# how to measure a rooms acoustics?



## kniffarn_ (Jul 10, 2009)

Hello, Im pretty New to this forum but it shure seems like you have some talanted persons here.
now I need some help on how to measure my rooms acoustic response.

I have rew, ecm 8000, behringer mixer and a calibrated soundcard so it's just the knowledge that lacks.
1. How do I position the speaker/speakers relative to the mic?
2. What is it I'm going to measure? Reverberation time? 

Best regards Tim


----------



## bpape (Sep 14, 2006)

You need to measure with the speakers where they'll be set up in the room and the mic where your ears will be when listening.

REW will measure a lot of different things. Frequency response, impulse response, decay times, etc.

Bryan


----------



## kniffarn_ (Jul 10, 2009)

How do I do when to measure the room modes then? I can't do the same there right?


----------



## bpape (Sep 14, 2006)

The modes in theory are calculated. You will see them in a combination of your frequency response and waterfall charts. They're not a specific 'item' that's labelled 'room modes'. But you'll more than likely see their impact.

Just remember - ALL rooms have room modes. No getting around it. It's more a matter of designing the space to have them spread as evenly as possible and then putting the seating in positions to best avoid them. Lastly, you take care to position the speakers and subs to get the best starting response you can.

Then you start looking at how to address the balance of the issues and the excessive decay times via room treatments.

Bryan

Bryan


----------



## kniffarn_ (Jul 10, 2009)

why i asked for the modes, was because you need som measuring from the peek of the mode to calculate a helmholtz resonator. Or is there others ways to in theory calculate the size of a helmholtz?


----------



## bpape (Sep 14, 2006)

Calculated room modes don't always exactly line up with the problems you actually have. You'd be better off to measure the room and see where the problems lie.

Bryan


----------

