Simple Explanation

A testing method where you compare two known sounds (A and B), then try to identify which one a third sound (X) matches—without prior knowledge.

Concise Technical Definition

A double-blind audio comparison test where listeners are presented with two known sources (A and B), and a third source (X) which is either A or B. The goal is to determine which it is, under conditions where neither the tester nor the listener knows the correct answer during the test.

Layman-Friendly Analogy

Like a taste test where you sample coffee A and B, then get mystery cup X and have to guess if it matches A or B—without knowing which is which until later.

Industry Usage Summary

Used by engineers and audiophiles to objectively compare components (like DACs, cables, or formats). ABX tests eliminate bias by ensuring neither the listener nor the tester knows what source X is during testing. Accuracy is determined statistically after the test.

Engineering Shortcut

ABX = blind A/B + hidden X; listener must match X to A or B without knowing which is which.

Full Technical Explanation

ABX testing is a double-blind comparator method for evaluating audible differences between two audio sources. The listener is given sound-A, sound-B, and sound-X (which is either A or B) and must identify whether X is A or B. The subject can switch between all three as many times as needed. The key feature of ABX is its objectivity: neither the tester nor the listener knows which source X corresponds to, preventing bias. The controller records selections, and results are only revealed after the test. This method is commonly used to verify claims about perceived sound differences between components under controlled, repeatable conditions.