# RT 60 in small rooms (useful?)



## sergioTOOL (Feb 12, 2009)

Hi 

I´ve been advised (in this forum) not to use RT60 (rev times) to calculate reverberation in small rooms. Why is that? Then how can I approach issues regarding reverberation in such rooms? what measurements/calcs?.

International standards for acoustics in classrooms (the topic Im dealing with now) state the reverberation times should be measured in this and that way and calculated with Sabine´s Eq. The average classroom is not that big of a room.

Or is it that the RT60 function in REW is not suitable for small rooms?

Thanks a lot

SERGIO


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## brucek (Apr 11, 2006)

> Then how can I approach issues regarding reverberation in such rooms? what measurements/calcs?.


RT60 results aren't meaningful in small rooms (less than a gym or church), and are only meaningful when using a full range speaker. 

For low frequencies (<200Hz) use the waterfall and decay plots.

For higher frequencies (>200Hz) use ETC.

brucek


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## Wayne A. Pflughaupt (Apr 13, 2006)

Hi Sergio,

You might find the information at these sites helpful for your project.

Reverberation in a Small Room
RT60 Acoustic Reverb Calculator
RT60 Option Information

Regards,
Wayne


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## sergioTOOL (Feb 12, 2009)

brucek said:


> For higher frequencies (>200Hz) use ETC.
> 
> brucek


Thanks

What do you mean by ETC?


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## brucek (Apr 11, 2006)

Energy-Time Curve. It's a function of REW. It will display your reflections in time from the main stimulus. REW has a nice tool to display distance, so you don't have to calculate it.

brucek


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