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:
$1,495.00 each

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Grotto i Specifications

Specifications are subject to change without notice

Frequency Response

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

Low Pass Filter Frequency

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

High Pass Filter Frequency


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)


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

Audio Controls

±10dB at 25Hz


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" x 15.2" x 13.8 "
(47.3cm x 38.6cm x 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.