The Optimal Audio Cuboid 6TX is a two-way loudspeaker with an integrated 70V/100V transformer, featuring a 6.5-inch LF driver and 60W programme power. Purpose-built for distributed commercial audio, it provides the extended low-frequency response of the Cuboid 6 with the convenience of constant-voltage line operation for long cable runs. Also available in white.
This TX model includes an integrated 70V/100V line transformer with rotary switch tap selection, allowing you to set the power draw per speaker across a distributed audio system. This makes it straightforward to balance coverage across zones with long cable runs, using a single amplifier channel to drive multiple speakers in parallel.
6.5″ LF driver for extended low-frequency response
Integrated 70V/100V transformer with rotary tap selection
60W programme power handling
Portrait or landscape mounting orientation
IP54-rated with optional outdoor connector cover (CIPKIT)
Compatible with Optimal Audio SmartAmp DSP-optimised amplification
Works with Zone controllers, ZonePad wall panels, and WebApp
Black finish for unobtrusive integration
The optional CIPKIT connector cover is required to achieve the full IP54 rating for outdoor or exposed installations. For low-impedance installations not requiring a transformer, see the standard Cuboid 6.
| Model | Cuboid 6TX Black |
| SKU | CUBOID6-BTX |
| Speaker Type | Two-Way with 70V/100V Transformer |
| LF Driver | 6.5″ |
| Power Handling | 60W |
| Line Voltage | 70V / 100V |
| Tap Selection | Rotary Switch |
| Ingress Protection | IP54 (with optional connector cover) |
| Mounting | Portrait / Landscape |
| Colour | Black |











