I received my ICBM-1 with the special offer 6 shor-stack PCA cables last week. After properly making all connections as stated in the owner's manual (mine is connected between the receiver/preamp and the Model 7100 amp), I experienced trouble with the subwoofer signal. My Hsu Research VTF-2 wasn't powering on automatically upon signal feed.
So, then I tried placing a Y-connector on the back of the ICBM-1's L & R subwoofer output jacks and "presto"! It work like a charm, even works better than before. The subwoofer wakes-up immediately, faster than before.
Many subwoofer manufacturers recommend the use of a Y-connector in the sub's line-level input for the Auto-On feature because it provides an additional +6Db gain in the signal to the subwoofer, therefore, preventing it from going into "premature" Standby mode.
I think this should be added the ICBM-1 owner's manual as a "note" for those using subwoofer's with the Auto-On feature. The Y-connector definetely improves the signal going from the ICBM-1's sub-out jacks into the subwoofer line-level input.