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Installs measuring room acoustics (1st reflections)

Discussion in 'Sound, Music, and Intercom' started by jamsession, Nov 11, 2008.

  1. jamsession

    jamsession Member

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    I want to do some basic room acoustic measurements

    specifically, slapback echo in a gym (speakers mounted front of house, 13' up, 50 ft apart), bouncing off back wall 71 feet away. (room is 106' wide)

    Sound is good on the floor, but when you're on stage you hear the slapback too much. Setting up drapes or sound absorption/diffusion panels on back wall now. Should make the room much better with that in place

    I want to do some before & after snapshots, to measure treatment effectiveness and target the problem frequencies/modes - it's mostly in midrange area.

    I've read of one method doing the same frequency sweep in different locations with a DB meter to map a frequency response chart.

    Anything with a percussive midrange (hand claps, rim shots) is most noticable
    (Michael Jackson's Streetwalker is a good example)

    Since I'm tuning the room for the PA, I would play the program source (similar handclaps) through the PA, record it with a flat mic, and see the bounce. Yes, can eq to minimize that, but don't want to change the great sound on the floor. Want to get the best natural sound with room treatment first.

    Curious if anyone else has a process (sample wavs they want to share? :^) ) and favorite programs (WinXP) that are useful for this.


    Apollo: Know thyself.
    Jamsession: Know thy room. THEN turn knobs.
    Last edited: Nov 11, 2008
  2. museav

    museav CBMod CB Mods Departed Member

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    Acoustical, audio and audiovisual consultant
    Marietta, GA
    Echoes are a time based phenomena, if you want to be able to see how it affects a specific reflection you're going to have to look at something that lets you see what's happening in both the time, energy/amplitude and frequency domains. Something like EASERA, Praxis, WinMLS or TEF. That way you can look at the actual reflection and see how it changes.

    Since you are dealing with not just the reflection itself but also how it interacts with the direct sound and with other reflections throughout the room, the effects will vary throughout the room. If you use a SLM or RTA there is no way to differentiate that reflection from the direct sound and all the other reflections.
    jamsession and (deleted member) like this.
  3. jamsession

    jamsession Member

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    yep, thanks Brad. :cool:

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