Sound Devices is a highly-respected maker of portable audio recorders, field mixers and computer audio interfaces. Their equipment is widely used in filmmaking, as well as radio productions and other audio projects. They’re known for solid construction, reliable operation, pristine sound quality – and – high prices. Here at Transom, we have long considered their 722 and 702 portable recorders the premier gear choice for audio producers who could afford the cost. But that was the catch: those 7-series recorders have always been priced in the neighborhood of $2,000 new, and on the used market, available for only a few hundred dollars less. In addition to the expense, the Sound Devices machines were larger, heavier, and more complicated to power than many of the recorders that have been popular with audio producers.
So, there was notable excitement when Sound Devices announced two new machines that were smaller, lighter, more versatile, and yes, even cheaper. The MixPre-3 and the MixPre-6 feature more microphone inputs, a smaller footprint, the ability to act as a computer interface, and cost less than their predecessors. The two models are physically very similar, although the MixPre-3 is slightly smaller and lighter. The MixPre-3 has three XLR inputs along with a stereo mini input, and can record three of those input channels as discrete tracks to SD card, along with a main Left-Right stereo mix. The 6 adds an additional XLR input and can record 6 discrete tracks plus the L-R stereo mix. Sound Devices has a detailed comparison chart on their website.
Did they succeed? Do these new models live up to the hype? The short answer is yes. The MixPre-3 and MixPre-6 have updated microphone preamps, named “Kashmir,” that live up to the legacy of excellent, quiet mic preamps in all Sound Devices equipment, even exceeding the performance of earlier models in terms of noise floor and dynamic range. Both of these new devices are smaller and lighter than the Sound Devices 722 or 702 recorders, yet retain sizable knobs and effective metering. Each has more XLR inputs than the 702 or 722 (three on the MixPre-3, four on the MixPre-6). They are easy to set up as USB audio interfaces that can connect high-quality audio inputs and outputs to a computer. And most significantly, these devices can be had for a lot less money than one would expect. At press time, the MixPre-3 could be purchased for $650, the MixPre-6 for $900.
That’s still more expensive than many competing products: there are good-quality audio recorders available for $200-400, many of them reviewed on this site. So, even if these new machines are much cheaper than their predecessors, why spend the extra money?
It’s worth the expense for three things: sound quality, reliability and versatility. The microphone preamps, and all parts of the input circuitry, are very clean, making it possible to get noise-free recordings with almost any microphone. These new MixPres are solidly built: the main bodies are die-cast aluminum, but feel much lighter than the 7-series recorders, and appear durable and well-made. The battery sleds that attach to the back of the devices are polypropylene, and also feel solid, like rubberized plastic.
The MixPre-3 has three latching XLR inputs which can be designated as mic or line level, as well as a stereo 3.5mm mini input that can accept mic or line level, or a timecode signal. It can record three of those inputs to independent tracks on the SD card, along with the main Left-Right mix.
The MixPre-6 adds a fourth XLR input, and can record six discrete tracks to the SD card, along with the main Left-Right Stereo mix.
Both machines feature rails on all four corners, allowing a strap to be attached in almost any orientation desired. When hung from a strap, the screen is easily readable, and controls are readily accessible. A camera can be fastened to the top of the recorder with a retractable tripod screw, and there’s a socket on the bottom for tripod mounting if desired. Those design touches make these devices useful not only as portable field recorders, but also as field mixers for feeding video cameras, or as USB interfaces for sending audio to your computer.
The recorders’ internal software provides the ability to store presets of favorite configurations; three presets can be stored in the machine’s internal memory. Or you can store as many as you like on the SD card — just remember that those presets will be lost if you reformat the SD card, which you should do with some regularity. Using these presets allows for quick changes between recording configurations, without your having to dig through menu pages to make sure all settings are as they should be. Having a preset for recording with a single dynamic mic, and another for a stereo condenser mic, and yet another for multiple mics connected to the device as a USB interface, can make moving between those modes much less daunting. Gain settings, channel pan positions, phantom power on or off, low-cut filter status, and many other parameters are all saved in the presets, making for quick setup, despite the complexity of the options.
Despite an overall very favorable impression, it must be noted that to achieve a reduced size and price, there have been a few compromises and feature deletions. Most of those are unlikely to cause problems for the average audio producer.
The new MixPres do not have digital audio inputs, so it’s not possible to take an AES or S/PDIF digital signal from a DAT machine, or digital mixer, and record it in the digital domain. The need for that particular function seems less common, but that’s an occasionally useful feature that I’ll miss from the 7-series recorders.
There’s also no balanced line-out, so feeding a signal to a video camera or another recorder has to be done through the stereo mini. That is sufficient in most cases, such as sending audio to a DSLR, but that change does make these devices less like a full-on field mixer, and may complicate connection to certain professional equipment or long cable runs.
Most dramatically, the big, bright, light-ladder input level meters have been replaced by a smaller color screen. That touchscreen also doubles as the menu interface, so if you’re searching through menus or adjusting certain parameters, the level meters are no longer visible. But you can easily return to the meter screen, which is surprisingly readable in a wide range of lighting conditions, even bright sun. The screen does eat some power, but its brightness can be adjusted down, and it remains easily readable even at low brightness levels.
It’s easy to get lost in the many layers of the touch screen, but these devices allow tweaking so many aspects of the recording and monitoring process, that a structure like this is really the only practical way to organize that many options. And after a little practice, the logic of the screens becomes clearer.
In Basic mode, both the MixPre-3 and -6 only record at the sample rate of 48 kHz. That’s a little annoying if you tend to work at 44.1 kHz, and prefer to avoid the complications of Advanced mode. But recording at 44.1 kHz, or at higher sample rates, is easy to set in Advanced mode, although entering into that mode does require a little more set-up work than staying in Basic mode. [UPDATE: Sound Devices reminds us that Custom Mode can be set to allow the sample rate to be 44.1 kHz, without opening up all the options of Advanced Mode.]
To switch modes, you have to turn all input knobs down to zero, and re-set the input gains. Not doing so can lead to persistent unpleasant noises on the inputs.
One of the appeals of the Sound Devices 722 recorder was that it had both an internal hard drive and a flash card slot, and recordings could be made to both media at the same time, providing real-time backup. Even the 702 recorder, which has no hard drive, only a flash card slot, can also record to an external firewire drive, providing that simultaneous backup.
The MixPre-3 and MixPre-6 do not have the capability to make two simultaneous recordings without involving a computer. They CAN record both to the internal SD card and to a computer, when the Mix Pre-3 or -6 is configured as USB interface. So, it is actually possible to make a real-time back-up, but it will require a computer and recording software.
It would be great if one of the USB connectors on these recorders could be configured to mirror the SD card, but that might not be technically practical.
One of the most noteworthy differences between these devices and popular recorders from companies like Zoom and Tascam is that the Sound Devices recorders have no built-in microphones. In general, the target audience for Sound Devices gear is likely to want to use specific external microphones, and the design of these boxes make it likely that they would be hung from a strap, or stashed in a bag. Built-in mics are not very useful in those circumstances. Though it is occasionally useful to be able to run-and-gun with a recorder without worrying about wiring anything up, I doubt the lack of built-in mics is a major disincentive to potential buyers of these particular machines.
The quality of the mic preamps, which Sound Devices has named “Kashmir,” is remarkable, even in comparison to their earlier, excellent mic preamps. They are extremely low-noise, with a huge dynamic range, making it possible to use both low-output dynamic mics and very sensitive condenser mics without making dramatic adjustments. In Basic mode, the recorder automatically sets a coarse gain range — there’s no need to go into a menu and set Low, Medium or High gain. And these preamps make almost any kind of mic sound great.
Audio Sample: Dynamic Omni Mic (Electrovioice RE-50)
Audio Sample: Dynamic Cardioid Mic (Audix I5)
Audio Sample: Condenser Cardioid Mic (Neumann KMS 104)
Audio Sample: Shotgun Mic (Audio Technica AT-897)
Audio Sample: Stereo Mic (Rode NT4)
The last few notes of an outdoor, open-air live performance by a brass band, amplified through a PA, followed by audience applause.
Audio Sample: Stereo Mic (Rode NT4)
Standing in dense woods at dawn, birds chirping, a light rain dripping through the canopy.
Audio Sample: Stereo Mic (Rode NT4)
Birds in the distance, a solo jogger passes on a roughly-paved country road. Most recorders sound fine recording loud stuff, but not all do as well as the MixPre-6 in capturing quiet, subtle details.
One of the major changes from earlier Sound Devices gear is the way the MixPre-3 and -6 are powered. The 7-series recorders used L-mount Lithium Ion rechargeable batteries, or could run from external power sources via a Hirose connector. These new machines have more choices: they come with a compartment that holds 4-AA batteries, or can be powered via the USB jack. Additionally, there are optional power attachments that can hold 8-AA batteries, or two (hot-swappable) L-mount Li-Ion batteries.
Sound Devices makes it clear that the stock 4-AA sled might not be sufficient for heavy field work, so most users will probably want to get one or more of the optional powering attachments. The 8-AA sled increases the size and weight of the recorder by only a little, but the L-Mount sled makes the shape and weight a bit more cumbersome. Two large-capacity L-mount batteries make the recorder look rather strange, but it can record almost infinitely with that much power, and the ability to hot-swap fresh L-mount batteries one at a time is appealing for marathon sessions.
The company warns that alkaline AA batteries are not a good choice. In some circumstances, that might be all that is available, so I wanted to give them a try. With four standard Duracell Alkaline AAs, the record time was almost comically short: with phantom power on, even on only one channel, those batteries barely lasted for 30 minutes of recording. In fact, phantom power, or even the recording process, didn’t seem to be the biggest power-suck: just scrolling through menus and adjusting settings would burn through four alkaline batteries in well under an hour.
But there’s good news: there are several adjustments you can make that reduce power usage. As mentioned before, the display can be dimmed, and it’s still remarkably readable, even at low brightness settings. Similarly, the LED rings around the input knobs, which serve as a secondary level meter — turning green when signal is present, and red when clipping — can be dimmed as well. The Bluetooth connection can be turned off, unless you are using the “Wingman” remote control smartphone app.
And most important: using high-capacity rechargeable Ni-MH AA batteries increases the operational life significantly. I was able to get 3-4 hours of record time when using four 2550mAh Eneloop Pro rechargeable batteries. When using eight of those same batteries in the 8-AA sled, I was able to record with two mics, with phantom power on, for over seven hours. Running three or four microphones, each with phantom power, will decrease those record times, but the 8-AA sled or L-Type sled should make it possible to get decent record times in any scenario.
Powering via USB is slightly more complicated. There is a USB-C connector on these new MixPres, which can be connected to a computer, or a power source, by:
–a USB-C to USB-C cable
–a USB-C to USB-A cable
–a USB-C-to-USB-A Y-cable
That (provided) Y cable allows the user to plug into two USB-A jacks, which can provide additional power if the voltage from one USB-A connection is not sufficient.
If the USB power is not strong enough to power all of the inputs, the MixPre will automatically revert to Basic mode, will only provide phantom power to mic inputs 1 and 2, and will automatically dim the display, so you can still use the recorder for relatively simple recording.
It’s helpful to have this option to power via USB, but the standard USB-C connector doesn’t inspire quite as much confidence as the threaded, locking Hirose connector used on other Sound Devices gear. (An aside: why don’t data connections ever have latches?) If you have batteries installed while using USB power, the recorder will switch automatically to battery power in the event of an unintentional USB cable disconnect. Even given the chance of a USB plug somehow disconnecting, USB power sources are much more affordable and easy to find than professional battery packs with Hirose connectors, so in many ways this design is much more practical, if a little less secure than the previous design.
Between AA, L-Mount, and USB, you should be able to find a powering solution that works for you. And if you’ll be near a wall outlet, there is an optional AC adaptor that connects to the USB-C input. Plugging into wall power does not add any noise to the recording, as occasionally happens with some 7-series recorders.
There is a menu item for setting what type of battery you are using, which helps make the battery indicator more accurate. The MixPre is also smart enough to detect what kind of power it’s connected to, so if you change the power source, it will often offer to change the battery setting to the proper value on its own.
As batteries approach the empty mark, a loud beep is sent to the headphones, warning you of imminent power failure. If you do run the batteries completely down during recording, the recorder will save your file before powering down.
The major difference between the new MixPre devices and earlier Sound Devices recorders, mixers and preamps is the touch screen. It’s not very large, but packs an amazing amount of information and functionality. It’s surprisingly easy to read, even in bright sun, and is still very useable even when dimmed to save battery life. If there’s an icon, or the name of something in a box, you can probably touch it and change it. If there are multiple dots in the box, that means there are multiple pages to scroll through. Even the meters will change what they display when touched. If there are up and down arrows, the values can be incremented up or down on the screen, or you can make the adjustment more quickly by turning the headphone volume knob. Pressing in on that knob makes the selection.
On screens that involve naming, a page appears with tiny letters and numbers, far too small to select via the touch screen. Instead you scroll through the letters with the headphone knob, and push in to select the highlighted character. This is similar to the way the menus work on other Sound Devices gear.
I have to admit that I occasionally touched the wrong spot on the screen, or needed to try a few times to get my touch to register, but overall, the screen responds much better than expected. I haven’t tried it in the cold, or in the rain, but it did behave pretty well with sweaty fingers during a summertime festival. It can be a little dizzying remembering how to access the many variables that can be adjusted, but with a little practice it gets easier. And in a very clever design, the “Basic” mode reduces the number of possible adjustments to the bare minimum, making it less likely to get lost in menus.
The MixPre-3 and -6 each have two main modes of operation: Basic and Advanced (there is also a Custom Mode that can be configured to include only selected options from Advanced mode). In Basic mode, the inputs can be assigned to Left, Right or Center, and input gain can be set to Mic (if you’re plugging microphones into the inputs) or Line (if you’re connecting the higher-level outputs of a mixer, or another recorder, or a keyboard, or some such “line-level” device). The fine input level can be adjusted with the front-panel knobs. The levels will be reflected on the meters on the screen and also on the colors of the lighted rings around each knob.
To adjust the settings for each input channel, you simply press in on the knob for that channel. That will switch the display to show everything you can adjust for that channel, such as:
–which physical input is assigned to that channel
–panning the input to the Left, Right or Center of the main Left-Right mix
–setting the input gain to mic or line
–turning phantom power on or off
–turning a low-cut filter on or off
Basic mode then records the main L-R stereo output to a stereo file, as if the MixPre was a field mixer attached to a stereo recorder. In Basic mode, the recording sample rate is set at 48 kHz. Other sample rates are possible, but require Advanced or Custom mode.
Basic mode will be sufficient for many users, especially those who are looking for the excellent sound quality of a Sound Devices recorder, but have no interest in adjusting every aspect of the recording chain.
If you are conducting an interview with one microphone, plug it into XLR input number one, press down on knob #1, which will bring up a new window on the touch screen. On that touch-screen, set the input to Mic, set the pan to Center. Turn on Phantom power if your mic requires it, turn the low-cut filter on if you’re hearing wind rumble or thumps from handling noise. Adjust your headphone levels, then hit record, and you’re underway.
Like the 7-series recorders, pressing the Record button starts recording: there’s no record-pause mode that might lead you to believe that you’re recording when you’re not.
If you want to add a second microphone, plug it into XLR input #2, and repeat the process above, perhaps panning one mic to Right, and the other to Left, to keep them on separate channels of the recording. This will allow you to adjust their respective levels independently later in the mix process. Or if you want to live dangerously, you can pan them both to the center, and mix the levels in real time while you’re recording, using the front panel knobs.
The MixPre-3 has three XLR inputs, each of which can be configured as mic or line inputs. You can also assign the mini jack to one or two of the input channels. The MixPre-6 has four XLR inputs, as well as the stereo mini input.
Levels and Limiters
In Basic mode, analog limiters are always on by default — on each channel and on the main Left-Right mix. That way, most loud peaks that would otherwise cause distortion can be tamed, and those peaks won’t cause clipping, which creates an unpleasant crunchy sound when your record levels are too high.
On my first outing with the MixPre-6, I thought the limiters were acting too aggressively; I was sure I could hear them working, pumping the volume up and down, to a degree that I never did on my Sound Devices 702 recorder. But after getting used to this new device, I realized that I simply had the input gain up too high. The very clean, quiet Kashmir mic preamps can be run a little lower than you’re used to, allowing for a greater dynamic range. If you have to raise the levels later in the editing and mixing process, you won’t get hiss or other noises from the machine along with the signal you want.
Of course, you still want to set healthy recording levels: you want the meters to show a consistent bounce in the green range, kissing the yellow from time to time. But you don’t have to push too hard to get your levels right up near the top of the range, pinging the red, in order to maximize the signal-to-noise ratio.
Once I got used to where the levels should sit, I had a hard time making the limiters sound bad. If you are hearing the limiters cause pumping in the levels, you’re probably recording too hot: turn your input gains down.
In Basic mode, the limiters are on. You can’t turn them off, and you can’t change any parameters. In Advanced mode, you can turn the limiters on and off, but there are no other adjustments to be made, such as determining threshold or ratio, attack or release. Just on or off. At first, this worried me, but as I mentioned above, with continued use, I found that the limiters sounded just fine in their default state, and in the rare instance that I didn’t like the sound, I could turn them off if I were in Advanced mode.
There’s also a Custom mode that allows even deeper tweaking of many of the devices controls.
In Advanced mode, the recording process is a bit more complicated. Before changing modes, always turn all input gain knobs all the way down. Setting up each channel now starts the same way: pressing the front panel knob for the track you want to tweak. This brings up a window on the touch screen that allows much more tweaking than in Basic mode. You can set the channel’s gain by twisting the headphone knob, and THAT gain level will be recorded to the SD card. The Pan position for each track can also be set more precisely; you’re no longer constrained to Left, Right and Center. That same window allows you to “arm” any of the tracks, which causes that input to be recorded individually to the SD card. The front panel knobs will not affect the level being recorded on the individual tracks. Instead, those knobs do affect how much of each channel is sent to the main Left-Right stereo mix. That stereo mix can also be recorded — allowing the MicPre to act like a field mixer, and a multi-track backup at the same time.
If you’re using a stereo mic, or any stereo source, you can link channels 1 and 2, so that knob #1 controls the input level of both channels.
Advanced mode allows many more adjustments to almost all aspects of the signal path, take a look at the user guide to see all the options.
The MixPre-3 and -6 have sophisticated timecode reading capabilities built in. If you are synchronizing with a camera that outputs HDMI TimeCode, there’s an input for that. Or you can feed linear timecode to the Aux In. With no external timecode, the audio will still include a precise time-of-day time stamp. Other than that time-of-day stamp, neither the MixPre-3 nor the MixPre-6 generate time code.
Transport can be controlled, and metering can be shown on iOs and Android devices, but using the free Wingman App. Make sure the MixPre’s Bluetooth is turned on, and then connect with your smartphone or tablet. It’s a fairly stripped-down control surface, but recordings can be started and stopped, and the metering is even more detailed than on the device itself. You can also edit filenames and metadata, and that’s actually a little easier on the app than on the MixPre itself.
In addition to recording to SD card, the MixPre-3 and -6 can operate as USB interfaces, connecting audio inputs to your computer. Audio from the computer can feed back into the MixPre for monitoring, or even for recording to the SD card, allowing you to record live microphones and computer-based audio such as a Skype call.
Connecting to a Mac or Windows computer, using either a USB-C to USB-C cable, or the (provided) USB-C to USB-A cable, will make the MixPre appear as an audio device that can be selected in your computer’s sound control panels. By default, both the MixPre-3 and the MixPre-6 may appear as 2-input, 2-output devices, registering the Main L-R stereo output of the devices as the audio input. But the individual inputs (as well as the stereo mic) can be used as discrete inputs, and multiple audio streams can be returned to the unit. On Windows computers, you may need to download an ASIO driver written to communicate with the MixPre. You should always be able to find the latest one on the Sound Devices site: www.sounddevices.com/support/downloads.
For Mac computers, if you’re not seeing each input as valid audio sources, you may need to go to Audio-MIDI set up (in Applications>>Utilities). Select the MixPre as the audio source, then select the number of inputs and outputs you would like to access, up to eight for the MixPre-6, and five for the MixPre-3 (each individual mic/line input, plus the main L/R Stereo mix).
Once the Audio-MIDI setup, or ASIO driver, is configured, those inputs will be available to audio software on your computer.
You can also use the USB connection for moving audio files from the SD card to your computer’s hard drive. Go to the System screen on the MixPre and tap File Transfer. This will disable USB audio while in this mode.
The headphone amplifier has lots of gain, so headphones can get very loud, use caution. Tapping the headphone icon on the touch screen will open a variety of monitoring options. L-R stereo and L-R mono are the most commonly desired monitoring setups, but you can also monitor USB streams from the computer when connected as an audio interface, or as audio from a camera when connected to the Aux input, soloed inputs (in Advanced or Custom modes), or any of four user presets.
The Sound Devices MixPre-3 a and MixPre-6 are extremely versatile audio field recorders, and USB interfaces. The sound quality of the audio, from the Kashmir mic preamps to the A/D converters to the headphone monitoring is all first-rate. The touch-screen menus offer a quick and logical way to control almost every aspect of the recording environment, and the Basic, Advanced and Custom modes of operation allow users to keep things simple, or to dig deep into adjusting every aspect of the recording environment.
My only major complaints about these devices are that I’d like to be able to record at 44.1 kHz in Basic mode, [Update: Sound Devices reminds us that 44.1 kHz is available in Custom Mode] I’d like the headphone presets to include an M-S Decode mode, so that users can easily record un-matrixed M-S stereo while monitoring in stereo, as is possible on the 7-series recorders. [Update: Sound Devices tells us that the presets can be edited to include an M-S decode mode. I’ll still suggest that perhaps that should be there by default.] But those are small exceptions. Overall the MixPre-6 (the model we tested) is a very impressive machine. The menus, especially in Advanced mode can get a little dizzying, but with only a little experience, they make sense, and you can quickly find a screen to adjust almost anything you need to tweak.
If you’re buying a MixPre-3 or -6, we highly recommend getting one or more of the optional powering attachments. The 8-AA sled adds only a little extra size and weight, but will allow a good solid 6-8 hours of record time when using good NiMH batteries. If you’ll be out recording for very long periods, the L-Type battery sled is your best bet, allowing the connection of one or two high-capacity Li-Ion batteries, and hot swapping of fresh batteries without stopping the recording.
Sound Devices sells their own SD cards, and recommends using those, but you can use any high-quality SD card with Class 10 speed or better. You can use SD, SDHC, or SDXC cards up to 512 GB. You must format the card in the MixPre before recording. It’s good practice to periodically reformat SD cards. Be sure to back up any recordings as soon as possible so that you can reformat the card, which erases all information from that card.
You’ll probably want either a camera strap or a bag to hold the MixPre while in the field. While they’re not all that big, they’re not really designed to be hand held. Hanging it around your neck, or placing it in a bag will make much more sense.
Even at the comparatively low prices (compared to other Sound Devices equipment), these recorders are still more expensive than most field recorders on the market. But the great sound quality, the versatility, and the solid build-quality make them equipment worth investing in.