I assume that the intention is to put a monitor on top of this cabinet (you too bldozer).
Have you checked to see if your monitor is suseptable to stray magnetic fields?
Don't belive the crap that AlNiCo JBLs do not affect CRTs. This is why when you look at my center channel speaker, all of the components were originally mounted at the bottom with the ports at the top.
But even just with a couple 130As, a 175/potato masher, and an 075 mounted low in the cabinet, the Mitsubishi 40" table top (CRT) would be subject to distortion/purpling toward the bottom of the screen. When I went to front projection with a Stewert screen, this was no longer a problem and the horn was raised in the cabinet to replace the center port and this port was put at the bottom. This also allowed me to put a tweeter on top of the cabinet.