ARNULL

ARNULL subtracts one signal from another and shows exactly what remains. Send the signal you want to test to the main input and the reference to the sidechain, and ARNULL aligns them, subtracts one from the other, and measures the resulting null depth. Automatic alignment finds offsets to a hundredth of a sample and can also detect an inverted reference. When two signals are identical apart from a whole-sample delay, the remainder is exactly zero and ARNULL reports them as bit identical. A reference shifted by half a sample was measured with a remainder 103.5 dB down. The display combines a single null-depth measurement with a spectrum of the remaining signal, helping reveal both how much the signals differ and where those differences occur. GAIN MATCH can compensate for level differences, while LISTEN GAIN raises the residual by up to 60 dB so subtle differences can be auditioned safely. ARNULL is designed for checking transparency, comparing processing chains, testing oversampling, and verifying whether an exported file matches its reference. It reports 8256 samples of latency, allowing references arriving up to 8192 samples early or late to be aligned while the DAW handles compensation.