IMHO a key point in Bruces reply is. Not being essential. I have three versions of DSP6000. The difference between the 18 bit and the 24/96 version 5.2 and 5.4 is negligible. In fact depending on the recording sometimes I think that I may prefer the 18bit units. I would not sweat the differences in FW. You have a great set of speakers that were once considered Class A for quite a period. Enjoy the MUsic!