MOTU 848 — a Thunderbolt 4 / USB4 audio interface with 4 microphone inputs

The American company MOTU demonstrates its technical strengths with a family of professional rackmount recording interfaces and modern workstation connections. The range includes AVB Ethernet for Mac and Thunderbolt 4 / USB4 for very low latency of 2 ms. Standard USB2 and USB3 remain supported when the maximum channel count is not needed. All interfaces in the new MOTU range have built-in DSP for audio processing. The mixer can be controlled conveniently from a computer or iPad application.

The MOTU 828, released a year earlier, targets a similar audience. How does the 848 differ? The 828 has 2 microphone preamps; the 848 has twice as many, at 4. The 828 has no AVB ports for networking interfaces over Ethernet. The 848 also has two Thunderbolt 4 / USB-C ports for chaining up to 6 devices, while the 828 has only one USB-C port. The less expensive 828 is therefore more suitable for individual users. The 848 is intended for larger commercial recording studios.

MOTU 848 key features

• Advanced computer connections: AVB Ethernet, Thunderbolt 4 / USB4
• 60 simultaneous audio channels: 28 inputs and 34 outputs
• 3.9-inch, 24-bit RGB LCD, 480 × 128 pixels, with accurate peak meters
• High analogue audio performance using ESS Sabre32 Ultra DACs
• High-performance MOTU drivers with very low latency: 1.8 ms round-trip latency (RTL) at 96 kHz with a 32-sample buffer
• Flexible connection through the supplied 40 Gbit/s USB-C cable, compatible with USB4, USB3 and USB2
• DSP-based digital mixer with 64 inputs, 32 buses and DSP effects: reverb, 4-band EQ, gate, compressor and high-pass filter, operating at sample rates up to 96 kHz
• Advanced microphone channels with high-quality components: THD+N below −114 dB, 118 dBA dynamic range and −129 dBu equivalent input noise (EIN). Each microphone channel has individual gain up to +74 dB, a −20 dB pad, +48 V phantom power and polarity inversion. All settings can be controlled remotely from a computer or an iOS device. Microphone inputs 3–4 have send/return inserts for external processing.
• Dolby Atmos: 12 outputs support 7.1.4 Dolby Atmos monitoring
• A clear Patchbay interface with virtual patch cables for routing any source to any destination
• 2 Gigabit Ethernet ports with AVB support
• Wi-Fi control from CueMix Pro on several mobile devices
• Precise analogue input/output level adjustment in 1 dB steps
• Control-room functions on the front panel: Talkback, A/B/C monitor selection, Mute and mono compatibility check
• Two flexible headphone outputs with independent volume controls. Each can monitor the other headphone output, the main outputs, any other analogue output pair, any mixer bus or any computer playback channels. Independent submixes and reverb are supported.
• Two optical I/O banks provide 16 ADAT channels at 44.1/48 kHz or 8 S/MUX channels at 88.2/96 kHz. Bank A can alternatively provide stereo TOSLink I/O at up to 96 kHz.
• Word clock input, output and thru at up to 192 kHz
• DC-coupled TRS outputs can send control voltage (CV) from the DAW to modular synthesizers
• Guitar reamping: connect a guitar to the front input and route the signal through CueMix to any output with virtually no latency. Use a reamping adapter if needed. Record both the clean guitar signal and a microphone in front of the guitar amplifier at the same time.
• Loopback for live streaming and podcasts
• Advanced front-panel metering with selectable views for analogue I/O, digital I/O and other channel combinations
• CueMix Pro mixer and hardware control from Mac, PC or iOS
• Performer Lite DAW software with more than 100 instruments, dozens of effects and 6 GB of loops for music production

The current MOTU range uses strong aluminium cases with metal knobs. Two bright 3.9-inch colour TFT displays provide metering in several viewing modes. Rack ears are included, and the case is 1U high.

The MOTU 848 connects to a Mac, PC or iOS device through the supplied high-quality USB4 cable, compatible with Thunderbolt 3/4. Full backward compatibility with USB3 and USB2 is provided. Two Thunderbolt 4/USB4 Type-C ports allow up to 6 devices to be connected in a chain. The AVB Gigabit Ethernet connection works only with Apple computers.

The total digital channel count is 256: 128 inputs and 128 outputs. Round-trip latency is 1.8 ms at 96 kHz with a 32-sample buffer. There are 12 balanced analogue inputs, including 4 microphone inputs, and 12 TRS line outputs. Two banks of 8-channel ADAT optical I/O are available. BNC word clock input and output, with optional Thru, provide external synchronisation.

The table lists input and output performance and maximum signal levels:

The analogue outputs use ESS Sabre32 DACs and achieve a measured dynamic range of 125 dB with THD+N of −114 dB. All input and output levels are adjustable in 1 dB steps.

The figures match those of the MOTU 828 and the MOTU 16A models released in 2025 because the electronics are similar.

The large TI Sitara 5716 ARM Cortex-A15 processor is still used. Audio processing runs on its TI C66x DSP using VLIW floating-point operations.

The outputs use the 8-channel ESS ES9026PRO DAC familiar from other MOTU interfaces. Some competing products use a separate, cheaper DAC for headphones. Here, two ESS ES9026PRO chips serve both the line and headphone outputs. Their specifications are 124 dBA dynamic range and −110 dB THD+N. TI OP1678 dual operational amplifiers are used at the inputs and outputs.

Two ADC chips are fitted: an 8-channel AKM AK5578 and a 4-channel AKM AK5574. Both have the same specifications: 121 dBA dynamic range and THD+N below −112 dB.

An OPA1688A integrated amplifier drives the headphones. Additional circuitry raises the output level to +13.3 dBu and reduces output impedance to 1 ohm.

As usual, the microphone preamps use the analogue PGA2500 with digitally controlled input gain. Equivalent input noise is −128 dBu. THD+N at 30 dB gain is only 0.0004%. Gain up to +74 dB allows even very low-sensitivity microphones to be used.

CueMix Pro provides the same clear user interface for all MOTU devices.

Hardware settings for the selected device include clock source and mixer sample rate. Effects can be used at sample rates up to 96 kHz.

On the MOTU 848, input settings can be changed in CueMix Pro or with the physical buttons below the front-panel gain knobs.

Each connection has its own peak meter and rotary level control. These controls adjust the hardware levels rather than the mixer faders. A selectable source for the headphone output is also convenient.

Patchbay provides a visual way to connect physical sources and virtual DAW channels.

The mixer in CueMix Pro provides 32 buses, plus main, reverb, monitor and solo buses. All mixer inputs and output buses have a double-precision 4-band parametric equaliser and a compressor. These are available at all sample rates up to 96 kHz.

The Routing view shows a conventional routing matrix.

The MIXING tab has familiar faders and lets users create a submix for an available bus. Each channel has its own EQ and dynamics settings. Reverb runs on a separate effects bus, with settings shared by all channels. All effects are good enough for practical use.

We measured round-trip latency with a 64-sample buffer at 44 kHz. Our USB3.0 connection gave 5.8 ms. At 96 kHz with a small 32-sample ASIO buffer, latency can fall to 2 ms.

The manufacturer includes a Thunderbolt 4 / USB4 cable marked 40 Gbps 240W. We decided to test this connection. We installed an ASUS ThunderboltEX 4 expansion card in a Windows 11 desktop computer and enabled Thunderbolt in the BIOS. When powered on, the MOTU 848 detected Thunderbolt and displayed TB beside HOST and the computer icon.

Thunderbolt Control Center in Windows also detected the MOTU Thunderbolt device. The operating system listed MOTU Pro Audio v2 (Thunderbolt Audio).

CueMix Pro started and worked normally, exactly as it does with a standard USB connection.

We measured RTL and obtained the manufacturer's advertised 1.8 ms. Would professional ASIO software work at those settings without clicks? Both playback and recording worked perfectly in our tests. Our system has a powerful CPU and is optimised for audio. Hardware power-saving features that can slow real-time work, including C-states and core parking, are disabled.

ASIO diagnostics

The device provides 12 analogue and 16 digital channels. Sample rates up to 192 kHz are supported.

RMAA PRO measurements

We measured the interface with its outputs connected to its inputs.

24-bit / 44 kHz measurements are provided on a separate page. The results confirm the published high performance and agree with our measurements of other MOTU interfaces.

The MOTU 848's functions are well designed for everyday studio work. The large colour displays make it easy to monitor all channel levels at once. Brightness is adjusted in the built-in menu using a dedicated encoder and two buttons. CueMix Pro becomes more attractive and easier to use with each version.

Recording and playback quality is as high as on the other MOTU models. We listened through active monitors and headphones and were pleased with the natural tone and dynamics. The hardware input effects are very good and can match standard DAW processing. Importantly, the effects add no latency and do not use the computer's CPU.

Conclusions

The MOTU 848 is well suited to large commercial studios that need many channels, interfaces placed in different locations and central control. The digital platform supports Thunderbolt 4 / USB4. Several interfaces can also be joined in an AVB network using ordinary Category 5 twisted-pair cable. Even a standard USB connection provides low latency. Thunderbolt reduces latency to as little as 1.8 ms at 96 kHz. Our tests showed stable operation even with a very small buffer.

For medium-size studios, the 12 TRS inputs and 12 TRS outputs are useful. The advanced internal routing can replace an external analogue patchbay. Signal processing is another strength. The interface can replace a basic 12-channel mixer and supports insert connections for analogue processors and synthesizers. The high-quality studio electronics make this a practical replacement for older equipment.

The MOTU 848 offers a balanced mix of microphone inputs and analogue outputs. If you need more microphone preamps, or none at all, consider the otherwise similar MOTU 10pre and MOTU 16A. These provide alternative I/O configurations.

Note. This is an adapted machine translation into English. It follows the “In simple terms” approach. Read the original article at https://prosound.ixbt.com/interfaces/motu-848.shtml.