.
    I have a Velodyne CHT-12 sub. which I run at almost half volume.
    My mains are Polk RT55i
    Rear Polk RT15i
    Center Polk CS400i
    Amp Onkyo 484
    55 watts per channel
    Any input on correct Velodyne sub volume?
    My other speakers are set with a sound level meter.
    I tried to set the sub with it and it did not sound loud enough.
    I was told by a few audio pros the sub needs to be set by ear.
    Any input on sub volume?

    Thanks'
    Marc

    If you set all your speakers including subwoofer at the same db you will be disappointed with your sub. Rule of thumb is to set your sub 3-6 db higher for the fact that human hearing is less sensitive below 100 hz. I set my sub 5 db higher.
  • 09-17-2004, 06:15 PM
    markw
    If you've been on this forum for a while, I'm sure you've heard or read about using a test DVD anda meter so do the initial setup of your speakers. If not, consider it. It's good advice. Then, you have a point of reference with a known. Should you then decide to "tweak" it a little, at least you will know how far off from the standard you will be should you decide to it.

    And, you should be able to adjust the subwoofer level on the receiver if I recall correctly.

    Learn to love your manuals.
  • 09-17-2004, 06:15 PM
    N. Abstentia
    Set it to where it sounds best. That's the only way to do it. You can't follow a 'formula' for setting the sub up, since there are way too many variables. Put it where it sounds good, leave it.
  • 09-17-2004, 06:27 PM
    Dusty Chalk
    To set it for music:

    Turn the sub all the way down. Put on some music, preferably, some with some particularly extended bass content (notice, I didn't say, "heavy" bass content -- not something with a lot of bass, but something that goes down very low). Turn the entire system up to the loudest you will ever listen to it. Now turn up the sub until it sounds right.

    To set it for movies:

    Turn the sub all the way down. Put on a movie, preferably some with some particularly extended bass content. Turn the entire system up to the loudest you will ever listen to it. Now, turn the sub up until it sounds right.

    Be particularly careful with movies -- a lot of movie-makers use "subliminal" sub effects to garner a mood. Really low level bass drones to enhance the "eerie". Make sure those aren't too loud -- if they're truly audible, rather than felt (as is often the case if you have your sub set too loud -- it starts to clip), the effect is ruined.
  • 09-18-2004, 11:31 AM
    Woochifer
    I think you also need to play around with the positioning. The thing about setting a sub with a SPL meter is that the reading can be distorted by large peaks caused by the room acoustics. This will equally influence your setting if you set the sub level by ear. These peaks make the bass sound boomy with some sounds, and anemic with all others. Conversely, cancellations can also occur at specific areas in the room, which cause gaps in the bass response. Also, keep in mind that in typical small-to-medium sized room the bass can sound very different in one part of the room than another.

    What you need to do is first reposition the subwoofer so that you get the fullest and most even sounding bass, not just where it's loudest. You'll often hear recommendations to place the sub in the corner, and that is where you get the maximum reinforcement. But, the corner placement can also be unpredictable with regard to the kind of bass that you get.

    If moving the subwoofer around and playing with the level does not give you what you're looking for, then you should do some testing using test tones and the SPL meter. If you find severe peaks in the frequency response at specific frequencies, then you should look into a parametric equalizer. I use one with my subwoofer and it single handedly transformed the bass in my room from unacceptably boomy to full, even, and well integrated with the rest of the system. Easily the best $120 I've invested in my system. Link to the before and after in-room response with my system is below.l

    http://members.aol.com/sfwooch/

    Cam's suggest of raising the subwoofer level about 4-6 db higher than the other speakers follows what a lot of others on this board have concluded is the optimal setting.