Zoom F6

With 32‑bit recording, six inputs and a stereo mix facility, as well as impressive battery life, this versatile compact recorder should have wide appeal.

Zoom’s F‑series field recorders are renowned for offering high‑quality multichannel audio recording at very attractive prices, and being notably more compact than the competition. The current range features five recorders, with the F8n as the flagship model. Its smaller multitrack sibling, the F4, was effectively replaced by the F6 which was first shown at NAB in 2019. However, whereas the F4 essentially followed the same conventional form as the F8 and F8n, the F6 takes a far more radical approach to its design, both inside and out. Most obviously, it takes Zoom’s miniaturisation to a whole new level while retaining most of the functionality of the F8n, and even adding some important new tricks of its own. When launched, the F6 was the first portable recorder to offer a native 32‑bit floating‑point recording format, obviating the need to set gain controls manually.

The F6 is fundamentally an eight‑track audio recorder, capturing six discrete balanced mic/line inputs to separate tracks, along with a stereo mix of those tracks (if required). To that end, the unit is equipped with six full‑size XLRs (three on each side), with most of the user controls on the front panel surrounding a small colour display. A caddy of four AA batteries slots underneath, while a bracket at the rear accepts a Sony L‑series battery pack. So far, so conventional but, incredibly, this is all contained in a package measuring just 100 x 63 x 120 mm and weighing 520g without batteries. It’s hard to work out where there’s space for the electronics amongst the connectors and batteries, and I know of nothing else this small that is able to match the F6’s remarkable capabilities.

Given the unit’s design and features, it would be reasonable to assume the F6 is designed primarily with video cameras and DSLR users in mind, its compact proportions making it ideal for fixing between a tripod and camera baseplate, or onto the base of a DSLR (and it comes with a suitable mounting plate for precisely that application). However, the F6 can be employed equally well in a ‘gadget bag’ for traditional location sound‑recordist applications, or on a desktop for podcast panel recordings. Its compact size also makes it ideal for hiding ‘on set’ for local recording, or even for placing in a waterproof bag for remote unattended field recording! This is a very versatile little product.

Form & Function

The F6’s construction appears pretty rugged and it certainly feels robust, and although the (very few) controls are necessarily tightly packed I didn’t have any difficulty operating this recorder. The unit comes with a 14‑page ‘Quick Start Guide’ which is enough to get going with the machine, but the F6’s capabilities are extensive and complex and there’s a lot of flexibility, so it’s well worth reading the full 202‑page operational manual, which is available online, to familiarise yourself with all the features and implications.

The F6 caters for both AA batteries and Sony L‑series battery packs, and when the latter runs out of power will switch seamlessly to the former. This obviously extends running time but it also allows you to mount another charged L‑series battery.The F6 is clearly intended to use a Sony L6 rechargeable battery pack as the primary power source, clipped onto the rear of the unit.A hinged flap on the base (secured with a thumbscrew) covers an internal 4 x AA battery caddy. Menu options cater for alkaline, NiMH, or Lithium chemistries to enable accurate run‑time calculations and to shut the unit down before cells are damaged. The unit’s core power consumption is remarkably low (around 1W) so the AA batteries alone can provide quite a decent recording duration, especially if you keep the display brightness down and don’t use phantom power. However, the F6 is clearly intended to use a Sony L6 rechargeable battery pack as the primary power source, clipped onto the rear of the unit. The AA batteries then act as an emergency backup; the unit automatically switches between available power supplies.

Towards the front of the unit base plate is a 1/4‑inch threaded insert to allow mounting on a camera tripod, although the balance is inevitably poor (especially with an L6 clipped to the back) so it would be better to mount the F6 on a tripod plate rather than just a threaded stud. A separate camera mount adapter plate supplied with the F6 can be bolted onto the top panel, and this allows the unit to be attached below a DSLR camera. The threaded stud in this adapter is movable over about 30mm fore/aft to allow the centre of gravity to be adjusted, which is a nice feature.

The F6 can be mounted on a tripod and a camera or mics (the author’s custom DPA setup is pictured) can be mounted on top of the recorder.For remote field recording applications, though, this plate (along with an appropriate thread adapter), can also be used to attach a mic or stereo bar to the recorder, making a very neat self‑contained system for high‑quality ambient recording. I attached my custom spaced‑omni rig to the top and acquired some lovely remote recordings in a local wood.

A covered slot on the F6’s rear panel accepts a single SDHC/SDXC recording card of up to 512GB, and this is obscured or protected (depending on your point of view) when a Sony L6 battery is fitted. The card formatting limits files to a maximum of 2GB, with an ongoing recording being split automatically and seamlessly into a new file. Although there is only a single recording card in the F6, it is possible to record simultaneously to both the internal card and a computer via the unit’s USB connection, though only at base sample rates.

Moving around to the unit’s left‑hand side, three standard XLRs accept balanced mic or line inputs for tracks 1‑3 with maximum input levels of +4dBu (mic) or +24dBu (line) — the line option really just introducing a 20dB pad to the mic preamp. The preamp circuitry here is similar to that in the F8n, boasting a decent EIN figure of ‑127dBu (A‑weighted at 75dB gain with a 150Ω source).

Phantom power can be set to 24 or 48 Volts, and activated on each channel independently (it remains available in ‘line’ mode). Other input‑conditioning facilities include a variable high‑pass filter (10‑240 Hz), polarity inversion, up to 30ms delay and a fully configurable hybrid limiter which has a look‑ahead option (introducing 1ms of extra latency) although that’s not available at the 192kHz sample rate. The limiter side‑chains are coupled automatically when input tracks are linked for stereo, M‑S or Ambisonic sources, and although I think the noise floor is raised slightly when the limiters are engaged that’s unlikely to be a problem in practice. If it is, selecting the floating‑point recording mode obviates the need for limiters entirely.

I mentioned Ambisonics there, and the F6 has provision for recording and monitoring various Ambisonic formats as standard. A‑format mics can be recorded directly, obviously, or converted and recorded in either the traditional Fuma (WXYZ) or modern Ambix (WYZX) B‑format variants (with options for different mic orientations, of course). Decoding to stereo is provided for monitoring.

A covered socket on the left side panel accepts Zoom’s optional BTA‑1 Bluetooth adapter, which allows remote control from iOS devices (as well as wireless timecode connections). Remote control is via the proven F‑Control app but it’s available only for iOS devices (iPhone, iPad). Various screens in the app display a mixer view with channel faders, pans, gains, transport controls etc, or an overview with meters, PFL buttons, track arming, transport controls, and so on. There are also facilities to name tracks and files in the usual way. With the small display and limited physical controls on the F6 the remote control option could prove very useful, but it’s a shame that, at the time of writing, there’s no Android option.

An unbalanced stereo line output is also provided on the left‑hand panel via a 3.5mm mini‑jack socket, intended for feeding the stereo mix into a camera or DSLR. The nominal level is ‑10dBV (clipping at +10dBV), and the D‑A converter’s dynamic range is specified at 95dB which isn’t great by modern standards but is perfectly adequate for the intended role.

The USB 2 type‑C port on the side panel allows connection to a computer for file transfer or as a duplicate recording destination. It also caters for an external keyboard (for text entry of file names, etc), or for the connection of Zoom’s popular F‑control hardware fader panel. It also allows the F6 to serve either as 2‑in/2‑out or 6‑in/4‑out USB interface for a computer. The 2‑in/2‑out mode is class compliant for Mac OS, Windows, and iOS (iPad), but the 6‑in/4‑out mode only works with Macs and Windows PCs, the latter requiring an ASIO driver. Sadly, a USB cable isn’t provided with the F6.

Top: the left panel, hosting inputs 1‑2. Middle: the rear panel hosts the SD XC card slot and allows direct connection of Sony L‑series battery packs. Bottom: the right side panel, hosting inputs 4‑6.Power can be provided to the F6 through the USB port too, either from an optional mains power supply, or a power‑bank battery. The F6 prioritises this USB power supply first, switching to the L‑battery if USB power is unavailable. The AA cells are the last resort. Impressively, I was able to power the F6 for a full working day using a 10,000mAh power‑bank via the USB port!

The right‑hand side panel carries input XLRs for tracks 4‑6, along with a small power on‑off button. This has to be held depressed for a few seconds, preventing accidental operation, and it could be fiddly to access if the F6 is used in a typical recordist’s padded bag. A detented edge‑wheel encoder positioned towards the front panel adjusts the headphone volume, and a 3.5mm socket provides a stereo headphone connection. The encoder wheel also has a push‑switch action which is used to lock the front panel controls as well as to switch between different headphone monitoring presets (selecting user‑configured combinations of source channels). The headphone D‑A converter has a dynamic range of 108dB, and the amplifier can deliver 100mW per channel into 32Ω headphones. I’d describe this as adequate, but it seems Zoom’s headphone amp design remains a slightly weak area in the otherwise very impressive F6. My 32Ω Sony MDR7509 phones were a noticeably better match with the F6 than my usual 70Ω Sennheiser HD25‑1‑IIs.

A second mini‑jack socket on the right‑hand panel provides timecode I/O, with external timecode input via the tip contact and internal timecode output on the ring contact. Some cameras use the same connection format, though, so a custom crossover cable or suitable adapters may be required to interface the F6’s timecode generator/reader correctly with a video camera. Alternatively, as I mentioned earlier, timecode can be conveyed via the optional Bluetooth adapter to/from a BT‑enabled timecode master clock such as Ultrasync’s Blue, which is an attractive possibility for videographers.

Finally, we reach the front panel which is delightfully simple. A 1.54‑inch colour LCD (240x240 pixel) dominates the panel, with three transport buttons arrayed below (Stop, Record, and Play/Pause). Pairs of small cursor buttons are arranged on each side, with Back and Enter on the left, Up and Down on the right (these last also act as skip forward/back keys during playback). Two columns of three rotary faders run down the outside edges of the panel (with off‑switches at the counter‑clockwise ends) and these set the stereo mix contribution levels. The fader range changes depending on whether the recording format is fixed‑point (‑48 to +24 dB) or floating‑point (‑60 to +60 dB). Preamp gain (in fixed‑point mode) is adjusted via a menu screen (see below).

I was surprised to discover that the display is not a touchscreen: all menu navigation is performed with the cursor buttons, but the operation is straightforward and logical, borrowing much from other F‑ and H‑series recorders. The screen is crisp and clear, and although there is a high‑contrast mode for outdoor use I found the standard display sufficiently visible when not in direct sunlight.

Bits & Hertz

There isn’t space here to go into every function of the F6, but it is a very capable machine with broadly similar facilities to the F8n recorder. It supports sample rates from 44.1 to 192 kHz (plus 48.048 and 47.952 pull up/down modes), recording mono, stereo, or poly‑WAV (2‑8 channel) files in the BWF format with iXML metadata. It’s also possible to record the stereo mix in MP3 at 128, 192, or 320 kbps at 44.1 or 48 kHz. To avoid missed starts, the F6 has a selectable pre‑record option, where the incoming audio is buffered through a memory so that cues can be captured from a couple of seconds before the record button is pressed. The size of this buffer depends on the sample rate: from 6s for base rates, 3s for double rates, and 1s at 192kHz.

In practice, I doubt that 192kHz mode will see much use, not least because the machine can only record the six raw input tracks at this rate; the stereo mix track becomes unavailable, as does the Ambisonic decoder and the ability to record dual‑formats simultaneously (see below). I imagine these restrictions are simply because the internal processor runs out of capacity to process such a vast amount of data at such a high rate, but most users will not find that too frustrating.

Six separate recording modes are available: Linear PCM (at 16‑ or 24‑bit), 32‑bit floating‑point, dual‑format (linear 16‑ or 24‑bit plus the floating‑point data), or stereo MP3. The dual‑format modes are unique to the F6, with the six raw inputs being recorded simultaneously in separate linear and floating‑point formats (along with a fixed‑point stereo mix). This mode eats through the SD capacity though, producing 14 separate tracks per recording!

Of course, the floating‑point format has been used in most DAWs for decades, as it ensures internal signal manipulation is always free from clipping and noise. However, it has only recently become practical to employ this format for source recordings too, a development pioneered by Zoom with the F6. (Sound Devices subsequently embraced the same idea in their second‑generation MixPre recorders).

Each of the F6’s inputs essentially uses a pair of A‑D converters set up with staggered gain structures, one to handle high signal levels, and the other for low levels. The outputs from these converters are analysed and their data combined to create the 32‑bit floating‑point information recorded to disk. The claimed benefit of this approach is that it removes the need to optimise the input signal level through the preamp in the traditional way, as there is far less risk of a track being overloaded or lost in the noise. Instead, this arrangement captures the full dynamic range capability of the input circuitry and, in this case, that means everything from +4dBu down to ‑127dBu (or +24 to ‑107 dBu in line mode).

If the captured floating‑point signal ends up a little high or low compared to other material when it’s all imported into the DAW, the track’s level can be adjusted without compromising the source signal quality at all. (Most DAWs can handle floating‑point source files directly, but the F6 comes with download codes for full versions of both Wavelab SE and Cubase LE just in case.)

...there is no danger of overload, no need for limiters, and actually no requirement even to monitor signal levels during recording! The machine can simply be put into record mode and forgotten about.

From an operational point of view, the preamp gain trim facility disappears from the input configuration menus when recording the floating‑point format, and provided the input signal doesn’t clip the input circuitry (you just select the line mode if it does) there is no danger of overload, no need for limiters, and actually no requirement even to monitor signal levels during recording! The machine can simply be put into record mode and forgotten about. No doubt this capability will appeal greatly to busy videographers! However, for Luddites such as me, conventional fixed‑point recording remains an option and in this mode the preamp gain trim can be adjusted in the Input menu page from +12 to +75 dB in mic mode, ‑8dB to +55 dB in line mode, or ‑35 to +30 dB for USB inputs when used as a computer interface.

Compare & Contrast

The F6 will inevitably be compared with Sound Devices’ MixPre recorders, particularly the MixPre 3 ii (which costs roughly the same) and MixPre 6 ii (which is a little more expensive but has an extra input and supports Ambisonic recording). However, the comparisons aren’t straightforward and I don’t feel that there is a clear‑cut winner here: these machines all have different strengths and weaknesses and really suit different working scenarios and preferences.

Both manufacturers’ machines now offer 32‑bit floating‑point recording, with support for sample rates up to 192kHz. The F6 and MixPre 6 ii can also both make Ambisonic recordings (although the optional Ambisonic plug‑in must be installed in the MixPre). Both manufacturers also offer an Automix facility, which favours the active input channel while minimising noise from other open channels. Again, though, while this is standard in the F6, the Mix Pre machines require a cost‑option plug‑in. Zoom’s Automix system is the same as that first seen in the F8 and F4, and while it’s arguably not the most sophisticated of its type I found it very effective in keeping control of complex panel‑type recordings and podcasts.

Another important difference for many potential users is that the Zoom F6 accepts an L‑series battery directly, while the MixPre machines need an optional mounting bracket. And actually the L‑battery seems to be physically integrated better with the F6 compared with the MixPre recorders. The F6 is also noticeably more power‑efficient than the MixPre models, which means it will run longer from any given battery power source.

In Sound Devices’ favour, though, the MixPre recorders can be controlled remotely from both iOS and Android devices, whereas the F6 only talks to iOS platforms. Another ‘win’ for the MixPre 6ii is its combi‑XLR inputs, which accept high‑impedance instrument sources. And both Sound Devices machines acquire clever overdubbing facilities (and some music‑focused effects and other facilities) if the optional Musician plug‑in is installed. The F6 can’t match any of that.

The quality of the preamps will obviously be a key factor in most people’s decision making, and there’s no doubt in my mind that the preamps in the F6 are capable of delivering excellent results in most circumstances. However, I think Sound Devices’ Kashmir preamps have the edge in the most demanding situations, being slightly quieter in extremis and offering a slightly wider dynamic range. The MixPre’s headphone amplifier design also seems a little more capable with compatibility across a wider range of headphones.

Yet the F6 boasts twice the input count of the MixPre3 ii and two more balanced inputs than the MixPre6 ii, while costing less, being physically smaller, and needing no optional cost‑extras to get up and running. The F6 is also unique in offering the dual‑format recording mode, capturing both fixed‑ and floating‑point data simultaneously, and that’s a feature which may appeal in unpredictable situations or where different formats are required by different recipients.

The bottom line is that the F6 is another very impressive and highly cost‑effective audio recorder and I’m finding myself somewhat reluctant to hand the review unit back!

Verdict

Bearing all that in mind, I see the F6 as an ideal recorder for solo video‑shooters as well as for mobile podcasters, and for all forms of high‑quality field recording where budgets are limited and compact size is important. For the seasoned professional location sound recordist, the F6 also makes a very cost‑effective backup recorder, and can serve as a handy extra recorder which could be hidden relatively easily on set. It’s obviously not quite as ‘pro’ to use in a hands‑on mode as well‑established field recorders like Zoom’s own F8n or the larger Sound Devices offerings, and it doesn’t include some mission‑critical features like dual memory cards, more versatile powering arrangements and so on. However, the floating‑point recording format largely obviates the need for any hands‑on control anyway, and its powering arrangements are still pretty flexible.

Most importantly, the sound quality and versatility of this diminutive F6 is remarkable, and certainly up to full professional standards. So while Zoom’s design decisions and the resulting practical compromises might mean the F6 won’t appeal to every potential user, there is nothing about it that, on balance, bears much criticism. The bottom line is that the F6 is another very impressive and highly cost‑effective audio recorder and I’m finding myself somewhat reluctant to hand the review unit back!