The PM-1 fills a void that was created when the Reference 800 series was upgraded to the Diamond 800 series. Each model in that line enjoyed a quantum improvement in performance but it also moved the price of each model up as well. That put the cost of acquiring an entry level pair of 800 series speakers out of the reach of many consumers. Thankfully we now have the PM1. At $3,000.00 MSRP it fills the price point left by the Nautilus 800. If you think it bears a striking resemblance to the Nautilus series you would be correct. At this price Bowers and Wilkins could not use a diamond tweeter but have devised a new carbon stiffened dome that results in treble extension beyond 40Khz and a stunning, open sound that allows these mini-monitors to disappear into any room. They have become an instant hit with staff and customers.