Sharing a subwoofer with 2CH and HTs rigs!

In the velodyne manual it expressly IN ALL CAPITAL LETTERS AND BOLD says do NOT use both low and high level inputs concurrently... 😕

Using the SYS, my thinking is that you could run a pair of RCAs to  input 1 from one amp and to input 2 from the other. Then run a pair of RCAs to the sub from the SYS output (or a y splitter to a single RCA if the sub has single input). Being very careful about having only a single amp on at a time, having both turned off when switching which to use.

I believe the same could be said for a switch box. 

Thanks, Mesch. That’s on point, and getting me closer to the answer I need - but your solution seems to say that the SYS or even any cheaper RCA switch box won’t keep the sub from being fried if the two amps happen to be on... Do passive switch boxes send current from both inputs even if only one is selected? I guess that’s the crux of my issue. It would really be the same as running both amps directly into the sub at once through different inputs and hoping I never make the mistake of having both on at once.... Does anyone know if there is a switchbox or rca cheap pre-device similar that will preclude having to worry about both amps being on at any point?? Or would the SYS and switch box be okay? Thanks a ton, guys. Flynn

I hope others will chime in on possible problem with use of a switch box. I would think any quality one completely isolates inputs. I doubt one would want one's sub to receive signal from two preamp outputs at the same time.

The issue differs between use while both amps on and use for selecting which audio vs. video amplifier to have on and selecting routing to sub without movement of cables.  Do you really need to have both amplifiers on at the same time. Is warmup a concern?

I am also interested in what others contribute.  

As far as 8 know the RELs are the only subs that can mix RCA stereo inputs and .1 LFE