Advice and questions on keeping your instruments in top form
By flamba
#35979
All,

I was just wondering whether anybody has an explanation why my djembe sounds so dull when I start up and dramatically improves after a few minutes when it is 'warmed up'.

Is this due to temperature or release of tension that builds up over time when the djembe is not used? An argument for temperature may be that skins stretch when they get warm, but then the sound may also change when hitting the ring with a hammer. The effect seems to be stronger for thicker goat skins...

Best,

flamba
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By michi
#35981
I suspect it's temperature. Much of the energy of the impact gets turned into heat, so the skin will definitely warm up a bit when you are playing.

Cheers,

Michi.
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By drtom
#35994
michi wrote:Much of the energy of the impact gets turned into heat, so the skin will definitely warm up a bit when you are playing.

Michi.
Is that a verifiable fact Michi? Not out to disagree with you here - just curious.

It makes sense to me that just putting your hands on a drum will transfer body heat it to it, but it does also seem intuitive that expenditure of energy gets the little atoms scurrying.

drtom
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By michi
#35997
drtom wrote:Is that a verifiable fact Michi? Not out to disagree with you here - just curious.
Yep, most definitely. Anything that moves gets warmer. In fact, temperature, by definition, is motion. What I'm not sure about is how much of a difference it really makes.
It makes sense to me that just putting your hands on a drum will transfer body heat it to it, but it does also seem intuitive that expenditure of energy gets the little atoms scurrying.
Just hitting the skin with hands of any temperature (even colder than the skin) will make the skin warmer. It's not just that heat gets transferred from the hands to the skin (though there will be some of that), it's also that the movement of the skin itself makes it warmer.

But, come to think of it, another part of this effect might well be that, as I start playing, it's my hands that are warming up too. I often find that, when I start playing, I'm really disgusted with my pronunciation. Slaps are muffled, tones are too bright and, basically, the sound just sucks. Then, after playing for ten minutes, I'm really quite happy with my sound. I suspect that my hands probably have more to do with it than the skin…

Cheers,

Michi.
By flamba
#35999
Thanks Michi,

Indeed, playing increases the temperature like any movement and friction (I also used the title 'cold' djembe having this in mind). The next question would be why could it improve when you hit the ring with a hammer.

I would continue stating:
1) when the skin warms up, it contracts, causing higher tension and a higher / brighter tone.
(one could check this with the audacity diagrams shown earlier on tone / slap quality).
2) If it is temperature alone, it would not need me playing but I could expose it to a warm summer's sun (just caught me thinking about doing this experiment in Australia :D, less easy here in NL).
3) After 10 min of play, I am indeed getting warm myself and play more precisely / relaxed, but my gut feel is that this is not the effect I hear (we could check by letting somebody else do a few slaps letting him/her wait for ten minutes and do it again).
4) When I leave the djembe alone for some time after having played, the sound becomes worse again. The effect is reversible.
5) This does not mean though that the skin is in exactly the same state as before. I assume that skins will settle down a bit differently depending on their structure. They are naturally grown and are not homogeneous. Tension will not distribute symmetrically any more after some time and resonances are not any more the ideal M's. Or alternatively, resonances decay earlier and hence sound dull? This effect may not occur immediately but after some time. Hitting the ring with a hammer then would reproduce a more homogeneous skin tension?

Thinking about it this could be an explanation. Just speculation though. If 5) would be true, I would also expect these effects to be absent on synthetically produced skins. May be somebody in the forum ever used a synthetic skin on a traditional African djembe :giggle: ... or a Remo?

Best,

flamba
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By boromir76
#36003
You can skipp the process of standard djembe warming, with simple circular rubbing of head with your palm until it gets warm. It's hard to tell, but sometimes in the exact same enviroment, the djembe sounds just great and at some other times it sounds worse, without no obvious reasons,.... I have heard that air pressure and other atmospheric changes contribute to sound, but sice it is not under our control, it does not matter. :-)
Last edited by boromir76 on Sun Apr 12, 2015 9:14 am, edited 1 time in total.
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By michi
#36004
flamba wrote:The next question would be why could it improve when you hit the ring with a hammer.
I never hit my djembe with a hammer (or mallet), except sometimes during re-skinning, so I don't know whether this makes the drum sound better. If you are hitting down on the rings, it'll increase tension (at least temporarily) and increase the pitch, which is usually perceived as sounding better.
1) when the skin warms up, it contracts, causing higher tension and a higher / brighter tone.
(one could check this with the audacity diagrams shown earlier on tone / slap quality).
Not sure whether a spectrum analysis would be able to tease this out. I suspect that the change is too subtle for that.
2) If it is temperature alone, it would not need me playing but I could expose it to a warm summer's sun (just caught me thinking about doing this experiment in Australia :D, less easy here in NL).
We'll leave the drum in the sun for a while, and it'll sound better and more lively, no doubt. Temperature definitely has something to do with it. (I remember playing outside on a cold day a few times. It made it hard to pull decent sound out of the drum.
If 5) would be true, I would also expect these effects to be absent on synthetically produced skins. May be somebody in the forum ever used a synthetic skin on a traditional African djembe :giggle: ... or a Remo?
John May in the Blue Mountains is a drum maker who offers synthetic skins. I don't know the exact material he uses, but it's quite different from what you find on a Remo and the like. (The material wasn't conceived as a drum head and comes from some other industrial application.) These drums are the closest thing I've come across to the sound of a real goat skin. Not quite identical, but I've heard many goat skins that sounded worse.

These synthetic skins are pretty much impervious to changes in humidity, don't seem to mind temperature changes all that much, and they last for years without tuning. So, yes, synthetic material is definitely less sensitive to changes than goat skin.

Cheers,

Michi.
By RingController
#36370
Hi,

I excercise at the beach close to my house so I have the same problem, humidity and temperature swings makes my djembe sound very different from day to day. Also my dj is more sensible than others because the ropes can adjust a lot when the membrane changes (this happens when you start with a poor initially tensioned dj and use lot of knots to compensate instead of reworking everything).


When playing is finished I remove some knots or the temperature changes will change the tension and make the problem worse the next time. Someone broke the skin just leaving too many knots on a cold day and leaving the djembe in a hot enviroment later.

Usually when I Start I play for a while to make blood fill my hands and prepare the djembe to receive the knots it needs for that environment. Than I put the needed knots for the sound I love.

I always have the mallet with me because my membrane tends to stick to the rim, a mallet will make it move and unsticks the membrane from the rim after you put the knots.
It provides the same"tik" sound that the membrane makes when moves on the rim when you raise the tension on ropes during the standard tuning process.
Any knot in the final stage of tensioning should change the pitch, if it is not changing the mallet will unstick the membrane, easy to recognize.
The chinese 2$ mallet is also my handle to make the knots so I find it really a must, it is always with my djembe.

I developed this by myself, I am an engineering mind so I tend to apply science on everything I do.
Reading this forum I started to think i am exagerating, happy to know you opinions :)
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By michi
#36374
I'm not a great fan of adding knots before playing and removing them again afterwards. I'm pretty sure that it shortens skin life because, each time I tune up, a few more fibres in the skin break. Personally, I think it's best to just leave the skin (unless I tune up very high specifically for a performance).

To get rid of stiction, I recommend teflon dry lube spray. Spray a little bit of that onto the bearing edge before mounting the skin, and the edge becomes nice and slippery, so it's easier to tune. The teflon doesn't interact with the skin or the wood (unlike stuff like bees wax or paraffin).

Cheers,

Michi.
By RingController
#36390
Hi,
I agree with you on skin erosion due to making knots over and over, I should be avoided and I agree also on teh exception you mentioned :)
My djembè just experiences swings of temperature that are risky for the tension I am used to play, I think it also may depend on where we store and how we transport them.
Thank you for the advice, I would surely use something to make the rim not abrasive if I should mount a skin, I was not in the mood for a full dismount of that particular dj in that particular day :)