Downfill element for GTO and C-12



Down-Fill element to form part of the GTO turnkey solution
Modular design to offer identical footprint to all other GTO system elements
Designed as the bottom cabinet within the array to cover the first section of the audience
Designed for bi-amplification Very high power handling (3200 + 1000 watts AES peak) and sound pressure (max 144.5 dB SPL peak at 1 metre)
Equipped with the high-precision GTO Rigging system to allow actuate aiming and coverage.
Ideal in “live” arena, festival, and stadium concerts


The GTO-DF is a proprietary ‘Down-Fill’ enclosure incorporating a newly-designed waveguide based on phased audio paths. It is engineered to provide exceptionally high quality sound to the first several rows of the audience at an event, filling the sonic gap often experienced by event attendees who are seated near the stage. With its downward oriented constant directivity horn with embedded acoustic lens, it is designed to reside on the bottom of a GTO array.

GTO-DF is mechanically identical to, and acoustically matched with, the GTO full-range cabinet, so it can be easily added to a flying array. Unique to the GTO-DF is a vertical dispersion range of zero-degrees to minus 25-degrees to ensure precision aiming of the sound into the audience and not onto the stage. The development of this acoustic lens has facilitated a much more compact design than is normally associated with products of this type. The proprietary waveguide offers 120-degrees of horizontal coverage from 315 Hz to 17.5 kHz.

The GTO-DF is intended for large-scale applications, as part of the GTO-turnkey solution. The GTO range is ideally suited to projects that demand no-compromise audio quality. This product is capable of outstanding electrical to acoustic power conversion. The GTO-DF has a useable frequency +/-3 dB from 250 Hz to 17.8 kHz.

The sensitivity is 105 dB SPL (for the mid frequencies) and 101 dB SPL (high frequencies) in free field. A maximum continuous AES input power of 800 W (mids) and 250 W (highs) will provide a power output of 134 dB SPL in free-field (mids) and 125 dB SPL (highs), while peak output power values can reach 144 dB SPL (mids) and 135 dB SPL (highs).

The GTO-DF’s high quality cabinet is constructed from 15 mm (phenolic-glued) baltic birch plywood and includes bracing throughout to increase the overall cabinet rigidity. The outer finish applied is a scratch-resistant, waterproof black paint. GTO trolley-board designed for ‘2-up’ aids handling and transporting on even or uneven surfaces. Recessed integrated handles in the side panels of the cabinet are used for a positive grip during handling. Weather protective shower caps also form part of the turnkey -package.

Connection to the loudspeaker comes in the form of two types of connector, wired in parallel. These are: one NL4 wired pins 1+/1- for midrange drivers, pins 2+/2- for HF compression drivers plus one LKI-8 wired pins E/F for midrange drivers and pins G/H for HF compression drivers.


FREQUENCY RESPONSE (-10 dB) 200 Hz – 18.5 kHz
Vertical: from +0° to -25° (on axis -12.5°)
IMPEDANCE Mid: 8 Ω (min 6.8 Ω)
High: 16 Ω (min 16.7 Ω)
POWER – WAES Mid: 800 (3200 peak)
High: 250 (1000 peak)
MAX SHORT-TERM SPL @ 1 m, free-field* 144.5 dB SPL


LOUDSPEAKERS AND LOADING Mid: 4 x 8″ NdFeB partially horn loaded mid woofers
High: 2 x 3″ diaphragm NdFeB compression driver loaded by acoustic lenses coupled to a constant directivity horn
WEIGHT – SINGLE UNIT 78 kg (172 lb)
DIMENSIONS (Net) Height: 465 mm (18 5/16″)
Width: 1126 mm (44 11/32″)
Depth: 655 mm (25 25/32″)
DIMENSIONS (With Pins) Height: 465 mm (18 5/16″)
Width: 1181 mm (46 1/2″)
Depth: 655 mm (25 25/32″)
* calculated using +10 dB crest-factor signal


GTO Brochure

Nov 2016

GTO-DF Architectural Specifications

Nov 2019

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