I suppose this is the start of a DIY thread, so get ready for lots of questions Thanks to 3Hz I have two drivers on their way. Im planning a DIY using these two SI HT 15" dual 4ohm subs wired to 2ohm each and one ran off each channel of a Cerwin Vega CV amp. Are the figures quoted on the Cerwin Vega website RMS? i.e. 2x900W RMS @ 2ohm for the CV1800, and 2x1400W RMS @ 2ohm for the CV2800? Ive modelled a 75L sealed box (one driver per box) in Win ISD, and with 900W (CV1800 amp) it hits xmax at 14Hz, but with the 1400W amp (CV2800) it will hit xmax at 32Hz, so the question is, am I better off going with the smaller Cerwin Vega CV1800 amp as a better match for these drivers?