[Ilkka]

The frequency response is a little bit better than at the 20 Hz tune. Naturally the same slope towards the high frequencies remains, but since the response extends lower, it doesn’t look quite that bad. The -6 dB point goes as low as 14.5 Hz which easily transfers close to 10 Hz extension in a typical room. The maximum output in mid bass range is slightly weaker than at 20 Hz tune, but the very low frequency output naturally gets a nice boost. The power compression grows rather large around the tuning frequency which suggests that the subwoofer is heavily under ported.

The THD profile is similar to the 20 Hz tune, though naturally the 16 Hz tune performs a little bit better at the very low frequencies. The group delay stays under the 1 cycle limit all the way down to 15 Hz. The spectral decay graph shows around 200 of ringing around the tuning frequency; slightly more that at 20 Hz tune.

Changing the tuning frequency by plugging one or more of the ports has some advantages, mainly the added extension, but also some drawbacks. The reduced port area is one major drawback which causes even more port chuffing and port compression at higher levels than with all available ports open. Therefore I would suggest choosing the subwoofer which has the native tune that you’re going to use, rather than buying a higher tuned subwoofer and then plugging its port(s).

Due its flatter frequency response, the 16 Hz tune is more suited to music use than the 20 Hz version. Movie fans will have more extension but also reduced output at higher.

+ High output in 15-40 Hz range
+ Low distortion
+ Extremely good extension

- Slightly uneven frequency response
- Medium upper bass output
- High power compression around the tuning frequency
- Slow decay rate at low frequencies