I agree with a previous post which recommends that you work on placement of the subwoofers to solve your sonic issues first. The 2Wq subs tend to work best very close to the corners of the room. Also, because your main speakers are Vandersteen 3A Sigs (and go deep enough to meet the sub properly), you shouldn't have to deviate from the recommended crossover setting for your amplifier's input impedance.
Start by getting the subs as close to the corners of the room as possible, make sure they are hooked up in positive phase with the speakers and each other, and then set the level to 90db and the "q" control to about 7. From there you can begin to adjust the level contol higher (one db at a time) until you have enough bass output.
As for better cable feeding the sub, you might try a high quality solid-core copper or silver cable for some improvement in sound. Remember, whatever cable you use on the sub is hanging off of the outputs of your amplifier all of the time, in parallel with your main speakers, which will affect the sound of your main speakers. Because the Vandersteen 2Wq sub is powered, the signal you are feeding it is only a voltage reference and does not require a very big or heavy gauge cable. I have used Audioquest Type 4 and CV-4 with good success. Good luck.
Dave
Ultra Fidelis Inc.
Start by getting the subs as close to the corners of the room as possible, make sure they are hooked up in positive phase with the speakers and each other, and then set the level to 90db and the "q" control to about 7. From there you can begin to adjust the level contol higher (one db at a time) until you have enough bass output.
As for better cable feeding the sub, you might try a high quality solid-core copper or silver cable for some improvement in sound. Remember, whatever cable you use on the sub is hanging off of the outputs of your amplifier all of the time, in parallel with your main speakers, which will affect the sound of your main speakers. Because the Vandersteen 2Wq sub is powered, the signal you are feeding it is only a voltage reference and does not require a very big or heavy gauge cable. I have used Audioquest Type 4 and CV-4 with good success. Good luck.
Dave
Ultra Fidelis Inc.