AI Audio Engineering: post #4100 — TG.ME

🎸 Recording Acoustic Guitar — Principles That Actually Matter

(Not tips. First-principles. Think in causes, not presets.)


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1️⃣ The Instrument Is a Resonant System, Not a String Source

An acoustic guitar radiates sound as a distributed vibrating body: strings excite the top, the top excites the air, the air excites the room.

The soundhole is not “the tone” — it’s a pressure vent

The top plate is the main storyteller

The room completes the sentence


🧠 Mic placement is epistemology: where you listen determines what you believe the guitar is.


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2️⃣ Distance Is a Spectral Filter

Closer ≠ better.

Too close → boominess, exaggerated low mids, transient aggression

Too far → loss of articulation, room dominance


Sweet zone (rule of thumb):

Start at 20–40 cm, then move laterally, not closer


🧠 Distance reshapes harmonic balance more than EQ ever will.


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3️⃣ Never Point Directly at the Soundhole

That’s like putting a stethoscope on a lung and calling it music.

Instead:

Aim between the 12th fret and the body joint

Or off-axis toward the lower bout


🧠 You want resonance, not turbulence.


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4️⃣ Player Motion Is Modulation

The guitarist is not static.

Head movement = spectral automation

Body sway = phase modulation

Picking angle = transient redesign


👉 Lock the player’s posture before locking mic position.

🧠 Most “inconsistent tone” is biomechanical, not technical.


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5️⃣ Strings Are Half the Instrument

Old strings don’t sound “warm.” They sound information-poor.

Fresh strings = harmonic clarity

Worn strings = collapsed overtones


🧠 Entropy is not vibe.


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6️⃣ Pick, Nails, Flesh = Different Transfer Functions

Each excites the top differently.

Pick → sharper transient, higher spectral centroid

Nails → complex noise + tone hybrid

Flesh → low-pass filtered articulation


🧠 Change the exciter before changing the mic.


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7️⃣ Phase Is Already There (Even with One Mic)

Reflections = delayed copies = invisible comb filtering.

Untreated rooms imprint static phase scars

Small rooms exaggerate low-mid cancellations


🧠 If the guitar sounds “hollow,” it’s geometry, not EQ.


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8️⃣ Compression Is Not for Fixing Dynamics

Acoustic guitar dynamics are meaningful.

Compress only if it serves intelligibility or density

Prefer slow attack, musical release

Or better: ride the fader like a human


🧠 Dynamics are syntax, not noise.


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9️⃣ Stereo Is a Choice, Not an Upgrade

Two mics = two truths that may disagree.

Mono → coherence, intimacy

Stereo → width, but phase risk


If stereo:

Think time alignment, not symmetry


🧠 Width without coherence is illusionary depth.


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10️⃣ Record the Intention, Not the Guitar

Ask silently:

Is this percussive? intimate? narrative? rhythmic? harmonic?


Then:

Place the mic where that intention exists naturally


🧠 The mic doesn’t capture sound. It captures intention filtered through physics.

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Final axiom

> An acoustic guitar recording fails not because of bad gear,
but because the engineer listened with concepts instead of ears.


🎧 Move the mic. Then move it again. Then stop when the guitar tells the truth.
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February 2, 2026 895 2