GRADIENT HELSINKI 1.5

Pre-owned. In good condition. Show signs of wear. Without original packaging.

The Helsinki 1.5 is conceived as a refined synthesis of the concepts that have long defined Gradient products, known for their unconventional forms and radical design choices. Its structure revolves around a thick, elegantly sculpted multilayer frame that tapers upward like an abstract treble clef. The wood, similar to a bamboo laminate approximately five centimeters thick, rests on a sculptural glass base supported by three soft feet. A second glass panel, sharp like a dorsal fin, accompanies the frame and helps control the output of the large 12" side-firing woofer, a Peerless unit with a paper cone that is rough on one side and smooth on the other.

The 5" SEAS midrange operates within a dedicated enclosure made of a plaster-like material and filled with acoustic foam. Its angled placement reduces early floor reflections and minimizes cancellation effects in the lower midrange. The 19 mm SEAS aluminum-dome tweeter, mounted from the rear on its metal support, completes the front emission with a gentler angle.

Connection is made via a four-pole Speakon connector, a practical solution that also allows for potential bi-wiring configurations. The crossover remains integrated within the structure.

During installation, the loudspeaker responds clearly to environmental variations and benefits from positioning that enhances low-frequency extension and midrange linearity. Moving it closer to the rear wall improves bass response, while a carefully set toe-in ensures effective control of direct sound. When correctly positioned, the system provides consistent timbre, precise high-frequency reproduction, solid vocal presence, and a spacious, well-defined soundstage, in line with the design goal of minimizing room dependency.

Technical specifications:

• Frequency response: 60–20000 Hz ±2 dB; 35 Hz at –6 dB
• Crossover frequencies: 200 Hz; 2200 Hz
• Impedance: 6 Ohm; minimum 4 Ohm
• Recommended amplifier power: 50–250 W
• Sensitivity: 88 dB / 2.83 V / 1 m
• Drivers: 300 mm long-throw woofer; 150 mm pulp-cone midrange; 19 mm aluminum-dome tweeter
• Radiation pattern: bass dipole; midrange and treble cardioid
• Features: bi-wiring and bi-amping ready (with Speakon connector)
• Connectors: binding posts; four-pole Speakon
• Weight: 27 kg