Frequency response, port open / port plugged (at 2 meters)
front left/right: 39 Hz to 20 kHz ±5 dB / 84 Hz to 20 kHz ±5 dB
center: 74 Hz to 20 kHz ±3.5 dB / 74 Hz to 20 kHz ±4.5 dB
surround: 78 Hz to 20 kHz ±5.1 dB / 78 Hz to 20 kHz ±4.5 dB
subwoofer: 31 to 79 Hz ±1.9 dB
Let's be honest: No one really cares about treble response. What's that all about anyway? "Air" or something? Give me a break. Frankly, if you are a real music lover or movie buff, you've been listening at loud levels for plenty long enough to fry your ears' high-frequency response anyway. Good riddance. And what's the deal with midrange?
The primary performance requirements for a good subwoofer are that it have smooth frequency response over its operating range and that it be capable of producing strong output down to 30 Hz or (preferably) below without obvious distortion.