The gray line is the active line, the live microphone signal. The orange line is the saved line, a max-hold spectrum that keeps the strongest reading in every frequency bin across your strikes. Several clean hits can build a clearer picture than one hit.

• F0 is the fundamental pitch of the fully resonating drum: the lowest frequency component created by both heads coupling through the air inside the shell. It is not the pitch of either head by itself, and it does not have to be the loudest component. The app rejects weak low peaks, then selects the lowest-frequency candidate in the dominant-amplitude group. If two candidates appear, tap the correct F0 to lock it until Reset spectrum.
• F1, or Overtone 1, is the batter head’s own resonance heard above F0. It is the first harmonic above F0, the second harmonic in this labeling, and is not created by the head-and-air coupling that produces F0.
• F2, or Overtone 2, is the next harmonic frequency above F1. Additional overtones continue upward as F3, F4, and so on.
• RTF is the numerical interval between F0 and a selected overtone. It is calculated as the selected overtone frequency ÷ F0. The interval description shows how that ratio relates to a musical interval.

The two strongest components detected above F0 are shown from lower to higher frequency. Tap either overtone to use it for the selected overtone readout, RTF, target guidance, and dual strobe.

Range changes only the graph. Detection still scans up to 20 kHz, so higher-pitched instruments can be analyzed too. Use 32,768 FFT for finer frequency resolution or 16,384 for faster response.

Enter the Desired F0 and Desired RTF. The tuner calculates target F1 as F0 × RTF, then compares both detected frequencies with those targets.

F0 is the pitch of the coupled drum system, not the resonant head’s own pitch. Raising or lowering the resonant head changes how both heads and the enclosed air couple, which moves the drum’s F0. F1 is the batter head resonance measured when you strike it.

• Tune the batter head toward target F1 first. The guidance tells you whether to tighten or loosen it.
• Once F1 is in range, adjust the resonant head to move the fully resonating drum toward target F0. Do not try to match the resonant head’s own lug pitch to the F0 number.
• After any adjustment, press Reset spectrum and make a fresh strike. Drumheads interact, so recheck both values before the next move.

Choose Dual strobe from the Analyzer view. The view holds two strobes, one for each line on the Spectrum. The Saved line strobe reads the orange saved line, so it holds the settled F0, F1, and RTF built from your strikes. The Active line strobe reads the spectrum's gray active line and updates continuously as the drum sounds, the way a strobe tuner tracks a ringing drum or timpani in real time; it never reads the saved line. The source line above the strobes tracks the active line strobe, and the Spectrum view and target guidance keep using the saved line.

Below the active line strobe sits a note picker for setting an exact F0 fast. Tap one of the 12 notes, then an octave, and that note's exact Hz is filled into Desired F0 in Target tuning. The active line F0 strobe then guides you to that pitch. To remove it, tap Clear F0 target under the picker: that empties Desired F0, unselects the note and octave, and turns off the note-target guidance until you pick another note.

F1 is shown above F0, and the same overtone selector stays available. With targets entered, each box uses a steady color:

The adjustment instruction waits one second before changing, which keeps short-lived readings from replacing it too quickly.

Open Lug match and choose the number of rods on the drum. The diagram numbers the tuning order rather than covering the head with arrows. Begin at 1, cross directly to 2, then move to 3 and continue in number order.

On drums with an even lug count, each consecutive odd-even set is a parallel pair: 1 with 2, 3 with 4, and so on. A five-lug drum has no direct opposites, so it keeps the star arrows and adds the same order numbering: 1 is the starting lug, 2 is next in the star, and so on. Both paths avoid chasing adjacent rods around the rim.

If the saved Spectrum already has an F1, the first lug strike must fall within one semitone of that selected F1 before it can become the reference. Every following strike is filtered to the same one-semitone window around the lug reference, which keeps F0, F2, and higher partials from replacing the lug pitch. An outside hit is labeled Out of range and still shows its raw frequency so you can see what was rejected. If there is no saved F1 yet, the first clear lug strike defines the reference on its own.

Every accepted strike shows its exact Hz difference from the reference and tells you whether the lug is high, low, or matched within 0.5 Hz.

When the pitches match, the tuner also compares their overtone balance. How it decides: the tone check only runs after a lug already matches the reference in pitch, within 0.5 Hz. Each strike gets a six-band overtone fingerprint: the peak level in six bands above the lug pitch, from about 1.25× to 7× that pitch, each measured in dB relative to the strike’s own fundamental. That compares the shape of the sound, not its pitch or loudness. Bands where both strikes are essentially silent, at or below −50 dB, are skipped, and if fewer than three bands can be compared, no tone verdict is given. Otherwise it says the tone differs when the average difference across the compared bands is 8 dB or more, or at least two bands each differ by 10 dB or more.

If it says Pitch matches, but tone differs, stay with that opposite pair. Loosen the tight-feeling rod and tighten the loose-feeling rod by small, similar amounts until the tone balances, then strike them again.

Use Clear reference whenever you want to restart the matching pass.

• Pause capture freezes the accumulated result without turning the microphone off.
• Reset spectrum appears in the Spectrum view and clears the orange saved line, F0 lock, overtone choice, and analyzer reading.
• Reset strobe clears only the active line strobe values. It keeps the saved Spectrum line and the saved line strobe, and the active line reading resumes with the next sound.
• Keep background noise low, use consistent strikes, and wait for the instrument to decay before striking again.
• While listening, the app asks supported browsers to keep the screen awake. Your browser or phone may still override that request.

Snare drum tuning is its own thing entirely. A snare does not respond like a tom. The thin, low-mass resonant head has less influence over the shape of the fundamental, and it still has to stay tight enough for the snare wires to respond.

For RTF, a snare acts more like a single-headed drum. The ratio mostly lands where the drum wants it. A shallower shell usually gives a lower RTF, and a deeper shell usually gives a higher RTF. The resonant head gives you a little room to move it, but not complete control.

Tune first, shape tone after. Get the drum in tune before you start moving both heads around to chase a different RTF.

• Get the resonant head in tune first. A lug pitch between 320 and 400 Hz is a good ballpark. That is a soft guideline, not a hard limit. If your drum sounds right at 300 or 410 Hz, that is fine. Everyone tunes differently.
• Tune the batter head as evenly as possible. Use Lug match to compare each batter lug with the first one, then work across the head in the numbered order.
• Aim for the desired F0 with the batter head. Do not chase F0 by tuning the resonant head. F0 is the coupling of both heads and the air in the shell, not a lug pitch.
• Shape the tone only after the drum is tuned. To widen the RTF, lower the resonant head a little, which lowers F0, and/or raise the batter head a little. To narrow the RTF, do the reverse.

These last moves are small adjustments. The drum still has a natural RTF, and the resonant head only gives you limited flexibility around it.

Never tune lug pitches to F0. F0 is the pitch of the complete coupled drum. Tune lug pitches to the batter head resonance, usually F1.

On a shallow snare, such as a 3.5-inch-depth drum, F1 may not reflect the batter lug tension. F2 is often the batter lug pitch instead. Use the two overtone buttons above the Spectrum to switch between the first and second overtone, then choose the one that actually follows the batter lug pitch on that drum. The selected overtone carries through to the overtone readout, RTF calculation, target guidance, and Dual strobe.

Use the ear and the graph together. If the first overtone stays put while the lug tension changes but the second moves with the batter head, use F2 for the batter lug work.

You can tune every resonant-side lug to the same pitch, even with the snare bed. Trust the tuner’s lowest-frequency reading, because your ear can lie to you around the bed.

The lugs at the high points of the bearing edge may sound higher, but the lowest frequency component can still be the same all the way around. It is only the overtone structure that changes across the resonant head.

Match every reso lug by that lowest-frequency reading. Do not chase the higher-sounding overtones you hear near the high points of the bed.

Chromatic tuners often struggle on snares because two close pitches can arrive at nearly the same decibel level. The tuner alternates between them and the number jumps around. The Spectrum analyzer shows the full picture instead, so you can see both peaks and select the one you mean.

Ring buzz happens when high overtones excite the snare wires late in the decay, commonly around 600 to 900 Hz. Watch that range on the Spectrum and listen through the decay. An RTF between 1.6 and 2.4 generally gives a drier sound with good articulation.