eigen modes in a room

[QMann]

In a rectangular room 10*8*5 how can the eigen modes belonging to octave and third octave bands centered at 50Hz be found ? I have the formula to calculate the number of modes but don't have the idea how to find the modes. Do I need to use Matlab for it ?

 

[GregLocock]

You could use Matlab, pencil and paper, a spreadsheet, your fingers and toes, or even your brain.

If you had two parallel walls 20 ft apart what would be the frequency of the first mode? Second mode?

Cheers

Greg Locock


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[QMann]

GregLock instead of answering my question you just placed another question. way away for any help.

 

[QMann]

And I can make out that the 1st frequency should be 29Hz?

 

[GregLocock]

If you can't answer my question you certainly won't be able to answer yours.

Cheers

Greg Locock


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[spongebob007]

I don't understand what you are looking for. Can you do a better job of explaining what you are trying to do? Are you trying to calculate natural frequencies? Mode shapes?

Natural frequencies and mode shapes are not really related to frequency bands. They are a function of the room geometry.

If you are looking for natural frequencies in the 1/3 octave band centered around 50Hz I am assuming that you mean the modes between 44.7Hz and 56.2Hz. Also, there is no standard octave band with a center frequency of 50Hz that I am aware of.

 

[GregLocock]

It's a pretty standard requirement for room acoustics. Beranek covers it in sufficient detail.

Cheers

Greg Locock


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