so im tryin to build an iso for recording and ive been doin some readin on what would be the best suited single speaker for the box.. the general consensus is the best speaker for the job is a vintage 30 but i own a traynor custom special 100 head that runs only 2 and 4 ohms and the vintage 30s are 8 and 16 .. so would there be any suggestions on another single speaker that runs at 4 ohms or is it safe to run an 8 ohm speaker with my 4 ohm amp?