Older vs. newer REL subs

Keeping the model, year, version the same with dual subs is smart. Buying a pair together closer in serial number helps ensure there is less chance of variation.

@wolf_garcia wolf_garcia
"...The bad news is that REL won’t service them. If one dies I would try to find somebody to fix it,..."

Good point to bring up for others to see.  This is the problem with buying older -2 prior generation used subs, and when the factory no longer stocks the replacement boards, amps, parts, drivers any more. It becomes a best effort self-fix situation.   Helped many friends rip out stock amps and drivers to replace with generic Dayton 250/500 amps and other drivers to keep them going. Got two DA 500s sitting her right now in fact.    So what's left, a cabinet? Rather build a new Rythmik or Dayton kit sub with a good driver than buy a 5+ year old factory sub that you can't get parts for any more because they've moved on to different designs. Just something else to be aware of when buying used vs. new subs.  And they DO rattle themselves apart after 5 years, and less so when when used more sparingly.  They want you to buy the new model when it happens, fwiw.   

A matching pair of the newer version REL T/9X, one per channel, would be plenty with your 2-way/6.5" Salk monitor speakers and 60wpc tube amps. Also prefer the forward firing woofer w/bottom firing passive design of the 9x.