What is A-B comparison testing?

A-B comparison is a way to test audio equipment or settings. It lets you compare two different things to see which sounds better. For example, you could compare two speakers, or two EQ settings on your stereo.

When you do A-B testing, you switch back and forth between the two things you are comparing. This lets you hear how they are different. Most of the time, you don’t know which thing is “A” and which is “B”. This is called a “blind” test. It helps make sure the test is fair.

The best way to do A-B testing is to be able to switch instantly between the two things. This makes it easier to hear small differences. If you have to stop the music to switch, it is harder to compare.

Why is A-B testing important?

A-B testing is important because our ears can play tricks on us. When you listen to something for a while, you get used to how it sounds. This makes it hard to tell if something else sounds better or worse.

By quickly switching between two things, A-B testing helps you notice differences. It is a more reliable way to compare audio than just listening to one thing for a long time.

A-B testing is also important because many audio things are very subtle. Small changes in equipment or settings can be hard to hear. But when you compare them head-to-head, the differences become more clear.

How to set up an A-B test

To do a good A-B audio comparison test, you need a few key things:

1. Two audio sources

The first thing you need is the two things you want to compare. These could be two different pieces of audio gear, like CD players or speakers. Or they could be two different settings, like EQ or compression.

It is important that everything else in your audio system stays the same. Only change the one thing you are testing. Otherwise you won’t know what is causing the difference in sound.

2. A way to switch between them

Next, you need a convenient way to switch between your “A” and “B” sources. Ideally, you should be able to switch instantly with the push of a button.

For gear comparisons, there are special A-B switch boxes you can buy. For comparing settings, many audio interfaces and mixers have an “A/B” button.

The key is to switch seamlessly without stopping the audio. This keeps your ears “calibrated” and makes subtle differences more noticeable.

3. Level-matched audio

One of the biggest mistakes in A-B testing is not having the levels matched. Our ears almost always prefer the louder of two sources. Even a small level difference can make one source sound better.

Use a SPL meter to set the levels of your A and B sources so they are exactly the same. Only adjust the level of one source, not your main volume. This is a critical step for valid testing!

4. A blind switch

For the most reliable results, use a “blind” A-B test. This is where you don’t know which source is which. Have a friend set up the A and B sources and do the switching for you. Tell them to switch at random times so you can’t guess the pattern.

Blind testing keeps our brains from playing tricks on us. If you expect source B to sound better, your brain can fool you into hearing it that way. Blind testing removes this bias and makes the results more trustworthy.

Doing an A-B comparison test

Once you have everything set up, it’s time to do some careful listening. Here are some tips:

• Take your time and don’t rush. Subtle differences can take a while to notice.
• Focus your listening. Don’t just hear the music, really analyze the sound. Pay attention to the bass, treble, clarity, soundstage, etc.
• Try different kinds of music. Some differences are more obvious on certain instruments or recordings.
• Take breaks to avoid fatigue. When our ears get tired, it gets harder to hear differences.
• Keep notes of what you hear. Write down what differences you notice between A and B.
• Try to avoid distractions. Do your testing in a quiet place without interruptions.
• Don’t stress over it. The differences between gear can be subtle. Don’t expect night and day changes. Trust your ears and don’t overthink it.

Analyzing A-B test results

After you’ve done your A-B comparison listening, it’s time to analyze the results. Look over your notes and think about what differences you heard consistently.

Did one source have deeper bass? Was the treble clearer on one? Did one have a wider soundstage? Was one more fatiguing to listen to?

Think too about what sonic traits are most important for your needs. A speaker with a very wide soundstage might be great for movies. But if you mostly listen to EDM, you might prefer one with fatter bass.

Also consider how much of a difference you really heard. Were the sources nearly identical? Or did one clearly sound better to you? Small differences may not be worth the cost of expensive gear.

Finally, if you did a blind test, reveal the identities of A and B. See if the one you preferred matches your expectations. The results can be surprising!

The limits of A-B testing

A-B testing is a powerful tool, but it is not perfect. There are some limits to what it can tell you.

First, short term A-B tests don’t always reveal long-term preferences. You might like the sound of one speaker at first, but find it fatiguing in long listening sessions.

Second, different people have different tastes. Your A-B winner might not be your friend’s favorite. There is no one perfect sound for everyone.

Third, A-B tests don’t always translate across different rooms and systems. Speakers that sound great in a showroom might be too boomy in your bedroom. Always test gear in your own listening environment when possible.

Fourth, your mood and the program material can affect A-B comparisons. You may get different results depending on what music you play or how you feel that day. For consistent results, try to keep your test conditions the same.