G22 Direct Servo subwoofer

Product features include:

GR Research 12″ paper high excursion driver

• Rigid one piece dish shape black anodized aluminum cone ensuring control at high SPL
• Low moving mass to ensure an exceptional transient response
• High flux density in the gap to ensure low distortion
• Flux de-modulation shorting rings to lower inductance and improve linearity
• Extended upper bandwidth response allowing a higher crossover point than most

While designed primarily for their sound quality, these custom designed drivers are also stylish in appearance with a anodized aluminum cone and rubber surround. Unfortunately, it’s not possible to judge the accuracy of a driver by observing its appearance. There are other drivers on the market which in fact look quite similar, and it’s tempting to think that they are comparable. Many of them are inferior in performance due to a heavy moving mass, the absence of shorting rings, wider gaps around the voice coil and high inductance which limits the useable high frequency cut off point. Many aren’t suitable for a crossover point higher than 50 Hz. This is very limiting when one considers the large number of home theatre speakers which perform better when relieved of bass duties.

We also provide a range of finishes. Our range of attractive and excellent value vinyl finishes including:

• black oak vinyl
• piano black

To suit different setups, we provide a 12 db and 24 db/octave crossover. If you are using an AVR, then we recommend “AVR/12” (or EXT/12 in older amps). If you are still using stereo receiver or conventional prea/power amp setup, then we recommend the 80hz/24 db/octave setting. To understand more about how to correctly integrate your subwoofer, read our phase alignment article.

We use high quality high excursion drivers which make it possible to achieve high output in a relatively compact enclosure. Only with Direct Servo is it possible to achieve such deep bass extension, high output and very high damping simultaneously. The effective system Q is 0.3. A lower Q factor represents a higher level of damping, indicating control of the cone. A typical subwoofer has a Q of 0.707 and some achieve a Q as low as 0.5. The penalty is that the box is larger and the output is lower in order to achieve lower damping, but Direct Servo can achieve much lower damping without sacrificing output and making the box bigger.

When more output than one subwoofers can provide is desired, it may be tempting to look for a higher output option. Our subwoofers represent what we consider to be the output limit for an affordable and accurate subwoofer. It’s possible to get higher output with one subwoofer, but not without significant compromise and additional cost. We suggest multiple subwoofers as a much better option. A side benefit is that this can also improve the integration with the acoustics of each particular room.

The bass extension controls allow the user to customize the deep bass extension and the rumble filter to control cone excursion. For high SPL, one can set a higher cut off. For music one may prefer a lower cut off. Changing the settings can also result in a better integration with the acoustic gain of the room.