[rtate]

So I'm about to start a couple of speaker projects and I'm looking around at different ways to finish the enclosure for an x-ls encore.
I came across a box that actually had the port on the top of the box !!
I'm sure there must be a reason why you should not do this , but I don't
know it. 
Can some one tell me why this is a bad idea?? 

[S Clark]

There should be no real issues as far as sound. Placing a port opening at the top might be an opportunity for misc. stuff to fall in- it seems that my Neo2X's always have something sitting on top of them.

[dB Cooper]

Dust would collect. If we are talking about a mini monitor type speaker on a stand, seems like downward-facing would work just as well.

[nickd]

Ports IMHO work best when on the back of a speaker. "Wind noise" will be less audible and the output will be supported by a room boundary. The sound from a port is usually 6db down (or more) in level from the woofer output, so a room boundary often helps improve the low bass response at the tuning frequency.

That and the "piggy bank" temptation of a top port will cause violent shaking of your loudspeakers as you try to get missplaced small objects out of a narrow tube using gravity.