The breaking in period i would recommend for the DMX is around 6 to 8 hours, out of the box with low volume low frequency being played threw it. If you have a frequency CD that's perfect. You really don't want to hear anything just have that cone moving up and down. If you have 1-DMX15 I wouldn't put anymore than 1,200 watts RMS for any music play so 1-D5000.1 would be perfect. But for straight SPL competition 2-D5000.1 strapped together would give you 5000 Watts RMS at 2OHM which could be used for straight SPL 30 second burbs.