Setting speaker levels (Sherwood AVP-9080R)

Discussion in 'Archived Threads 2001-2004' started by MCollins, Feb 10, 2003.

  1. MCollins

    MCollins Auditioning

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    I need to recalibrate my speakers to ensure equal 75dB and have a question about the proper procedure. I have Video Essential, so can use it or the pre-amp to generate the pink noise. I also have a sound meter from Radio Shack to measure the right dB. My question is this...does the actual volume of the pink noise affect the sound meter? Is there a specific volume setting I should use, or just play it by ear? Thanks in advance for your feedback.

    -Michael
     
  2. Bill Kane

    Bill Kane Screenwriter

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    Michael,

    here is a LINK to a calibration overview from the HTF Beginners Primer and FAQs, you find the icon bug on top of the Basics Forum. Lotsa tutorials.

    If you have more questions about yr particular receiver, after checking the manual, come back...

    bill
     
  3. MCollins

    MCollins Auditioning

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    Bob,
    Thanks for the link. After reading the FAQ, I'm still a bit confused. Here are two line items from the FAQ re: speaker calibration:

    - The majority of discs start with the left speaker tone. While the left speaker tone is playing- increase the master volume position until you reach a reading of 75db on your meter.

    -Note that it doesn't matter at what position your master volume knob is placed, or for that matter what number it says. Calibration is a measure of OUTPUT, so even if the volume knob was marked with Japanese characters- you should still be able to calibrate with no problem.

    So, this appears to be contradictory. The first instruction says to adjust the left speaker to 75dB with the master volume control, not the individual speaker control...leading me to believe that this matching volume level should be used when calibrating the rest of the speakers. Also, this would lead me to believe that the individual left speaker volume control would be set to 0.

    Now, the second instruction says that volume control doesn't matter and all speakers should be adjusted to the 75db w/ their respective individual speaker controls.

    So, help me here. If I set all my speaker levels to 0, how do I know where to set my master volume control, to ensure that I can adjust each speaker level volume control to 75dB and have true calibrated sound.

    Thanks,
    Michael
     
  4. Bill Kane

    Bill Kane Screenwriter

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    Michael,

    Vince Maskeeper's tutorial tries to cover the TWO METHODS used by rcvr makers to handle MAINS calibration. Since you haven't told us what yr Sherwood manual says, I'll try to touch on each. (I use AVIA disk)

    A. Call this the Yamaha Method. Using the remote for spkr setup, ONLY the Ctr and two Surrounds have individual output adjustment scales; here it's -10 to +10. To calibrate the Mains, typically start with the LeftMain. As the VE in yr case plays its tone/noise for this spkr, the rcvr's main volume control (use the remote) is raised until you read 75dB on the RS meter. The volume reading will be less than max and you note/remember this number.

    For ex, on the Yamaha volume scale of 0 to -99, the reference level ends up at -16.5dB. [This is only specific to this rcvr, played in this room, with the listening chair at X distance from the spkrs.]

    Yamaha then has you go to the RightMain and use the balance control to match the same level set for the LeftMain. Leaving the volume control at this LeftMain level setting, one then plays the tone/noise thru the other spkrs, using the scale adjustments thru the remote.

    B. You appear to have spkr adjustments for the Second Method. These rcvrs will have you set 0 on the volume first. Typically, these rcvrs also go up to +10dB max main volume scale. In this method, the LMain tone is played and there will be individual L & R main adjustment scales in the Spkr Setup. These wud be raised individually until seeing 75dB on the meter.
    Afterward, setting the rcvr main volume to 0 plays the reference level (which most of us find too loud for ordinary HT listening).

    Does this help clear it up?

    bill
     
  5. MCollins

    MCollins Auditioning

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    Bill (sorry, I called you Bob in my last post),
    It's getting there. My sherwood is a pre/pro that I've had for a few years and it does allow for raising and lowering individual speakers levels by +/- 10db. Let me re-phrase what you have told me and what I read in the FAQ to ensure I understand what I need to do. For my preamp, I'm dealing with two volume controls: Master Volume Control (MVC) and Speaker Volume Control (SVC). So, am I to infer that the level of my MVC does not impact how the sound meter will read 75db's for each SVC? It would make sense to me that there is a correlation between the 2. I guess my question is...what baseline MVC should I use for all speakers to adjust the SVC? Does my question make sense? I know the baseline for each SVC is 0db, so that's obvious. I adjust each SVC until the sound meter hits 75dB However, what volume should my MVC be to ensure the right baseline for the actual pink noise tone? It would seem that the higher my MVC/louder the pink noise is, the less I'll have to adjust the individual SVC to reach 75db. If that's the case, it seems there should be a specific MVC baseline that I need to use.

    Thanks,
    Michael
     
  6. Bill Kane

    Bill Kane Screenwriter

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    Michael,

    In the end, it doesnt matter where the MVC ends up if you are able to calibrate the LCR and Surrounds to 75dB range within the +/-10dB offered for each spkr. You just remember that MVC number as your "reference" level set point.

    But you are correct, there's a two-handed adjustment balance (correlation) here betw MVC amd SVC.

    Try this:

    A. If the prepro MVC goes above 0 say to +10, use 0 as your MVC set point and adjust the SVCs accordingly. If they fit inside the +/-10dB range, you're good to go.

    B. OR set all SVCs to 0, play the pink noise track for the LeftMain then turn up the MVC until you read 75dB on the meter. Now, where does the MVC end up? [See my first graf].

    bill
     
  7. Brent_S

    Brent_S Second Unit

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    Michael, as a fellow owner of the 9080, I would recommend the following, using your terminology of MVC and SVC.

    a) set all SVC levels to zero.

    b) play your left main test tone, either built-in or VE.

    c) adjust MVC until you register 75 db (record the volume MVC readout if you like...it'll probably be minus teens to minus 20s, depending on your speakers/room/amp)

    d) without changing MVC, cycle through the other channels and use SVC to get a 75 db reading from each speaker

    e) you're done.
     
  8. MCollins

    MCollins Auditioning

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    Thanks Bill and Brent. You guys have been quite helpful.

    Brent - Following your instructions, I can expect that my left main's SVC will remain at zero, while the remainder of my speaker's SVC's will be adjusted upwards to hit the 75db mark. In this scenario, won't I only achieve reference sound when I turn my MVC way up (to the low 20's or teens)? When listening to lower MVC volumes, won't the calibration be off, given that my left main's SVC will be lower than the other's and my MVC won't be playing at reference level?

    Thanks,
    Michael
     
  9. Brent_S

    Brent_S Second Unit

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    Michael,

    assuming your speakers have similar sensitivies (your L/R mains are identical, no?) and similar distances with similar/identical amp channels, you shouldn't have to adjust the SVCs by more than +/- a couple of decibels. I think my center and one surround are -1, while my mains and other surround are zeroed. I think my subs are at -1 as well, but they actually read a couple of db hotter than the mains...-3 would make them flat on the meter.

    With the SVC, you're setting a relative level for the speakers to each other. Once you've set that relative level, your speakers will be calibrated to each other at any setting of the MVC. Ideally, if you had 5 identical speakers equidistant from your meter, your SVC would all stay at 0. Does that clear it up any?

    Also, the 75db calibration point is really kind of arbitrary. You could calibrate your speakers to each other at any volume that consistently registers on your meter. Calibration discs use 75db or 85db depending on the recorded level of the test tone to achieve the max volume THX? spec of 105db per speaker...75+30/85+20. In reality, as Bill mentions above, a lot of people find this "reference" level to be too loud in a home theater setting so just calibrate the speakers to each other and then pick the volume you like and enjoy the movie. :)

    wbs
     
  10. Philip Hamm

    Philip Hamm Lead Actor

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    Nice preamp BTW. I used to have one myself and it's a fine performer. Great DD and DTS 5.1 performance.
     

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