Fyne Audio F501 Loudspeaker

Keeping the Dream Alive

Equipment report
Categories:
Floorstanding
Fyne Audio F501 Loudspeaker

The story of Fyne Audio is underscored by the resolve to maintain an audio manufacturing base in Scotland. Tannoy was acquired by the international holding company Music Group in 2015, and by 2016 the new owners announced the decision to close the Scottish Tannoy factory at Coatbridge and move production to a new facility in China. This played a significant part in the motivation of a team of experienced ex-Tannoy employees to embark on a journey to start Fyne Audio. With financing in place, Fyne Audio was officially launched in January 2017. At the end of 2019, Fyne Audio had a manufacturing base near Glasgow in Scotland, where mid-to-high-end products are built. Affordable gear, including the entire F500 range, is manufactured in China to Fyne Audio’s exacting standards. These days, manufacturing in the East has become essential to staying competitive at entry-level price points. Product reception has been enthusiastic, and while the UK is a core market, distribution arrangements already span 50 countries. 

Similarities between the $1750-per-pair F501 and Tannoy’s Revolution XT6F loudspeaker are unmistakable, and probably not surprising, since they were designed by essentially the same technical teams. The obvious question that came to mind had to do with the actual differences between the Tannoy and Fyne implementations of the coaxial point-source technology. So, I reached out to Fyne Audio for answers. Fyne’s acoustics design was carried out by its technical director, Dr. Paul Mills, who has many years of experience in point-source driver design. He explained that while a time-aligned point-source driver concept is not new in itself, the way it’s implemented is critical. According to Dr. Mills, Fyne Audio has developed its own waveguides, cones, driver surrounds, magnet systems, and high-frequency compression drivers to move the art form forward significantly. Fyne has also found new ways of integrating its IsoFlare coaxial into speaker cabinets to maximize overall system performance. Dr. Mills emphasized that the nature of Fyne Audio’s waveguide is different than anything Tannoy ever did, and therefore there are no intellectual property conflicts with Tannoy products

Not all speakers are born time coherent. In particular, multiway box speakers with a multiplicity of conventional drivers struggle to achieve time coherence. My appreciation of coaxial drivers spans several decades and is due to the fact that functionally they perform as wide-range drivers with excellent coherency, ensuring that the music’s fundamentals and their harmonics originate from essentially the same spatial location. Fyne’s coaxial driver is built around a rigid cast-aluminum chassis. The tweeter, a titanium dome, is located in the throat of the midrange/woofer cone and shares a common acoustic center with the woofer section. A vented rear chamber in the tweeter’s neodymium magnet pushes its low-frequency resonance well below the crossover region. Multi-fiber paper is used for the bottom woofer and mid/woofer cones. The coaxial’s low-frequency section is operated up to a second-order low-pass crossover at 1.7kHz, where the tweeter comes in with a first-order high-pass filter. The bottom 6" woofer operates up to a frequency of 250Hz with a second-order low-pass filter. The woofer surrounds feature a computer-designed variable geometry to better terminate cone energy and minimize reflections. Fyne’s fancy name for this is FyneFlute technology.

The bass loading is no ordinary bass reflex. The woofers are loaded by twin chambers connected via an internal port. The lower chamber vents to the exterior through a down-firing port at the bottom of the cabinet. In contrast with a conventional bass-reflex alignment, which is tuned to a single frequency, this loading system broadens the tuning frequency to further reduce cone excursion. My impedance measurements showed exceptionally well-damped twin bass-reflex peaks, widely spaced in frequency at approximately 20 and 60Hz, more so than you would expect from a conventional loading. Below the vent in the base of the loudspeaker, a diffuser is used to improve dispersion. Dubbed the BassTrax, its profile is rather unusual being Tractrix-shaped. The cabinet base features spiked feet for anchoring the cabinets on carpeted surfaces. In a clever bit of engineering, the spikes are adjustable from the top using an Allen wrench. Grilles are supplied, which are held in place by magnets hidden beneath the wood veneer. Be sure to remove the grilles for critical listening. Simply move them from the front to the back, above the bi-wire speaker terminal, where another set of hidden magnets will hold them neatly in storage.

Note that even though the F501’s impedance magnitude is rated at a nominal 8 ohms, it touches 4 ohms below 100Hz and even dips slightly below that in the range between 80 and 100Hz. However, Fyne Audio believes that since this is over a narrow frequency range it does not compromise the overall impedance rating. The impedance magnitude varies from about 3 to 32 ohms, not unusual for most box speakers. But in the case of tube amps with multiple impedance taps, typically 4- and 8-ohm, it wouldn’t be obvious at all which choice would be optimal. My advice is to experiment with both sets of taps before making a final decision.

In practice, the ideal of a point-source coaxial driver has been difficult to execute without serious side effects in the form of cavity resonances. Fyne’s tweeter design is pretty well behaved with only a few small bumps in the frequency response between 5 to 15kHz. Above 15kHz there is a response lift on-axis which flattens out at off-axis listening positions. More serious, however, is a response dip of as much as 4dB in the upper midrange between 2 to 3kHz where the auditory system is quite sensitive. Both the factory-provided response curve as well as my own measurements show a similar upper midrange dip. More about that later.