Good stuff John. The SMS algorithm factors in SPL adjustments for that ecm5000 microphone so no other corrections are necessary when tweaking from the display. Like yourself I then go back to doublecheck with the SPL metre for a final adjustment since there is now less volatility on the metre.
One thing to be mindful of with the SMS, it appears its mapping function is off slightly at frequencies less than 25hz. Depending on your unit it could be off by 1.5-2.5hz. So if you are seeing a peak at say 27hz it could be occurring at either side of 25 HZ. Its not uniform across all the SMS devices but you can easily tell on yours looking at the scope of the EP500 with its brickwall DSP filter. The steep drop in response occurs at 19-20hz.
A year and half ago Velodyne asked me to beta test the latest firmware version and I pointed out this discrepancy but I suspect Velo decided it wasn't worth redoing the mapping function for such a small adjustment. It doesn't detract at all from its effectiveness and I wholeheartedly recommend it as the final tweak for anyone determined to tame room acoustics or employing multiple subs.
