Audio Electronics Calculators
17 free calculators with formulas and worked examples.
Speaker crossover design, room modes, amplifier power and clipping, headphone power, class-D efficiency, audio SNR, equalizer Q factor, and subwoofer box calculators.
Audio Amplifier
Calculate amplifier output power from supply voltage and speaker impedance. Get max power, RMS power, THD estimate by class (A/AB/D), SNR, and input sensitivity for speaker matching.
Speaker Crossover
Calculate passive 2-way speaker crossover component values for 1st order (6dB/oct) and 2nd order Butterworth (12dB/oct) networks.
Room Modes
Calculate room axial modes using f = n·c/(2L). Find all standing wave frequencies, Schroeder frequency, and mode spacing for acoustic treatment and speaker placement.
Speaker SPL
Calculate speaker SPL at any power and distance from the rated sensitivity (dB/W/m) specification.
Headphone Power
Calculate the amplifier output power, voltage, and current required to drive headphones to a target SPL.
Audio SNR
Calculate audio SNR and dynamic range. 16-bit audio = 98 dB, 24-bit = 146 dB theoretical SNR. Formula: SNR = 6.02·N + 1.76 dB. Enter bit depth or signal/noise levels in dBV.
Op-Amp Slew Rate
Calculate op-amp full-power bandwidth from slew rate and signal amplitude, and verify the op-amp can handle your signal without slew-rate distortion.
Audio Transformer
Calculate audio transformer turns ratio for impedance matching between source and load, plus secondary voltage and current.
Cable Rolloff
Calculate the high-frequency rolloff (-3 dB point) caused by cable capacitance interacting with source impedance.
Subwoofer Box
Calculate subwoofer box volume for sealed and ported enclosures from Thiele-Small parameters (Vas, Qts, Fs). Get optimal internal volume, port tuning frequency, and −3 dB cutoff instantly.
Tweeter Capacitor
Calculate the capacitor value for a first-order tweeter high-pass filter to protect tweeters from low-frequency damage.
Class-D Efficiency
Estimate Class D amplifier efficiency from MOSFET conduction losses and quiescent current at a given output power.
ADC Dynamic Range
Calculate the theoretical SNR and dynamic range of an audio ADC from its bit depth, and the improvement from oversampling.
EQ Q Factor
Free EQ Q factor calculator — enter center frequency and bandwidth to get Q, octaves, and 3dB points. Convert between Q factor, fractional bandwidth, and octave bandwidth for parametric equalizer design.
Amp Clipping
Calculate amplifier clipping voltage, power, and dBV level from supply voltage and load impedance.
Delay Time
Calculate audio delay time in milliseconds from BPM and note value — quarter, eighth, dotted, triplet. Also computes acoustic propagation delay from speaker distance for live sound alignment.
Amplifier Gain
Calculate amplifier gain in dB from input and output voltage or power. Get voltage gain (V/V and dB) and power gain (W/W and dB) — useful for setting amp gain, matching levels, and system design.
About Audio Electronics Calculators
Audio electronics encompasses the analog signal chain from microphone or pickup through preamplification, equalization, crossover filtering, power amplification, and speaker loading — a domain where noise floors in the microvolt range, distortion at the 0.001% level, and impedance matching across reactive loads all matter simultaneously.
Speaker crossover networks divide the audio spectrum between drivers (tweeter, midrange, woofer) using passive LC filters. A 1st-order Butterworth crossover at 3 kHz uses a single capacitor in series with the tweeter and a single inductor in series with the woofer. Higher-order crossovers (2nd, 3rd, 4th) provide steeper roll-off but introduce phase shifts that must be managed to maintain coherent wavefront summing at the crossover frequency.
Power amplifier design centers on output stage topology: Class A (always conducting, lowest distortion, ~25% efficiency), Class AB (output transistors biased near cutoff, ~50-70% efficiency), Class D (switching output stage, >90% efficiency). The output power into a speaker load depends on supply voltage, output transistor saturation, and load impedance: P = V²_peak / (2 × R_load). Clipping occurs when output swing exceeds supply rails, introducing harsh distortion.
Room acoustics impose standing wave resonances (room modes) at frequencies where room dimensions are multiples of half-wavelengths. A 4 × 5 × 3 m room has axial modes starting at 43 Hz (length), 34 Hz (width), and 57 Hz (height) — bass frequencies that peak and null at predictable positions. Subwoofer box design (Thiele-Small parameters) determines bass extension, sensitivity, and group delay for vented and sealed enclosures.