The Behringer DEQ2496 has a spectrum analyser function, and is cheap enough to be bought simply for this feature. (About $350 including microphone). Much easier to use than the RS meter and test CDs.
Furthermore, after you see your in-room frequency response, and recover from the shock, you can go about fixing it using the automatic equalization feature.
Furthermore, after you see your in-room frequency response, and recover from the shock, you can go about fixing it using the automatic equalization feature.