Just a little update if anyone is interested. For those of us with a Bandmaster and want a little more clean headroom, I found a great solution. Also, it doesn't involve removing and replacing the transformer. I recently had Eminence make me a custom 4 Ohm Swamp Thang speaker for me.
Let me tell you, this speaker is insanely loud. The former speaker I had in my cab was a 4 Ohm 12" Eminence 1218 rated at 97.2 SPL. The 4 Ohm Swamp Thang is rated at 99.8 SPL. I am not a technical guy, but apparently that is a huge difference.
We had a decibel meter device about 5-6 feet in front of us when we practiced last night, and it was constantly rating us between 120-124 dB (we all wear ear protection). My Bandmaster was surprisingly keeping up! Another added bonus, there was no more high end distortion like my old speaker had.
It took over two months for Eminence to make the speaker, and it really added a lot of weight to my cab. Having said that, it was totally worth it. Anyway, I just wanted to let you guys know about this simple way to increase the headroom in your Bandmaster.
—MooreLoud.com - A tribute to Dick Dale.