The Swing Headshell is an interesting device from the South Korean company Nasotec. Conceptually, the headsell adds another layer of damping with its embedded springs, working along the damping effects within the installed cartridge to absorb side force exerting on the cartridge. This approach is claimed to achieve near zero side force on the stylus during playback, an ideal situation. On the downside, the "swing" may incur unpredictable tracking errors.
My test data obtained with a low-compliance MC cartridge does not show any noticeable difference compared to the case of installing the same cartridge on a regular headshell. Similar amount of anti-skating force is still necessary to approach balanced THD on both channels. And with insufficient anti-skating force, significant distortions appear in the right-channel waveform.
In
tests using the same cartridge sample, the Swing Headshell demonstrates two key
areas of measurable differences from a conventional headshell. 1) The natural
resonance frequency of the cartridge/tonearm combo is broken up into two bumps,
one at lower frequency with smaller magnitude and one larger magnitude at
higher frequency near the 20Hz mark, significantly higher than the ideal 8 to
12Hz range. 2) Channel separation numbers are lower, along with wider phase
differences between the channels, possibly due to the "swinging"
actions during play when side force is present.
In A/B listening comparisons using two cartridges of the same make/model, the Swing Headshell is found to alter the sonic characteristics of the installed cartridge, turn the overall presentation toward the softer side, consequently hiding the sharp edges. Such forgiving attributes can be pleasant to the ears when the cartridge is not precisely installed/tuned. The price paid though, is perceived in the somewhat dulled transients, less focused bass notes, and shallower/narrower sound stages. The overall effect is in some way akin to softening the cartridge's damping mechanism, or swapping a line-contact stylus with the elliptical or conical variety.