Wut i do, whether its beats from hardware or on the computer:
I have little $20 Powered Monitors from creAtive that i got at staples. I use those and some studio headphones for just layin out the beat pretty much, no mixing though. Then when i wanna get into detail or start mixing i use Carver Studio Monitors (or somethiing with a flat frequency range). And I have some car subs hooked up to an amp so i can fine tune the bassline and really tell what the lowend sounds like up close.
I use the creAtives and the headphones to lay down the beat so that i dont use up too much power and i dont have to go and turn on the amps and all the monitors every time i wanna work.
I really sugges using a setup something like this, its a lot neater (not cool neat, i mean neat like clean), and its easier for me. If it dont sound like you, thats cool but i think its worth a try.