Subwooofer with Monoblocks set up question

Speakon is high level input (speaker output on the amplifier). Putting Schiit in the chain does not make sense, especially such low powered  one (15W) with 450W Gatos. The whole system would be big time out of whack. Use line out from preamp, as already suggested.

@knock1 this is what i was wondering about. Does the amp’s current capacity matter with the high level input given that the REL (Arrow or direct to the T/9x) isn’t drawing current from the amp at all (the subwoofer high-level impedance is 150k ohms)?  Is the timing of the subwoofer affected and out of sync because the speakers would be driven by the 250 wpc monoblocks and the Arrow transmitter is  taking the signal only from the flea watt Schiit, even though the T/9x is actively driven by its own amp?

Kirk, I fully understand what you are trying to do.  You want to use a spare stereo amp to preserve a speaker (high) level connection to Rel sub.  For the sake of simplicity, let us set aside air transmitter for now.

One coveat (you might have already been aware) is, by doing so, the Rel sub hears (sees) the spare amp while your main speakers hears (sees) the Gato MBs.  Since the sub / main speakers do not hear (see) the same amp, is the high level connection advantage that the Rel sub is designed for is still there?

You will find out if the unconventional method works sonically by auditioning both.  As you mentioned, if it does not provide sonic benefit, you have already know what to do.  Less is more!  Good luck on your experiment and I would love to hear your feedback.

One coveat (you might have already been aware) is, by doing so, the Rel sub hears (sees) the spare amp while your main speakers hears (sees) the Gato MBs.  Since the sub / main speakers do not hear (see) the same amp, is the high level connection advantage that the Rel sub is designed for is still there?

Yes. That question seems to cut to the heart of this, assuming i can mechanically get it to work. The alternative — going out of the Raven directly to low level —-will clearly work if i don’t use the Arrow, but that limits my placement flexibility. But the sonic difference between high level and low level in this case, as @lanx0003 crystalizes the point, may not exist at all, given that the REL will not be seeing the same amp as the speakers.

Further research tells me what i feared: the line level outs of the RCA cannot drive the high level input on the Arrow ; there is a serious voltage output problem and also likely a grounding issue and might actually damage the Raven’s output buffers.  (Unlike the Airship II, which has a low level input option, the Arrow accepts only the Speakon high level input or LFE/.1 input (designed for 5.1 systems the manual says). 

So i think I better find a longer RCA tipped interconnect (ideally a Y summing one)   to get from the Raven to the REL directly. Then i can compare the 2d amp jerry rigged approach to what now seems like a more sensible direct, low level approach.

Thank you all.

I am confused a bit.  HT-Air Mk2 is exactly designed for RCA.  Maybe you have different transmitter.  But two of these for $149 seems a steal.