Power cables for AvantGarde speakers

No, power cables for the Duo subwoofers

You don't mention your budget, might be too expensive, but Townshend Podiums will tighten and extend bass response, much more than any power cord you can find. Read the recent reviews, mine and ozzy,  improved bass is one of the biggest benefits. You will also get much greater detail and imaging, with the speakers disappearing, something power cords will not even be able to touch. But this will not be at the risk of changing the overall character of the speakers like what might happen with interconnects or speaker cables. All the great qualities you like now will be there, only with a lot more clarity, focus, and with greatly improved bass.

Thank you @millercarbon. I have installed IsoAcoustics Gaia 1 isolation stands and i already have all the sonic improvements you mentioned. The bass and imaging are very good in very well recorded records. My feeling or guess is that my next step to try to improve bass quality a little bit could be better power cords. Mine are Furutech power cords, but i think they are also a little long. I’m new with power cords for subwoofers and it’s impossible to just read reviews in other speakers/systems completely different. I could try add your Townshend podiums to listen their impact.

Interconnects and/or speaker cables will bring the biggest change. 

Speaker placement and acoustic treatments will yield the greatest results.