I have been running RE SRX12D4 in my car for half year now. From outside, it looks very solid and well built. The cool thing about it is that it digs quite low and plays with authority while running in a 1.25 cu ft sealed box off only 250watt RMS amp. With its 18mm xmax, modeling software shows that it could take even 500watts RMS without reaching its xmax limit. I prefer to cross it no higher than 60Hz@18dB because upper end is weak and muddy. But lows are great. Given $100 price online, it's a good value. I assume RE SE/X series is very similar, only better.