Improving Headphone Sound

Hi; We’ve recently moved to a MUCH smaller house and I now find myself pretty well restricted to the use of headphones for most listening. I use a PC source out to a Benchmark DAC1 USB and directly from the DAC to a pair of Sennheiser 650’s equipped with a 10’ Cardas cable.

Given that I have no alternative to using the ‘phones, can anyone suggest ways that the sound might be improved. It’s already “pretty darn good” (at least to these 63 year old ears), but I’m guessing that there might be room for improvement.

As a start, I’m considering replacing the Cardas cable with a Moon Silver Dragon (Version 2), but any and all suggestions would be appreciated.

Thanks & Regards,

Bob Holmes