Shell size - newb question

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Uggernaut

New Member
Hello.
Can anybody shed some technical light on this for me.
How does the diameterXdepth effect a drum shell.
For example a bass drum could be 22x18 or 24x14 ect ect.
What does the diameter size change. And what does the depth change.
From my limited knowledge I assume the diameter changes how deep the bass tone is. And the depth adds to that, but is more about the projection or volume. And the resonance.
Am I on the right track with that.
 
Diameter affects the head tension you’ll need/get tuning to a particular pitch. A drum with a larger diameter will need more tension to achieve the same pitch as a smaller one will. So this affects your “feel”.

Shell depth affects timbre. A deeper shell will tend to favor lower harmonics compared to s shorter one. A deeper shell will have shorter sustain and less resonance compared to a more shallow one (everything else being the same).

Projection and volume have more to do with shell stiffness than shell depth.
 
dboomer said:
A deeper shell will have shorter sustain and less resonance compared to a more shallow one (everything else being the same).
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This part is debatable. The sustain I believe is the opposite. IME deeper shells have longer sustain, and people often recommend a 12” depth for a quick punchy bass sound. That said, sustain is also affected by resonance, more resonance can mean longer sustain. And resonance is dependent on the entire system working together: the dimensions, the tuning, the materials and construction. Depth is relevant insofar as the chamber size and shape are part of the equation, but it wouldn’t be right to say deeper or shallower are more resonant.
 
diameter is going to be pitch
depth volume

except -the more shallow the depth- can -like a splash or ice bell- cut further than a 24" light or medium ride
because we can easily over power one - (the 5 x14) and is much harder to over power the other ( 16x16 or 18 x20)

So -nothing -neither- depth or diameter- is finalized without the third element- the force of the strike - has to be taken into consideration too

we're (even the Hulk) limited how hard we want to swing in general constanly dynamically the stick and the foot- so we pick depth and diameter to what fits our musculature- looking to get the most range- we want from each piece

I give up . Lunchtime.
"Style of Force" determines dictates choices
and you're on right track @Uggernaut

and we as drummers like to get -enjoy getting- the most from the least even if we have 17-piece sets with 11 cymbals
 
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bongoman said:
This part is debatable. The sustain I believe is the opposite. IME deeper shells have longer sustain, and people often recommend a 12” depth for a quick punchy bass sound. That said, sustain is also affected by resonance, more resonance can mean longer sustain. And resonance is dependent on the entire system working together: the dimensions, the tuning, the materials and construction. Depth is relevant insofar as the chamber size and shape are part of the equation, but it wouldn’t be right to say deeper or shallower are more resonant.
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I'm with Bongoman on this one. Deeper bass drums sustain way more than shallow bass drums.

Deeper = boomier
Shallower = punchier

 
It’s simple physics. When you hit a drum head it generates a wave that travels down to the reso head. Then it bounces off the reso head back up to the batter head and vibrates it, and on and on, back and forth. That wave is gonna diminish in power the longer it travels so how many times it can bounce back and forth will be fewer.

I think the confusion comes if one mistakes “sustain” for “timbre”.
 
Ehh the formula you propose would only work if sustain was *just* from bouncing off the heads—but it’s not. The wave also interacts with the shell (plus vent holes and other variables). A deeper shell allows more interaction with the shell, the waves bouncing in every direction. And the heads pass a lot of energy through them, so a big part of the sound is specifically in how much does *not* bounce back and forth.
 
Although the OP did not specifically ask this question, I will go ahead and point out that the larger the drum the more space it takes up in a performance area and car, and the (usually) heavier it is to carry. Also, the larger the diameter the more one must be aware of how that affects where toms can be placed. Larger diameter bass drum with deep toms means toms must either be higher up or further to the side.
 
If you play in any situation where it’s loud enough that you must be mic’d up, then it doesn’t really matter what sizes your drums are, so keep that in mind. For me if I’m mic’d up, that means the venue will be larger as well and I’ll use my biggest sizes available because I personally like those better.
 
bongoman said:
Ehh the formula you propose would only work if sustain was *just* from bouncing off the heads—but it’s not. The wave also interacts with the shell (plus vent holes and other variables). A deeper shell allows more interaction with the shell, the waves bouncing in every direction. And the heads pass a lot of energy through them, so a big part of the sound is specifically in how much does *not* bounce back and forth.
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Actually a tiny part. The heads move much more than the shells and the shells move even less the larger they are since you are sending X amount of energy over a larger surface if the shells are large. The shells don’t “amplify” the energy, they just absorb it. More shell, more absorption.

Take the reso head off. Then how much sustain do you have. If you were getting it from the shells they are still there ;)
 
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Nobody said anything about amplifying energy. The material absolutely does reflect as well as absorb; it also vibrates sympathetically, which creates resonance. If you have a 14x20 Tama Star Maple and a 14x20 generic 70’s lauan with water damage, with the same heads and tuning, will they have the same sustain? If you want to play the reductio ad absurdum, which bass drum will have longer sustain: a 14” depth or a 2” depth?
 
Don’t confuse tone/timbre with sustain. Deeper shells will sound “fatter” because you will lose higher harmonics.

The major component of sustain is the drum heads acting together. Tune them to the identical pitch and you’ll get max sustain regardless of the depth. Take the reso head off and you’ll get almost none. The shells don’t contribute much to the sustain.

Simply, the shorter the distance between batter and reso heads, the more trips back and forth. If you lengthen the distance the number of round trips will become fewer as the energy dissipates with distance.

The longer the drum, the shorter the sustain - John Good

Deeper drum = shorter sustain - Craig Lauritsen

the depth influences articulation and resonance, with the longer the drum, the shorter the sustain (Modern Drummer, March 2008, p.167)
 
dboomer said:
Don’t confuse tone/timbre with sustain. Deeper shells will sound “fatter” because you will lose higher harmonics.

The major component of sustain is the drum heads acting together. Tune them to the identical pitch and you’ll get max sustain regardless of the depth. Take the reso head off and you’ll get almost none. The shells don’t contribute much to the sustain.

Simply, the shorter the distance between batter and reso heads, the more trips back and forth. If you lengthen the distance the number of round trips will become fewer as the energy dissipates with distance.

The longer the drum, the shorter the sustain - John Good

Deeper drum = shorter sustain - Craig Lauritsen

the depth influences articulation and resonance, with the longer the drum, the shorter the sustain (Modern Drummer, March 2008, p.167)
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Then why does my 14x14 drum resonate longer than my 14x6 drum?
 
the third factor is the velocity of the strike
 
Diameter affects head pitch or tuning range.
Depth affects shell pitch or frequency emphasis i.e. "tone". Also affects rebound especially on a snare drum.
Sustain could depend on how close your tuning is to the pitch of the shell (air column), but that's just my speculation. If you've played with a synth or a parametric equaliser, you'll hear the self-oscillation ring longer if the input signal has a frequency close to that of a resonant filter. If that's the case, then a deeper shell should sustain longer at a lower tuning (kick), and a shallower shell longer at higher tuning (rack toms).
 
Rattlin' Bones said:
They have to - there is more wood vibrating.
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When you strike a drum most of the energy from that strike vibrates the heads because you strike the head. Sometimes you can actually see the heads vibrating. For wood to vibrate it has to take energy away from vibrating heads and heads are a much much bigger part of the sustain. Did you ever see the shell vibrate? Well just like a speaker, the longer the travel of the cone the louder it is.

Try a simple experiment. Hit a tom and listen for the sustain. Now hold that tom with two flat hands damping the shell from vibrating. The result … barely any difference. Now take the bottom head off that tom and hit it again letting the shell ring out. Barely any sustain. Or turn the drum upside down with the reso side up and put a penny on the reso head. Strike the batter head and watch the penny bounce. You just aren’t gonna see that penny bounce if you turn the drum on its side and put that penny on the shell. It may rattle but its but it isn’t going to bounce.

Even had a drum resonate from your bass player’s amp if he played a certain note? If you took the heads off your not gonna hear the shell resonate at the same level.

That bass drum video isn’t a good example because they cut a hole in the reso head and they are pointing a mic directly at the batter head. The reso head is on the dead side of the mic and barely picks up.
 
Boomer I’m sorry but if you’re going to keep insisting that wood (and metal and acrylic etc) neither reflects nor vibrates much, you’re going against not only physics but common sense.

Tell me about the incredible sustain from that 2” deep bass drum, where the waves bounce between the heads so many more times, and there’s much less shell absorbing the energy.
 
Uggernaut said:
Hello.
Can anybody shed some technical light on this for me.
How does the diameterXdepth effect a drum shell.
For example a bass drum could be 22x18 or 24x14 ect ect.
What does the diameter size change. And what does the depth change.
From my limited knowledge I assume the diameter changes how deep the bass tone is. And the depth adds to that, but is more about the projection or volume. And the resonance.
Am I on the right track with that.
Click to expand...
You are on the right track with that. Deeper Drums also affect pitch as well. So a Deeper Tom will have lower Fundamental note capability.
But im no expert either. Great question.
 
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