Hi, and welcome to the forum!
I agree with most of what "radiorog" said about DM range, and recomended amps for the Dyns 2/7.
I have a pair of Excite X12 and actualy they are being diven by a Rega Brio R, but before of the Brio R they were driven by a Oldy NAD 3020i with only 30-35wpc.
Yes the DM range is low sensibility as the Excite is, and yes they are at 4 Omhs, and yes you will be able to drive them with a 50w amp, but never at their full potencial, my Brio R runs out of gas first that the Dyns do...
And that's where opinion differ !!! :?
I was not after disco levels, I wanted: detail, claraty, tranparancy, neutral sounding speakers, and I have exacly that, with a lovely and silky mid range, Dyns IMO reproduce voices (especialy female) and unplugged instruments like no other.
If you are after disco level a 50w amp and DM or Excite range will not work for you, it is always a matter of prioraties.
Another issue is that DM and Excite range have big ports, and they really beneficiate with a litle space around, more then 25 cm from back wall, mines are at 40cm...
Now, regarding matching amps for the Dyns or DM range, FROM ON LINE READING
Naim pair well with Dyns, but I didn't like it, too analitycal and I demo my Dyns with a pre/power Naim combo, Naim Nait 5i mkI and mkII.
I like very much how my combo souns, it's all I can say!
The best piece of advice I can give you is, go out and try for your self!
It is so much fun to demo equipment, you can learn so much from it.
:cheers: