Loudspeaker drivers in push-pull

[StigErik]

We see quite often that woofers are mounted in a push-pull arrangement. A popular example is the Linkwitz Orion, where the woofers are facing opposite directions.

Its been claimed that 2. order harmonic distortion is reduced.

What else will happen, or is expected to happen?

[Inductor]

The Pi 12 kit (diy) is a good example of one of the best subs in the world, from Wayne P. at Pi Speakers.

(picture from WP@PS: Pi Speakers - unmatched quality and state-of-the-art performance)

[StigErik]

Good link, thanks a lot.

As I suspected, even order distortions (2nd, 4th and so on) is reduced, while odd order (3rd, 5th ...) remains unaffected.

Its interesting that the distortion reduction with push-pull is affected by the air loading of the driver. IB or OB woofers benefit the most, while boxed woofers benefit less from push-pull.

[StigErik]

A conclusion here could be that drivers with very low 3rd harmonic distortion is preferable in push-pull configs.

The drivers I'm using have 3rd order distortion 10-15 dB below the 2nd order. Great for push-pull!