At the suggestion of Bo Putnam I'm putting this thread out to start gathering information on the 4350 monitor. Hopefully everyone out there with 4350's will slam this thread and pile in the info. Let's try to break it down to specific versions of the 4350. From my research over the years I have 3 versions - 1. The original 4350 offered in 1974 only. Called the 4350 with white compliance 2230 woofs, 2202 mid base, 2440, early style 2405 with split ring mounted on face of baffle and 3107 x-over. The serial numbers (written on the baffle plate around the hi-freq adj was a simple 5 digit number 10 _ _ _. I have never seen a pair of these in person, only pictures. 2. The second version, also called the 4350 (but loosely refered to as 4350A's by some) came out in 1975. 2231 dark cone woofers, 2202, 2440 and new style 2405 with 4 hole mounting plate and same x-over. The serial numbers looked to be an extension of the 1 0 _ _ _ numbering but had an "A" suffix added. They ran up to the start of the 4350B's and only changed with the addition of the 2231A woofer when it came out. I suspect that there may have been one or more revisions to the x-over schematic but have no way of knowing for sure. I think the 4350B hit the streets in 1980 with the intro of the ferrite magnet(have to check my notes). 2231H, 2202H, 2440, 2405 and 3107. The serial numbering started new with this series. The scale of calibration also changed on the hi freq. control. The cabinets also changed slightly over the different series and I have some details that I can add to the thread later. These are my observations from being a 4350 fan. If you own 4350's and can supply additional info (even to the contrary) on your model please post it. Detailed pics of the internals and baffle would be nice. I have detail drawing of cabinet internals from 4350's and 4350B's and will try to get that info posted soon. Rick