Assuming the amp can handle 2.5 Ohms (Gene said it is a "Beast"), based on the SPL calculator, 50W will produce about 102dB from 12 FT away on a speaker with 93dB/w/min.
Handling 2.5 Ohms is a huge assumption!
http://myhometheater.homestead.com/splcalculator.html
However, if this amp is actually a "lightweight" and not really a total "Beast", then it might be different.
I read through Gene's review and did not see anything to indicate the MX5000 was well suited to low impedance.
I'm betting he called it a beast primarily because it can power 11 channels!
It is not a bad amp, but not the kind of amp Gene would recommend for use with his 8T's.
If you compare it to the Outlaw 5000,
you'll find that the $650 Outlaw 5000 and $3000 Yamaha MX5000 are very close in their power capabilities:
2Ch, CFP-BW, 8 Ohms, 0.1%THD,
Y=177WPC, O=170WPC
2Ch, CFP-BW, 4 Ohms, 0.1%THD,
Y=250WPC, O=230WPC
5Ch, 1kHz Psweep, 8 Ohms, 0.1%THD, Y=138WPC,
O=139WPC
5Ch, 1kHz Psweep, 8 Ohms, 1.0%THD, Y=144WPC,
O=148WPC
2Ch, Dynamic PWR, 8 Ohms, 1.0%THD, Y=225WPC,
O=230WPC
2Ch, Dynamic PWR, 4 Ohms, 1.0%THD,
Y=396WPC, O=390WPC
5Ch, Dynamic PWR, 8 Ohms, 1.0%THD, Y=205WPC,
O=212WPC
https://www.audioholics.com/av-preamp-processor-reviews/yamaha-aventage-cx-a5000-mx/processor-and-amp-measurements
https://www.audioholics.com/amplifier-reviews/outlaw-5000/measurements
I made the better reading bold, but the amount one beats the other is small enough that we can pretty well say these are equivalent amps ... except the Yamaha is an 11 channel amp!
For $1700, we can get 2 Outlaw 5000's and an Outlaw 2200 monoblock for the center to give us our 11 channels. That would put more power on tap and still save $1300!
But my real point is that the Yamaha MX5000 is notable among amps in that it has 11 channels of amplification. That amplification is somewhat better than typical AVR amplification, but certainly not the kind of increase you would normally look for from a premier external amp.
Gene says of amplification for the 8T's:
In order to achieve the full potential this speaker system has to offer, it’s recommended that you select an amplifier that is as close to an ideal voltage source as possible, doubling down in power as impedance halves (ie. 300wpc at 8-ohms, 600wpc at 4ohms, 1200wpc at 2ohms). It’s a good idea to verify with the amplifier manufacturer of your choice if their product is truly stable down to 2-ohm loads. Using an amp not capable of sourcing lots of current into 4- and even 2-ohm loads will result in clearly audible inferior results especially at louder listening levels with bass intense program material. I had excellent results pairing these speakers with amplifiers from Classe and Pass Labs and I am confident you would too but also check out options from ATI, Anthem, Boulder, and Bryston to name a few.
So, you're a dealer, get Yamaha to tell you that the MX5000 is "truly stable down to 2-ohm loads" and I'll believe (good luck with that)!
The MX5000 is a good solid amplifier for routine duties (as is the Outlaw 5000),but it simply does not keep company with Classe, Pass Labs, ATI, Anthem, Boulder, and Bryston that Gene suggests for driving the 8T's!
If you want 11 channels in one box, this is your amp. If you want it to match your Yamaha Processor, this is the one to get!
