SVS Phase Settings

Discussion in 'Archived Threads 2001-2004' started by Pete Austin, Mar 7, 2003.

  1. Pete Austin

    Pete Austin Agent

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    Hey All,

    Contrary to the advice of many fellow forum members I've been runnig my SVS PC+ in conjunction with an older Sony 12" powered sub for a few months now. I am totally happy with the sound I'm getting with my system but the more I read on the forum the more I start to wonder about my two subs being out of phase. Both subs are in the front of a 10x16 room in their own corners. Since I've never previously messed with the phase settings I can't help but wonder if I'm missing out on any performance/output. I'm not sure what to listen for when adjusting the phase knob on the SVS. My question is; how do I properly calibrate phase settings, and can I use AVIA to do it? Thanks.
     
  2. Edward J M

    Edward J M Cinematographer

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    Since the Sony is probably only 0 or 180, I would leave the Sony at whichever setting provides the best bass with it alone, and then of course use the variable control on the SVS to fine tune.

    You will need a partner for this - one to watch the SPL meter at the key listening positions and the other to run the SVS' phase control through its entire range while a continuous bass calibration tone runs (at a reasonable volume). If you have a CD burned with individual bass tones, I would try this experiment at a few different frequencies to make sure room modes aren't giving you false positives.

    You will hit a "sweet spot" on the phase control where the subs obviously reinforce each other and the SPL meter will jump right up; and it will be equally obvious where they cancel each other and you create a null and the meter will drop right off.
     
  3. Pete Austin

    Pete Austin Agent

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    Thanks,

    That's kind of what I figured the process was. Seems simple enough. Any advice on where I can acquire a continuous bass calibration tone, or for that matter bass tones of various frequencies? Burning them once I have them is not a problem. Does AVIA have anything on it that is continuous and not a sweep? Thanks again.
     
  4. jeff_coil

    jeff_coil Stunt Coordinator

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    Hi Pete try these

    Waves

    And be careful not to run these to long or to loud. Below is an E-Mail I sent to the SVS fellas on the same subject

    Hello Fellas! Hey I remember I think Ron stating on the HTF that sine waves can smoke a sub? I am planning on doing some analysis this weekend and was going to use these tones/waves (using Avia I can see I have some serious house curve issues) I found here http://www.snapbug.ws/sinewaves/ These were recommended from a home page on how to setup a BFD. Can I use these or do you have or recommend something different?

    Thanks Jeff

    SVS Reply

    Hi Jeff,

    Those sinewaves will work, but do NOT have the subwoofer producing more than say 70-75dB measured 1 meter from the subwoofer. And I would only run these about 10-15 seconds at a time too…allowing the voice coil to cool down for 30 seconds or so between each test.

    Tom V.
    SVS

    Hope this helps...Good Luck
     
  5. Pete Austin

    Pete Austin Agent

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    Thanks Jeff,

    I apreciate the link for the waves but I'm a little worried about having to look at my watch, work the remote to stop the cd at the right time, adjust the phase knob, and communicate with my helper at the same time with very little room for error. Not to mention the possibility of nuking my driver. Are there any other alternatives or bass tones that I can use that I don't have to be quite so exactin with? Since no one has chimed in on the AVIA issue I'm going to assume that there is no constant bass test tones within it.
     

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