Grotto i

Compact and Accurate

The world's most affordable servo-controlled subwoofer, Grotto i proves that a precise, compact subwoofer can have the heart of a beast.

A powerful 300 watt (900 watt peak) low-distortion, high-reliability amplifier gives Grotto i extremely articulate bass without need of exaggerated amplifier power ratings or transient-blurring ported or passive radiator enclosures common to many modern subwoofers. A proprietary servo system further ensures that output from Grotto i's 10-inch high-resolution aluminum cone woofer is dramatically free of distortion and provides a faithful replica of the audio input signal.

Launched in 2007

Price when discontinued:



Specifications are subject to change without notice

Frequency Response

22–120 Hz ±3dB; Anechoic through LFE effects input


Line level RCA: 20,000 Ohms. Compatible with 4, 6, or 8 Ohm rated amplifiers.

Low Frequency Transducer

10" (25.4cm) high excursion, aluminum cone with extended throw drive assembly, sealed non-resonant asymmetrical chamber format


300W (at less than 0.5% THD)
900W (peak)

Audio Controls

±10dB at 25Hz

High Pass Filter Frequency


Low Pass Filter Frequency

30, 35, 45, 55, 65, 80Hz


Left/Right RCA Line Level, RCA LFE, Speaker Level

Power Draw

Max: 250 Watts
Idle: 15 Watts
Standby: 10 Watts


51 lbs. (23.2 kg)


18.6" × 15.2" × 13.8"
(47.3cm × 38.6cm × 35cm)

Customer Reviews For Grotto i

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Dan Petri

  • Sunday, June 9, 2013

What Subwoofer ??
I used to hate subwoofers until I paired the Grotto with my Magnepans. They integrate very well and are fast enough to keep up with the Maggies.


  • Wednesday, March 7, 2012

Good Sub
This sub is awesome!!! Worth every penny. Went from a bose system to this and its night and day. Wouldn’t be surprised if the foundation of my house has moved.


  • Sunday, November 8, 2009

The subwoofer sounds great. The bass is smooth and tight. I wish I would have bought two of them at the time of purchase. I may add another one later. I also like the cabinet design.