Drop C Tuner Online — CGCFAD Heavy Tuning

Drop C tuning is CGCFAD from low to high: standard tuning lowered a whole tone, with the sixth string lowered one further whole tone to C2. The sixth string C2 sounds at 65.41 Hz. It is common in metal, metalcore and hard rock, where the lowered sixth string makes one-finger power chords available a whole tone below drop D.

How to use it

1. Tune to standard first if the guitar is close. Starting from EADGBE makes every move a known interval rather than a guess.
2. Lower every string by a whole tone. That gives D G C F A D, which is D standard. Targets: D2 = 73.42 Hz, G2 = 98.00 Hz, C3 = 130.81 Hz, F3 = 174.61 Hz, A3 = 220.00 Hz, D4 = 293.66 Hz.
3. Lower the sixth string one more whole tone, to C2 (65.41 Hz). This is the drop that defines the tuning.
4. Bring each string up into pitch from below. Even though you are tuning down overall, approach the target from underneath so the string seats cleanly on the post and holds.
5. Play the bottom three strings open. C–G–C is a C5 power chord with no third, available under one finger anywhere on the neck.
6. Check the whole set again. Six strings have moved and the tension has dropped across the instrument, so the neck relaxes and earlier strings can drift.
7. If you keep the guitar in drop C, consider the setup. Nut slots, intonation and truss rod may need attention once the string gauges change.

If you tune by ear, drop C is drop D a whole tone down: the low C should sound two frets below the low D, and the octave check against the open fourth string (C3) confirms it.

Drop C string frequencies

String	Note	Frequency (A4 = 440 Hz)
6th (dropped)	C2	65.41 Hz
5th	G2	98.00 Hz
4th	C3	130.81 Hz
3rd	F3	174.61 Hz
2nd	A3	220.00 Hz
1st	D4	293.66 Hz

Heavy genres and riff shapes

Drop C is one of the standard tunings of modern heavy music because it combines a low, heavy fundamental with shapes players already know:

• One-finger power chords, a tone lower. The bottom three open strings spell a power chord, exactly as in drop D. Any drop D riff can be played in drop C with the same fingering and will sound a whole tone heavier.
• The rest of the fretboard is D standard. Strings five to one are tuned in fourths with the usual major third between the second and third strings, so scale and chord shapes follow standard tuning, shifted down a tone.
• Chugging sits on the low C. Palm-muted open-string work on the sixth string lands on C2, which is the note that gives the tuning its weight.
• Clean passages use the open strings. Because the tuning is built on fifths and fourths, open-string arpeggios and drone chords work well in the lower register.

String gauge and setup

Tension is the practical issue. Tuning a standard 9–42 set down a whole tone leaves the strings noticeably looser than the guitar was set up for. The consequences are a soft attack, bends that go sharp when fretted, and fret rattle on the low strings.

• Go heavier. A set in the region of 11–56 or 12–60 restores tension close to a standard set at standard pitch, which keeps the feel and the tuning stable under hard picking.
• Longer scale helps. A baritone or longer-scale guitar reaches the same tension with lighter strings, and the low C stays clearer.
• The nut and intonation may need work. Thicker strings sit differently in the nut slots and need the bridge saddles moved for accurate intonation. A guitar set up for standard strings will not be perfectly intonated at drop C.
• Check the truss rod. More string tension pulls the neck forward; less lets it relax. A permanent change of gauge is worth a setup.

Accuracy and limits

C2 is the hardest note this page asks the tuner to read. Below 70 Hz the detector routes it through the decimated low-frequency path: the 4096-sample frame passes a 33-tap Blackman-windowed sinc anti-aliasing filter, is decimated 4x to 11.025 kHz, and the full 1024-sample decimated window (~92.9 ms) is correlated — several full cycles of C2. The difficulty that remains is the microphone, and that applies whatever hardware you use.

• The low C is read on the decimated low-frequency path. For notes below 70 Hz a 33-tap Blackman-windowed sinc anti-aliasing filter decimates the analyser’s 4096-sample frame by 4x to 11.025 kHz, and the detector correlates the full 1024-sample decimated window (~92.9 ms). At C2 that window holds several full cycles of the string, well past the 2–3 periods that pitch-detection methods generally want.
• An octave jump is the weak-fundamental symptom. When the reading leaps up an octave, the detector has locked onto a harmonic of a weak or decaying fundamental. Mute the other five strings, re-pluck firmly, and confirm the low C by ear against the open fourth string (C3) rather than trusting a single frame.
• Small microphones weaken below roughly 100 Hz. Laptop and phone microphones typically lose sensitivity at the bottom of their range, so the low C can arrive quiet even when the string sounds loud in the room. Pluck firmly over the 12th fret and select the neck pickup on an electric guitar.
• C repeats at two octaves. The sixth string is C2 and the fourth is C3. If the fourth string rings, the display can report the higher C — the right note, the wrong string. Compare against the string cards when it matters.
• A fresh heavy set settles slowly. If you have just fitted heavier strings for drop C, expect to retune several times over the first hour of playing.

Safety

• Drop C only lowers strings. The sixth string drops four semitones from E2 and the others drop two, so reaching the tuning removes tension from the neck rather than adding it.
• Returning to standard is the risky direction. The sixth string has to rise four semitones from C2 to E2. Do it in small increments, let the string warm up as you go, and stop at the target. A string that has sat at C2 for months is worth inspecting before you crank it back up.
• Never jump a slack string straight to pitch. This is how strings break and how tuning pegs are damaged. Raise gradually and check the reading as you go.
• Do not tune sharp to fix a floppy string. If the low C feels loose or rattles, the answer is a heavier gauge or a setup adjustment. Tuning above the target adds tension, puts the guitar out of tune and shortens string life.
• Bend with care. Lower tension makes bending easy, but it also makes it easier to pull the string out of tune or slip it on the tuning post. Keep the windings neat and tight.
• Respect the setup. A guitar that buzzes across several strings in drop C is telling you the action or neck relief no longer suits the tuning. Fix that before blaming the strings.