Calibrating Monitors: Scarlett 2I4 Setup Simplified

Calibration is the process of setting up a monitor mix, which balances the input signal and the DAW playback. The Focusrite Scarlett 2i4 is a popular audio interface for music makers, but it can be tricky to calibrate. The process involves using an SPL meter, playing pink noise, and setting the volume to -20db. One common issue is not knowing how to set the output level to 0dB (unity) due to unlabelled monitor knobs. Additionally, users may encounter a Buffer size warning when using ASIO drivers. To resolve this, the buffer size can be adjusted in the ASIO control panel. When calibrating monitors with the Scarlett 2i4, it is important to consider the input sensitivity settings on the monitors, as well as the output level of the interface, to ensure optimal sound quality and volume.

Setting the monitor knob to the playback position

When calibrating your monitors, you will want to set the monitor knob fully to the right, which is the playback position. This means that only the signal coming from your Mac or PC will be heard through the Line and Headphone outputs.

To understand this better, let's consider the other positions of the monitor knob. When the knob is set fully to the left (INPUT), only the signal arriving at the Scarlett 2i4's two inputs will be heard from the outputs. When the knob is in the middle (12 o'clock position), you will hear a 50/50 mix of both the input and playback signals.

In a recording scenario, this knob allows you to fine-tune the balance between your input signal and the backing track. It is beneficial for practising with instruments, checking final mixes, testing input and output gain structure, and optimising acoustics in recording spaces.

Therefore, when calibrating your monitors with the Scarlett 2i4, ensure that the monitor knob is set to the playback position to receive the signal solely from your computer, providing you with an accurate representation of the output for calibration purposes.

Using an SPL meter to play pink noise

To calibrate monitors with a Scarlett 2i4, you can use an SPL meter to play pink noise. Here's a step-by-step guide:

Step 1: Understand SPL Meters

SPL stands for Sound Pressure Level and is used to measure absolute sound volume levels. SPL meters contain a built-in microphone and preamplifier connected to a readout that displays the sound level in decibels. They are "reference" devices and must be calibrated at the factory using known volume levels. Most SPL meters also have a range control to accommodate different sound levels.

Step 2: Choose Pink Noise as the Test Signal

When calibrating loudspeaker levels, you can use either static sine waves or pink noise as the test signal. Pink noise is a better choice because it contains all frequencies and provides a more accurate measurement. It also helps to avoid standing waves in the room, which can create peaks and nulls in the frequency response.

Step 3: Set Up the SPL Meter

Place the SPL meter where your head would typically be when listening to the monitors. If you're calibrating a surround system, point the microphone straight up, with the element at the same height as the tweeters in each speaker. Ensure the SPL meter is set to "C" weighting and "Slow" response time.

Step 4: Play Pink Noise Through the Monitors

Play pink noise through the monitors one at a time, starting with the left and then the right. Adjust the volume on the Scarlett 2i4 interface so that the output level is set to 0dB (unity). You may need to refer to the interface's manual to find the correct settings.

Step 5: Read the SPL Meter

Note the level displayed on the SPL meter for each monitor. Due to the random nature of noise, the volume may fluctuate, so it's essential to take an average reading over a few seconds. Take note of the levels for each monitor.

Step 6: Adjust the Monitor Levels

Use the monitor's volume controls to adjust the volume until both monitors have the same volume level according to the SPL meter. This ensures a consistent listening experience and accurate sound reproduction.

By following these steps, you can use an SPL meter to play pink noise and calibrate your monitors with the Scarlett 2i4 interface, resulting in a more balanced and accurate sound output.

Setting the volume of the audio interface's output level to 0dB

• Understand the Basics: 0dB is often referred to as the maximum loudness setting. It is the point beyond which increasing the volume may cause audible distortion or "clipping". In the context of calibrating monitors with a Scarlett 2i4, 0dB is the level at which you want to set the audio interface's output.
• Use the Right Tools: Ensure you have the necessary equipment for calibration, such as an SPL meter, pink noise, and the appropriate cables. These tools will help you measure and adjust the output levels accurately.
• Adjust the Controls: Start by turning the monitor knob on your interface to a low level. Then, play pink noise through the system and use the SPL meter to measure the output. Adjust the monitor knob until the SPL meter reads 0dB. This may require some fine-tuning, as simply turning the knob all the way up may not result in a 0dB output.
• Compare Measurements: If your interface has multiple outputs, repeat the calibration process for each output to ensure they are all set to 0dB. This will provide a consistent listening experience across all outputs.
• Consider Gain Settings: In addition to the monitor knob, your interface may have gain controls or trim pots that affect the output level. Adjust these settings to find the optimal balance between reducing self-noise and maintaining sufficient headroom to accommodate louder signals.
• Use a Reference: Compare your settings with online resources or forums specific to your audio interface. Other users may have insights or recommended settings that can help you achieve the desired 0dB output level.

Remember, calibration is a process of fine-tuning, and you may need to make adjustments specific to your equipment and listening environment. Take your time, use the right tools, and don't be afraid to experiment until you find the settings that work best for you.

Using the right cables

To calibrate monitors with a Scarlett 2i4, you need to use the right cables to connect your audio interface to your studio monitors or powered speakers. The best option is to use balanced cables, as they offer better sound quality and are less prone to interference and noise.

Balanced Cables

1/4" TRS Cable

The first option is to use a balanced 1/4" TRS cable. This is the simplest and most effective way to connect your Scarlett 2i4 to your studio monitors. The balanced connection offers the best sound quality and facilitates longer cable runs if needed. These cables are easy to source and the connection is simple, but make sure you connect the left and right outputs to the corresponding speaker.

1/4" TRS to XLR Cable

If your studio monitor only has XLR inputs, you can use a balanced 1/4" TRS to XLR cable. This setup offers the same benefits as the previous option, with the added convenience of working with XLR connectors. XLR extension cables can also be used if you need a longer cable run.

Unbalanced Cables

1/4" TS Cable

If you choose to use an unbalanced cable, a 1/4" TS cable will work, but it is more susceptible to interference and noise. This setup is identical to the balanced TRS cable option, except without the benefits of a balanced connection. If you notice any buzzing or humming noises, you may need to upgrade to balanced cables.

1/4" TS to RCA Cable

RCA inputs are less common on studio monitors, but if your speakers only have RCA inputs, an unbalanced connection with a 1/4" TS to RCA cable is your only option. This setup is simple, but RCA connections are considered antiquated. Some studio monitors have two RCA inputs on one speaker, while others have a single input on each speaker, requiring you to split the RCA end of the cable.

In summary, when calibrating monitors with a Scarlett 2i4, it is important to use the right cables to ensure optimal sound quality and connectivity. Balanced cables are recommended for their superior performance and noise resistance, while unbalanced cables are more susceptible to interference.

Setting the input sensitivity

If you are using balanced cables, such as XLR or TRS, the input sensitivity on your monitors should be set to +4dBu. Balanced cables typically provide better sound quality and noise rejection compared to unbalanced cables. This is because they use an additional wire to create an inverse version of the audio signal, which helps to reduce electrical noise and interference.

On the other hand, if you are using unbalanced cables like RCA or TS, you should set the input sensitivity on your monitors to -10dBV. Unbalanced cables are more susceptible to noise and interference, but they are often more convenient and cost-effective. They are typically used for consumer electronics and shorter cable runs.

It's worth noting that the Scarlett 2i4 manual specifies that the line outputs are electronically balanced and can work with either balanced or unbalanced connections. However, to ensure the best sound quality and avoid potential clipping issues, it is generally recommended to use balanced cables and set the input sensitivity on your monitors to +4dBu.

Additionally, when calibrating your monitors, it is important to adjust the volume levels accordingly. Start by zeroing the monitor volume and setting the monitors to +4dBu. Then, slowly raise the monitor volume until you reach the desired maximum output level. This ensures that you are getting the hottest signal out of the interface, improving the signal-to-noise ratio and utilising more DAC resolution.

By following these steps and choosing the appropriate input sensitivity setting for your cable type, you can achieve optimal sound quality and performance when calibrating your Scarlett 2i4 with your monitors.

Frequently asked questions