Crosstalk on Headphone Mixes

What is the real difference between listening to music on headphones and listening to it on loudspeakers? Most people know that there is a difference but can’t exactly tell what it is.

This article will help you understand the biggest difference between the two —Stereo Imaging i.e. How Crosstalk benefits us.

Stereo Imaging is one of the biggest problems you’ll face when mixing with headphones so it’s important to understand it well. Keep in mind that Crosstalk on the other hand, is a good thing.

When there is a delay in sound, there is direction

Say you are listening to a song on a pair of loudspeakers in front of you. If someone went and pulled out the speaker cable from the left speaker, you will be hearing the sound come out of the right speaker. You will feel slightly unbalanced since the sound is only coming out of the right speaker, but keep in mind that your left ear will still be able to hear what is coming out of the right speaker. The left ear will be hearing a little direct sound, some reflected sound, etc. Most of the sound that the left ear will hear will be slightly delayed than what the right ear will be hearing. This delay is what causes that unbalanced feeling. It’s the thing that gives us a sense of where the sound is originating i.e. our sense of direction.

No delay on headphones

Now let’s look at what it might feel like on headphones. If you were listening to the same song on headphones and the left ear-bud fell out of your ear. You will not hear any delayed effect on the left ear. This is because the sound from the right ear-bud cannot travel to the left ear (of course). You will obviously not hear anything on the left. The sound will simply be right-heavy.

The difference in the ‘feeling’

One of the goals of mixing is to give sounds and instruments their own place on the sound canvas. When you ‘pan’ an instrument to the left you will notice a big difference in how you perceive it while using loudspeakers as compared to using headphones. There is a real difference between the ‘Unbalanced’ feeling you get from loudspeakers and the ‘Heavy’ (or weighted) feeling from headphones. This difference plays a big role when mixing.

Balanced Versus Weighted

I think we’ve just developed a couple of terms here. I’m not sure if these are the technical terms but they sure sound sensible to me. So let’s quickly elaborate on the terms.

When both loudspeakers sound, there is a delay that each opposite ear hears. So the sound from the right speaker reaches a fraction of a second slower to the left ear, while the sound from the left speaker reaches a fraction of a second slower to the right ear. As we’ve established, this delay helps us perceive ‘Direction’.

Here is an image to give you an idea of this 3 dimensional effect we perceive when delay is present. As the sound is panned from the left to the right, notice that there is a sense of direction (shown by the red moving dot) to the listener. This is the balancing effect on loudspeakers in action.

Loudspeaker in Action

Without the presence of delay (when using headphones), the perception of sound is more like in the image you see below. As the sound is panned from left to right you get the impression of a growth in volume. This is not really a directional feel. It just feels heavier on the right. This is weighting in action.

Headphones Stereo Image

For the term sticklers

Please keep in mind that the terms Balance and Weighting are terms that I’m using to describe this phenomenon. I feel they are quite accurate. I haven’t yet found anything that defines this by giving it appropriate terms and if you do, or know of the term, please let me know. Otherwise, I’ll assume that I’ve just coined a new term.

What is Crosstalk?

Crosstalk happens when the sound on the left loudspeaker leaks into the right ear and the sound from the right loudspeaker leaks into left ear. This leaking is (as we’ve said) delayed a little bit because it takes time to reach that opposite ear and is called Crosstalk. Crosstalk is a good thing and as we mentioned, it gives us our sense of direction. Crosstalk is an important element to grasp when trying to understand Stereo Imaging on headphones. Once you know about Crosstalk, you can introduce it in your headphones to make the sound seem like it’s coming from around you, rather than from in your head.

What Can Be Done to Improve Listening?

During a mix when you pan a sound, say slightly to the right, the headphones will not accurately give you a sense of direction. To get the accurate sense of direction that you need to edit your mix, there are two things you can do:

  1. There are headphone amps that have circuitry built in that will delay sounds for the opposite ears. This is a complex procedure since it’s not just a matter of delaying all the sound. They delay has to be shaped to account for the sound passing over the persons face to get to the far ear. Other considerations include:
    - Certain frequencies take longer to get to the far ear. For example, a 500 Hz frequency signal takes longer to get to the far ear than a 2 KHz signal.
    - Then there is the question of Harmonics and all of a sudden we’re into a scholarly discussion.
    So for our purposes, it’s possible to get half decent headphone amps that will include Crosstalk technology that generate delays to the far ears.
    This technology is by no means 100% accurate. But it’s good. It gives you the sensation that the music coming from the headphones isn’t playing in your head—it’s playing around you.
  2. Nothing will replace listening to the stereo image of your track on loudspeakers. Not for a long time. As different manufacturers create different algorithms to get closer to the natural feel of listening to loudspeakers, they are really trying to get close to what is already an end solution (listening on loudspeakers), and by definition, the technology will always remain inferior.

Even though there is technology to help, always check the stereo imaging of your mix on loudspeakers before mixing it all down. For listening and enjoying music, the technology is sufficient (IMHO). But for mixing, you should consider checking your mix on many different systems to be sure that the mix sounds the best. It’s an art of balancing losses.