I was thinking of doing some informal frequency response tests of my Schroeder 1210 bass cabinet using an SPL meter. I was able to download some third octave-wide warble tone mp3 files (about 20 seconds for each tone) from the HSU Research Forum for the following frequencies: 250hz, 200hz, 160hz, 125hz, 100hz, 80hz, 63hz, 50hz, 40hz, 31.5hz, 25hz, 20hz and 16hz. My plan was to play the 250hz tone through the cabinet and set the volume level so that my SPL meter gives an average reading of 90db (C weighting, slow response) when I'm standing about 6 or 7 feet away from the cabinet (similar to where I'd normally stand while playing) as a starting point and then continue recording the SPL levels for the rest of the frequencies. I could then plot those levels on a graph to give me some idea of the cabinet's response. Does anyone know if this would yield a fair representation of the real world frequency response of the cabinet, or are there better ways of doing it? Please keep in mind that I don't have an RTA, just my cheap and trusty R/S digital SPL meter. Any suggestions and ideas would be appreciated! - Ugly.