Larry,never having heard the Z5500, I am going to assume it is designed for home entertainment as the other Logitech systems are designed.
As you know, DJ work, you better have the "Big" bottom to handle dance music. I'm not sure you can get it from this small system.
Larry, I just re-read your post..Do I understand correct, you are going to use the Yorkville sub woofer instead of the Logitech sub?
If so[not knowing the model Yorkville], it may work for you..
BTW, I use a 700 watt Yorkville subwoofer, and it will carry any room/or outdoors..
[This message has been edited by Fran Carango (edited 09-19-2005).]