which set up will sound better

Hello,

Here's my situation. Currently I have an Alpine MRP-M500 mono block amp that puts our 300 watts @ 4 ohms and 500 watts @ 2 ohms. Right now I am running two single voice coil MTX Thunder 4000's at 2 ohms. These subs are rated at 200 watts RMS/600 watts max. My next door neighbor gave me a pair of 2006 model Kicker Solo Baric L5 dual voice coil 12 inch subwoofers. He told me he could not get them to work and I could have them if I wanted. After inspecting them, I noticed that the tinsel leads were broken on 3 of the coli pairs. I got my local shop to resolder the broken leads. After testing with a DMM and a C battery it would seem that I have two dual voice 12 inch subs with only one working coil on each. With all this eing said is it worth for me to bulid a box for one of the 12's in place of my two 10's? I know it will sound better but will it be louder, the same, or lower that what I have now being as how I can only sent 300 watts to it. Also, if I was to build a box for it should it be ported, or seal and what size etc. Any help is greatly appreciated.

2005 Honda Accord DX

my opinion, unless your local shops are solder gods, those tinsel leads are going to break again, sooner rather then later. i went through 4 of those exact subs in their early years. kept blowing the tinsel leads off. also IMO, kicker subs sound better in their bigger spec. sealed boxes. if you're determined to build a box reguardless, you'd probably want to go with it's largest spec sealed box anyway. all that sealed air and polyfil will caress the cone like silk.