I am seriously considering buying a combo with a 15" driver. The MarkBass mini cmd 151p. But I am concerned that it will be loud enough for a medium sized venue without pa support. My band isnt extremely loud, but earplugs are definitely required. Portability is my primary concern, so if I have to add an extension cab it would becomes less attractive to me. Here are the specs of the one I am considering: SPEAKER 1x15" TWEETER piezo BASS REFLEX rear IMPEDANCE 8 ohms SPEAKER POWER HANDLING 400W RMS (AES Standard) FREQUENCY RESPONSE 40 Hz to 18 kHz CROSSOVER FREQUENCY 3.5 kHz SENSITIVITY 100 dB SPL WEIGHT 40.79 lbs / 18.5 kg HEIGHT 18.27 in. / 46.4 cm WIDTH 18.27 in. / 46.4 cm DEPTH 18.9 in. / 48 cm One possibility is to replace the stock 8 ohm driver with one that is 4 ohm to utilize all 450w. Maybe the KappaLight Pro? This combo looks very promising to me... just gotta know that it can handle my volume requirements. So who routinely plays with a single 15 cab with great results?