Quality metal shells, Zero wearing pressure, Brilliant modular cable, Inviting light warm tone, Dynamic and punchy bass, Well-detailed in class, Customisable nozzles offer two flavours of sound
Mediocre isolation, Brighter lower-treble won’t suite all, Treble lacking some air, MMCX connectors can affect comfort, Requires a more powerful source
The FD5 is one of the strongest buys in its price class, especially for those wanting an earphone that is well-built, tastefully coloured and customisable on top.
Fiio is a world-renowned company, once for their price-effective sources and now for a whole slew of products spanning every facet of audiophilia. Their in-ears have been making a lot of noise recently and one hat piqued my eye was certainly the FD5, their current flagship single-DD model. This earphone hops of the Berrylium train with a customised 12mm driver and arsenal of acoustic features designed to deliver a balanced and spacious sound. With the FD5, Fiio turn their focus to the fundamentals of audio design and, in so doing, deliver a strong audio performance at a similarly unsophisticated asking price. As before, modularity and user customisation are a focus here, granting the user as much control over the listening experience as possible.
The FD5 retails for $319 USD. You can read all about it on Fiio’s website here and treat yourself to a unit on HiFiGO.
I would like to thank Sunny from Fiio very much for her quick communication and for providing me with the FD5 for the purpose of review. All words are my own and there is no monetary incentive for a positive review. Despite receiving the earphones free of cost, I will attempt to be as objective as possible in my evaluation.
- Drivers: 12mm Be-coated DLC dynamic driver
- Impedance: 32 ohms
- Sensitivity: 109dB
- Frequency Range: 10Hz – 40kHz
Behind the Design –
Customised Dynamic Driver
Whilst Beryllium drivers are nothing new, the FD5 takes this concept in a new direction. Conventional earphones use a mylar film driver then add a Be coating. Some models have implemented pure Be diaphragms, however, this is not cost-effective and, therefore, not suitable for most buyers. The FD5 takes a unique approach by building atop an already rigid and lightweight diamond-like carbon diaphragm (DLC) which is further strengthened with Beryllium plating.
This is reinforced with N52 neodymium magnets providing 1.5 Tesla magnetic flux for high driver-control and enhanced dynamics. Fiio claim this unique combination provides a more dynamic experience than conventional drivers. In addition, the FD5 has been tuned to provide a slightly more relaxed and natural take on the Harman target.
The FD5 implements a 2-chamber housing alongside a semi-open back design. The front section is designed to divide and channel frequencies to optimise phase coherence and minimise standing waves. Meanwhile, the rear implements what Fiio dubs a “volcanic field system”, a structure at the rear of the driver that breaks up low-frequency standing waves specifically. Fiio suggest this enhances the bass performance in addition to providing a clearer overall sound.
Meanwhile, the semi-open back design further aids a comfortable and pressure-free wearing experience in addition to permitting a more open soundstage. A tuned vent system balances pressure across the diaphragm to minimise wearing pressure and modal distortion of the driver. Finally, metal cylindrical housings provide mass loading for quicker decay and reduced resonances.
Fiio have always excelled with the unboxing experience on their IEMs and the FD5 takes this to a new level. The box is huge with a neat outer sleeve that slides off to reveal a soft-touch box. Inside are multiple levels of accessories with the earphones presented front and centre up top within a protective foam inlet. Beneath is the carrying case and assortment of ear tips. The case is large and protective with a hard structure and magnetic latch. It has two internal pockets, one for each earpiece to prevent scratches, but an additional mesh pocket would have been nice as there is ample room inside to house other accessories too. Finally, below is a separate box containing the exchangeable plugs for the module cable, alternative nozzles, cleaning brush and smart MMCX tool ala Final Audio. The tip selection is prolific as can be expected but even more so to suit both the large and narrow nozzles supported by the earphone.
The FD5 offers a charming compact cylindrical design with metal mesh grill and stylish sloped lines forming a timeless tribute to vintage technology. The 3-piece stainless steel shells feel superlative in-hand with awesome density and lustre across their perfectly polished exteriors. Seams are visible but tolerances and matching are very tight. Of note, some glue was evident on my unit but was easily cleaned off and I haven’t experienced other issues with the construction since. As the cable connectors are colour coded, it is easy to orientate the housings.
As we’ve seen on a few earphones in the past, the FD5 has removable nozzles and include an additional pair in the box. However, the second set offer a narrower sound tube diameter that not only permits use with different ear tips, but also changes the inherent sound. The nozzles offer a robust all-metal construction and attach to the earphones with a simple screw-in thread. A small O-ring guarantees a seal so channel matching isn’t a problem. We’ll dive into the granular sound changes in the sound section below.
The earphones utilise a removable MMCX cable system that feels clicky and even between sides. The cable itself has a pleasing 8-core construction with a square braid below the y-split and flat braid above. The insulation is supple with minimal memory making it easy to coil for storage. However, it does have a slightly rubbery texture that can make it a little harder to untangle than most. Otherwise, the cable upholds a high level of construction quality with metal connectors and comfortable pre-moulded ear guides.
Modular plugs further elevate the experience. Those familiar with the EM5, will note a similar implementation here with 4-prong connectors that interface with the included 2.5mm and 4.4mm balanced plug in addition to your standard 3.5mm single-ended connector. However, as opposed to the twist-lock system implemented on the EM5, the FD5 uses a screw down locking system that is a bit less fiddly during use. I found the connectors reliable and hugely convenient for source pairing, while slightly bulky, it is about on par with your typical custom-cable connector in size so nothing overly cumbersome.
Fit & Isolation –
The FD5’s compact design works much to its benefit with regards to fit, slotting quite comfortably and stably into the outer ear. It sits impressively flush too due to its small dimensions and rounded design though I still wouldn’t sleep on them due to their metal construction that can wear on the ear if pressed. I do have one main gripe, however, that being the design of the mmcx connectors at the top. The sharp edges do press into my ear if I’m not careful with fitting similar to older DUNU earphones. However, rotating the earphones forwards does mostly alleviate this.
Still, this is something to keep in mind if you have smaller ears as this may cause pressure and discomfort. Otherwise, the earphones are perfectly comfortable, possessing a medium depth fit and minimal wearing pressure as promised by Fiio’s marketing. No driver flex is present, and despite the abundant venting, they do seal and isolate quite well. Fit stability is excellent, and isolation is slightly above average compared to your usual vented DD design. They are easily suitable for commute though I would want more isolation for air travel or other especially loud listening environments.