I started to tune with the lugfrequencies long before I had a tunebot using an app for the iPad. And I remember I had to learn some elementary facts about the physics of a drum that I did not know for the 35 years of drumming before. This is the concept of the DRUM- fundamental and the HEAD lug frequency.
Lets define we talk two headed drums here - if you use concert toms this might only apply in parts...
What is the fundamental note or frequency of a drum? It is the deepest frequency the drum can resonate at (given its actual tuning of the heads). It is also the pitch you hear when the drum is played with a stick. This ist what you aim for when you want to establish intervals between e.g. your toms.
Now this is important: there is one fundamental note/frequency for the drum - it is the same for the batter and reso head! There is no such thing that the batter can resonate higher or lower than the reso - they are on the same fundamental note! This does not mean, that it is not possible to tune batter and reso different - we do this all the time to manipulate the resulting properties of the drum! But whatever you do to your batter and reso - the drum has only one fundamental note that is equal for batter and reso!
If you think about this statement you can come to the following conclusions: If the fundamental is the same for both heads the tunebot has to use other frequencies than the fundamental of the drum to make it's job. Of course you can measure the fundemental note of the drum with the tunebot (and we do this when we want to get to defined note values for single drums). But to equalize the head within itself we can not use the fundamental because it doesn't change from lug to lug. This is why we use the lug frequencies for the tuning process.
Another aspect of this common fundamental note of the heads is that this is the key to influence the sustain of a drum: If you tune both heads to the exact same pitch both heads will resonate very easy on the given frequency -there is not much loss. The result is a long sustain of the drum. This is why the sustain is the longest when both heads are tuned exactly the same - no loss to resonate on the common frequency. Now think what happens if you tune one head higher than the other: both heads have to find a common frequency to resonate at, but one wants to go faster and the other one wants to go slower. They will find the middle frequency where they resonate, but not as freely as before. This means the sustain of the drum will get shorter. It will go more shorter the bigger the difference between the heads is. This concept is used by the apps (e.g. tunebot app) when they calculate lug frequencies for long or short sustain.
Whats the deal now with the lug frequencies? How do we get them? This is how we not get them: the drum is hanging on its tom mount and both heads are free to resonate - then we get the fundamental note of the drum. So we have to mute one head to get the lug pitches - this for practical reasons is the one head you don't want to tune at that time
Make the opposite head dead with whatever means you have, but make it dead! First important step to make full use of a system like a tunebot or the respective apps. You can put your drum on your throne with a t-shirt or small towel between the head and the throne or take a piece of foam and fix it with a rubberband under the drum or whatever you can think of, but the head not tuned at the moment has to be dead.
When you now hit the to be tuned head near the lugs you will get the lug frequency which is roughly 1.5x the fundamental frequency of the HEAD. Wait - didn't he said this does not exist? It does of course, but you will not hear it on a two headed drum because the two heads always resonate together. You can hear it if you remove the other head. Now the deal is: as the lug-frequency is the fundamental of the HEAD times a constant factor (around 1.5 depending on drum and head) you can use it to tune the head without interference from the other head. And you can not only bring the head to the desired pitch - you can also equalise the tuning from one lug to the other to the point where they are all the same. Bingo! And you can apply different tension to the batter and the reso to influence the sustain of the drum by dialing in different lug pitches! The more span you have in the lug pitches of the batter and the reso the shorter the sustain will be!
Out of this theoretical aspects the concept to tune a drum with a device like the tunebot is as follows:
Select a note or value you want to bring your drum to - the boundaries are the tuning range of the drum. Say you want to have your 10" tom at the note C in the 3rd octave. This equals roughly 131 Hz. This is the fundamental the drum needs to resonate to as a whole system of both heads and the shell. You could use the rough formula to come to the lug frequency by multiplying with 1.5 - this would be lug pitch 196 Hz. In the real world the lug pitch for a fundamental of 131 Hz will be higher depending on the size and material of the shell - say it will be 220 Hz.
Now you take your drum, mute one side and tune the other side to equal lug pitch of 220 Hz on every lug. Then you turn your drum around and do the same for the other head while totally muffling the other side. Then you remove muffling and hit the drum and read out the fundamental note of the drum which will be around the 131 Hz or C3. Because both heads are tuned to the same frequency, the drum resonates long.
Relevant information. If you want it to be shorter, you have to change the ratio from 1:1 to say 0.8 : 1.2. The resulting fundamental (in theory) will stay the same, but the heads will not resonate freely together and therefore the sustain will be shorter. Applying the above would give you 176 Hz for one head and 264 Hz for the other. Tune the drum to these lug pitches while muting the opposite head and you will get the same fundamental note of the drum, but shorter sustain. It's up to you to decide if you want the batter to be higher than the reso or vice versa. I prefer higher reso than batter, but doing this exercises with a tunebot gives you the chance to decide what fits your ears most. Once a head is in tune with itself it is quite easy to bring it down or up to other frequencies by turning the tuning rods all the same amount up or down in small steps (101 of tuning applies here, a factor that people sometimes forget that you need to know the basics of drumtuning even if you use a tunebot).
Of course you can use other ratios then 0.8 to 1.2, your drum will set the limits for you! If you tune the reso on a tom 3 times higher than the batter you get a super narrow tuning range of the drum and probably a shitty sound
Everything between 1:1 and 0.7 : 1.3 will work on most drums (toms to be precise, snaredrums are other animals).
If you want to start easy go to the app store of your choice and install the tunebot app even if you are not using it. You can select your drumsizes there and select what sustain you want (short or long) and it will calculate you the appropriate lug pitches you can use as starting point. If the app says it should result in C3 with XYZ lug pitches and it does not with your drum: welcome to the real life!
Yeah, I suspect it's not going to work already. Shell material, size and heads and other magic ingredients influence the individual results, but you can rely on that the factor will be a constant for your drum with these heads. If you land too low then raise your lug pitches a little bit until you are at your desired C3 or whatever your desired pitch is. Dont forget to write you values down (lug pitches batter and reso and the resulting fundamental of the drum) - you can use this as later reference!
And the best part of it comes now: once you have crunched all this theoretical concepts and used the tunebot or an app for some time you can apply your knowledge to your manual tuning: if you want to equalise the lugs mute the other head and listen to the lug pitches. If these are the same all around, your head is in tune with itself. You can get roughly the same effect by putting the finger of one hand in the middle of the head without pressing on the head - this mutes the fundamental and brings up the lug frequencies.
I don't use a cellphone, is this the same application for the browser?
Introducing tune-bot Studio, the new advanced drum tuner from Overtone Labs. Welcome to precision in the palm of your hand.
tune-bot.com
One practical experience for working with the tunebot: You get better results if you don't clamp it to the rim but move the mic of it to the lug where you hit.
Ok I saw that