sub not switching on

I have a 10 in def tech sub as a second sub. I use this only for 40 to 20 hz and the paradyne for 100 to 20. The Def Tech is not always turning on... I have is on a 30' rca cable run...any suggestions? Thanks
The sub is not getting a constant signal if it is set for such low frequencies. You may have use the always on power switch if it has one.
Try setting the level controls on both your subs higher, and the level control on your processor lower. This worked for me when I had the same problem with a Sunfire sub...
Thanks for the suggestions. The problem is...I only like the def tech on the lower freq and I don't think that it has an always on. I may consider opeing it up and over-riding the switch...but I am very lightly skilled below 120 volts.