Helix Compose i7 Ci7 T20FM-SC Tweeters 0.75 Inch 20mm FlexMount Silk Dome

The Helix Ci7 T20FM-SC is a pair of 0.75 inch (20 mm) silk dome tweeters from the Helix Compose i7 series, made in Germany. They feature a neodymium magnet, solid aluminium housing and dampened coupling volume, designed for high-end component systems with FlexMount20 vehicle-specific installation.

Key specifications

• Size: 0.75 inch / 20 mm silk dome
• Impedance: 4 ohm
• Frequency response: 1,500 Hz – 30,000 Hz
• Resonance frequency: 950 Hz
• Sensitivity: 91 dB @ 2.83V / 1m, 88 dB @ 1W / 1m
• Installation diameter: 27.2 mm
• Installation depth: 19 mm
• Minimum crossover: above 3,000 Hz at 12 dB/octave

These tweeters require a highpass filter: either an active DSP channel or the matching Ci7 FX-UNI.2 Flex-Crossover. Flush mounts and angle-mount pods are included; car-specific FlexMount20 adaptors and WireKits are available separately.

Helix Compose – universal speakers evolved

The Helix Compose platform was developed to meet the increasingly complex demands of modern vehicle installations. It combines classic universal speakers with the practical advantages of vehicle-specific systems — delivering high efficiency, strong dynamics and excellent sound quality in a wide range of vehicles.

i7 – High-end car audio made in Germany

The Compose i7 series represents Helix's uncompromising high-end tier, developed with clear influence from sister brand BRAX and manufactured entirely in Germany. All speaker impedances are matched for use with Helix and MATCH amplifiers. The i7 is part of the broader Compose range, which also includes components such as the Compose i5 M80FM-S3 3 inch midrange speakers.

Brilliant treble response

The i7 tweeter uses a fine-meshed silk dome with visco-elastic Acronal coating on both sides for a smooth, detailed treble response. Pure lamb's wool and a dampened coupling volume lower the resonance frequency and allow deep acoustic coupling.

FlexMount20 – universal meets car-specific

FlexMount is a mounting system using specially developed adaptor rings that allow Compose FlexMount speakers to be installed in a wide range of vehicles. The matching FlexMount20 adaptor ring lets the universal tweeter drop into the vehicle's original tweeter position in an acoustically optimised way.

WireKits – plug and play installation

Helix WireKits connect Compose components to the vehicle's original wiring harness, or optionally to the crossover, via arrestable adaptor cables built to automotive industry standards. They are sold separately.