Watching a lot of YouTube videos about how to make a clean double stroke roll, and I was wondering why so many people on the videos say "do not rely on the rebound"!
Is it a bad habit to perform a double stroke roll based on the rebound ? Is it not "clean" ?
At faster tempos, using the rebound of the drum to support the second stroke is the entire purpose of double strokes. There are pitfalls, however, that you may run into if you rely on the rebound, as they say-
At slower speeds, you need to actively support both strokes to clearly articulate both strokes. If you simply press down and let the rebound cause the second note, you may have
"Crushed" double strokes, where there is too little space between the first and second note
Weak second notes, which of course is not desirable
Perhaps this can cause the inability to play only two notes and exactly two notes every time. This is very common among beginners.
You should practice the "open closed open" exercise (not to be confused with "open rolls" or "closed rolls"), where you start painfully slow, R R L L R R L L..... And gradually speed up until a maximum speed, then slow back down. You will find that certain tempos feel more or less awkward to play, and you need to support the individual notes more at lower tempos, and you gradually allow the rebound to do more work for you as you speed up. And as it turns out, most double strokes you play will be below the "full rebound" speed.
It is not.
But, in order to successfully learn how to properly do doubles, you also have to learn and practice as there was no rebound.
In fact, both the videos you posted in the comments are suggestions about other ways to improve it.
The point is that the second stroke does use the rebound, but it cannot only rely on it. Practicing on a surface that offers little or no rebound allows you to improve the way you "reply" to the rebound (for both the upstroke and downstroke), improves the strength and endurance of muscles and tendons of your arms, wrists and hands, allowing you to only use the energy and movements required to properly play the second stroke, without wasting anything.
Also consider that, while the general technique is almost the same at any speed, it actually isn't, and deciding the amount of energy (and relying on rebound) it's up to you, your experience, your practice and the musical result you want to achieve.
Clearly, at higher speeds, you cannot control each second stroke as you would at slower speeds; you may try, but you have to be sure you're up to it, otherwise you could risk injuring yourself (tendinitis is a very bad thing).
At lower speeds you cannot obviously count on the rebound in any way, as there's no enough rebound "height" that could match the speed.
At "medium" speeds, choosing whether to use more rebound or more control can dramatically change the musical result and feeling, as the energy (and timing) that is put on the strokes is very different.
So, yes, you should also practice without rebound, but remember that it's only part of the practice.
It depends on a lot of things- you can go into extreme detail with this depending on the type of music you are playing.
When I played snare in drum corps, some of my techs and instructors would disagree on minute details on at what exact tempo you switch from using primarily your wrist to double stroke to using primarily the rebound to double stroke. One of my instructors would suggest that you use your wrist to rebound literally as long as you possibly can until the notes are simply too fast to crank out wristed double strokes. This offers a very powerful, clean sound if done correctly. I personally prefer this method, as the wrist strength you develop naturally transfers over to naturally rebounded double strokes and makes your rolls much cleaner in every scenario you play them in. However, this is strictly in a marching percussion setting. In a concert band, you generally do not want to hear the snare player in the back cranking out some beefy-a** double strokes in a gentle, melodic orchestral piece.
Whether or not you use your wrist vs the rebound (or how much of a combination you want to use) is often dictated by what your intention is with the music you're playing- is it an exercise to strengthen your muscles? Is it intended to be loud and forceful? Are you playing in a symphonic orchestra on a concert snare?
But to answer your question more generally, and more likely to actually apply to your level of skill- you should be generally attempting to practice both while focusing primarily on wrist powered double strokes to strengthen your muscles to augment the rebounded strokes where you have to rely more on the rebound of the drum.
Knowing the fine line of when to go from wristed double strokes to arm/rebound double strokes is something only an experienced player can do, and the only way you get that experience is through practicing and fine tuning your muscles to be strong and smart enough to switch seamlessly within a single song. You will have to switch all the time- triplet rolls at 180bpm will necessitate pure rebound double strokes, where as eighth note double strokes at 120 BPM will necessitate pure wrist double strokes)
In summary, and to specifically answer your question: The reason people say "do not rely on the rebound" is because they are trying to teach you to strengthen your muscles to end up with cleaner sounding rolls. At faster levels of play, you simply, physically have to rely on the rebound, and not doing so will be literally impossible.
