Tuning Test Signals
How to use this page
Sweeps, pink noise, phase checks and test tones for tuning a car. Everything plays right here in the browser; use the Download buttons on each tile to save a WAV to a USB stick or your phone for the head unit.
Microphone RTA: tap Use microphone, play pink noise from the car's source, pick a target curve, and the chart shows the car against it. The delta view flattens the target into a line at 0 so you tune toward flat; the EQ readout gives 1/3 octave cut values to type into an Arc, Mosconi or Goldhorn graphic EQ. Averaging slows the display the same way TrueRTA and REW do. Medium settles in about a second, Slow in a few seconds, Forever keeps accumulating until you hit Reset (use Forever with a slowly moving mic for the most repeatable result). Periodic pink noise is built to be exactly pink over each loop, so it reads far steadier than random pink noise; use it for measuring. Chart key: white is the averaged response, the thin ghost line (if Show live is on) is the raw feed, orange dashed is the target, green is a snapshot, pink is the spatial average.
Spatial averaging: hold the mic at the driver's head position, let the average settle, tap Add position, then move the mic a few inches (left ear, right ear, forward, back, up) and repeat for 4 to 6 positions. Score and EQ readout then use the pink spatial average, which is far more repeatable in a car than any single spot. Load mic cal file takes a UMIK-1 or any REW-style frequency and dB text file.
Start with the head unit and the output level low, then bring them up. Sweeps and pink noise at full level can damage tweeters.
1/3 octave EQ readout (from the spatial average when positions are held, otherwise the rolling average)
Sine Sweep
What it is for
Log sweep from 20 Hz to 20 kHz. The readout above shows the exact frequency as it moves.
Correlated Pink Noise
What it is for
Identical pink noise in both channels, like a mono signal. Loops until you stop it.
Uncorrelated Pink Noise
What it is for
Independent pink noise in each channel. Sounds wide instead of centered. Loops until you stop it.
Phase Check
Plays the same signal in both channels, then flips the right channel polarity, back and forth. The readout above says IN PHASE or REVERSED so you know which one you are hearing.
Test Frequencies
Tap a frequency to play a steady tone. Tap it again to stop. Pick a channel first if you are checking one side.
Zero Bits Gain Setting Tones
Full scale sine tones for setting amplifier gains with a scope or DMM. 0 dBFS uses every bit, nothing hotter exists on a digital source. Download these and play them from the head unit with EQ, loudness and bass boost off. Browser playback here runs through the level slider, so it is for auditioning only, not for setting gains.