The Sonata-001 are a pair of feature laden monitor speakers. Within its 8.5"x14"x13" (WHD) frame, it packs in a 5" composite cone woofer, 3" bamboo paper mid woofer and a 1" AMT tweeter. Frequency response is 55 Hz to 27 KHz with a nominal impedance of 8 ohm and a sensitivity of 87 dB. The speakers does require some "power" to drive them (manufacturer recommends 50W and more) which we did not hesitate to give because these speakers relishes power and "comes out" with a full scale presentation when we fed with it 200W of power. The speakers can be a bit picky with types of amps but we found them to sound best with high powered tube amplification or warmer sounding solid state amps (like McIntosh, Acurus etc). Positioning them in our listening room did take a bit more experimentation but when we found their optimum spot and with solid, heavy stands anchoring them, these speakers disappeared in the background and just laid out the beautifully layered soundstage. Imaging was impressively big for monitor speakers of this size and there was good depth to it.
Being that this is Bache Audio's only monitor speakers at this point of time, your choice may be limited. But if monitor speakers are what you need and your budget is under $1,500, then the Sonata-001 should be on your shopping list. Built and finish may face a bigger challenge if you were to shop at its $2,800 price tag but for under $1,500 now, its a fair price for its high quality finish and sound. Speakers had one original owner from new and except for some minor polishing swirl marks, speakers look very good. We have the original boxes (speakers are shipped in two boxes). So factor in x2 for actual shipping.