I was part of Sigma's design team and can tell you catagorically that Sigma is a fine speaker; however, it is influenced greatly by the power amp., other electronics and connecting wire. Sigma is slightly bass heavy in a small room, therefore, room size is of consequence. The speaker must be kept on tiptoes to keep it raised off the floor for cleaner, more articulate bass response. The system should be biwired for optimum results. Separate power amps will produce even better sound but the amp on the bass end must have high current capability. Sigma's impedance, as I remember, is quite low and will turn off mediocre power amps with flimsy power supplies and heavy limiting in the output stage. If you require additional input, let me know.