Q: I recently installed a new system with two dual 18” sub cabinets. No matter how much I increase the gain on the amps or in the DSP they are barely audible even with the others cabinets turned off.

A: Double-check the settings in your DSP. When setting up your high pass and low pass filters for the sub cabinets it can be easy to get them crossed essentially eliminating all low frequency information from the signal path. For example if you had intended for you HP filter to be set at 45hz and it was mistakenly entered as your LP filter then the only low frequency information being allowed to pass on to your subs is that below 45hz which doesn’t amount to much. So the result is no matter how much you increase the gain at any point in the signal chain the low frequency is still being filtered out.