Okay Andy, it would have been helpful to include the info in your post here that Randy copied from the other site. You should try a more substantial increase in the sub trim level on your 2600 than -2.5dB to 0. The 2600's sub output has lab tested at 6.9 volts and you can try substantially above 0 on it. If even turning it all the way up doesn't keep the sub amp "awake" there's a chance than your particular amp has a defective auto-on circuit and should be replaced. If so, contact Axiom directly about it.
As to the 2600's auto-calibration setting a 160Hz crossover, simply set the calibration to "skip" the crossover setting and set it at 80Hz manually.
