Foam or keep mouth little above mic capsule
Whenever I do whistling in a track I keep my mouth a full 90 degrees away from the front of the mic (assuming a cardioid polar pattern is used). So, I usually stand to the side of the mic and blow across the face rather then directly at the face. Also, I think many people think they have to be really close for a good whistle to come through, but I believe that creates much more of a problem and allowing some distance is always best.
Also for a whistle, I will usually go as far as to roll off everything below 300HZ.
In certain applications, record the same thing on 2 mono tracks and pan them wide for a stronger presence. Just make sure your timing is good for both recordings or it will sound sloppy.
What Tim said. Also, there are some whistle sample instruments out there(Whistler?) that don’t sound great alone but can sound good blended with real whistles if you’re doing a gang whistle kind of thing. It has worked for me because I’m a terrible whistler!
Great advices here. Thanks from me as well
I find that a doubling preset of some sort, with a little delay and modulation, really makes whistling sound pro.
Thanks for all the tips! I did buy the Whistler sample library after struggling with getting a good enough real whistling sound… But the samples sound too sterile, so I will make another attempt at the real deal! Maybe mixing them together is the best way…
No pop/splut/spiz/sfiz problems arise if you whistle inwards.