How to correctly measure a rooms frequency response?

Discussion in 'Archived Threads 2001-2004' started by Dom H, Oct 8, 2001.

  1. Dom H

    Dom H Agent

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    In my bid to cure the problem I have of dialogue becoming unclear at moderate to high volumes I need to know how to correctly measure the freq responce of my room as I think this is the problem.
    My ht produces a very 'peaky' sound at high volumes, u can actually hear the peaks in the sound.
    My goal is to implement some room treatment to solve the problem.
    I will be recording the output on the comp at the sweet spot using a series of tones generated on the comp. I will use a standard cheapy mic.
    My questions:
    How much will the cheap mic affect the results?
    At what intervals do I measure the sound to get an accurate picture, say every 20Hz?
    Seeing as dialog clarity is my main concern do I need only measure frequencies relevent to dialogue?
    As soon as I have measured the freq response I will be back [​IMG] Hope fully the clever peeps here will be able to solve my probs as its starting to dampen the enjoyment of my ht.
    Many Thanks
    Dom
     
  2. James Mudler

    James Mudler Stunt Coordinator

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  3. James Mudler

    James Mudler Stunt Coordinator

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    Sorry for the double post. The software will allow you see room problems and you will be able experiment with treatments and locations on the walls etc. A decent mic is very important. The link above will explain in much more detail.
     
  4. Bob McElfresh

    Bob McElfresh Producer

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    There are some PC software packages that will do "Real Time Analysis" of a room/speaker system. One good one is called "Seven Shades" or "7 Shades". It is designed to assist when using an equalizer.
    Search the web for "RTA" or "Real-Time analysis"
     
  5. Wayne A. Pflughaupt

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    Dom,
    With all due respect, I think you might be beating the wrong end of the horse, as it were. Typically room acoustics have minimal affect on the vocal range (providing you don’t have something like bare concrete or hard-wood floors, walls and ceilings, that is!).
    It sounds to me like the problem is more likely the speakers and/or amplifier limitations. If your receiver is underpowered for the size of your room and/or the particular demands of your speakers it could be straining the amplifier section.
    Since you say it sounds “peaky,” the more likely problem is that your speakers have poor response. Speakers with a spike in response will become increasingly more irritating the louder the volume gets. It might be helpful to post your equipment and the size of your room, so we can take that into consideration.
    However, your room response-plotting project will certainly let you know where your speakers are letting you down.
    Since any mic has its own frequency response, obviously the mic will make or break any stand-alone RTA or spectrum analysis software. A stand-alone RTA is calibrated to give accurate readings with the supplied mic. A software program must also have a recommended mic, or provisions to compensate for the inadequacies of the mic you choose to use.
    Regards,
    Wayne A. Pflughaupt
    ------------------
    My Equipment List
     

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