Tongue Drums

GnarlyErik said:

The soundboard/tongue top

There's been enough interest in the tongue drums I've built, I've decided to make a blog entry to share what I have learned, much of it through trial and error, as well as what research as I can find. Plese keep in mind that I am NOT a musician, so there's been a lot of trial and error on my part. I've lost count now, but I've made well over a dozen of these things, with no two of them exactly alike.

I will attempt an ongoing blog to describe the process and what I've learned. Since this is fairly complicated to describe I will begin with the business end of tongue drums since that is what everyone seems to want to know about - the top, or sounding surface.

In general terms here's my input:

Top Material: I believe any dense hardwood which #rings' should be fine. So far I've tried the following, ranked from best on down. this is my own opinion of course, and others may disagree:

Red cherry

Padauk (African)

Honduras mahogany

Walnut

White ash

Hard maple (I was surprised at this one)

#A sample should 'ring' when held close to your ear and tapped with a fingernail. (You'll recognize it when you hear it!)

Top Thickness: 5/8" to 3/4" seems about right. The 5/8" red cherry top I've recently finished and which you can hear played in the video has a very 'sweet' sound to my ear. The 3/4" Padauk on the other hand has a more sonorous 'heavy' sound, but seems to have a better range.

Tongue pattern: There are many variations including those you invent for yourself. Mine shown here are derived from a combination of those I've tried to figure out from online pictures, more precise harmonic calculations, Hertz measurements, etc. Some generalizations:
The thicker the tongue material is, the 'thunkier' the sound;
The longer a tongue is, the deeper the note towards bass;
Tongues may be tuned higher by thinning it at the tip;
Tongues may be tuned lower by thinning near the fixed end;
(within reason.)

The illustrations are full-sized scanned images of my latest twelve-key red cherry top tongue drum. It is too long to fit on my scanner, so the scans are in two parts with a 'witness' tape intended to help you print out and join together each half into a full-sized pattern. I am not a musician, but my drum sounds very sweet to my ear. For precise tuning a Hertz measurement app or tool is probably mandatory, but if you know your stuff, tuning by ear should be possible too.

(Click on links below for printable tongue patterns):

https://www.lumberjocks.com/assets/pictures/workshops/2302524.jpg
https://www.lumberjocks.com/assets/pictures/workshops/2302525.jpg

Tutorial: https://ikindawannalearn.wordpress.com/2018/05/22/how-to-make-a-tuned-tongue-drum-step-by-step/

Here is another twelve-key pattern available online: https://www.viep.org/2020/10/04/wooden-tongue-drum.html

Lumberjocks: https://www.lumberjocks.com/projects/15495

In a future blog entry(s)on this subject I will include information on building the base for the soundboard, joining the soundboard to the base, mallet making & material sources.
I also plan to find a piece of old-growth southern heart pine and will try a soundboard made from that. I hcen't heard of SYP being used, but old-growth is incredibly dense, straight-grained and brittle, but I believe it should make good tongues if you don't get too fancy with the ends. I have a wide piece piece of purpleheart also which I've been told works well. Incidentally, I use no metal fasteners at all in my tongue drums except for small screws to hold the bottom resonater panel in place so it can be removed for tuning if need be.

Click to expand...

GnarlyErik said:

Mallets - more than you need to know!

Tongue Drum Mallets

What I have learned about Tongue Drum mallets:

The softer the business end of the mallet head, the softer the sound;

The bigger the mallet head, the louder the sound - up to a point;

I've tried mallet heads made from 'Crazy Balls' with very good results.

I've made mallets using tennis balls filled with foam which seemed to work quite well, but are not as much fun to use. I've also made some from those filled tennis sized balls made for dogs and they're not too bad, just clutzy;

I've made one pair of mallets using small hardwood toy balls which were too hard on the tongue drum, so I modified them by wrapping them in several layers of gaffers tape, which is then coated with a rubberized liquid coating which is normally used for insulating electrical wires. Each application ends up about 1 - 1.5mm thick, and I put on five or six applications, tape, then coat, tape, then another coating etc. Though these seem flexible when you squeeze them, they still produce quite a piercing sound when used to play - around 100 decibels by my meter, which immediately drives my wife away and hurts my own ears too.

"Crazy Balls" for the tips are cheap and widely available, either by ordering or from a toy store. When you order, you won't know how firm they are until you receive them, but can tell by feel if you shop in person at a local store.

6/7/21 edit: I have now added a short 3-minute video to demonstrate the various sounds which different type mallets produce:

The best handle length for me is between 14" & 16", with the longer ones preferable.

Nowhere have I found information about how soft or firm any particular crazy ball is and have had to use a shotgun approach to order from several different sources. What I've received has been a variety in different firmness from medium soft to very firm. That's OK because they are so cheap and come in bags of from 10 to 25, 50 and 100 or more;

The harder balls produced a very pronounced sharper, sometimes even discordant sound, while the softer ones can produce a lighter, feathery, and pleasant sound. My favorites so far have been the medium soft to firm in the 1-1/8" size;

(I'll try to get around to doing a short video demonstrating the different sound characteristics of the various mallets.)

I've made a few handles from scratch, but find it quicker to simply buy hardwood dowels from the lumber store and haven't broken any yet. I usually turn the handle ends on my lathe. Sometimes, I don't put handle ends on them at all, but instead make a sailor's 'whipping' using heavy twine, but the handle ends do feel better in my hands;

The smaller mallet heads are 1" diameter and the larger ones are 1-1/8" diameter, except for the tennis ball ones. 1/4" dowels work well for the 1" balls, and 5/16" for the larger ones;

I give all my mallets three coats of varnish, including the twine whipping if present;

I had trouble drilling the mallet heads for the dowels until I figured out a soft pine jig which works great. It's simple and effective, and sized for both the 1" and 1-1/8" diameter balls. Pockets are drilled partially thru the jaws using Forster bits, and sized about 1/8" - 1/4" smaller than the ball diameter. This jig will hold any ball quite securely.

The balls are placed in the lower jaw of the jig with care to make sure they are placed with the seam (if there is one) is level with the lower jaw, then the upper jaw is screwed down with a single screw just firm enough to hold the ball securely without squeezing it too much to deform it. There are pilot holes in the upper jaws for the drill bit. A drill press is best of course, but a handheld drill can be used if done with care. A drill stop should be used so the hole only penetrates about 3/4 of the way through the ball, and the hole should be the exact size of the dowel. The best results are by using a Forstner bit. If too small, the ball with split, and if too large the ball can come off. Using a very hot glue gun, the hole is filled about halfway, and the handle shoved in carefully with a twist. after the glue cools, any excess which has squeezed out can be trimmed away with a razor knife.

As you can see, I like to have several sets of mallets (about a dozen pair), and each pair is color-coded to match its mate to keep everything in order!

6/7/21 edit: I have added a short video to demonstrate the various sounds produced by different mallet types. You can view that hers:

Click to expand...

GnarlyErik said:

Mallets - more than you need to know!

Tongue Drum Mallets

What I have learned about Tongue Drum mallets:

The softer the business end of the mallet head, the softer the sound;

The bigger the mallet head, the louder the sound - up to a point;

I've tried mallet heads made from 'Crazy Balls' with very good results.

I've made mallets using tennis balls filled with foam which seemed to work quite well, but are not as much fun to use. I've also made some from those filled tennis sized balls made for dogs and they're not too bad, just clutzy;

I've made one pair of mallets using small hardwood toy balls which were too hard on the tongue drum, so I modified them by wrapping them in several layers of gaffers tape, which is then coated with a rubberized liquid coating which is normally used for insulating electrical wires. Each application ends up about 1 - 1.5mm thick, and I put on five or six applications, tape, then coat, tape, then another coating etc. Though these seem flexible when you squeeze them, they still produce quite a piercing sound when used to play - around 100 decibels by my meter, which immediately drives my wife away and hurts my own ears too.

"Crazy Balls" for the tips are cheap and widely available, either by ordering or from a toy store. When you order, you won't know how firm they are until you receive them, but can tell by feel if you shop in person at a local store.

6/7/21 edit: I have now added a short 3-minute video to demonstrate the various sounds which different type mallets produce:

The best handle length for me is between 14" & 16", with the longer ones preferable.

Nowhere have I found information about how soft or firm any particular crazy ball is and have had to use a shotgun approach to order from several different sources. What I've received has been a variety in different firmness from medium soft to very firm. That's OK because they are so cheap and come in bags of from 10 to 25, 50 and 100 or more;

The harder balls produced a very pronounced sharper, sometimes even discordant sound, while the softer ones can produce a lighter, feathery, and pleasant sound. My favorites so far have been the medium soft to firm in the 1-1/8" size;

(I'll try to get around to doing a short video demonstrating the different sound characteristics of the various mallets.)

I've made a few handles from scratch, but find it quicker to simply buy hardwood dowels from the lumber store and haven't broken any yet. I usually turn the handle ends on my lathe. Sometimes, I don't put handle ends on them at all, but instead make a sailor's 'whipping' using heavy twine, but the handle ends do feel better in my hands;

The smaller mallet heads are 1" diameter and the larger ones are 1-1/8" diameter, except for the tennis ball ones. 1/4" dowels work well for the 1" balls, and 5/16" for the larger ones;

I give all my mallets three coats of varnish, including the twine whipping if present;

I had trouble drilling the mallet heads for the dowels until I figured out a soft pine jig which works great. It's simple and effective, and sized for both the 1" and 1-1/8" diameter balls. Pockets are drilled partially thru the jaws using Forster bits, and sized about 1/8" - 1/4" smaller than the ball diameter. This jig will hold any ball quite securely.

The balls are placed in the lower jaw of the jig with care to make sure they are placed with the seam (if there is one) is level with the lower jaw, then the upper jaw is screwed down with a single screw just firm enough to hold the ball securely without squeezing it too much to deform it. There are pilot holes in the upper jaws for the drill bit. A drill press is best of course, but a handheld drill can be used if done with care. A drill stop should be used so the hole only penetrates about 3/4 of the way through the ball, and the hole should be the exact size of the dowel. The best results are by using a Forstner bit. If too small, the ball with split, and if too large the ball can come off. Using a very hot glue gun, the hole is filled about halfway, and the handle shoved in carefully with a twist. after the glue cools, any excess which has squeezed out can be trimmed away with a razor knife.

As you can see, I like to have several sets of mallets (about a dozen pair), and each pair is color-coded to match its mate to keep everything in order!

6/7/21 edit: I have added a short video to demonstrate the various sounds produced by different mallet types. You can view that hers:

Click to expand...

GnarlyErik said:

Building Individual Tongue Drum Keys


A few months ago I took the top off of a tongue drum in order to try to fine tune the tongues. In the process I accidentally split the top at the anchor ends of a couple keys. I re-glued it and it didn't seem to make any difference. That got me wondering about building a tongue drum with individual keys, which could be tuned before assembly into the top. Tuning is really a tough proposition because it's hard to determine the Hertz level of the key you are tuning since the sympathetic vibration of the adjacent keys can seriously interfere with the reading.

So, why not simply make individual keys, tune them individually, then assemble them into a finished soundboard? My theory is, so long as you are consistent with your key construction, and the way it is anchored at the fixed end, you should be able to tune it pretty close and avoid all the frustration of tuning it as part of a set.

Another advantage I see is a more consistent key width (via table saw), and incidentally, keys which are much easier to sand - a hassle with a one-piece sound board. A third major advantage I can see is with individual keys the width of you stock is not critical as long as it's wide enough for each single key. Furthermore, you can select for the best available grain in your individual keys, and not be constrained by the edge grain of wide stock being inconsistent with the overall construct.

I haven't done this yet but I am going to give it a try on my next build. I've made a rough sketch which should be self-explanatory. Briefly, The keys are made on a table saw. If your key is to have an end offset (as in the sketch), obviously the offset side must be done with a bandsaw or reciprocating jigsaw. If there is no offset end, then roughing out the keys can done entirely on the table saw.

When a key is finished, sanded, etc., it is tightly clamped to an end piece exactly how it would be it a finished soundboard, it is tuned and set aside until all the keys are made and then glued together with the other keys in the proper configuration. Fixed spacers are glued to the anchor ends during construction, with temporary spacers at the free ends. ("A" & "A2" respectively in my rough sketch).

If anyone tries this before I get to it, please let me know how it works out for you!:

Click to expand...