Something always seems to go ary between the paper specs, and real world performance of the subsystems. Example in point, my altec 902/909's are never rated more than 106/108dB/watt. The jbl4648a-8's are rated variously at 97 to 100dB/watt. With MY meter, in MY room, the actual difference between the two shows to be 12dB. The altecs consistently do 112dB/watt or so, the jbls 100dB/watt.
Level wise, after calibrating the output controls of the XM9, I've consistently found the best tonal balance, across the widest musical spectrum and variety, to be with the HF padded 14 dB's below the LF using 909's. With the slightly less sensitive 902's, only 13dB of pad is needed. Too bright? Change your HF pad resistors to the next lower level(actually, the next HIGHER amount of attenuation). Sam
did I already mention VERIFY YOUR REFLEX TUNING frequency? a quick run around the block with "boxplot" will convince you that being off by a few Hz. IS a BIG DEAL as far as low end capability is concerned...