I have my new Ruby connected to my older Pinnacle Baby Boomer powered subwoofer. So far I have no issues whatsoever. The Baby Boomer has left and right speaker level in lines and then lines back out to the speakers themselves.
I too was concerned at first about hooking up a sub to the Ruby because of the above quote, which is a strange one coming from a Marantz rep, but I have been assured by several other reputable sources that any such concerns are simply strange and wrong... Perhaps if one is hooking up a non-powered sub, there might be a legit concern of draw on the amp? I don't know, but two reputable Ruby sales sources and both SVS and REL reps have told me there shouldn't be any worry at all.
I guess if one is concerned, there are (too expensive) external crossovers available and also inexpensive speaker line to "RCA"-in converters as well...?
As for external crossovers, though, imo it'd be best just to replace my sub w a more modern one that can be more fully controlled for a customized blend... think SVS.
The Pinnacle is a heck of a nice, tight sub in a compact form, dual 8" drivers facing opposite directions, sealed design, attractive finish. I do wish my Pinnacle had a lower crossover so I could cross it at 40 instead of the 50 which is the lowest the Pinnacle offers. 50 is good with the Heresy IV speakers, but 45 or 40 would be better in my current room as the Heresy do a pretty good job down to 50. 40 or 35 would be better for my EPI speakers with Human parts which do an amazing tight articulate job down to about 45. But a new SVS would have the advanced customization capability to blend close-enough to perfectly with either speakers, and based on the information that I have, hooking up via speaker level a sub to the Ruby should not be a problem at all.
