Sound Devices MixPre-6, an in-depth review

Sound Devices released their MixPre series of audio recorders earlier this year, with the MixPre-10 the most recent to have been introduced. We had the opportunity to try out a MixPre-6, a recorder that can handle eight channels.

MixPre recorders are said to be Sound Devices’ entry-level equipment aimed at Youtubers, wedding reporters, documentary makers and also movie professionals. These recorders have the Kashmir pre-amp on board, a pre-amp Sound Devices developed in-house. The Kashmir pre-amp delivers a high-quality sound and it’s one of the main reasons why anyone serious about sound quality should consider this recorder. Only the MixPre-3 records up to 96kHz. From the MixPre-6 upwards, you get a full 192kHz sample rate at a 24-bit depth. Furthermore, the MixPre series uses a 32-bit precision DAC that has a 115dB dynamic range (A-weighted) and its headphone output is of audiophile quality and can be used with any impedance headphones.

Although the MixPre models aren’t as flexible as their high-end siblings in terms of expansion, built-in timecode generators and what have you, they can be triggered by a timecode capable camera such as the Sony A7s and Panasonic GH4 (and GH5 I should imagine) or using wireless timecode equipment like the NanoLockit by Ambient Recording.

If timecode over HDMI doesn’t make you tick, the MixPre-6 also supports HDMI flag, a set of status bits sent in the HDMI data stream that indicates the data stream can be recorded. It’s becoming boring, but if that doesn’t work for you either, the device also lets you synchronise your sound with your video frames via LTC, also known as SMPTE Linear Timecode, the most commonly used standard. Finally, Time of Day can be used instead of a proper timecode as well.

Simply put, the MixPre-6 adapts to whatever environment you throw at it and that’s the first observation I made — I doubt if there is any environment or situation where you would want to record sound and to which the MixPre doesn’t allow 100% adaptation. It will perhaps cost you some effort to find out how it’s done, but you can depend on it that it is possible. Having said that, using a MixPre on the set of a full-blown movie production is probably not going to cut it as you can only record to SD-cards of 512GB max.

Ports, inputs, outputs

My second observation was that a MixPre-6 is surprisingly small and lightweight when powered by its standard four AA cells. It is so small that some buttons — the ones you rarely use, like the On/Off switch — are too small to handle with gloves on. The good news is that all the knobs and buttons you do tend to use regularly while recording are big and robust. Most of them also come with LEDs that change colour according to status or setting. Speaking of batteries, you can power the unit with four AA batteries, for which a sled is delivered in the box. However, there’s also a sled for eight AA cells available and a whole range of products, such as Hawkwoods adapters, Anker chargers, etc, which you can use to power the unit. Included with the device is also a USB-C to mains adapter and a USB-C to USB-A Y cable to transport power as well as data.

The MixPre-6 has four (phantom-power capable) XLR inputs, two channels that accept a mini-jack (Aux — which is also used for LTC), a micro-HDMI port for timecode recordings and a USB port that also accepts input — e.g. from a computer. There’s a total of eight channels to record to. You’ve got four channels for monitoring or plain audiophile quality listening (with the headphones or speakers to match, of course).

Practically all of those ports, channels, buttons and knobs have multiple functions that are all controlled from the brilliant colour LCD screen (which allows readout in sunlight, really!) that gives access to an elaborate menu system. And, although the MixPre-6’s Basic mode is simple enough, the menu system goes pretty deep once you start venturing out into the Advanced and Custom modes. At that point, there are too are many settings hidden behind some buttons not to first read the user guide if you’re new to Sound Devices equipment.

One very minor criticism is that the user guide has clearly gone through an editing phase by the marketing department because the instructions are regularly interspersed with prose, which in my opinion seriously distracts from understanding the capabilities of the product quickly and efficiently.

Of course, the user guide is not what you want to buy the MixPre-6 for. The two major reasons why you would want to do that are the quality of sound and the incredible flexibility that enables you to use this device for almost every conceivable possible audio recording task.

Sound quality

I first tested the MixPre-6 with three microphones — two sE Electronics sE2200a large diaphragm condenser mics and a sE Laser video mic. For all my tests, I put the MixPre-6 in Advanced mode. My first test involved using the three mics, putting each on its own channel. My second test involved using the two sE2200 mics on channel 1 and 2 but in linked mode. This made the first channel knob behave like the fader and the second one like the balance control.

Both recordings resulted in a WAV file that wasn’t recognised by Logic Pro X unless I dragged the file to its tracks window. What I didn’t understand at first was that I inevitably ended up with three tracks of which one was always much quieter than the other two. After having read the user guide for the fourth time, I suddenly realised I was mistakenly doing what you always need to do when working with a software-based audio recording application — you need to arm the channel before recording.

With the MixPre-6, however, arming a channel means you’re actually recording a pre-fade version of the channel to its own isolated (ISO) track. Not arming the channel still gives you three tracks, but the third one is empty. If your DAW still doesn’t recognise such WAV files, you can always remove that extra channel with an app like Myriad from Aurchitect Audio Software or Sound Forge Pro for Mac from Magix Audio.

I kept testing the MixPre-6 under different circumstances, both in the studio and outside. In the studio, one of my experiments involved recording the same audio with one sE2200a plugged into an Apogee Duet iPad/Mac, an old Zoom H4n, an iRig Pro I/O and the MixPre-6. It’s in these tests that I really grew to appreciate the Kashmere pre-amps. The sound you get out of the MixPre-6 is indeed like cashmere — very silky, warm but not overdone, clear and detailed. Comparing some of the recorded results between these three recording technologies, I would place the MixPre-6 on the same level as my trusted Duet. With some recordings, I noticed I preferred the MixPre results for its slightly higher output of low frequencies, with others the Duet’s — exactly for the same reason…

The iRig Pro I/O performed well but fell apart when driven somewhat harder, while the Zoom’s sounded like rubbish and really is only good for amateur usage.

The MixPre-6 has, of course, its own soft limiter and low cut filter. In Advanced mode, you can set the low cut filter to various frequencies as preferred. More importantly, though, is that the MixPre-6 never once recorded distorted signals, not even when setting the gain ridiculously high (76dB, anyone?) and turning the fader up to a level that even a five-year-old would understand only be good to break the recording.


Well, Sound Devices has done an incredibly good job at making an 8-channel field recorder that you can also use as a computer audio interface, with a sound quality that can easily compete with the most expensive equipment around.

The MixPre-6 is truly a joy to work with and has enough capabilities to record any sort of audio — I can easily see it used by small audio teams recording concerts, interviews, nature’s sounds, street noise, anything at all, really, that isn’t too big in terms of production needs.

In absolute terms, at €885 (£829 – $899) it’s not the cheapest device on the market. But if you take into account — as you really should — the number of inputs, its portability, flexibility and quality of build and sound, it’s actually quite inexpensive.