Piega Coax 611 Gen2 Silver (pack of 2)

Heiress to the Coax 511, this three-way floorstander marks the entry point of the Gen2 models presented in Munich in 2022. Piega deploys its C112+ coaxial ribbon driver here in a slim format and a seamless extruded aluminum cabinet. With its five front-mounted drivers and a weight of 45 kg for a height of 117 cm, the 611 is a compact yet substantial speaker, designed for medium to large rooms.

The C112+ coaxial ribbon, a two-way driver

At the heart of the Coax 611 is a coaxial driver where the ribbon tweeter is housed at the center of the ribbon midrange. This concentric layout aligns the two drivers on the X, Y, and Z axes, creating a single point source. Frequencies between 450 Hz and 50 kHz are emitted from the same geometric point, ensuring phase coherence regardless of listening position in the room.

The aluminum diaphragms used in this coaxial module are 0.02 mm thick and weigh only a fraction of a gram. Piega states they are thirty times lighter than conventional domes. This extremely low mass allows for a fast and precise transient response.

For the Gen2 generation, the C112+ driver received several improvements over the C112: additional transverse reinforcements on the front plate, an extra neodymium magnet above the tweeter to increase efficiency, and a special coating on the midrange diaphragm that linearizes the response in the lower part of the spectrum and allows a lower crossover frequency with the woofers (450 Hz versus about 800 Hz on the previous generation). The magnetic rods have also been mechanically decoupled to eliminate micro-resonances.

Bass section: two active woofers, three passive radiators

The Coax 611 uses five 160 mm drivers on the front baffle, but only the top two are active. The three lower ones are passive radiators. Compared with the Coax 511, which had only two, this third radiator allows more effective acoustic loading of the increased internal volume.

The UHQD (Ultra High Quality Definition) drivers are manufactured by SEAS to Piega specifications. Their moving mass remains low enough to keep up with the speed of the coaxial module, preserving overall sonic consistency. The response extends down to 32 Hz, which is respectable for a portless speaker of this size.

The absence of a bass-reflex port is an advantage for placement: the Coax 611 can be positioned closer to a rear wall than most floorstanders in this category without the bass becoming overbearing.

The aluminum cabinet and the TIM2 module

The seamless extruded aluminum cabinet has been a Piega hallmark since 1997. This material offers high rigidity for moderate mass, but aluminum can resonate if not treated properly. Piega developed the TIM (Tension Improve Module) system to counter this phenomenon.

The TIM2 version, introduced with the Gen2 series, works differently from its predecessor. The old module exerted outward pressure on the inner walls. TIM2 uses tensile stress: machined aluminum plates are inserted horizontally between the drivers and fixed to the internal rails of the extruded cabinet, then manually tightened to a precise torque. This inward tension increases the rigidity of the whole assembly. Residual resonances are absorbed by viscoelastic damping sheets bonded to the inside of the cabinet.

Compatibility and setup

With a sensitivity of 90 dB/W/m and a nominal impedance of 4 Ω, the Coax 611 poses no difficulty for modern amplifiers. Piega indicates a recommended power range of 20 to 250 W. The impedance remains stable across the entire frequency range, which makes life easier for the power stage.

Two pairs of binding posts allow for bi-wiring or bi-amping. Jumpers are supplied for single-wiring use.

The Coax 611 requires a run-in period of several dozen hours before reaching its full potential. Early on, the sound may seem a little restrained.

This floorstander can serve as the main channels of a home cinema system together with the Coax Center 211 center speaker, which shares the same C112+ driver and the same design language.

Technical specifications

Technology and design

• C112+ coaxial ribbon
  • Coaxial tweeter and midrange on the same plane for a single point source
  • Optimized temporal and impulse response
  • Clear, natural and dynamic sound
• UHQD bass drivers
  • Two active 160 mm bass drivers
  • Three 160 mm passive radiators
  • SEAS manufacturing according to Piega specifications
  • Deep, dynamic and precise bass
• TIM2 module (Tension Improve Module 2)
  • Enclosure under controlled tension to effectively reduce resonances
  • Pure and homogeneous sound
• Aluminum enclosure
  • Seamless extruded aluminum for maximum rigidity
  • Optimized construction to eliminate unwanted vibrations

Acoustic specifications

• Type: 3-way floorstanding loudspeaker
• Recommended amplifier power: 20 - 250 W
• Sensitivity: 90 dB/W/m
• Impedance: 4 Ω
• Frequency response: 32 Hz - 50 kHz
• Drivers
  • 2 active 160 mm UHQD bass drivers
  • 3 160 mm UHQD passive radiators
  • 1 C112+ coaxial ribbon

Physical characteristics

• Dimensions (H × W × D): 117 × 21 × 31 cm
• Weight: 45 kg
• Construction: extruded aluminum with TIM2 module

Finishes and design

• Standard finishes
  • Brushed silver or black aluminum
  • White lacquered