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18i20 3rd Gen specifications

Updated

Performance Specifications

Where possible, we measure all performance figures following AES17.

Supported Sample Rates

44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz

Bit Depth

24-bit

Microphone inputs

Frequency Response

20Hz - 20kHz ± 0.1dB

Dynamic Range (A-weighted)

111dB

THD+N

﹤0.0012%

Noise EIN (A-Weighted)

-128dBu

Maximum Input Level (at minimum gain)

+9dBu

Gain Range

56dB

Input Impedance

3kΩ

Line Inputs

Frequency Response

20Hz - 20kHz ± 0.1dB

Dynamic Range (A-weighted)

110.5dB

THD+N

﹤0.002%

Maximum Input Level (at minimum gain)

22dBu

Gain Range

56dB

Input Impedance

60kΩ

Instrument Inputs

Frequency Response

20Hz - 20kHz ± 0.1dB

Dynamic Range (A-weighted)

110dB

THD+N

<0.03%

Maximum Input Level (at minimum gain)

9dBu

Gain Range

56dB

Input Impedance

1.5MΩ

Line Outputs

Frequency Response

20 Hz - 20 kHz ±0.1 dB

Dynamic Range (A-weighted)

108dB

THD+N

<0.002%

Maximum Output Level

+15.5dBu

Output impedance

430Ω

Headphone Outputs

Frequency Response

20 Hz - 20 kHz ±0.1 dB

Dynamic Range (A-weighted)

104dB

THD+N

﹤0.002%

Maximum Output Level

7dBu

Output impedance

<1Ω

Physical and Electrical Characteristics

Analogue Inputs 1 & 2

Connectors

XLR Combo type: Mic/Line/Inst, on front panel

Mic/Line switching

Automatic

Line/Instrument switching

2 x front panel switches or via Focusrite Control 2

Pad

10 dB attenuation, selected per channel from Focusrite Control 2

Phantom power

Shared +48 V phantom power switch for inputs 1 to 4

AIR function

Selected per channel from Focusrite Control 2

Analogue Inputs 3 to 8

Connectors

XLR Combo: Mic/Line, on rear panel

Mic/Line switching

Automatic

Pad

10 dB attenuation, selected per channel from Focusrite Control 2

Phantom power

Shared +48 V phantom power switches for inputs 1 to 4 and 5 to 8

AIR function

Selected per channel from Focusrite Control 2

Analogue Outputs

Main outputs

10 x balanced ¼” TRS jacks on rear panel

Stereo headphone outputs

2 x ¼” TRS jack on front panel

Main monitor output level control

On front panel

Headphones level controls

Other I/O

Optical I/O

4 x TOSLINK optical connectors; 8 channels @ 44.1/48 kHz or 4 @ 88.2/96 kHz

S/PDIF I/O

2 x phono (RCA) or via Optical I/O (selected via Focusrite Control 2)

Word clock output

BNC connector

USB

1 x USB 2.0 Type C connector

MIDI I/O

2 x 5-pin DIN sockets

Front Panel indicators

USB/Power

Green LED

Phantom power

2 x red LEDs (Chs 1-4, 5-8)

Instrument mode

2 x red LEDs (Chs 1 & 2)

AIR mode

8 x yellow LEDs

Pad active

8 x green LEDs

MIDI data received

Green LED

Lock indicator

Green LED

Talkback active

Green LED

ALT speakers selected

Green LED

Monitors DIM and MUTE

Yellow LED (DIM); red LED (MUTE)

Weight and Dimensions

W × D × H

482.6 mm x 46.6 mm (1U) x 259.8 mm

19 in x 1.83 in (1U) x 10.23 in

Weight

3.195 kg

7.16 lb

Channel listing tables

The 18i20’s inputs and outputs appear in Focusrite Control 2 with different channel numbers depending on the sample rate being used. The channel numbers also vary when the optical ADAT ports are in use, depending on which Digital I/O Mode you select (see Digital I/O Modes below).

Digital I/O modes

The 18i20 supports three Digital I/O modes: these are selected from the Device Settings pane of Focusrite Control 2. The modes determine how the audio inputs and outputs are mapped to the optical (ADAT) ports and the S/PDIF input and output coaxial (RCA) sockets.

Mode 1: Coaxial (RCA) S/PDIF

This is the factory default mode, and your 18i20 will adopt these assignments “out-of-the- box”. Use this mode if you need a coaxial S/PDIF audio input, or if you wish to use a coaxial S/PDIF signal as a clock source.

Digital port

Sample rate (kHz)

44.1/48

88.2/96

176.4/192

Inputs

S/PDIF IN

S/PDIF

S/PDIF

S/PDIF

OPTICAL IN 1

ADAT 1-8

ADAT 1-4

x

OPTICAL IN 2

x

x

x

Outputs

S/PDIF OUT

S/PDIF

S/PDIF

S/PDIF

OPTICAL OUT 1

ADAT 1-8

ADAT 1-4

x

OPTICAL OUT 2

ADAT 1-8

ADAT 1-4

x

Mode 2: Optical S/PDIF

Select this mode when you are working at 44.1/48 or 88.2/96 kHz sample rate, and you need to send or receive an S/PDIF signal via an optical port. Also use this mode if you want to use a clock source sent as an optical S/PDIF signal.

Digital port

Sample rate (kHz)

44.1/48

88.2/96

176.4/192

Inputs

S/PDIF IN

x

x

x

OPTICAL IN 1

ADAT 1-8

ADAT 1-4

x

OPTICAL IN 2

S/PDIF

S/PDIF

x

Outputs

S/PDIF OUT

S/PDIF

S/PDIF

S/PDIF

OPTICAL OUT 1

ADAT 1-8

ADAT 1-4

x

OPTICAL OUT 2

S/PDIF

S/PDIF

x

Mode 3: Dual ADAT

Select this mode when you need more than four ADAT input and/or output channels when working at

Digital port

Sample rate (kHz)

44.1/48

88.2/96

176.4/192

Inputs

S/PDIF IN

x

x

x

OPTICAL IN 1

ADAT 1-8

ADAT 1-4

x

OPTICAL IN 2

x

ADAT 5-8

x

Outputs

S/PDIF OUT

S/PDIF

S/PDIF

S/PDIF

OPTICAL OUT 1

ADAT 1-8

ADAT 1-4

x

OPTICAL OUT 2

ADAT 1-8

ADAT 5-8

x

The tables below list how the 18i20’s inputs and outputs appear in Focusrite Control 2 for each of the three Optical I/O modes, at each of the three sample rate pairs. Note that the first digit in the entries relating to the ADAT channels refers to the port in use: so “ADAT 1.1” to “ADAT 1.4” are ADAT Chs 1 to 4 at the right-hand port of each pair, while “ADAT 2.1” to “ADAT 2.4” are ADAT Chs 5 to 8 at the left-hand port of each pair.

At 44 .1 kHz and 48 kHz sample rates:

INPUTS

DIGITAL I/O MODE

COAXIAL S/PDIF

OPTICAL S/PDIF

DUAL ADAT

Input 1

Input 1

Input 1

Input 1

Input 2

Input 2

Input 2

Input 2

Input 3

Input 3

Input 3

Input 3

Input 4

Input 4

Input 4

Input 4

Input 5

Input 5

Input 5

Input 5

Input 6

Input 6

Input 6

Input 6

Input 7

Input 7

Input 7

Input 7

Input 8

Input 8

Input 8

Input 8

Loopback 1

Loopback 1

Loopback 1

Loopback 1

Loopback 2

Loopback 2

Loopback 2

Loopback 2

Digital In 1

S/PDIF 1

(via coax socket)

S/PDIF 1

(via optical port)

x

Digital In 2

S/PDIF 2

(via coax socket)

S/PDIF 2

(via optical port)

x

Digital In 3

ADAT 1.1

ADAT 1.1

ADAT 1.1

Digital In 4

ADAT 1.2

ADAT 1.2

ADAT 1.2

Digital In 5

ADAT 1.3

ADAT 1.3

ADAT 1.3

Digital In 6

ADAT 1.4

ADAT 1.4

ADAT 1.4

Digital In 7

ADAT 1.5

ADAT 1.5

ADAT 1.5

Digital In 8

ADAT 1.6

ADAT 1.6

ADAT 1.6

Digital In 9

ADAT 1.7

ADAT 1.7

ADAT 1.7

Digital In 10

ADAT 1.8

ADAT 1.8

ADAT 1.8

OUTPUTS

DIGITAL I/O MODE

COAXIAL S/PDIF

OPTICAL S/PDIF

DUAL ADAT

Output 1

Output 1

Output 1

Output 1

Output 2

Output 2

Output 2

Output 2

Output 3

Output 3

Output 3

Output 3

Output 4

Output 4

Output 4

Output 4

Output 5

Output 5

Output 5

Output 5

Output 6

Output 6

Output 6

Output 6

Output 7

Output 7

Output 7

Output 7

Output 8

Output 8

Output 8

Output 8

Output 9

Output 9

Output 9

Output 9

Output 10

Output 10

Output 10

Output 10

Output 11

S/PDIF 1

(via coax socket)

S/PDIF 1

(via coax socket and optical port)

S/PDIF 1

(via coax socket)

Output 12

S/PDIF 2

(via coax socket)

S/PDIF 2

(via coax socket and optical port)

S/PDIF 2

(via coax socket)

Output 13

ADAT 1.1

ADAT 1.1

ADAT 1.1

Output 14

ADAT 1.2

ADAT 1.2

ADAT 1.2

Output 15

ADAT 1.3

ADAT 1.3

ADAT 1.3

Output 16

ADAT 1.4

ADAT 1.4

ADAT 1.4

Output 17

ADAT 1.5

ADAT 1.5

ADAT 1.5

Output 18

ADAT 1.6

ADAT 1.6

ADAT 1.6

Output 19

ADAT 1.7

ADAT 1.7

ADAT 1.7

Output 20

ADAT 1.8

ADAT 1.8

ADAT 1.8

At 88.2kHz and 96kHz sample rates:

INPUTS

DIGITAL I/O MODE

COAXIAL S/PDIF

OPTICAL S/PDIF

DUAL ADAT

Input 1

Input 1

Input 1

Input 1

Input 2

Input 2

Input 2

Input 2

Input 3

Input 3

Input 3

Input 3

Input 4

Input 4

Input 4

Input 4

Input 5

Input 5

Input 5

Input 5

Input 6

Input 6

Input 6

Input 6

Input 7

Input 7

Input 7

Input 7

Input 8

Input 8

Input 8

Input 8

Loopback 1

Loopback 1

Loopback 1

Loopback 1

Loopback 2

Loopback 2

Loopback 2

Loopback 2

Digital In 1

S/PDIF 1

(via coax socket)

S/PDIF 1

(via optical port)

ADAT 1.1

Digital In 2

S/PDIF 2

(via coax socket)

S/PDIF 2

(via optical port)

ADAT 1.2

Digital In 3

ADAT 1.1

ADAT 1.1

ADAT 1.3

Digital In 4

ADAT 1.2

ADAT 1.2

ADAT 1.4

Digital In 5

ADAT 1.3

ADAT 1.3

ADAT 2.1

Digital In 6

ADAT 1.4

ADAT 1.4

ADAT 2.2

Digital In 7

x

x

ADAT 2.3

Digital In 8

x

x

ADAT 2.4

OUTPUTS

DIGITAL I/O MODE

COAXIAL S/PDIF

OPTICAL S/PDIF

DUAL ADAT

DUAL ADAT OUTPUT PRESET*

Output 1

Output 1

Output 1

Output 1

Output 1

Output 2

Output 2

Output 2

Output 2

Output 2

Output 3

Output 3

Output 3

Output 3

Output 3

Output 4

Output 4

Output 4

Output 4

Output 4

Output 5

Output 5

Output 5

Output 5

Output 5

Output 6

Output 6

Output 6

Output 6

Output 6

Output 7

Output 7

Output 7

Output 7

Output 7

Output 8

Output 8

Output 8

Output 8

Output 8

Output 9

Output 9

Output 9

Output 9

Output 9

Output 10

Output 10

Output 10

Output 10

Output 10

Output 11

S/PDIF 1

(via coax socket)

S/PDIF 1

(via coax socket and optical port)

S/PDIF 1

(via coax socket)

ADAT 1.1

Output 12

S/PDIF 2

(via coax socket)

S/PDIF 2

(via coax socket and optical port)

S/PDIF 2

(via coax socket)

ADAT 1.2

Output 13

ADAT 1.1

ADAT 1.1

ADAT 1.1

ADAT 1.3

Output 14

ADAT 1.2

ADAT 1.2

ADAT 1.2

ADAT 1.4

Output 15

ADAT 1.3

ADAT 1.3

ADAT 1.3

ADAT 2.1

Output 16

ADAT 1.4

ADAT 1.4

ADAT 1.4

ADAT 2.2

Output 17

x

x

ADAT 2.1

ADAT 2.3

Output 18

x

x

ADAT 2.2

ADAT 2.4

Output 19

x

x

x

x

Output 20

x

x

x

x

*To obtain eight ADAT output channels, please select Focusrite Control 2’s DUAL ADAT OUTPUT preset.

At 176.4kHz and 192kHz sample rates:

INPUTS

DIGITAL I/O MODE

COAXIAL S/PDIF

OPTICAL S/PDIF

DUAL ADAT

Input 1

Input 1

Input 1

Input 1

Input 2

Input 2

Input 2

Input 2

Input 3

Input 3

Input 3

Input 3

Input 4

Input 4

Input 4

Input 4

Input 5

Input 5

Input 5

Input 5

Input 6

Input 6

Input 6

Input 6

Input 7

Input 7

Input 7

Input 7

Input 8

Input 8

Input 8

Input 8

Loopback 1

Loopback 1

Loopback 1

Loopback 1

Loopback 2

Loopback 2

Loopback 2

Loopback 2

Digital In 1

S/PDIF 1

(via coax socket)

S/PDIF 1

(via optical port)

ADAT 1.1

Digital In 2

S/PDIF 2

(via coax socket)

S/PDIF 2

(via optical port)

ADAT 1.2

Digital In 3

ADAT 1.1

ADAT 1.1

ADAT 1.3

Digital In 4

ADAT 1.2

ADAT 1.2

ADAT 1.4

Digital In 5

Digital In 5

ADAT 1.3

ADAT 1.3

ADAT 2.1

Digital In 6

ADAT 1.4

ADAT 1.4

ADAT 2.2

Digital In 7

x

x

ADAT 2.3

Digital In 8

x

x

ADAT 2.4

OUTPUTS

DIGITAL I/O MODE

COAXIAL S/PDIF

OPTICAL S/PDIF

DUAL ADAT

DUAL ADAT OUTPUT PRESET*

Output 1

Output 1

Output 1

Output 1

Output 1

Output 2

Output 2

Output 2

Output 2

Output 2

Output 3

Output 3

Output 3

Output 3

Output 3

Output 4

Output 4

Output 4

Output 4

Output 4

Output 5

Output 5

Output 5

Output 5

Output 5

Output 6

Output 6

Output 6

Output 6

Output 6

Output 7

Output 7

Output 7

Output 7

Output 7

Output 8

Output 8

Output 8

Output 8

Output 8

Output 9

Output 9

Output 9

Output 9

Output 9

Output 10

Output 10

Output 10

Output 10

Output 10

Output 11

S/PDIF 1

(via coax socket)

S/PDIF 1

(via coax socket and optical port)

S/PDIF 1

(via coax socket)

ADAT 1.1

Output 12

S/PDIF 2

(via coax socket)

S/PDIF 2

(via coax socket and optical port)

S/PDIF 2

(via coax socket)

ADAT 1.2

Output 13

ADAT 1.1

ADAT 1.1

ADAT 1.1

ADAT 1.3

Output 14

ADAT 1.2

ADAT 1.2

ADAT 1.2

ADAT 1.4

Output 15

ADAT 1.3

ADAT 1.3

ADAT 1.3

ADAT 2.1

Output 16

ADAT 1.4

ADAT 1.4

ADAT 1.4

ADAT 2.2

Output 17

x

x

ADAT 2.1

ADAT 2.3

Output 18

x

x

ADAT 2.2

ADAT 2.4

Output 19

x

x

x

x

Output 20

x

x

x

x

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