i have the one larger speaker in it already, which is essentially going to be the subwoofer as it produces nice deep tones. sadly its located in the front. the smaller laptop speakers that i have will fit just about anywhere and if i can isolate just the high frequency sounds to them alone then i will be happy. im going to head to radio shack today and see what i can find there to do this. there are also a few car stereo shops in the area and im sure the guys there will be able to tell me exactly what would be needed along with helping me find something i can fit inside the tank. the nice thing is that whit almost all my electronics inside the turret it leaves plenty of room in the lower hull to work with!!