Yamaha NS 5000 w/ NAD M33

You don't need the extra wattage. Typical listening levels for most systems are just a few watts. The rule of thumb is 10X the average power to handle dynamic peaks. 

The NAD is class D (bad nad). The class d emperor never had clothes with certain types of speakers.

Return it and get a pair of Schiit Tyr monoblocks ($3200) + a Kara preamp for the under 5k price bracket to do that speaker justice. It will let you see the special something about this speaker.

After that, you could end up spending ~ upwards of 20k to beat the schiit and still doubt if you got 'the wallet's worth or not (from time to time).

I'd be surprised if you need more power, but consider room treatment.  Dampening extra reflections can really help the bass bloom.

You would be much better off with a higher quality amplifier then more power class ass d is very precise and  articulate but misses some of the warmh and body of a conventional class a ab amplifier

We are an nad dealer so we have direct experience with your gear

Dave and troy

AUDIO INTELLECT NJ

NAD DEALERS