Speaker distance measurements: midrange drivers

This guide covers various speaker driver configurations and how to locate the midrange drivers for distance and up-close speaker measurements.

In this article: 

• Which are the midrange drivers on my speakers, and why is it important?
• Different speaker driver configurations
  • Two-way speakers
  • Three-way speakers
  • Three-way twin-driver design speakers
  • Tweeter between two identical woofers (MTM)
  • Coaxial speakers
  • Four-way driver (or more) speaker designs

Which are the midrange drivers on my speakers, and why is it important?

The key here is the microphone locating signal that is set to 1 kHz (1000 Hz). The 1 kHz frequency is generally covered by the midrange drivers; therefore, those are the ones used. However, there are so many different types of speaker driver/layout configurations out there that sometimes it's not obvious which speaker drivers should be used - see the examples below for clarification. If you are still unsure, see the user manual of your speakers, as it should have the information on the specific frequency ranges covered by the individual speaker drivers. 

Note that midrange drivers help define the speaker distance measurements. Depending on the speaker's design and orientation (vertical/horizontal), midrange drivers may not be centered, leading to a difference between their distance and the distance between the speaker unit centers. Use the distance between the midrange drivers to fine-tune the distance measurements. When you check the measured distance with a tape measure, measure from midrange driver to midrange driver, not from tweeter to tweeter.

Note: Most errors during this speaker measurement stage are unrelated to the midrange driver specifics. If you're getting stuck with an error message or an incorrect distance measured, the cause is most often an object between the speakers and the microphone (for example, a screen or laptop), a delay or other DSP setting on the speakers, or the microphone position. See solutions for this in the Speaker measurement troubleshooting guide.

Different speaker driver configurations

Two-way speakers

Plain and simple - this basic configuration only features two drivers. The tweeter is covering the top-end, while the woofer is covering both bass and midrange. Use the woofer, since it covers 1 kHz:

Three-way speakers

In a three-way configuration, there is a dedicated midrange driver that covers the 1 kHz frequency, so that is what we're using in this case:

Three-way twin-driver design speakers

In this setup, there is one tweeter and two drivers that, while the same size, serve different purposes. Typically, one of the twin drivers is a dedicated midrange driver, and the speaker units are labeled as A and B on the back (check the speaker product manual). Other models are more advanced and have the capability of swapping the woofer driver/midrange driver functionality using a dedicated switch.

Studio work standard would be midrange drivers on top in a vertical layout, or on the inside in a horizontal layout. There's no right or wrong method, though; it depends on personal preference. Whichever you choose, set up both speakers the same way: for example, the midrange drivers on the inside on both speakers, or on the outside on both.

The same principles apply to vertical twin-driver designs with built-in subwoofers on the sides: the two equally sized drivers on the front usually cover dedicated frequency ranges - check the speaker manual. You'll still need to use the drivers that cover the 1 kHz frequency. If this doesn't answer your question, see the Speaker measurement troubleshooting guide.

For horizontal layout, speakers are often marked A and B at the back of them if there is a dedicated midrange driver. Others, like Focal Twin6 BE in the example below, are compatible both ways and have a left-right switch at the back which flips the driver functionality. Keep in mind that the distance is going to change depending on this layout:

Tweeter between two identical woofers (MTM)

If the tweeter sits between two identical woofers, both woofers usually cover the bass and the midrange, including 1 kHz. If your speaker manual says that only one of them covers the midrange, use that one. Otherwise, use the upper woofer in a vertical layout and the inner woofer (the one closer to the other speaker) in a horizontal layout.

Coaxial speakers

Coaxial speakers need no special setup. The locating signal is 1 kHz, so point the microphone at the coaxial driver, which covers it.

Four-way driver (or more) speaker designs

Things are getting simpler again when there is a dedicated midrange driver for the 1 kHz locating frequency. Hot tip: use the midrange driver that is the smallest, as long as there is an even smaller additional tweeter.