Hello I am going to buy a Yamaha 440 series receiver and then buy a Phase Technology velocity series 10" sub, would this work out well or no? (14x14 room)
No. You can not use computer speakers with a receiver. Computer speakers have amps built in, and a receiver is an amp. You can not amplify the signal twice.
Brian the ProMedia's use an amp that is located in the subwoofer. There is no amp in the speakers. The speaker is the same as basically any satellite you would find in a normal HT setup. You should be alright, I tried my ProMedia on my reciever once, ran perfect.