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post #1 of 5 Old 03-04-15, 12:08 PM Thread Starter
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Unhappy Averaging impulse measurements

Hi,

Im trying to measure the reverberation time over 125Hz - 4kHz 1/3 octave bands in a small music venue, using the impulse response available in REW.

Due to room modes and spatial changes in the sound field, I'm taking 10 individual measurements around the room to get an 'overall' response.

Is there any way to combine the individual measurements and view an 'averaged' response for each 1/3 octave band; i.e. an average RT60, impulse response etc?

Thanks for the help!
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post #2 of 5 Old 03-04-15, 01:24 PM
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Re: Averaging impulse measurements

You can average pairs of responses using the trace arithmetic controls on the All SPL graph, so you could use that to produce an average of 8 of your 10 measurements - first average 4 pairs, then average 2 pairs of the averages, then finally average those two results. Before averaging make sure the impulse responses have the same time alignment (peak in the same place primarily), you can adjust their timing using controls of the impulse graph if necessary.
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post #3 of 5 Old 03-05-15, 05:41 AM Thread Starter
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Re: Averaging impulse measurements

Thanks for the quick reply! When you say 'make sure the impulse responses have the same time alignment', do you mean i should 'Estimate IR' then 'Shift IR' on each individual IR before averaging?

If I'm looking for an average 'RT60' and 'IR' over all measurement positions, should i average all the 'IR's" and then apply 1/3 octave band filtering on the 'averaged IR' to get the IR for each 1/3 octave band?
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post #4 of 5 Old 03-05-15, 08:04 AM
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Re: Averaging impulse measurements

> The 'Estimate IR' most often works very well to align the IR's correctly. The alignment function can be fooled however sometimes depending on the shape of the IR. It is important to view the 'overlay' of the IR's to visually assure they are well aligned. Manually shift them as needed so they overlay each other as well as possible.

> The octave filter settings will not impact the averaging of IR's so the settings is not important.

> The averaged IR will be charted on its RT60 panel and there the controls can be set to show either the full octave or 1/3 octave results.
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post #5 of 5 Old 03-06-15, 03:22 AM Thread Starter
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Re: Averaging impulse measurements

Thanks again for the fast reply, much appreciated!
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averaging , impulse , impulse response average , measurements

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