Calibrating front speaker output level: +/- dB vs. L/R balance

Discussion in 'Archived Threads 2001-2004' started by TonyTone, Nov 14, 2002.

  1. TonyTone

    TonyTone Supporting Actor

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    It seems that some receivers allow calibration of front L/R speaker output levels via independently adjustable +/- dB level (i.e., -10 dB to +10 dB), whereas others allow adjustment via L/R balance control (knob or electronic "slider"). I have a Pioneer VSX-811S that does the former, and a Sony DA4ES that does the latter.

    So...on the 4ES and others with similar L/R balance controls, when I slide the balance control towards one side (let's say left speaker), is the receiver increasing the output level of the left speaker, decreasing the output level of the right speaker, or a little of both when the control is moved towards the left? And no, I don't have access to two SPL meters so I can't easily determine if adjusting the front speaker level controls is increasing and/or decreasing the front speaker outputs simultaneously.

    In summary--why the two different types of L/R front speaker adjustment methods? Is one type necessarily preferable to the other?
     
  2. Saurav

    Saurav Cinematographer

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  3. TonyTone

    TonyTone Supporting Actor

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    Saurav--I a bit confused here; you mention that I should stand in front of the speakers (plural); to hold the SPL meter a foot away from the speaker (singular); mention that the output from both speakers (plural) should be the same; move the balance control and measure output from both speakers (plural) again; then mention that when I'm a foot away from the speaker (singular) I should only more or less pick up output from the one speaker.

    So...where exactly should I be standing when I take the SPL reading? You say that I should stand in front of the speakers, but to hold the SPL meter a foot away from the speaker--are you now saying I should stand in front of either speaker? I sort of lost you...please clarify.

    Thanks!
     
  4. Saurav

    Saurav Cinematographer

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    Sorry about that. Make that "stand in front of each speaker, one at a time". The idea is to get close enough to the speaker so that your SPL meter is only registering that speaker's output and not the other, but not so close (like just a few inches away) that you overload the SPL meter (of course, you could always turn the volume down).

    There's another way you could do it. Connect only one speaker, say the left speaker. Now move the balance control to the left and see if the speaker's output stays the same, or gets louder. Then move the control to the right and see if the speaker's output stays the same, or gets softer. That should also tell you what your receiver is doing.
     
  5. jeff peterson

    jeff peterson Supporting Actor

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    Trying to think logically:
    The balance control can't make a single speaker's volume louder than the master volume control is set at.
    Therefore, moving the balance control to the left must be decreasing the right speaker's volume.
    Let us know if your real world tests bear this out.
     
  6. KevinQ

    KevinQ Stunt Coordinator

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    Guys, I am confused by that too. My CD player has only the L/R balance control option Tony mentioned.

    Can I adjust the output level of individual channel using that option?

    Thanks.
     
  7. TonyTone

    TonyTone Supporting Actor

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    Okay...is this test plausible:

    Disconnect front left speaker (make sure speaker wire doesn't accidently get shorted); on receiver, center the L/R balance control and set master volume to some reference point (doesn't matter what level as long as it doesn't change during the test); place SPL meter directly in front of front right speaker; enable test tone to output through front right speaker only; slide balance control towards the left; see if SPL reading drops. Or alternately, disconnect front right speaker (reconnect front left speaker if need be); slide balance control to left (do not change master volume level from previous test method); check SPL output of front left speaker.

    Note--it cannot be easily determined from using the above testing methodology as to how adjusting the balance control affects speaker output when only one front speaker is connected versus when both speakers are connected, unless someone knows for a fact that balance adjustment is not totally dependent on whether or not one or both speakers are connected.
     
  8. Saurav

    Saurav Cinematographer

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    That sounds like a good test. I doubt the balance control's function will change based on whether a speaker is connected or not. I would leave the test tone as being set to come from both front speakers, that should make your receiver think there's a speaker attached. I really doubt the receiver will test the line to see if it detects a speaker there and change its behavior accordingly.

     
  9. John Garcia

    John Garcia Executive Producer

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    To the original question - I have never used the L/R ballance, only test tones to set the level of each speaker independently. By adjusting each speaker independently, there should be no need to use the ballance control for calibration purposes.

    Ballance is not a system volume control, AFAIK. The need for the L/R ballance is more likely now suited to trouble shooting and testing/comparison purposes. Maybe you want to try out two different speakers on the left vs right with a tone generator. With music, you could compare L to R, then swap speakers and try it again, or something to that effect.
     
  10. TonyTone

    TonyTone Supporting Actor

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    John--the issue with the DA4ES is that there is no adjustment that will allow you to adjust the level of either front speaker, independent of the other. IOW--the 4ES doesn't have individual -x to +x level adjustments for the front speaker; all you can do is slide the L/R balance control so that you can get a balanced output from both front (surrounds and sub have individual channel -/+ dB adjustments) speakers. As far as the DA4ES is concerned...when you think about it--for any given seating position, you would need to adjust the master volume in order to get a reference output level from your mains, whether it be 75 dB or 85 dB; whereas on receivers unlike the DA4ES, you can adjust the individual channel levels to achieve 75 dB for any given master volume level...well, almost any master volume--kinda hard to get 75 dB output if your master volume is at -90 dB.
    If what I just said sounds confusing...well, the bottom line is that you cannot adjust the speaker levels for the mains individually and independently of each other on the DA4ES since no such control is offered for the mains, hence my original question as to why the 4ES--if not other receivers--allow adjustment of the mains solely via L/R balance control, as opposed to +/- adjustment of each and every channel...
     

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