I just spent the last few days in London demo listening to both the 11s and 13s
Monday 13s.
Wednesday 11s.
Thursday 13s again.
13s have even more clarity...if that's possible.
Clearer imaging.
Better away from the sweet spot area too.
The 13s are also more effortless.
As if the 11s push the bass at you where the 13s just hand it to you, giving more with less effort.
However, they both sound the same flavour....
The 11s sound amazing.
The 13s sound better.
Larger and more rounded
More impressive.
No question.
I wouldn't describe the difference as you suggest... either subtle or in your face... perhaps somewhere between those two.
However, the difference is clear as day.
More than enough to make me want the 13s after hearing both.
It's a big enough difference to be totaly aware of when listening to both.
I would be happy with the 11s.
However....
I bought the 13s.
If any London or UK members see this please message me...
I'd like Ark advice and amp matching advice....