If I put marcato articulations on a string part (the little hat-like ^), the music plays back heavily accented.
Good.
but if I have a playback technique that is “marcato sempre”, extending over a whole passage, it seems the playback isn’t quite as accented/loud.
the playback technique is defined as marcato for playback.
is there any reason the single articulation marking gives a slightly different playback result than the playback technique?
where would I look to have them match?
You should see the playing technique in the Key editor no? Are both appearing to be marcato?
edit. I just created a small sample. It seems to be, that they have a different CC1 curve.
Is it possible that you have Dorico apply an extra accent on the default marcato in the expression map, but not on the your custom marcato sempre?
I usually set all this humanization to 0 and start matching from there.
hmmm, good questions… of course, I probably don’t understand them at all!
I suspect you’re asking me things that are way above my pay-grade! 
I know I haven’t changed anything to Dorico’s default settings, so anything that’s affecting playback would come from that new “marcato sempre” playing technique I added.
could someone, using really small words, explain to me (the quintessential “dummy” 
that all those books are aimed at) how I might go about fixing this?
It’s not that it’s REALLY important or anything, but there’s still a small difference during playback that would be nice to smooth out.
If you are happy with the amount of accent in your default marcato, you could try matching your marcato sempre to it: by narrowing the range and raising the overall volume in the expression map (for example: try 30 to 127 instead of the usual 1-127 for the expression controller and/or velocity).
What sound library are you using?
Noteperformer.
where would I find this function?
how do I alter something in the expression map? (like I said… “dummy” )
Oh, I’m sorry - I’m not using it and don’t know the first thing about it! Perhaps an NP user would read and respond.
