https://www.amazon.com/Electes-Grounded-Outlets-Extension-Indicator/dp/B07JNFNLJ3/ref=sr_1_4
this is what I use on spike/spike2 games where I cant reach the switch for whatever reason... I don't have them on all my newer sterns, just the ones that are in the middle of the row... I then use a couple of cord retaining clips and mount the "button" in the normal powerswitch location under the bottom right corner.
it would work for your sub as well since there are three outlets on the receptacle end.
good luck.
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