Least Ringy Snare Shell?

kanefsky

Senior Member
Being hard, high mass, & rigid, makes it a prime candidate for unbalanced high overtones - essentially, the opposite of the desired result.

Is it really hard, high mass, & rigid? The reviews of the DW drum all say that it isn't particularly heavy. According to this page, concrete is actually lighter than aluminum for a given volume (let alone brass, steel, etc.). It's just that you rarely see very thin concrete or very thick aluminum so you think of concrete as really heavy and aluminum as really light.

Many of these terms are probably kind of meaningless without being properly defined. I'm not a physicist but I would think "rigid" means something different in the context of musical frequencies than in an earthquake, for example. For what it's worth, it seems like bare concrete has a higher sound absorption coefficient than wood at pretty much all frequencies (source here). I don't pretend to know how meaningful that statistic is when you're building a drum out of a material versus using it for the walls of the room the drum is located in.

Again it's all kind of meaningless without empirical testing, since there is a very wide range of materials you could call concrete and supposedly the DW drum is some kind of mixture of soapstone and resin. It's probably safe to say that DW didn't set out to make something with annoying overtones when they decided to market a snare drum made from concrete :)

--
Steve
 

larryace

"Uncle Larry" - Administrator
Staff member
I'm with you on this Larry. When I play my Ludwig Supraphonic alone by itself it sounds pingy, ringy, and annoying (loud).
Put it behind a rock, blues or funk band and it sounds beautiful !!!

.

That's the key. Sure when drums are all by themselves, you are going to hear every little frequency in all it's glory.

Most of the frequencies that we want to eliminate, are the ones that go away when the band comes in.
 

loach71

Senior Member
Folks this is a great discussion in which drums meet physics!

Rigidity is defined as Young's Modulus.
https://en.wikipedia.org/wiki/Young's_modulus

Rigidity is good for a drumshell -- you don't want the stick's strike energy being wasted on a floppy / flexy drumshell. One of the design goals of metal or composite drumshells is to transfer the highest percentage of the strike energy to the heads and the column of air inside the shell. A floppy / flexy drumshell wastes this energy by moving itself -- it acts as a parasitic resonator, that because of its relatively high rest mass (when compared to the heads and the column of air in the drum) ruins the acoustic attack and efficiency of the drum system. This makes the drum relatively less able to cut though the sound front of big bands or amplified instruments.

By acoustic attack I mean in musical terms how quickly in milliseconds a drum system can rise to its theoretically maximum sound pressure level. (For the fellow nerds viewing this, dp/dt is the first derivative of air pressure divided by the first derivative of time. For sound guys this is transient signal response.)

If you want to hear extreme acoustical attack, try listening to a pipe band snare drum. The players of these drums don't beat the hell out of their instruments, but their sound cuts through the din of the bagpipes!

Tim
 
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Ghostnote

Guest
Slightly off-topic, but I'm wondering if any of you have ever been in an
anechoic chamber.

https://en.wikipedia.org/wiki/Anechoic_chamber

They're really bizarre, and you kind of have to experience it.
Hard to describe, but it'll swallow up pretty much all audio reflections.

I'm in the process of building a soundproof room in my garage, and before I had the inner walls and ceiling sheeted over with drywall and all the insulation was exposed, the room was almost like an anechoic chamber. It felt weird to walk in there- almost like I was wearing earplugs. Definitely a very alien feeling, and my drums just sounded terrible with the room like that. Music on my blaster sounded pretty good though. Made me realise the importance of installing bass traps in smaller rooms.
 

loach71

Senior Member
In my undergruaduate engineering years (admittedly in the dark ages) I took several acoustics courses. My university had three anechoic chambers at that time. My senior-level acoustics course required its students to do several hours of live test work in one of the anechoic chambers. When you spend time in one of these rooms you feel very odd... these feeling stayed with me for at least an hour after exiting that room.

I will return to the OP's questions about shell ringing in subsequent posts. My apologies to the OP for an apparent thread hi-jack. It was unintentional.
 
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Ghostnote

Guest
In my undergruaduate engineering years (admittedly in the dark ages) I took several acoustics courses. My university had three anechoic chambers at that time. My senior-level acoustics course required its students to do several hours of live test work in one of the anechoic chambers. When you spend time in one of these rooms you feel very odd... these feeling stayed with me for at least an hour after exiting that room.

I will return to the OP's questions about shell ringing in subsequent posts. My apologies to the OP for an apparent thread hi-jack. It was unintentional.

No apologies required. I contributed to the derailment myself, lol. I felt really weird working in my room too until I got it about halfway sheeted in. I found that I felt almost a bit confused or distracted and it was hard to motivate myself to get things done when the room was totally absorbent.
 

Red Menace

Platinum Member
There is some interesting discussion going on here about the physical properties of a shell. I love a good "geek out" thread.

To directly address OP's issue though, I would go with a deep wood shell. Just about any shell is going to give you a lot of overtones when tuned low. For that low, low 80's ballad sound the trick in the studio has been to tune very low and muffle with whatever you have at hand. Usually a leather wallet but moongels/tape will do the trick too.
 

picodon

Silver Member
In my undergruaduate engineering years (admittedly in the dark ages) I took several acoustics courses. My university had three anechoic chambers at that time. My senior-level acoustics course required its students to do several hours of live test work in one of the anechoic chambers. When you spend time in one of these rooms you feel very odd... these feeling stayed with me for at least an hour after exiting that room.

I will return to the OP's questions about shell ringing in subsequent posts. My apologies to the OP for an apparent thread hi-jack. It was unintentional.

Loach in your first post you said imperfect tuning is the most aggressive generator of overtones, can you elabrate on that? How does "crank the snare head till it almost cracks" tie into that? Does that promote overtones? My guess is it does.
 

loach71

Senior Member
Loach in your first post you said imperfect tuning is the most aggressive generator of overtones, can you elabrate on that? How does "crank the snare head till it almost cracks" tie into that? Does that promote overtones? My guess is it does.

You have to tune the heads for the desired primary output frequency (tone). To do this you must take into account the following:

1) drum size (diameter and depth)
2) ratio of tuning frequency (pitch) between the batter and reso heads
3) the type of batter and reso heads you are using
4) the type of sticks you are using
5) the maximum volume output (loudness) you will anticipate

My goal in drum tuning is to get that big, fat tone one would get from calfskin heads. As I said before, I detest the 'oingy-boingy' overtones from badly tuned heads based on the 5 parameters I mentioned above. This is the drum SYSTEM.

I use a calibrated condensor microphone with a real-time analyzer (an old DoD brand RTA) to give me graphical results from which to measure. For a particular drum size, my tuning is heresy -- I do the primary tune with the reso head off the drum. I tune the batter head to the drum's resonant frequency (tone or pitch) -- I measure this as the maximum sonic output of the drum when struck with the same stick strike force at the same position on the head. What I am doing is tuning the head / air column system to its primary resonant frequency. The bigger the diameter and the longer the shell, the lower primary resonant frequency will be. If you want an example of this, look at a pipe organ in a cathedral. The low notes are generated by HUGE diameter and length pipes, while the high notes are handled by their relatively tiny siblings.

I then flip the drum over and do the reso head. What I look for with the spectrum analyzer is to minimize the 3rd, 5th and 7th order harmonic resonances from the drum system. By way of experimentation I have found tuning the reso head between 1 - 1.5 octaves above the batter head works best for the removal of the 3rd, 5th and 7th order harmonic resonances from the drum system. Here are some links about DoD RTA. I am not the author. They show 31 frequency bands (pitches) from 20 Hx to 20 KHz,

https://www.youtube.com/watch?v=WOW56y0dBos

https://www.youtube.com/watch?v=LLQBdXD61_A

I did one experiment to ascertain if I could tune a drum to make it sound as 'oing-boingy' as possible. I used a 14 x 14 floor tom with indentical batter and reso heads, tuned to the exact same pitch. It rang like a bell and required so much gaffer's tape on the batter head that stick response was horrible. I brought it to a 23 piece band rehearsal in Golden Gate Park. The rhythm section asked me to take it off stage at the next break!

These are my findings for the heads. Upcoming postings will deal with the shall materials, bearing surfaces and how they interact with the heads.

Tim
 
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loach71

Senior Member
I think cedar is a little too soft to make a good-sounding drum.

I would say that any softwood would be too mechanically weak to make a durable and reliable and 'tuning repeatable' drum. This is especially true for jazz nuts like me who want tightly tuned heads in order to do finger control technique like that of Joe Morrello. I would look at a strength of materials chart to ascertain the shell material with the least flex and highest strength. Your choice based on these engineering parameters may LOOK bad, but do not despair -- it can be covered with various wraps or gorgeous wood veneers in order to attain your aesthetic goals. A commentator in this thread named CompactDrums can help you with drum aesthetics -- I do not have the mental prediliction to deal with visual aesthetics -- I'm an engineer whose focus is numbers, numbers, numbers....

In short choose your drums with your ears NOT your eyes.

Tim
 
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Push pull stroke

Platinum Member
For almost $900 it better be impressive. I like the wood grain. It's purdy enough.
Yeah, the only Cypress I'm familiar with is the Cypress that grows in Nor Cal. And I used to use shavings for my pet rat to nest in.

I thought it sounded amazing at the mid-range tuning. But yeah, it had better sound amazing at all tunings to be worth $900.
 

CompactDrums

Silver Member
I apologize in advance for my crummy, fat-finger typing.

I'm approachng this question from an engineering and physics perspective. If you look at the tensioned heads as a Helmholtz resonator you will notice a dominant (primary) sound frequency that you can hear depending upon the tuning. There are integral sub-multiples (undertones) and integral mutiples (overtones) of this primary frequency because the whole drum, (heads, shell, hardware, attachments and dampening material) exhibit sympathetic vibrations generated by the air column inside the drum and this heads. Some refer to these viibrations as Eigentones. The stick strike is the primary exciter of this system.

Every system depends upon the mass of its components parts, excitation energy and mechanical energy transfer. The drum as a system generates its own dominant Eigentone and smaller sympathetic Eigentones. Change one, any or all of these factors and you will change the Eigentones of the drum SYSTEM.

Most snare drums (at least in the jazz genre) are tuned to a high pitch. Many jazz drummers (but not all) prefer metal shells with single ply heads, and high tensioning tuning for increased sensitivity. I am a memeber of this group. I have several Ludwig Super Sensitive and Premier snare drums -- and if you have sub-optimal batter and reso head tuning you have an oversupply of dominant, secondary and tertiary Eigentones. This situation makes the drum resonate like a cheap brass bell.

Metal shells are very rigid and offer geat support for high levels of head tension. I bought a tired, old Ludwig Super Sensitive snare drum as a rebuild project. After I stripped everything off the shell for rebuild I started to think of the drum as stated above -- as an Eigentone generating system.

As an engineer / applied physicist, I am an empiricist -- I want numerical data to support my own sensory assesments. My first sensory assessment was that many undamped metal shell drums exhibit irritating, high pitched resonances in the 2KHz - 5 KHz audio passband. Some drummers call this the oingy-boingy basketball resonance effect. I certainly don't like it.

We can apply MoonGel, Gaff tape, dampening rings or multi-layer heads to help ameliorate this problem. But on a jazz or concert snare drum where sensitivity and rapid rebound is king, these solutions carry serious performance degradations.

My empirical experimentation started by using calibrated condensor microphone, tube preamp with phantom power supply, a real-time analyzer, and a Fast Fourier Transform (FFT) analyzer to see in a graphical and numerical format what was happening with the drum Eigentone generation system.

I found that the most aggressive generator of objectionable Eigentones was a poorly (or should I dare say imperfectly) tuned batter / reso head system. The second most aggressive generator of objectionable Eigentones was a 'ringing' undamped shell.

Going back to my Ludwig Super Sensitive rebuild project, I decided to attempt to damp the inside of the shell of the assembled drum with 1/8 inch of Plasti-Dip neoprene coating. This stuff is easily removable by anyone with good manual dexterity and patience. Sounds like a drummer doesn't it?

I tested this drum with identical head tensions and the same heads with and without the Plasti-Kote on the inside of the shell. The Plasti-Kote version of the test showed an average reduction of 15dB on the 2KHz --> 5KHz areas of the audio analysis spectrum. This is very significant -- talk to your sound technician if you dont believe this! This experiment also found that the Plasti-Koted version of the snare drum was not so picky about tuning -- there was a significantly widened window of imperfect tuning in which objectionable Eigentones (ongy-boingy tones) were acceptably low.

In my perspective, this means that an undamped, ringy drum shell is a significant factor in the production of objectionable Eigentones (ongy-boingy tones). My next step in this project is further testing on various composite shells that I am building. These are wound fiberglass / epoxy, wound kevlar / epoxy, wound carbon fiber / epoxy, and mixed wound kevlar / carbon fiber / epoxy. Did I say I was a materials scientist? I also have filthy, sticky hands from these engineering materials.

I am doing this as a personal, non commercial project to enhance drummers' knowlege of the materials science and physics of their drum systems. Music is physics with a human touch... Any comments or questions are warmly welcomed.

Tim

I'm sure I'll have some questions or comments after I read it a few more times. :) Super-interesting stuff but takes a while to absorb and process...
 

loach71

Senior Member
If you guys nerd out, I hope to get the privilege of being a fly on the wall. I promise to try to keep quiet. :)

DON'T keep quiet. The more questions and comments the better. We are working on a classic drum problem -- a repeatable tuning method the helps mitigate the cheap rubber ball sound all of us have experienced with our drums! I'm just trying add scientific method discipline to this discussion...

Tim
 
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