Replacing and Clearing a Timpani Head

Replacing and Clearing a Timpani Head by Mark Wessels

In order to reach your full potential on playing the timpani, the instrument must be in good working condition, with heads that are in tune. This article will briefly describe the process for changing a timpani head and tuning (clearing) it so that it produces a pure characteristic sound.

WHEN SHOULD I REPLACE THE TIMPANI HEADS?
In a normal school environment, a timpani head that is well maintained may last for 4 or more years before needing to be replaced. However, if the heads accumulate dust and grime from outside use, or are not stored properly (with timpani covers), heads may need to be replaced on a yearly basis. Dents, scratches and other damage to the heads will definitely affect the drum's ability to sustain a pure tone, in which case they will need to be replaced as soon as possible.

WHAT SIZE TIMPANI HEADS SHOULD I ORDER?
Don't make the mistake of just ordering a standard set of timpani heads without first checking to see which type of timpani you own. Although most claim to be standard sizes (32", 29", 26", 23"), there are many cases where this isn't the size of head you'll need.

Begin by measuring the size of the bowl from one side to the opposite. In some cases (with especially very old models or with Dresden type timpani), the bowl will actually be smaller than the stated size. Next, check to see if the collar is “standard” size (next to the shell, as a drum rim) or “extended” (where there is 2" of head that extends beyond the bowl). If it is standard, order a head the size of your bowl measurement – if it’s extended, add 2" to the bowl size (therefore, a 32” extended collar timpani will require a 34” timpani head).

When in doubt, remove the heads that are currently on the drum and measure them, or contact the instrument manufacturer of the drums with the model number to obtain the correct head size.

TAKING OFF THE OLD HEAD
IMPORTANT! You must keep your foot on the pedal in the lowest position as you begin to unscrew the tension rods (a student with nothing better to do would come in handy here). The spring on the pedal will cause it to jump to the highest position as you loosen the tension on the head and possibly cause damage.

It's best to unscrew the tension rods in the same manner that you do when putting a new head on the drum – one full turn on each rod, in opposites. Fully loosening one rod at a time places stress on the collar and could cause it to warp (it's not likely, but why take the chance?). After all the tension rods are detached from the receivers, you can slowly allow the pedal to return to the highest position and take your foot off. Remove the collar and old head.

CLEANING AND GENERAL MAINTENANCE
This is the perfect time to perform general maintenance to ensure that the instrument is in proper working condition! Even if you're not replacing the heads, most of these suggestions should be performed on a yearly basis.

Check the counter hoop to see if it is flat and round. A bent or warped counter hoop is the number one cause for timpani not sounding true, not matter how much effort is put into tuning.

Clean the instrument thoroughly inside and out with a damp cloth (yes, even the dust and spider webs on the base that have accumulated for years and years)! Tension rods and receivers should be wiped free of dust, debris and accumulated grease. Use a small bowl of water mixed with dishwashing liquid and Qtip where necessary.

Dents in the bowl can be removed with a rubber hammer, though if the bowl integrity has been compromised, it'll only be a cosmetic fix. Use small strokes around the edge of the dent and work towards the center.

Clean the bearing edge (lip) of the bowl. If you have older drums that have years of accumulated grease, you can lightly polish the bearing edge with #0000 steel wool or fine sandpaper using small circular strokes (don't sand or scrape horizontally). In most cases, simply wiping with a slightly damp cloth is sufficient. You may wish to apply a dry teflon spray which will lubricate the bearing edge (eliminating the annoying "creaking" sound when changing pitches). Just a light coating is necessary - don't over spray! Allow to fully dry before putting the new head on. Cork grease is a somewhat acceptable substitute if applied in a very, very light coating (a thick layer will cause the head to loose its resonance).

MOUNTING THE HEAD
Put the new head in the counter hoop and place both on the bowl. Check that the head makes contact fully inside the hoop and that there are no wrinkles or waves in the head (indicating a possible warped hoop or head). You may wish to line up the logo, if it exists, at this time (across from the pedal) – or the “spine” (as in the case of Remo heads) across the middle of the head (left to right). Apply a light lubrication to the bottom of each tension rod with cork grease, then thread it into its receiver until the top of the rod makes contact with the counter hoop. At this point, check that the head and collar are centered on the bowl with an even amount of space around the rim (very important).

Depress the pedal to the lowest position (hopefully, your student helper didn't leave...) and thread the rods until each is “finger tight” with the counter hoop. Don’t over tighten - just get each one with the same degree of light tension all the way around the drum. At this point, the head should be properly seated on the bowl with no wrinkles or waves.

With your timpani tuning key (not pliers or crescent wrench), give each rod one half turn in a crisscross pattern (5 o'clock, 11 o'clock, 7 o'clock, 2 o'clock, etc), moving around the drum fully until there is a recognizable pitch. Press the pedal to the mid-point and play a soft stroke in the proper beating area (use a hard mallet for easiest pitch recognition). Listen for a pure tone and sustain. If the sustain is uneven (the pitch has waves in it) or does not have a decent resonance (length of sustain), it may be necessary to once again check the evenness of rod tension around the drum and adjust accordingly. Measuring the rods or using a tension measuring device such as a “DrumDial” might help, but these methods don't work 100% of the time.

At this point, if you can't get the drum to sound a decent sustainable pitch, it's best to start over rather than kill yourself trying to fix the problem. If a warped head or rim (or bowl) is causing the problem then you can do your best, but it'll never sound great.

Lower the pedal to the bottom position and continue to tune the drum up until it has reached the lowest note in the pitch range (* this is what I prefer. Others prefer to raise the pedal to the highest position and tune up until the drum has reached it's highest note in the drum's pitch range).

GENERAL PITCH RANGES
(These are my personal preferences for most common drums. Refer to your instrument's manufacturer for specific ranges):
32” – D to A
29” – F to C
26” – A to E
23” – D to A

FINE TUNING, OR “CLEARING THE HEAD”
To get the best possible sound from your timpani, you must spend a good amount of time getting the head to sustain the same pitch at each tension rod. This is a difficult procedure that requires a great ear, concentration and quiet environment! It might be helpful to place a small mute in the center of the drum and to tune in the mid to upper range of the instrument. (And if you have the ability to put the timpani on a platform or chairs to bring the playing area up to ear level, it can save you from a backache)!

Start by striking the drum softly in the proper area with your ear close to the drum head (play at a mid point between two rods, not directly on top of a rod). Listen carefully to the fundamental pitch (not the overtones) and hum the pitch to yourself. Next, strike the drum at a forte level and listen to the sustaining pitch. If the loud stroke sounds flat (lower) relative to the soft strokes, one or more of the tension rods directly across from your beating area is flat. If the loud stroke sounds sharp (higher) than the soft strokes, it's the opposite. If this is the case, you'll need to find the offending tension rod (ACROSS FROM THE BEATING AREA) and make the adjustment with a quarter turn.

Strike the drum softly 2-3 times, listening for the fundamental pitch – then forte. If the forte stroke sounds the same pitch, then this area of the head is clear. Move over to the next “channel” and compare to the first. Repeat the process until the drum is clear and sustains a true pitch from soft strokes to loud.

Try not to spend more than 10 minutes fine tuning any timpani without a significant break. Ears are easily fatigued and after a point, you'll start second guessing yourself and possibly do more harm than good.

PEDAL ADJUSTMENT
Generally, if the drum is in the correct pitch range, the pedal should work throughout the full range of the instrument – but occasionally you’ll need to adjust the tension on the pedal (these instruction details standard Ludwig timpani models, which are common in school music programs and notorious for being out of adjustment. If you have other instruments, consult the manufacturer for specific instructions for pedal adjustment).

Start with the pedal fully depressed into the highest position and remove your foot. If the pedal moves back (down), apply more spring tension by dialing the tension knob clockwise (checking every couple of turns until the pedal remains in the top position). If the pedal remains steady in the upper position, but won't stay in the lowest position, the spring is too tight. Return to the upper range position and gradually DECREASE the spring tension by dialing the knob counter clockwise.

It's important here to note that there is a finite amount of thread space on the rod which secures the pedal spring. Over-dialing the knob can damage your spring (if too much tension is applied), or separate the rod from the pedal altogether. TURN THE KNOB IN SMALL INCREMENTS UNTIL THE DESIRED TENSION IS ACHIEVED! You'll definitely know if you've turned it too much... that loud gunshot you'll hear means that the drum needs to go to the shop to get fixed.

In many cases, you'll have to adjust the pedal where the spring tension works in “most” of the pitch range. At this point, you can adjust the pressure pads using a drum key. This is the mechanism under the base of the timpani that squeezes two small “brake pads” against the pedal rod – which is accessed through the small hole in the side of the base under the pedal. Apply just enough tension on these pads to allow the pedal to retain it's position through the full range of the instrument – but not so much that the pedal doesn't move freely.

If this adjustment mechanism doesn't secure the pedal, carefully turn the drum on its side to inspect it. 9 times out of 10, one (or both) of the brake pads are missing! You should replace them by ordering a new part from the manufacturer. In a pinch, you can find a rubber-like substitute at a hardware store and cut it to size.

FINAL RECOMMENDATIONS
To get the best possible sound from your timpani, it’s necessary to fine tune your drums frequently. I've never found tuning gauges or devices to be reliable substitutes for a good ear – and the only way to develop the ear is by frequent practice!

Don’t simply accept bad sounding, out-of-tune drums which cannot obtain a true pitch. Only if you properly maintain your instruments and tune them frequently can you (or your student) be successful at becoming a true musician on the timpani!

Article source: http://www.vicfirth.com/education/articles/replacing_timp_heads.html