Might I suggest using high level speaker outputs instead of low level pre amp outputs to your sub(s); if of course your sub(s) have speaker level inputs.
In my case, since I did not have pre amp outputs from my integrated, I was forced to use speaker level connectivity instead of trying to level match with a fixed preamp output - which I tried with limited success.
In any case, using speaker level & utilizing my subs internal crossover to meet my speakers lowest frequency yields surprisingly excellent bass integration.
My bass quality is very engaging; give it a try if your subs can accommodate speaker level inputs.
In my case, since I did not have pre amp outputs from my integrated, I was forced to use speaker level connectivity instead of trying to level match with a fixed preamp output - which I tried with limited success.
In any case, using speaker level & utilizing my subs internal crossover to meet my speakers lowest frequency yields surprisingly excellent bass integration.
My bass quality is very engaging; give it a try if your subs can accommodate speaker level inputs.