I ordered the "Mackie CR5-XBT" last Saturday and got them on Tuesday. I assembled them and tried some music and a movie. I have an uninterrupted power supply [UPS] that cleans the power from the wall and eliminates any hiss. However, I found that sometimes speaker sound fades in and out randomly and the speakers have too much heavy bass – the bass overwhelms percussion and vocals - mid and high range sounds. Bass overwhelms vocals very badly – garbled/faded vocals. While Amazon.ca offers these at $478, I bought them from a local music store for $270 canadian dollars. I don't know if these speakers require break-in time to work properly; time will tell, I guess. A well known online reviewer 'TTL' (I love very much) said (I'm paraphrasing) that these speakers don't do well without a sub woofer - at high volumes these speakers will distort badly because they can't manage bass at high volume. However, will a subwoofer remove the burden of low frequency bass from the speakers? Thus, in theory, after you add a sub, can you turn the speakers up for the mid and high frequencies and then manually adjust bass on the subwoofer volume control. (I may get a subwoofer for this reason) So, mainly, do these speakers require "break-in" time? If so, how long?? Yes Tom, I love you like a cool brother. Your reviews are very nice, thats why I bought the "Mackie CR5-XBT", but did I get a dud from the factory??" [[A blast from the past: I saw your review of the Corsair SP2500 speakers - great review bro. and so I bought them and I loved them so much for 12 years. Sadly the sub stopped working 5 day ago - thats why I needed new speakers]]