Re: 500watts @2ohm or 500watts @4ohm
The short answer is 'yes'. The subs should sound relatively the same. If its a MTX class D(usually optimized for 2ohm operation) running it at 4ohm will most likely result in lower THD and much better thermal conditions for the amp.
'some ppl are just STUPID. i am not perfect or know everything. the main reason i called you a moron is due to the fact that YOU yourself have took it upon your self to talk this dudes sub worth up and trying to prove to ppl with it is in fact worth.'