Shell size - newb question

[dboomer]

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.

No, it absolutely is physics. How can the shell that basically receives it energy from a vibrating head compare to a head that you have struck with a stick?

A 2” bass drum? Then please tell me exactly why removing the reso head essentially kills the sustain as the shells are still free to vibrate (Actually at this point they even resonate more with no hoop restricting them)? That’s pretty easy for anyone to see.

Again, the answer to your 2” bass drum question is physics. You need minimum distances to generate wavelength. 2” might work for a snare drum tuned really high. But not much at all for a bass drum

 

[dboomer]

Then why does my 14x14 drum resonate longer than my 14x6 drum?

You have two identical drums … same shells, same hardware, same heads and both tuned to the highest pitched drum?

 

[jda]

only thing that matters



is you have to carry them

unless you never leave the studio or have a crew

 

[Iristone]

The concert tom is a whole other boundary condition for the air column inside. The resonant frequency itself drops to half, and sustain and whatnot are totally different. Just try and tell Phil Collins that his concert tom didn't sustain, especially on Abacab!

You have two identical drums … same shells, same hardware, same heads and both tuned to the highest pitched drum?

Of course the 14x6 will sustain longer if it's tuned to its sweet spot... What if we tune them both lower so that the 14x14 is at the sweet spot?

 

[trynberg]

You need minimum distances to generate wavelength. 2” might work for a snare drum tuned really high. But not much at all for a bass drum

You were doing well until this nonsensical statement. A 22" bass drum is generating a fundamental in the 50 to 70 Hz range, where the wavelength is 16 to 22 feet long...so by your statement, no existing bass drum could generate that fundamental. You want to stand in front of my 5-inch deep Legero bass drum and tell me that it isn't generating a 60 Hz fundamental?

This statement is similar to audiophiles saying you can't have low bass in a small room because the room dimensions are smaller than the wavelengths.

 

[dboomer]

The concert tom is a whole other boundary condition for the air column inside. The resonant frequency itself drops to half, and sustain and whatnot are totally different. Just try and tell Phil Collins that his concert tom didn't sustain, especially on Abacab!

Of course the 14x6 will sustain longer if it's tuned to its sweet spot... What if we tune them both lower so that the 14x14 is at the sweet spo

Then the test is no longer fair. Again wavelength. There is a minimum necessary but no maximum.

You were doing well until this nonsensical statement. A 22" bass drum is generating a fundamental in the 50 to 70 Hz range, where the wavelength is 16 to 22 feet long...so by your statement, no existing bass drum could generate that fundamental. You want to stand in front of my 5-inch deep Legero bass drum and tell me that it isn't generating a 60 Hz fundamental?

This statement is similar to audiophiles saying you can't have low bass in a small room because the room dimensions are smaller than the wavelengths.

You only need a certain fraction of a wavelength, not the whole thing because as it bounces around inside that fraction gets multiplied. But you are not hearing the wave inside that is bouncing. You are hearing the wave created externally by the heads and the shells vibrating. And the size of that space does matter.

 

[cbphoto]

You have two identical drums … same shells, same hardware, same heads and both tuned to the highest pitched drum?

Yes, in my tests, everything (including the pitch) was equal except the depth of the drums. What am I doing wrong that makes my 6" deep drum resonate less than my 14" deep drum?

 

[timmdrum]

Then why does my 14x14 drum resonate longer than my 14x6 drum?

14x14 floor tom sustaining longer than a 14x6 snare? Tuning, likely.

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.

It's true that shells don't vibrate nearly as much as the heads do. His description of the evidence is 100% accurate. This doesn't mean that they don't vibrate enough to affect timbre; if that was the case, there would be no need for drums of varying shell materials, except for cosmetic reasons. For example, directly to my ear acoustically (as in, not through a mic signal) I hear more shell timbre in deeper snare drums than shallow ones, because the audible timbre is coming directly from the vibration of that shell itself. When close mic'd, this effect is greatly reduced in the signal, because the mic is pointed directly at the head at a close distance, so less shell timbre makes it into the mic signal, and different shell materials don't make the heads produce different timbres. Shell material and construction is mostly important in order to provide the means for the heads to do what they do. Being true cylindrically round and true flat at the bearing edge (and the edge's shape) both affect head sustain much more than maple/birch/poplar. Add good room mics, and more of the shell timbre is present.

 

[Ironjim55]

There are many great videos on deep vs shallow bass drums. When I cut my Yamaha Live Custom 20"x 16" to 20" x 12" it sounded deeper and punchier. This is a function of the fundamental sound cutting through better on the shallow drum. Here is a video on this effect:

 

[tris66]

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.

Um? I do not agree. The head is tuned to a pitch not the shell. The diameter of the shell and thickness of the head limit the tuning range. A 16" roto tom and a 16"x16" floor tom with the same head will have nearly the exact tuning range. Resonance and projection are a different thing. Just like with guitar strings the thickness of the vibrating head effects the possible tuning range. Thicker= lower. Thinner= higher. Thin heads get flabby when tuned low. Thick heads get hard, tight, and will not resonate much when tuned too high. An ambassador is perfect on a 10" tom but may be papery on a 28" kick because of less tension needed to get it to pitch.

 

[Iristone]

Then the test is no longer fair. Again wavelength. There is a minimum necessary but no maximum

It's not fair only because it doesn't support your conclusion. I think it's perfectly clear now.

 

[cbphoto]

I had a PM with @dboomer about my tests. Like me, he wanted audio files. I failed, but have contacted a Keller in New Hampshire to see if I can get some pre-drilled 14" maple shells with depths of 14" and 6" or 8".

In the meantime, here's where I failed:

I used my 14" floor tom (bubinga) and my spotted gum snare (a bit harder wood than bubinga), stripped off the strainer & butt, and replaced the hazy 300 with a clear G1 (like my tom). After a tuning the 14" deep tom to a decent note, I struggled with the naked snare. After a few minutes of wonky sounds, I figured the snare bed was probably causing me problems. That's when I realized I couldn't do a proper A/B comparison. I didn't read any of the links you provided 'cuz I thought my experiment would work.

I'm still on the side of: the larger air chamber (deeper drum) resonates longer, but don't have the proper drums for a decent comparison.

Tama made a style of tom called "hyper drive" (a misnomer, IMO) where the mounted toms are very shallow compared to their "normal" sized toms. I always figured those were designed for a short note, but in the Tama catalogs they market them as drums that can be more easily positioned around the kit.*

As I was reassembling my spotted gum snare, I realized—to my chagrin–that the shell thickness of the two drums aren't the same either. Shame on me for such a poor setup for my experiment. I wonder if @GetAgrippa has made that kind of n00b mistake in his bio-lab.

* Hyperdrive toms.

 

[dboomer]

Since I don't have identical drums the best I can do is use someone else's recording. This is the only example I can find on Youtube ...

Listen for yourself. To save you the embarrassment of picking the wrong one I'll show you that the shorter tom sustains longer than the deeper tom. I took the last hit from each example, normalized them to exactly match the peak level of each drum and here is the result visually.

It's pretty easy to see that the shorter tom sustains longer than the deeper tom. Had these drums both been tuned up a bit the difference would have been even larger.

 

[GetAgrippa]

Since I don't have identical drum the best I can do is use someone else's recording. This is the only example I can find on Youtube ...

Listen for yourself. To save you the embarrassment of picking the wrong one I'll show you that the shorter tom sustains longer than the deeper tom. I took the last hit from each example, normalized them to exactly match the peak level of each drum and here is the result visually.

It's pretty easy to see that the shorter tom sustains longer than the deeper tom. Had these drums both been tuned up a bit the difference would have been even larger.

View attachment 143930

Cool experiment. So same pitch so sustain not from one having lower pitch and longer sustain. But timbre is really different though- the shorter sounds clearer richer better. The deep is muddled. I wonder if go shallower shell would it flip or be more pronounced sustain?