I was not able to get a close up of the male IEC on the back of the speaker. I think you have to be careful because I can't tell if all power cords will fit it or if you need a specific shaped female IEC at the end of the power cord. I say this because my Von Schweikert DB 99 speakers required a specific shaped female IEC to fit into the back of the speaker. None of the power cords I had at the time would fit into the recessed opening.
I had SL3s for a number of years. I could never hear a difference between power cords. I did have a problem with the large heavy power cords slowly coming loose. In the end I just used the original cords. If I still had my SL3s today, I might try the Shunyata Venom that are the same size and shape as the standard power cords.
I agree with mgreen27. Power cords have little potential to make a difference unless there is a fault with the current cords. Remember the power has traveled many many miles through all sorts of electrical cables and the expectation that the last meter of cable is going to change or improve it seems unlikely to me from an engineering point of view.
Ok, I will be the odd man out. Power cords WILL make a difference on your crossover and class D amps in your [expensive] speakers.
I would not go TOO crazy, but you really should demo a variety of cords less than $250/ea. Maybe start with Pangea (Audio Advisor), Cullen Cable, Signal Cable, VH Audio, TG Audio, etc.
Then decide for yourself if the improvement is worth the additional cost.
Well for all the doughters or no it alls yes power cords on my 15a's really do make a big difference. I was able to use two of my Audioquest wild blue yonder cables since moving the system to its new location. Gone is the sense of electronic glare that was present. Things sound more natural and the bass dropped down an octave along with better definition.