B&W DM603 S3 a 3 Ohm load? I don't think so.
I felt compelled to respond to this thread after seeing it quoted on another audio forum.
The B&W DM603 S3 is specified as a nominal 8 Ohm load, only dipping below 4 Ohms (3.1 Ohms) at very high frequencies (15 kHz) where little energy is exerted. In low frequencies where most of the power is demanded it remains above 4 Ohms. The B&W DM603 S3 also has a higher than average sensitivity, measured at 89dB/2.83V/1M. Any amplifier with moderate power and which is rated to handle a 4 Ohm load should work fine with this loudspeaker, including many receivers. Sure, a powerful amplifier with a large toroidal transformer and copious filter capacitance will control the bass section better. But, to say they are in effect a 3 Ohm load which affects its bass reproduction is inaccurate.
See the August 21, 2005 Stereophile review of the B&W DM603 S3 for measurements.
I thank the Audioholics forum for the opportunity to respond to what I feel should be considered dubious assertions.