Description

Lii Song / Lii Audio Fast-15

15” Full-Range Driver with Greater Detail, Soundstage and Musical Presence

The Lii Song Fast-15 is a 15-inch full-range loudspeaker driver, sold as a matched pair, created as a more refined evolution of the well-known F-15. According to Lii Song, the Fast-15 was developed after years of experimentation as an upgraded model within the Fast Series, with special attention paid to detail, frequency response, imaging and soundstage.

Its purpose is clear: to preserve the natural scale, efficiency and immediacy of a large full-range driver, while offering a more present image, fuller sound body and improved musical articulation. The Fast-15 is designed for listeners who want a bigger, more open and more expressive sound without the complexity of multi-way crossover systems.

Sound Character

The Fast-15 offers a presentation that is open, vivid and physically convincing. Compared with the original F-15, it is conceived as a more detailed and spacious driver, with a stronger sense of presence and a more developed soundstage. Lii Song describes its bass as deeper and more elastic, with energy that can be released and recovered quickly, giving the music a more dynamic and responsive character.

This makes the Fast-15 especially attractive for systems where musical flow, immediacy and coherence are essential. Voices are projected with presence, instruments occupy the space naturally, and the overall sound has the kind of directness that many audiophiles associate with classic high-efficiency loudspeaker designs.

The high-frequency extension reaches up to 18 kHz, according to the manufacturer, helping the Fast-15 deliver a more vivid and agile listening experience while maintaining the simplicity and coherence of a full-range concept

A Natural Upgrade from the F-15

One of the most interesting aspects of the Fast-15 is that it uses the same basket as the F-15, allowing it to be used as a direct upgrade by replacing the driver unit. This is especially useful for owners of existing F-15-based loudspeaker projects who want to move toward a more refined, detailed and spacious presentation without redesigning the entire cabinet.

For open-baffle projects, handcrafted loudspeakers or high-sensitivity systems with tube amplification, the Fast-15 is a very serious option. It keeps the esential charm of the large full-range driver: simplicity, scale, speed and emotional immediacy.

Main Features

• 15-inch full-range loudspeaker driver.
• Sold as a pair.
• Developed as an upgraded model after the F-15.
• Optimised for detail, frequency response and soundstage.
• More present imaging and fuller sound body.
• Deeper and more elastic bass response.
• High-frequency extension up to 18 kHz.
• Suitable for open-baffle and high-efficiency loudspeaker projects.
• Direct upgrade path from F-15 thanks to the same basket design.
• Very suitable for tube amplifiers and low-power amplification.

Technical Specifications

• Model: Fast-15
• Type: 15-inch full-range speaker driver
• Nominal impedance: 8 ohms
• Power handling: 40–80 W
• Frequency response: fo – 18 kHz
• Fs: 36.5 Hz
• Sd: 245.703 cm²
• Qms: 7.583
• Qes: 0.324
• Qts: 0.528
• Magnet: Y47
• Mean sound pressure level: 97.1 dB / 2.83 V / 1 m
• Cone material: compound pulp
• Weight: 12 kg
• Package dimensions: 46 × 52 × 52 cm

Lyric Audio Comment

The Lii Song Fast-15 is a driver for those who love the immediacy of full-range loudspeakers but want a more refined and developed presentation than the classic F-15. It keeps the beauty of the concept — one large driver, no complicated crossover, direct musical communication — but adds greater detail, a more spacious image and a fuller tonal body.

In the right cabinet or open-baffle design, and especially with carefully chosen tube amplification, the Fast-15 can deliver a sound that feels large, natural and deeply involving. It is not about chasing technical complication; it is about recovering something very valuable in music reproduction: coherence, presence and emotion.

Selected by Lyric Audio Élite for listeners who want the scale of a large full-range driver with a more refined, detailed and spacious musical presentation.