I'm currently using a Mesa RR 2x15 cab from the old series and have been pretty satisfied with it. Today I came over a 2x10" in the same series. I've been thinking about getting one for some time and the thing that have stopped me is the impedance matching problem. The 2x15 is 4 Ohms and the 2x10" is 8 ohms, I guess Mesa never meant thoose two to get married. Anyway as I see it the only sollution is to exchange the elements in the 2x10" but what elements should I put in? Ordering elements from mesas new series feels a bit overkill and I suppose they are pretty expensive. Worth mentioning is that I'm using a Tube head and I got to get this combination to work in either 4 or 8 ohms. Two 8 ohms speakers in the 2x10" and then running the two cabs in series is supposely the only option. HELP!