Sound variables of drum shells

Migaluch

Senior Member
I thought Bobdadruma's experiment was interesting.

And sorry to be off topic, but what's with all of the provocative avatars!!!!!???

Look what you have done Bo!!!! You have caused a sexy avatar Renaissance!!
 

bobdadruma

Platinum Member
I believe that there is a curve in the relationship between shell depth and sound.

Example,
There may be only subtle differences between a 7x12 and an 8x12 tom.
There may be a big difference between a 6x12 and a 7x12 tom.
There may be a big difference between an 8x12 and a 9x12 tom.

I believe that once a drum becomes shallow or deep beyond a certain point the sound difference is more pronounced.
There is a big difference between a 5x14 and a 5 1/2x14 snare.

If you look at the depth history of what manufacturers have produced in the way of 10 and12 inch toms. They have pretty much kept in the 7 to 9 inch depth range.
It is only recently that shallower than 7 inch depths have been more popular. These drums do sound different.
Tama has the 6.5x10 and the 7x12 inch toms on the Hyperdrive kits.
That 1/2 inch less on the 10 inch tom depth seems to make a difference in the sound. Notice that they didn't go with a 6x10 inch tom.

Drum dimensions are whacky things!
If I set my old Gretsch kit up as a four piece, I always use the 9x13 tom.
If I set the same kit up as a 5 piece, I use the 8x12 and the 10x14 toms on top. I don't like the 9x13 with any of the other rack toms.
 
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drumtechdad

Gold Member
I recently took the time to experiment with two of my kits.

One kit is finished maple with 7x10 and 7x12 toms. Cast hoops.
The other kit is wrapped poplar with 8x10 and 8x12 toms. Flanged hoops.

I put the same type of heads on all 4 of these toms and I tuned them as close as I could to being the same tension.
I had coated single ply heads on the batters and clear single ply heads on the resos.

I set all of the tension rods on the 4 drums to 76 on the drum dial and then I fine tuned by ear.

I was surprised to note that the drums sounded almost the same when I played them side by side.
The main difference was heard only when the drums were hit hard. It was minor!
During medium to light attack I could detect very little difference between the like diameter drums even though there is a 1 inch depth difference and a shell composition difference.
The difference is so minor that if I were to close my eyes and have someone play the drums I would have a hard time telling which drum was hit.
The shallow maple toms are slightly sharper and louder.

The floor toms on these two kits are the same dimensions, (12x14) and I found the same to be true when comparing them.
The maple drum was slightly louder and higher pitched. Not as warm sounding.
Thanks for this post. I believe you've basically proved that shell depth doesn't make much difference in the scheme of things.

I have an old Gretsch kit with round bearing edges and shells that are half as thick as my other kits.

If I compare the sound of the 8x12 Gretsch round edge thin shelled tom to the 8x12 sharp bearing edge thick shelled Tama tom, I have apples and oranges.
These two drums do not sound alike at all!
Not even close.
I believe that it is the round bearing edge that is making the most difference.
Although you don't describe the differences you heard, I would venture that it's shell thickness that's making much more difference than the bearing edges.
 

bobdadruma

Platinum Member
I have an old Gretsch kit with round bearing edges and shells that are half as thick as my other kits.

If I compare the sound of the 8x12 Gretsch round edge thin shelled tom to the 8x12 sharp bearing edge thick shelled Tama tom, I have apples and oranges.
These two drums do not sound alike at all!
Not even close.
I believe that it is the round bearing edge that is making the most difference.
 

keep it simple

Platinum Member
These are generalizations.

Diameter mostly affects pitch. Bigger the diameter, lower the pitch.

Depth mostly affects sustain and loudness.

Diameter-to-depth ratio: see above.

Thickness affects the pitch of the sweet spot. The thicker the shells, the higher the pitch they resonate at. Thinner shells resonate at a lower pitch.

Rerings tend to raise the pitch of a shell, so you end up with a thin shelled drum that resonates at a higher pitch than if it had no rerings.

All of these depend a lot on heads and tuning, and shell composition makes a difference, too, so these are only tendencies.
A great resume. Just about spot on in my experience.
 

bobdadruma

Platinum Member
I recently took the time to experiment with two of my kits.

One kit is finished maple with 7x10 and 7x12 toms. Cast hoops.
The other kit is wrapped poplar with 8x10 and 8x12 toms. Flanged hoops.

I put the same type of heads on all 4 of these toms and I tuned them as close as I could to being the same tension.
I had coated single ply heads on the batters and clear single ply heads on the resos.

I set all of the tension rods on the 4 drums to 76 on the drum dial and then I fine tuned by ear.

I was surprised to note that the drums sounded almost the same when I played them side by side.
The main difference was heard only when the drums were hit hard. It was minor!
During medium to light attack I could detect very little difference between the like diameter drums even though there is a 1 inch depth difference and a shell composition difference.
The difference is so minor that if I were to close my eyes and have someone play the drums I would have a hard time telling which drum was hit.
The shallow maple toms are slightly sharper and louder.

The floor toms on these two kits are the same dimensions, (12x14) and I found the same to be true when comparing them.
The maple drum was slightly louder and higher pitched. Not as warm sounding.
 
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drumtechdad

Gold Member
I have questions for all the drum sound experts:

What do the following variables (in relation to drum shells) do to a drums sound?:

  • Diameter
  • Depth
  • Diameter-to-depth ratio
  • Thickness
  • Re-inforcment rings

...I ask myself this question when I notices the vast contrast in timbre between square sized toms of the 80s (a deep, boomy sound) to the more modern shallow fusion toms (a singing sound with a quick attack and mellow set of tones).
These are generalizations.

Diameter mostly affects pitch. Bigger the diameter, lower the pitch.

Depth mostly affects sustain and loudness.

Diameter-to-depth ratio: see above.

Thickness affects the pitch of the sweet spot. The thicker the shells, the higher the pitch they resonate at. Thinner shells resonate at a lower pitch.

Rerings tend to raise the pitch of a shell, so you end up with a thin shelled drum that resonates at a higher pitch than if it had no rerings.

All of these depend a lot on heads and tuning, and shell composition makes a difference, too, so these are only tendencies.
 

BassDriver

Silver Member
I have questions for all the drum sound experts:

What do the following variables (in relation to drum shells) do to a drums sound?:

  • Diameter
  • Depth
  • Diameter-to-depth ratio
  • Thickness
  • Re-inforcment rings

...I ask myself this question when I notices the vast contrast in timbre between square sized toms of the 80s (a deep, boomy sound) to the more modern shallow fusion toms (a singing sound with a quick attack and mellow set of tones).
 
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