Interesting observation

Discussion in 'Speakers & Subwoofers' started by Ilia, Jan 10, 2005.

  1. Ilia

    Ilia Extra

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    While tuning my sub/speakers setup, I heard a gap between base and mid-range. Adire Rava sub was crossed at 80 Hz to match my Nakamichi AV-10 receiver crossover point while listening to stereo. B&W 602 S3 speakers were set to small. The gap disappeared and base "connected" to the rest of the frequencies when I notched up the sub to 100Hz - the problem is that base lost a bit of accuracy. Does anyone hava any idea why speakers and sub don't blend in at 80 Hz? Nakamichi AV-10 is a reveiver.
    BTW, lower freq/ cut-off used in sub - absolutely hated "Full" setting on Rava.
     
  2. Ricky c

    Ricky c Stunt Coordinator

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    I believe you need to set the sub crossover all the way or disable it.
     
  3. Jeff Gatie

    Jeff Gatie Lead Actor

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    This is the problem. You are essentially applying two crossovers to the sound. Since a crossover is not a brick wall, it rolls off higher frequencies to the sub, but they are still there, although lower in volume (i.e. the sub is playing part of these higher frequencies and the mains are playing the rest). Since you are applying two 80Hz crossovers, the first rolls off the higher frequencies correctly, but the second crossover also rolls them off, thus increasing the slope of the crossover and losing those higher frequencies (i.e. the main speakers are still playing their part of the frequencies, but the sub's part has been significantly reduced). Ricky's advice is correct. Set the sub's crossover to the highest setting or disable it if possible.
     
  4. Ilia

    Ilia Extra

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    Let me understand it. Receiver's crossover distributes everything above 80Hz to the mains and LFE signal (160Hz and below) to the sub. Therefore, the interval between 80 and 150Hz is being reproduced by both mains and sub. It felt like the sound was too reach or perhaps boomy in the lower rantge with this setup, and that's why I decided to play with sub's crossover. 80Hz created a gap as I atated earlier but 100Hz seems to sound fine. Jeff and Rickie, you're saying I have to turn subs cross to max (160Hz)since I can't disable sub's cross. Should I decrease the subs volume then? Thanks!
     
  5. Jeff Gatie

    Jeff Gatie Lead Actor

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    Yes, but it will probably sound no different from the 100Hz setting, due to what I said above (lack of > 80Hz LFE) and the fact you are now above the greatest roll off for the 80Hz crossover. As for decreasing the volume, you should always recalibrate using a test tone and a SPL meter when significantly changing the settings on the sub.
     

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