Sound Devices MixPre-10 II Review

I have acquired a Sound Devices MixPre-10 II, which is a big step up from the Zoom F4 I have been using primarily for nearly three years. This review will largely be written as a comparison between those two devices.

[Be warned that many of the features of the MixPre-10 II are not present in the MixPre-3 II or MixPre-6 II. Neither of those devices have TA3 outputs or 4-pin Hirose power connectors. The MixPre-3 II does not have combo inputs to accept 1/4″ TRS connections, and it just doesn’t have enough inputs to support ambisonic microphones. There may be software/feature limitations in those devices. This review is about the MixPre-10 II.]

32-bit Float

The big game changer is obviously the wide dynamic range and the ability to write to 32-bit float WAV files. This same functionality exists in the Zoom F6, about which I don’t have many specifics, except that it works similarly.

The important factor with 32-bit float files is not the amount of dynamic range, but that they can record values above 0 dB. This means your recordings won’t clip when the signal exceeds 0 dB; the samples will simply be written in the file as positive dB values. In your DAW, they will appear clipped, but as soon as you adjust the gain, a clean, undistorted waveform is recovered.

Sound Devices and Zoom both refer to this feature as making the recorder virtually unclippable. It is still theoretically possible to exceed the recorder’s dynamic range and clip the signal, but in practice, your microphone will reach its max SPL and distort before the recorder clips.

What does this mean? It means a location sound recordist no longer needs to be quite so careful to avoid clipping. It means it is no longer necessary to create safety tracks. It means limiters are irrelevant (and indeed, the MixPre-10 II disables limiter functionality when in 32-bit float mode).

Be warned, however, that this amazing functionality can be defeated by other devices in the signal chain. Specifically, the dynamic range of radios used for wireless mics can still be a limiting factor. I will have to do some testing to see where the ceiling is. The Sennheiser EW 100 radios I use have a lot more dynamic range than I’ve been using, so 32-bit float still increases the headroom. I’m just not sure how much.

32-bit float WAV files are larger and require more storage.

Anyway, if you were wondering: yes, 32-bit float absolutely works as advertised, and no it is not hype.

Power

The one big disadvantage of this recorder versus the Zoom F4 is power consumption. Depending on configuration, this recorder draws two to three times as much current as the F4. This has a worse than expected impact on battery life.

While it comes with a AA battery sled, Sound Devices doesn’t really expect you to use it. The recorder hates alkaline batteries, because they can’t put out enough current. A fresh set lasts less than an hour. It loves expensive, non-rechargeable lithium batteries, but even with those, battery life is a little more than four hours. My F4 liked NiMH batteries the best, but this recorder only lasts about two and a half hours from a full charge.

One has little choice but to invest in a dedicated high-capacity battery system, which is then connected to the recorder’s 4-pin Hirose DC input.

I ended up purchasing an eSMART battery system, which cost me $660 to get started. That’s two Inspired Energy 98 Wh lithium-ion batteries, an Audioroot charger, and an adapter cable. Following the same testing methodology, a full battery lasted just over twelve hours.

I have been experimenting with the recorder, powered from the included AC adapter, through a power meter, and so far I have discovered the following tips for saving power:

• Turn off unused inputs. Note that disarming the input channel is not enough. Go to the Input setting on the channel menu for each input, where you normally select Mic or Line, and set it to Off.
• Do not leave a USB flash drive connected. Simply having it connected uses a noteworthy amount of power. Instead, connect it occasionally for backups, and at the end of the job to hand off to the client.
• Turn down the LCD and LED brightness. The default is full brightness, which is intended to be useful in full sunlight, but there is a power cost. Indoors, having the LCD turned all the way down and the LEDs set to 2 seems to be sufficient, and it helps reduce the power demand.

User Interface

The user interface on the MixPre is much simpler than the one on the F4. This is partly due to the touch display, and also the usefulness of the Wingman app, but also because the MixPre simply offers fewer configuration choices than the F4. In hindsight, the F4 has numerous configuration choices that no sensible person would ever use.

There is only one configuration item I miss. The MixPre records polyphonic WAV files. That’s it. For film, I don’t care about MP3 or any of that crap, but I know that polyphonic files are frequently a bit of a challenge for inexperienced editors. There’s no option to record isolated tracks to their own files.

Anyway, the menu is laid out sensibly, and it’s easy to figure out how to set things the way you want. In fact, it’s so easy that Sound Devices didn’t bother to document much of it in the User Guide. (I own other products from Sound Devices, and they are all documented better than this; I am surprised by this cutting of corners.)

There is one big annoyance regarding the user-interface. Many functions are controlled using a jog wheel, the same jog wheel that controls the headphone volume, which is located on the side of the unit. When used in a bag (which must be how 95% of their customers use it), this is buried inside where it isn’t easily accessible. No one knows what Sound Devices was thinking, but it’s very inconvenient.

The power switch is similarly inaccessible on the other side. This, at least, seems like it could have some rationale behind it, since you wouldn’t want to accidentally turn the unit off.

Wingman App

The MixPre is intended to be used to be used with an iOS/Android app called Wingman, which connects via Bluetooth. You can, of course, use the recorder without the Wingman app, but then you’re missing out on a major source of simplicity, namely the ability to use the keyboard* to enter metadata. I have only used the Android app.

By metadata, I mean scene name, take number, labels for each track, and notes for the recording. You can edit this on the recorder’s screen, using the jog wheel that is impossible to reach, but no one is going to wait all day for you to scroll around the alphabet, picking one letter at a time.

The MixPre allows you to do one simple but profound thing that the F4 does not: edit metadata in a recording after it has been recorded. Not only can you easily fix things like the scene name, but you can also enter notes about the take after it has been recorded. On the F4, you can only enter notes before the take, which means you can’t make any notes about things that happened during the recording. (F8 users are telling me they can edit metadata on existing recordings, so that is apparently a limitation only to the F4.) This simple capability makes a huge difference because it means the sound report can actually be useful.

Speaking of the sound report, it comes as a CVS file, not an XML file, which means it is easily useful to people who aren’t XML coders.

The Wingman app does lack one simple feature that seems like it should have been obvious. You cannot create or rename the project from the app. This must still be done directly on the recorder, using the jog wheel keyboard, which is that much more painful since this is the only thing you need to do that way. I am hoping Sound Devices will fix this in a future update.

I find the Wingman app to be such a central piece of my workflow that I bought a dedicated tablet to run it on. Why a dedicated tablet? It’s so I don’t have to worry about radio interference, right next to my bag, from the much stronger cellular network radio transmitter in a smartphone. One can’t use airplane mode and still use Bluetooth, and there’s no other way to turn off that radio. A non-cellular tablet eliminates that radio interference.

(* The MixPre does theoretically support USB keyboards directly. I should try that out. However, I’m sure you can see how a USB keyboard would be useful on a cart and not so useful in a bag.)

Connectivity

The MixPre-10 doesn’t have fifty kinds of audio inputs and outputs. Instead, it basically has two of each, but the recorder makes good use of those.

There are eight XLR and 1/4″ TRS combo inputs. On the F4, the XLR is mic level and the TRS is line level. On the MixPre, mic/line level is menu selectable, and either type of connector can be used either way. Both XLR and TRS can be balanced inputs.

There is also a 3.5mm (1/8″) TRS stereo “Aux” input, for channels 9 and 10. This input can be set to mic, line, “camera”, and timecode. The mic mode supplies plug-in power, and it’s intended to be used with consumer-type microphones. The camera mode is intended to be used for camera return audio, and I guess it must operate at headphone level. The timecode mode can be used to input linear timecode audio (I don’t know why anyone would want to do that, given the presence of BNC connectors for that purpose).

That’s it for audio inputs. For outputs, there are two TA3 connectors and a 3.5mm X1/X2 connector.

The TA3 connectors output the left and right mix channels by default. I would have preferred XLR outputs, since that’s what the rest of the world uses. Even though I don’t intend to use them often, I felt obligated to buy a pair of TA3 to XLR adapter cables. They output at a line level, but you can adjust the output gain from -40 to +20 dB. (It’s worth noting that the F4’s XLR outputs, when configured for line level, output at a consumer line level, as used by consumer audio appliances. The MixPre outputs at the level used by professional audio equipment, like sound mixers.) The routing is fully configurable and can output any channel, either pre- or post-fader.

The X1/X2 connector is a 3.5mm stereo TRS connector. Like the TA3 outputs, this outputs at a line level, its output gain is adjustable from -40 to +20 dB, and the routing is fully configurable. I tend to use this output for my IFB transmitter. I have been meaning to test whether I can lower the gain and connect it to the mic input on a DSLR.

None of the rest of the connectors are used for audio. There is a Type-A USB connector, which can be used to connect a flash drive for backing up recordings, a keyboard for entering metadata, or a control surface. It can also be used with a hub to combine all three. There is a separate Type-C USB connector which connects the device to a computer and can also supply power (but not enough power to run all features).

There are two BNC connectors, one for timecode in and one for timecode out. There is a 4-pin Hirose connector for supplying power, using either the supplied AC adapter or an external battery pack or power distribution system. The back has a battery sled attachment, for which Sound Devices sells a few options. There is one SD card slot. There is a micro-HDMI input, which is yet another way to input timecode. The headphone jack is 3.5mm rather than 1/4″.

Overall Impressions

I love this recorder.

For one thing, it just sounds better. I realize this is a totally subjective statement, and I am unable to articulate why or even how it sounds better, but it definitely does. I’m not talking about noise. Every input seems hotter. Not louder, but more dynamic range? There is almost certainly a quantifiable difference in the way the inputs do A/D conversion, but I don’t have the tools or the knowledge to measure or demonstrate it. All I know is that the recordings sound noticeably better.

The 32-bit float recording is huge. It means (almost) never again having to tell the director that I clipped the take he loves, and it has to be re-shot. Heck, it means I barely have to look at the meter.

Going from 4 to 8 inputs won’t really make a big difference for me. However, never having to create a safety track is effectively a big increase in inputs, because on the F4 and F8, each safety track consumes a second input.

Buying the battery system was a drag, but now that I have it, power is one more thing I don’t really need to worry about.

Being able to produce meaningful sound reports is really nice, and it’s one more degree of professionalism I can offer.

The better user-interface is a somewhat intangible improvement, but I know (from screwing around with my old H4n) that if I ever go back to look at the F4, I’ll be disgusted with its clunky and complicated menu.

The bottom line is that I am very happy I made this step upward.