The physics of feet — Magico Loudspeakers

Magico gets more customer inquiries about loudspeaker feet than anything else. It’s only natural. Audiophiles are constantly looking to make that next big improvement. And few system tweaks are easier – or more rewarding – than a proper set of new feet. While we understand the importance of loudspeaker feet, we’re also acutely aware of the thorny challenges inherent in their design.

Successful feet must achieve two apparently conflicting goals: block the transmission of vibration between the loudspeakers and the floor – while securely anchoring the speakers to the floor. It’s not as simple as placing a soft cushion like a rubber mat under the speaker. Without a firm foundation, the speaker will tend to rock, vibrating in response to driver motions. (Think about trying to push something when you’re wearing roller skates.) Speaker rocking results in constant signal smearing, which hampers microdynamics and introduces a veil between you and the music.

It also seems easy to eliminate rocking by firmly anchoring the speakers to the floor. But this permits the direct transmission of vibration between the speakers and the floor, the very problem we seek to eliminate. It’s a paradox.

What’s needed is some method of controlling vibration without compromising the solid anchoring that loudspeakers also require. This challenge led Magico’s engineering team to create the Pods family. Rather than isolating the speaker from vibrations, which degrades anchoring, we use elaborate Constrained Layer Damping (CLD) that dissipates vibrations away from the speaker while maintaining firm anchoring. The story of Magico’s Pod mechanisms has been public knowledge for years. Now thanks to the scanning laser vibrometer, you can actually see the difference as well as hear it.

These screenshots show actual enclosure side rocking on our loudspeakers, comparing Magico Mpods to another set of high-end feet. As in the previous article, cabinet motion is shown by deviations in the shape of the cabinet surface, while the velocity of the cabinet surface is color coded from purple (or blue) at the low end to red at the high end. At the bottom of each chart, spectrum analysis confirms the tremendous difference in surface velocity between Mpods and the alternative.

The effect of two sets of loudspeaker feet on the side of a Magico M6. Cabinet surface speed is color coded from zero micrometers per second (blue) to 40 µm/s (red). On the right, alternative high-end feet permit substantial cabinet rocking, as seen… — The effect of two sets of loudspeaker feet on the side of a Magico M6. Cabinet surface speed is color coded from zero micrometers per second (blue) to 40 µm/s (red). On the right, alternative high-end feet permit substantial cabinet rocking, as seen in the color shifts at the top and bottom. Peak surface velocity is about 30 µm/s. In comparison, the Magico Mpods are extremely stable, with peak velocity less than 12 µm/s

The Magico Pods family achieves the ideal combination of isolation and coupling. Thanks to our new laser vibrometer, this achievement is now easily illustrated.