The 5000d will run at .5-ohm as long as the voltage is 15v or under. RIGHT AT 15v the amp shuts off. I tested this amp for weeks trying to find the happy point. it seems this amp LOVES low impedance, but only when voltage is at 15 or lower. this is a 1-ohm amp above 15v.
it will pull MASSIVE current at .5-ohm...like 700+amps, so expect to blow fuses if you run for more than 20 seconds or so at full output. If you are burping for comps either don't fuse (I hate not fusing but you SPL guys think fuses eat dB's) or use 200A fuses paralleled on each power cable. Don't forget to feed it,either...3 batteries per amp and upgrade your alt.