Scarlett 18i16 hardware features

The 3-pin XLR Input connectors are designed to accept at microphone level signals.

You can control your microphone level using the corresponding input gain control on the front panel. 48V phantom power is also available if you are using a condenser mic, you can enable phantom power using the front panel 48V button.

You can enable 48V phantom power on a per-channel basis.

The preamp input gain controls how much signal you are sending into your computer and recording software.

It's essential to set a good level for the preamp input gain so you get the best quality recording. If the preamp input gain is too low, your signal will be too quiet and when you try to boost its level later you may hear noise in the recording; if the preamp input gain is too high you might 'clip' the input and hear harsh distortion in your recording.

To increase the input gain, turn the gain control clockwise. As you move the gain control, the Gain Halo gradually lights clockwise to show you the gain level. This diagram shows the gain at various levels:

When you adjust your input gain while you send a signal into your preamp, the ring lights the same way as above but a colour, green, amber, or red, shows how much level is going into your computer. Shortly after you stop adjusting the gain the meters revert to input meters (see Input Metering).

Software Gain Control

You can also control the preamp gain remotely using Focusrite Control 2.

To adjust the preamp gain in Focusrite Control 2:

1. Click the virtual knob for the channel you'd like to adjust or use the tab key to select the preamp gain control.

2. Move your mouse up and down or use the arrow keys to increase or decrease the gain (in ±1dB increments).

The following images show the preamp gain at minimum, medium and maximum gain.

No input gain

50% Gain

100% Gain

Input Metering

When you're not moving the input gain control the input metering uses the entire Gain Halo. As the incoming signal gets louder (for example with a higher input gain setting) the Gain Halo lights from green through to amber before the entire Gain Halo flashes red to show you the input has clipped.

This diagram shows the meters at different levels to show the input signal level:

1. No input signal

2. -42 dBFS

3. -36 dBFS

4. -24 dBFS

5. -18 dBFS

6. -12 dBFS

7. -6 dBFS

8. 0 dBFS, clipping - turn down the input gain to avoid distortion and clipping.

Tip

If your signal clips the clip indicator at the top of the meter lights red. If this happens, select that channel and reduce the gain.

Software Metering

In the same way as the input meters on your Scarlett 18i16's front panel, you can see the incoming signal on the meters in Focusrite Control 2 to set the correct preamp gain.

As the signal gets louder, the meter in Focusrite Control 2 lights from green to amber (pre-clip).

The indicator above the meter shows you the peak level (in -dBFS), the highest level on this track since you started monitoring the input. When you hover over the Peak level meter, you can click to Reset the value.

Tip

When you're recording, it's a good idea to aim for a -12dBFS peak level. This ensures you have enough headroom when you've recorded all your tracks.

Waiting for an input signal.

-18dB input signal.

Click to Reset the Peak Level meter.

When you overload the preamp, with too much input signal, or by adding too much gain, the Peak Level Meter lights red. Hover over the Peak Level Meter and click to Reset the value.

The Input has clipped.

Click to Reset the Peak Meter.

Many front panel controls on your Scarlett 18i16 are shared across the preamp inputs. The Select button moves the preamp controls to different inputs.

At least one preamp is always selected, to change which preamp(s) the controls are affecting, press the Select button. When you do this, the newly selected preamp's number lights green and the preamp setting lights change to match the new preamp.

When you turn on your Scarlett 18i16 the last selected preamp before you turned it off remains the selected preamp.

Linking preamps allows you to control two preamps simultaneously using one set of preamp controls. You can match gain controls for two preamps and enable other preamp controls. This is useful for stereo recording, for example, a microphone pair, stereo synthesiser, or keyboard.

When you've made the Preamp Link :

48V, also commonly referred to as 'Phantom Power', sends 48 Volts from your interface's XLR connector to devices needing power to work. The most common use is sending power to condenser microphones, but you may also need 48V for inline mic preamps, active dynamic microphones and active DI boxes.

To turn on 48V:

The 48V icon lights green to show it is enabled.

48V phantom power is now being sent to the selected XLR input and to any devices connected to the XLR input.

48V (Phantom Power) Software Control

To enable 48V (Phantom Power) from Focusrite Control 2 click the +48V button for the input you want to enable it on. This is the same as pressing the 48V button on the Scarlett 18i16 hardware.

+48V Phantom Power off

+48V Phantom Power on

Inst, or instrument, changes the impedance and input level of the 6.35mm (1/4") jack inputs on your Scarlett so the inputs sound their best for either an instrument or line-level source. We list the input impedance values in the Specifications section. If you don't turn on Inst and connect an electric guitar, the resulting sound can be muddy and quiet compared to with Inst on.

The Inst (Instrument) button only affects the 6.35mm (1/4") line input for the selected channel, either input 1 or input 2. It changes it from an input suitable for line-level devices to an input better suited for instrument-level devices.

To enable, or disable, instrument mode for the 6.35mm (1/4") jack input, select the channel and press the Inst button once. Green shows Inst is enabled, and white shows Inst is disabled. When you enable Inst and connect a jack to your Scarlett, the minimum gain for the input is changed to +7dB.

When Inst is enabled (green) you can connect instrument-level devices to the 1/4" inputs such as, but not limited to:

When Inst is disabled (white) you can connect line-level devices to the 6.35mm (1/4") inputs such as, but not limited to:

Instrument/Line Software Control

To change inputs 1 or 2 between instrument and line from Focusrite Control 2 click the Inst button once.

Line	Instrument

Air lets you change your Scarlett's preamp sound with two different modes; Air Presence or Air Presence and Harmonic Drive.

Air affects the mic, line, and instrument inputs.

To enable Air, select your input, press the Air button once for Air Presence, again for Air Presence and Harmonic Drive and again to turn off. The Air LED changes colour to show which mode you have selected:

Air Software Control

To enable AIR from Focusrite Control 2 click the Air button. This is the same as pressing the Air button on the Scarlett 18i16 hardware.

Air Off

Air Presence selected

Air Presence and Drive selected

When you click Focusrite Control 2's Air button, the last selected Air mode becomes activated. To change the selected Air mode (Presence or Presence and Drive) click the arrow to show the dropdown menu.

Air Presence selected

Air Presence and Drive selected

Auto Gain allows you to send a signal into your Scarlett 18i16 (for example singing or playing your instrument) for 10 seconds and let the Scarlett set a good level for your preamps. If you find the levels aren't right, you can adjust the gain controls manually to fine-tune the levels before recording.

To use Auto Gain:

If the Auto Gain was successful, the meter lights green before the gain value is shown for a second. The gain is now set at a good level for your recording.

If Auto Gain fails, the Gain Halo lights red. Please see the section, The Gain Halo turned Red, for more information.

Auto Gain Software Control

To use Auto Gain in Focusrite Control 2:

1. Click the Auto Gain button in Focusrite Control 2.

2. Speak or sing into the microphone, or play your instrument during the Auto Gain countdown. Perform as you would while you're recording to make sure Auto Gain sets a good level.

   The Auto Gain process starts and the software Gain halo turns into a countdown timer.

If the Auto Gain was successful, the meter lights green before the gain value is shown for a second. The gain is now set at a good level for your recording.

Auto Gain failed and the gain halo turned red

If the input signal is unsuitable for Auto Gain (for example there's no signal detected), after ten seconds, Auto Gain stops and the Gain Halo lights red for a second. The gain returns to the value you set before starting Auto Gain.

Hardware Gain Halo

Focusrite Control 2 Auto Gain unsuccessful

Before running Auto Gain again, make sure your input has something connected to it correctly, if you're using a condenser microphone, 48V is on, and you are making sound while Auto Gain runs.

Auto Gain allows you to send a signal into your Scarlett 18i16 (for example singing or playing your instrument) for 10 seconds and let the Scarlett set a good level for your preamps. If you find the levels aren't right, you can adjust the gain controls manually to fine-tune the levels before recording.

Multichannel Auto Gain starts the Auto Gain process for all the preamp channels on your interface. This is particularly useful for quickly setting levels for situations where you are using multiple channels simultaneously, for example:

To start the multichannel Auto Gain process:

If the Auto Gain was successful, the Gain Halos light green before the gain value is shown on the Gain Halos for a second. The gain is now set at a good level for your recording.

Multichannel Auto Gain in Focusrite Control 2

You can also run multichannel Auto Gain from within Focusrite Control 2. To do this:

1. Open Focusrite Control 2 and go to the Inputs tab.

2. Click the dropdown arrow to the right of the usual Auto Gain button.

3. Choose Auto Gain all or Auto Gain multiple….

   • Auto Gain all starts running Auto Gain for all the channels on your Scarlett 18i16.

   • Auto Gain multiple allows you to choose the channels you want to run Auto Gain for.

4. If you clicked Auto Gain multiple, tick the channels you want to run Auto Gain for.

5. Click Start Auto Gain.

Once Auto Gain has finished, Focusrite Control 2 shows the channels that have been set and their new gain levels:

All Channels

Multiple Channels

Multichannel Auto Gain failed

Multichannel Auto Gain might fail during the process for one, multiple, or all channels. If this happens, you'll see one of two messages:

If Auto Gain fails for all channels, you'll see the Auto Gain failed message.

If Auto Gain fails for one or some channels, you'll see the Auto Gain complete message, but with the option to Retry Auto Gain on all channels.

You can either:

• Click Retry and all Auto Gain runs again for all the channels you ran Auto Gain for, even the successful channels.

• Click close and run Auto Gain for any failed channels.

• Click close and manually adjust the gain for any failed channels.

The Safe button applies Clip Safe, which automatically adjusts your preamp gain if you're at risk of clipping.

Clipping happens when your gain is set too high for the sound being recorded and your input overloads the preamp. A clipping symptom is preamp distortion, which is often unpleasant and can ruin a recording. Clip Safe helps you avoid this so if your input gets near to clipping, Clip Safe reduces the preamp gain, so you won't have to re-record your take.

To enable Clip Safe:

When you enable Safe, the Safe icon lights green.

When you have two inputs selected using Preamp Link, Safe is applied to both preamps.

Clip Safe Focusrite Control 2

To enable Clip Safe from Focusrite Control 2, click the Safe button:

Safe off

Safe on

The Scarlett 18i16's Alt (alternate) button lets you quickly route a source to different analogue outputs or change sources feeding a set of analogue outputs. This is useful for referencing your mixes on a different set of speakers, or referencing two different sources on the same outputs.

To set up the speakers for speaker switching:

The Output control and Output level meter are related to the signals going to Outputs 1 and 2 on the back of your Scarlett 18i16, the outputs you'd most often connect to monitor speakers.

You can also assign the Output control to other outputs, for example if you're using two pairs of speakers. For more information, see Speaker Switching (Alt).

The Output control sets the level at the outputs from nothing (fully anti-clockwise) to full-scale output (fully clockwise).

The Output Level meter around the Output level control is a pre-fade meter (it is not affected by the control's position) showing you the signal level coming from your computer.

Focusrite Control 2 Output section

On the right-hand side of Focusrite Control 2 the Output section is a visual representation of the Output control and level meters.

Output control dial

The dial in Focusrite Control 2 is a software representation of the Output control on your Scarlett 18i16's front panel. When you change the control on the hardware, the software updates, when you move the control on the front panel, the dial in Focusrite Control 2 updates.

Speaker Switching (Alt) software control

The Output section allows you to control the Alt, or speaker switching, function. Click Main or Alt to switch between your Main or Alt monitors.

For more information, see Speaker Switching (Alt).

Output level meters

The output level meters mirror the front panel meters are pre-fade meters (they aren't affected by the Output control's position) showing you the signal level coming from your computer going to Outputs 1 and 2 (or 3 and 4 if you enable Alt).

Mute and Dim

See the Mute section.

The Dim button reduces the output level being sent to your outputs by 18dB.

The Mute button silences the signal being sent to your outputs.

Mute off.

Mute on.

By default, Mute affects the Main monitor outputs 1 and 2, but in Focusrite Control 2 you can change this to control your Alt outputs.

Mute Software Control

To enable/disable Mute in Focusrite Control 2 click the Mute button in the Outputs section on the right.

The Mute button works in the same way as the Mute button on the front panel of your Scarlett 18i16. When active, Mute lights green.

Mute off.

Mute on.

The Sync Status icon on the front panel lights green when your Scarlett 18i16 is 'locked' to or 'synchronised' with a clock source.

The Sync Status indicator is most useful when you're trying to expand the channel count using your Scarlett 18i16 with other equipment connected to your Scarlett 18i16's digital inputs or outputs; the ADAT or S/PDIF IO.

When you're using the digital inputs your Scarlett 18i16 and the other audio devices need to have their internal clocks synchronised, using clock signals, so their audio is recorded in time.

Depending on what type of digital device you're connecting to your Scarlett 18i16 (ADAT, coaxial S/PDIF, or optical S/PDIF) you need to make sure the digital IO mode is set correctly; for more information see Setting the digital IO modes.

There are a few principles when you're trying to synchronise multiple digital audio devices:

Setup 1 - Scarlett 18i16 as a Clock Follower

This is the most basic setup and involves one expansion device, increasing the channel count of your Scarlett 18i16.

We've outlined the steps for an ADAT expansion device, but the same theory applies for S/PDIF expansion devices. Depending on which S/PDIF type you are using (coaxial or optical) you may need to change your Digital IO Mode settings in Focusrite Control 2, for more information see Setting the digital IO modes.

Equipment:

• An external ADAT preamp - such as a Clarett+ OctoPre.

• One TOSLINK cable (also referred to as an ADAT cable).

Setup:

1. Connected the TOSLINK cable from the ADAT preamp's ADAT Out port to the ADAT In port on the Scarlett 18i16.

2. Set the ADAT preamp clock to Internal and your chosen sample rate.

3. In Focusrite Control 2, set the Scarlett 18i16 clock to ADAT and match the sample rate to the ADAT preamp.

4. In your DAW, set your channels to inputs 13 - 20, these are the eight ADAT inputs.

Setup 2 - Scarlett 18i16 as a Clock Leader

This is similar to Setup 1; however, it involves more cables. It's useful if you only use your expansion device occasionally, so you'd prefer to keep your Scarlett 18i16 as your clock leader.

We've outlined the steps for an ADAT expansion device, but the same theory applies for S/PDIF expansion devices. Depending on which S/PDIF type you are using (coaxial or optical) you may need to change your Digital IO Mode settings in Focusrite Control 2, for more information see Setting the digital IO modes.

Equipment:

• An external ADAT preamp - such as a Clarett+ OctoPre.

• Two TOSLINK cables (also referred to as an ADAT cable).

Setup:

1. Connected the TOSLINK cable from the ADAT preamp's ADAT Out port to the ADAT In port on the Scarlett 18i16.

2. Connect a second TOSLINK cable from the Scarlett 18i16's ADAT Out to the ADAT preamp's ADAT In.

   This cable is just to send clock data, but if your ADAT preamp has outputs, you can also send signals back out of your computer to gain extra analogue outputs.

3. Set the ADAT preamp clock to ADAT and your chosen sample rate.

4. In Focusrite Control 2, set the Scarlett 18i16 clock to Internal and march the sample rate to the ADAT preamp.

5. In your DAW, set your channels to inputs 13 - 20, these are the eight ADAT inputs.

Setup 3 - Using more than one expansion device

In this setup, we’re using two expansion devices: an ADAT device and an S/PDIF device. For ADAT, you might use a preamp like an OctoPre or a mic preamp. For S/PDIF, you could connect another interface in standalone mode or a guitar amp modeller.

Using the Scarlett 18i16 as your clock leader is useful if you only use your expansion devices occasionally, so don't need to turn them on every time you use your Scarlett 18i16.

Equipment:

• An external ADAT preamp - such as a Clarett+ OctoPre.

• A S/PDIF device - such as a guitar amp.

• Two ADAT cables.

• Two S/PDIF cables.

Setup:

1. Connected the TOSLINK cable from the ADAT preamp's ADAT Out port to the ADAT In port on the Scarlett 18i16.

   Connect the S/PDIF cable from the S/PDIF device's S/PDIF Out to the S/PDIF In on the Scarlett 18i16.

2. Connect a second TOSLINK cable from the Scarlett 18i16's ADAT Out to the ADAT preamp's ADAT In.

   Connect a second S/PDIF cable from the Scarlett 18i16's S/PDIF Out to the S/PDIF device's S/PDIF In.

3. Set the S/PDIF preamp clock to S/PDIF and your chosen sample rate. Some S/PDIF devices don't allow you to change these settings, if this is the case, see ….

4. Set the Scarlett 18i16's clock to internal and match the sample rate.

5. Set the ADAT preamp to clock to ADAT and match the sample rate (it's getting its clock from the Scarlett 18i16 via the second ADAT cable).

Note

At dual-band sample rates (88.2kHz and 96kHz) it's only possible to get the following configurations using two devices:

• Two coaxial S/PDIF channels and four ADAT channels

• Two optical S/PDIF channels and four ADAT channels

• Eight ADAT channels

At all sample rates, it is not possible to use coaxial S/PDIF and both ADAT ports simultaneously. See the Scarlett 18i16 input channel order for more information on the possible input combinations.

Your Scarlett 18i16 has two headphones outputs. Both headphones outputs are completely independent of the other analogue outputs, so they can have their own dedicated mix.

The headphone outputs are 6.35mm (¼”) TRS jacks. Many headphones have a 3.5mm TRS jack, to connect them to your Scarlett 18i16 you must use a TRS 6.35mm to 3.5mm adaptor.

The controls above the headphone outputs control the level going to your headphones.

The USB Type-C port labelled USB is to connect your Scarlett 18i16 to your computer.

Use the included USB-C cable to connect to a USB-C port on your computer, or use the USB-C to A adaptor to connect to a USB-A port on your computer.

The S/PDIF ports give you two channels of digital I/O to connect to other audio equipment with S/PDIF I/O such as guitar amps, mic preamps or any device with an S/PDIF output.

There are many ways to connect and clock your Scarlett 18i16 when you're using an external device connected via S/PDIF. For information on clocking and digital IO setups, please see the Sync Status Indicator section.

The Sync Status Indicator on your Scarlett 18i16 should light green. When you send audio from the external device to your Scarlett 18i16 you should see the S/PDIF channels coming in on channels 11-12.

The two Optical ports (input and output) give you eight channels of digital ADAT I/O, to connect to other audio equipment with ADAT I/O such an eight-channel mic preamps.

There are many ways to connect and clock your Scarlett 18i16 when you're using an external device connected via it's optical ports. For information on clocking and digital IO setups, please see the Sync Status Indicator section.

The Sync Status Indicator on your Scarlett 18i16 should light green.

The MIDI In and Out ports allow you to use your Scarlett 18i16 as a USB MIDI interface. MIDI In receives MIDI signals from keyboards or controllers; MIDI Out sends MIDI information to synths, drum machines, or MIDI-controllable equipment.

The MIDI IO doesn't require any setup for you to use your Scarlett 18i16 as a USB MIDI interface. The Scarlett 18i16's MIDI ports appear in your MIDI-enabled software, and you can either send or receive MIDI data between your computer and MIDI hardware via the Scarlett's 5-pin DIN MIDI ports.

Outputs 1 and 2 are line-level outputs to connect your Scarlett 18i16 to an amplifier or active monitors. The outputs are balanced 1/4" TRS jack outputs, you can use them with either unbalanced TS or balanced TRS jack cables and connect to speakers with 1/4" jack, RCA or XLR inputs.

Your Scarlett 18i16's front panel Output dial controls the level sent to Outputs 1 and 2.

Line Outputs 3-4 have identical electrical characteristics to the Monitor line Outputs 1 to 2 but aren't controlled by the Output control.

You can set the signals available at these outputs using Focusrite Control 2, and use the outputs to drive additional speakers in a multichannel monitoring system, such as a subwoofer or to send signals to outboard effects processors.