Subwoofers are designed to stay powered ‘ON’ 24/7. What are your concerns with leaving your sub ON - 24/7?
In any case, you can use the following on/off switch for easy reach,
https://www.amazon.com/Leviton-1470-W-125-Volt-3-Wire-Grounded/dp/B01894YMX4/ref=pd_bxgy_2/134-30203...
In any case, you can use the following on/off switch for easy reach,
https://www.amazon.com/Leviton-1470-W-125-Volt-3-Wire-Grounded/dp/B01894YMX4/ref=pd_bxgy_2/134-30203...