My brother came to me a few days ago saying he wants a new bass cab for practicing. He is currently using a Hartke 4x10 with an outboard 350w amp. When hes practicing with his band (in a warehouse) he said everyone else drowns him out and hes looking to get more output. He was looking at an Ampeg 2x15 that costs $899 and I told him I would see what I could do to save him money, and possibly build him something nicer. I have a year of recent speaker building behind me and am very familiar with using computer box programs like WinISD and all the jargon behind it. What Im looking for are tested boxes that people have built themselves with drivers available off the internet, preferably Parts Express. If you know of a design that hasnt been tested but you feel would perform really well, please speak out. This box must be able to have a higher output than the Hartke 4x10 and preferably be more sensitive so my brother doesnt have to buy a new amp. Hes looking to spend $400-$500 for everything, but could pinch a few more pennies if needs be. I have extra MDF and plywood lying around so that should help reduce the cost. Dual cabinets are not a problem. Thanks for any input and taking your time to help my brother and me out!