I recently purchased a 4T Hybrid system connected to a Onkyo 808 receiver, and I've been having some issues getting the sub working correctly.
When I first setup my system and ran the AVR's auto-calibration, it seemed as though the sub worked fine. However, recently, I've noticed that the sub doesn't seem to output any sound.
I've connected the sub to the two sub outputs from the receiver using a Y-adapter and cable supplied by Aperion, set the crossovers for the fronts, centers, and surrounds to 80hz, and set the sub to "On" rather than "Auto". The sub is also set to Movie mode. After going into my AVR's level calibration menu, there doesn't seem to be any sound coming from the sub, even after setting the volume levels on both the receiver and sub to max.
I'm having the same problem. Recently the sub had a blown fuse so I called in and had a few new ones sent out. After replacing them tonight I noticed that the sub was not outputting any sound. Even when I go into my receivers setup (I'm using a Sony DA5500ES receiver), I cannot get any sound from the sub when engaging the test tone. I was going to call in but by the time I tried using the sub again I noticed it was past 5pm Pacific time. Hopefully I'll figure it out soon but if not I'll call in Monday.