Sound Level Meter Calibration Issues

Discussion in 'Archived Threads 2001-2004' started by Jason Lovely, Mar 11, 2002.

  1. Jason Lovely

    Jason Lovely Stunt Coordinator

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    Greetings. I just set up my new Pioneer HTP-710 home theater system over the weekend, and I need some input as to whether or not I calibrated everything correctly using the AVIA disc. First of all, I set the receiver's master volume to -20. I then proceeded to adjust each channel's level to whatever it had to be to achieve a sound level of 75db, using AVIA's test tones. Since I calibrated it to 75db, does this mean it won't sound right if I play something at a volume higher than -20? Right now, the only other thing I'm confused about is the subwoofer setup. I've got the LFE attenuation set at 0, and the crossover frequency set at 200Hz. All the speakers are satellites with the exception of the center speaker, which is a Pioneer S-DC1-K. Is this center speaker considered to be large? If so, my receiver will only let me designate it as a small speaker. I did what the AVIA disc told me to do; I set the subwoofer volume knob and the channel level so that the subwoofer signal was at the same level as the high frequency signal. The sub is set at -9db right now. However, I'm worried that I've set it up wrong, because it seems that I'm not getting good lows. I've watched a few DVDs including Gladiator and T2: Ultimate Edition. Of course, I only have an 8" sub, but it seems as if the bass is coming out of the center speaker. I watched "O" last night, and there were a lot of hip-hop songs on the soundtrack. On one particular song, especially, it definitely seemed as if it was all coming out of the center speaker. Am I doing something wrong? Is there some other way to make sure I've got everything calibrated correctly? Any help would be greatly appreciated. Thanks.
     
  2. Vince Maskeeper

    Vince Maskeeper Producer

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  3. Jason Lovely

    Jason Lovely Stunt Coordinator

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    Thanks for your help. The receiver's default setting for the LFE attenuation is 0, but I had set it to 10 during calibration; I can't remember why. I do know that I changed it back to 0 because some guy on audio review said that's the only way to get bass out of this receiver. He said setting it to 10 would cause it to filter stuff and would not let anything below 40Hz through. I guess I'll set it back to 10. My main speakers are satellites with 3" woofers and 3/4" tweeters. I didn't know any better, so I set the crossover to 200Hz thinking they couldn't handle anything lower. If you think it's safe, I'll set it to 100Hz as you suggested. Is the LFE pad the same thing as LFE attenuation? Also, does it matter whether you change the sub output level with the knob on the sub or with the channel level on the receiver? I compared what I calibrated with AVIA to the receiver's test tones, and the results were almost identical. Finally, since AVIA suggest calibrating at 85db, would this be more accurate? Would I then simply play stuff at -30 (master volume)?
     
  4. Vince Maskeeper

    Vince Maskeeper Producer

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    Since you were able to calibrate your levels to 75 with the master volume at -20... You might just try setting the receiver mater volume to -10 and simply calibrating again at 85 spl reading, just to double check everything.
    Then you'll know -10 is dolby ref level, and you can find whatever volume is comfortable to you.
     
  5. Jason Lovely

    Jason Lovely Stunt Coordinator

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    Vince, you've been very helpful. Thanks again. I'm gonna re-calibrate after work.
     
  6. Greg_R

    Greg_R Screenwriter

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    The RS SPL meter is not accurate in the lower frequencies. You need to apply an offset to get the true reading. Here are the offsets:

    10Hz add 20

    12.5Hz add 16.5

    16Hz add 11.5

    20Hz add 7.5

    25Hz add 5

    31.5Hz add 3

    40Hz add 2.5

    50Hz add 1.5

    63Hz add 1.5

    80Hz add 1.5

    100Hz add 2

    125Hz add .5

    160Hz add -.5

    200Hz add -.5

    250Hz add +.5

    315Hz add -.5

    400Hz add 0

    500Hz add -.5

    630Hz add 0

    800Hz add 0

    1kHz add 0

    1.25kHz add 0

    1.6kHz add -.5

    2kHz add -1.5

    2.5kHz add -1.5

    3.15kHz add -1.5

    4kHz add -2

    5kHz add -2

    6.3kHz add -2

    8kHz add -2

    10kHz add -1

    12.5kHz add +.5

    16kHz add 0

    20kHz add +1
     
  7. Vince Maskeeper

    Vince Maskeeper Producer

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    Greg,
    The "correction" values are usually used in conjunction with dialing the freq response of the sub, or the overall system. These values are used, traditionally, when supplying freq specific tones and using a RS SPL meter to determine and graph the response curve of your room.
    The correction value is usually not used in conjunction with setting the overall channel level using filtered pink tones from a calibration disc like AVIA or VE. These values are of no use in the setup issues put forth in this persons question.
    I would be careful drpping that kind of information on someone just trying to grasp the basics, you will often serve to confuse rather than help. I'm actually struggling to figure a good reason why you posted them at all, unless maybe you yourself are confused at how they are used.
    -Vince
     
  8. Brad Craig

    Brad Craig Stunt Coordinator

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    "A 200hz crossover setting is awfully high in my opinion. I'm not familiar with your specific speakers- but the goal is usually to get the xover setting as low as your main speakers can handle."

    Hey Vince,,,

    In another thread you told me I should crank the crossover over to Max (which for me = 150) and allow the receiver vs the subwoofer to filter the crossover point...

    Why the change or did I confuse something???
     
  9. Vince Maskeeper

    Vince Maskeeper Producer

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  10. Brad Craig

    Brad Craig Stunt Coordinator

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    Thanks Vince... You are awesome w/ you intelligent and quick replies...
    [​IMG]
     
  11. Jason Lovely

    Jason Lovely Stunt Coordinator

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    Vince,

    You were correct in assuming I was talking about the crossover on the receiver. I lowered the crossover to 150 last night, and I changed the LFE Attenuation to +10db; these changes seemed to help. I also re-calibrated to 85db, so that reference is now at -10 (master volume). I set the crossover at 150 based on the fact that the pioneer site says my satellite speakers have a frequency response from 150-20k. I watched The Last Castle, and there was plenty of bass.
     

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