calculate resonant frequency

Hello all... I'm trying to find information on how to calculate the resonant frequency of a "sandwich" of materials like plywood and sheet rock for a panel to be used for a drum riser. Is there an equation for this that anybody would like to share? I don't yet know what the final sandwich will be - I have some left over construction material that I would like to use. Thanks in advance, Rick

Maybe this helps: http://www.earsc.com/HOME/engineering/T ... asp?SID=61 http://www.earsc.com/HOME/engineering/T ... itePapers/ Florian :D

Thanks, I looked over it quickly yesterday. Hopefully one of those equations fits my application... Best regards, Rick