We first saw THX Multimedia Certification on the excellent Klipsch ProMedia 2.1 (which have aged very well, and to this day are probably the best 2.1 setup you can buy). In our original article, we explained exactly what THX Multimedia is all about. To avoid confusion, here's that info again:
"First of all, This is NOT the same certification you see in theatres, or even on home amplifiers. THX sets different standards for different platforms of media. All Klipsch sets, and this Logitech set fall into the THX Multimedia standards. This means that they are capable of producing a natural frequency response of 31-21000 Hz. Folks, this is the difference between SAYING you have good frequency response, and actually HAVING one. THX tests this. So although your Creative Labs speakers SAY they sound great, if THX didn't say so, you can bet that Creative is FOS (now there's something new...).
THX Multimedia also assures of two other things (both of which are self-explanatory):
Controlled directivity for accurate spatial imaging and precise sound localization.
Broad dynamic range and low distortion design for unstrained high output sound reproduction (+105 dB)"