I require I piece of hardware I don't know the name of. I want it to be able to take a measurement of the sound pressure level over a broad frequency. And display it in a graph, also handy to be able to send data to and from a laptop. I want to use this device in this manner. I will put a cd of known frequencies, or pink noise or whatever I need to into a stereo. And place this device around where a user would sit, get a reading of the room. Adjust eq's until spl is flat across as broad a spectrum as I can get. People don't trust an ear. /I've been trying to do this with a Behringer mic, using the known frequency magnitude response graph I should be able to extrapolate what actual spls are there... but the data is bullcrap and I have no way of generating a known spl in order to calibrate the mic. Matlab is a devil. Cheers in advance.