A workhorse that has paid for itself many times over

The Focusrite Scarlett 18i20 is a professional-grade audio interface that combines extensive I/O capabilities with solid technical performance. This 1U rack-mountable interface is positioned for professional studios, project studios and live recording environments needing multiple simultaneous inputs and outputs.

I've mixed audio projects for worldwide TV broadcast using this interface, and it's earned me many times over what I paid for it. My unit and this review are the 3rd Generation; the Amazon listing is the current generation of the same interface.

Focusrite Scarlett 18i20 rack-mount audio interface front panel

The details

  • Format: 1U 19-inch rack-mount USB audio interface
  • Preamps: 8 microphone preamps with phantom power and pads
  • Inputs: 8 line inputs, 2 dedicated instrument inputs
  • Outputs: 10 analogue outputs, dual headphone outputs
  • Digital: dual ADAT and S/PDIF, MIDI I/O
  • Connection: USB-C (USB 2.0 protocol)
  • Power: external mains supply
  • Amazon ASIN: B0D7YFNMRG

Professional features

  • Main/Alt speaker switching
  • Built-in talkback system
  • Loopback for streaming and podcasting
  • Hardware input pads on all preamps
  • External power supply for clean power delivery

The preamps

The eight microphone preamps offer professional-grade specifications: a clean gain path with a 56dB range, a very low noise floor (-128dBu EIN A-weighted), excellent THD+N (under 0.0012%) and a flat 20Hz - 20kHz response within 0.1dB. The line inputs and instrument inputs are equally well-behaved, with high input impedances and strong dynamic range throughout.

Where it excels

  • Professional studios: multiple simultaneous inputs, ADAT expansion, and proper monitoring control with speaker switching.
  • Project studios: comprehensive I/O and quality preamps for multiple sources.
  • Live recording: rack-mountable, pads on every preamp, reliable USB connection.
  • Podcast production: talkback, loopback and dual headphone outputs cover a multi-guest session neatly.

Where it's less suitable

  • Mobile recording: it needs mains power.
  • Basic home studios: potentially excessive I/O if you only need a couple of channels.
  • Ultra-critical applications: the specs are thoroughly professional but not class-leading in every metric.

Verdict

The Scarlett 18i20 is a solid choice for anyone needing lots of I/O in a reliable, well-featured interface for multitrack recording, live recording and studio work. Practical touches like talkback, speaker switching and hardware pads on every channel show a clear understanding of real-world studio needs. A workhorse in the best sense, and mine has more than earned its keep.