Only the Creative Gigaworks T40 Series II gives the user some real control over frequency response via bass and treble knobs. Here are results showing the ranges that these controls can affect:
You can see how these controls have an effect on the higher and lower frequencies, giving the user some influence on the sound.
The only other speaker in our roundup that offers control over the audio spectrum is M-Audio's Studiophile AV 40s, with a bass boost switch on the back of the right speaker. Here’s the difference that it makes:
You can see how the bass boost switch adds a little pepper to the bass range, which is a nice touch for those who crave a deeper sound from their two-channel speakers.
Finally, we examine what advantage that Bowers & Wilkins MM-1 set offers with its built-in DAC. The following chart doesn’t indicate frequency response, but instead, the difference in frequency response between the kit's built-in DAC and an analog output from either SigmaTel HD integrated audio or Realtek ALC889 high-definition audio. A flat line would mean there’s no difference between USB and analog output, and a curved line would indicate notable differences in the audio spectrum:
Clearly, the built-in DAC has notably different output from the SigmaTel HD codec. But when the Realtek ALC889 high-definition audio codec is used, there’s not even more than a decibel’s difference from 20 Hz to 15 kHz. So, while the MM-1’s USB input can offer some benefits on machines with poor audio hardware, a decent integrated audio codec with analog output will perform as well as the speaker system's integrated DAC.