I am looking to build a more portable cabinet for my son . He has 2 peavey 410tvx's but wants something more portable for smaller venues.He uses a Peavey Nitrobass head and a Fender Deluxe Jazz 5 string. I can get an Eminence Legend CB15-8 locally. would this be ok on it's own or does it need a mid? Also when I model it in winisd, I am exceeding xmax (6mm) from 55 to 90 hz in a 4 cu ft box tuned to 40 hz. how can I fix that. If it needs a mid, is the Eminence Alpha 8mra good to use? I can't figure out how to model the alpha to see what it adds. If I need the mid, do I have to use a crossover? Any help would be greatly appreciated.