Using sound meter

Discussion in 'Speakers' started by John*DB, Nov 7, 2004.

  1. John*DB

    John*DB Stunt Coordinator

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    Okay, I have a Yammy 5760 with YPAO (auto calibration)

    I used this ... and it sounds fine, but...

    I have know idea if it can sound better.

    I have AVIA but have NOT A CLUE on how to us a sound meter. I know most everyone on here suggests a simple Radio Shack brand (which model?), but I need STEP BY STEP, "hold-my-hand" and "spoon-feed-me" instructions on how to use one of these properly.

    Any advice guys?
     
  2. Frank Zimkas

    Frank Zimkas Supporting Actor

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  3. JackRI

    JackRI Stunt Coordinator

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    Location:
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    Jack Richard
    And this. At the bottom of that page you'll see a link referring to "FAQ and Primer." That link will lead you to a wealth of articles about Home Theater which you may (or may not) find useful.
     
  4. John*DB

    John*DB Stunt Coordinator

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    what is the recommended model from Radio Shack...or do they only have one type?
     
  5. Phil Iturralde

    Phil Iturralde Screenwriter

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    Read over my DETAILED CALIBRATION: YAMAHA RX-V1300 webpage using Dolby Labs "Explore Our World" DVD DD-EX w/dedicated LFE Test Tones.

    In your case w/AVIA, just Replace 75 dBc w/85 dBc.

    NOTE: From what I've read from the various Yamaha YPAO product reviews, the YPAO works extremely well.

    Phil
     
  6. John*DB

    John*DB Stunt Coordinator

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    Great Phil. Question for you. Before I "screw up" what the YPAO did for me, is there a way to know if the sound is at optimum performance? I guess I still need to buy an SPL meter and see what it measures.

    What am I looking for in the readout? How do I know if it is already as good as it can get?
     
  7. Phil Iturralde

    Phil Iturralde Screenwriter

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    Without a SPL Meter, the only way you can determine that you equalized your SPL @ your 'sweet spot' is by playing some DVD's with encoded 360-degree effects.

    One I use is "Dragonheart" CE, ... where the dragon is discussing the old knights code with Dennis Quaid. Sean Connery's voice is tied to the flying dragon's movement while he circles around Quaid about 3 times. The sound and visual images matches pretty well and it's one of my DD-5.1/(forced 6.1 Matrix) surround effects demo's.

    Otherwise, you'll need an SPL Meter to visually see what the SPL is @ your 'sweet spot'!

    Phil
     
  8. Frank Zimkas

    Frank Zimkas Supporting Actor

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    ZERO, your looking for ZERO. When you set the meter to correct scale, lets say 75 for the sake of argument. After you turn on the test tones, either from your receiver or from a DVD, You will be adjusting the output from your receiver so that the needle reads ZERO. If your output is greater than 75db, the neddle will deflect to the right. Let's say it peaks a "+4". This would indicate that you are measuring a signal 4db above the current setpoint on the meter (75 db). Therefore 75db+4db=79db. If the meter indicates -4db, then you subtract from the 75db that you are calibrating too. Any reading above your setpoint means you cut the volume for that speaker, and any negative number means you need to boost the volume for that speaker.

    Make sense?

    As long as you get the output for each channel as close to the reference point as possible, well that's about it. Of course you might find that your current placement may not be ideal, your speakers may sound better if toed-in a bit more, or a bit less. The mains may need to be moved farther apart or closer together to form a perfect equal-lateral triangle (or not). The center channel may not be angled properly toward the primary listening position (sweet spot). Your direct radiating surround speakers may seem too directional and distracting, therefore an upgrade to Bipole/Dipole speakers is in order. Don't forget to re-calibrate after every change, no sense in not getting the most out of that new meter.[​IMG]

    The list goes on and on. Start with a basic setup, calibrate it so you have a starting point, and then start playing around. Have fun. If it isn't fun, well why bother?!?
     
  9. Ryan Tsang

    Ryan Tsang Second Unit

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    Frank:

    I have the trusty RS analog sound meter and the scales are in mutiples of ten from 60 to 120. Unless you are talking about a different meter, you are not looking for zero.

    if you want 75db, you should set the scale to 70 and read +5. The positive side has equal gradations to +6 so it is easier to read and probably more accurate, so you don't want to choose "80" on the scale and read "-5"

    Am I mistaken?
     
  10. Frank Zimkas

    Frank Zimkas Supporting Actor

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    Ryan,
    You are correct, it is in multiples of 10, but please note I said.....Just using a number (75db) that was used earlier. Sorry if I'm adding to the confusion.

    I should point out that before using the SPL meter it's a good idea to take a look at the manual and determine the proper scale to use. Don't assume that 70, 80, or even 90 is the correect scale without surveying the manual first. Page 4 of my instructions lists the switch position and the cooresponding range of measurement. As an example, a switch setting 70 db will provide for a measurement range of 60-76db. Calibrating a system to a 75 db reference level is difficult to do when your reference point is near the top of the range. A seting of 80 will allow for a range of 70-86db.

    I've been using the switch position that puts me as close to the center of the range that I'm measuring.
     
  11. John*DB

    John*DB Stunt Coordinator

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    Hey guys, thank you so much!! I will do this soon! Thank you for speaking in non techy terms...it sure helps!!

    Thank YOU!!![​IMG] [​IMG]
     

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