I'd like to respond to this post:
http://www.drummerworld.com/forums/showpost.php?p=1415241&postcount=494
but do it here instead of the sticky.
I don't consider myself real experienced with double bass, I don't play gigs,
and when I did used to play gigs, I never used double bass.
That said, here's my take on it.
Heel/toe only sounds like a shuffle/swing beat when using a single foot.
When using both feet, it's possible to get even velocity hits that sound like singles,
although I can't do it at a real high speed.
It sounds like a swing beat with a single foot, for the reason I gave in post #5.
With a single 1/4 note - four 16th's; 1-ee -and-ah; - when using a single foot, you get hits from the heel on the '1', and from the toe on the 'ee'.
On the 'and', and the 'ah', your leg is moving upward.
So there's a 'gap' in the sound that can be put to good use.
If using both feet, your other foot is hitting when the 1st foot is moving upward.
For a shuffle/swing, substitute quick H/T hits (one foot) on 1 and 3, keeping the snare (and ghosts) on 2 and 4, while swinging on the ride.
Works like magic. YMMV
This is just the way I do it. I'm not saying it's right, wrong, or the only way.
It could even be completely 'wrong' compared to how someone else approaches it.
I just tried different stuff and use what seems to work best for me.
Keep in mind also that I use a double pedal for practicing, and a single pedal while playing.
Edit: Single or double foot constant release gives me hits on '1' 'ee' 'and' 'ah' (or any other combination at speeds I'm capable of).
Single foot triplets too with a little concentration and effort. No gaps so it's always even sounding.
At slower speeds, heel down still feels most natural to me. But I can switch between the three methods pretty smoothly.
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