Recording Measurements

The Recording screen lets you play a test signal (sine sweep) through your speakers and record the result with a measurement microphone. The captured impulse response can then be used in the Convolution plugin or fed into the Room EQ optimizer.

What You Need

• SotF (Terminal or Desktop)
• A calibrated measurement microphone (e.g., miniDSP UMIK-1, Dayton Audio UMM-6)
• The microphone’s calibration file (.txt or .csv)
• Your speakers connected and at their final positions

Workflow Overview

1. Navigate to the Recording screen
2. Select your output device (speakers) and input device (microphone)
3. Configure the sweep signal
4. Record and save the impulse response
5. Use the file in Convolution or Room EQ

Step-by-Step

1. Select Devices

In the Recording screen, choose:

• Output device — your speaker output (the device you want to measure)
• Input device — your measurement microphone input

If using USB microphones (UMIK-1, etc.), they appear as separate audio devices.

2. Configure the Sweep

Setting	Recommended	Notes
Sweep duration	10–30 s	Longer = better SNR in reverberant rooms
Sweep level	-10 to -6 dBFS	Leave headroom; avoid clipping
Sweep start freq	20 Hz	Covers full audio band
Sweep end freq	20 kHz

3. Set Up the Microphone

• Place the microphone at the primary listening position, ear height
• Point it toward the ceiling (omnidirectional capsule) or at the speaker (cardioid)
• Load the microphone calibration file if you have one (corrects the mic’s own response)

4. Record

Press Record (or the keybinding shown on screen). SotF will:

1. Play the configured sine sweep through the speakers
2. Record the microphone signal simultaneously
3. Deconvolve the recording to extract the impulse response (IR)

The recording takes slightly longer than the sweep duration due to tail capture.

5. Save the Result

After recording, SotF displays a summary (peak level, SNR estimate). Save the IR to a .wav file. Use descriptive filenames:

living-room-L-seat1.wav
living-room-R-seat1.wav

Using the IR

In the Convolution Plugin

Load the saved .wav file in the Convolution plugin. This applies the room’s transfer function as a convolution filter, useful for:

• Cabinet simulation
• Room reverb
• Custom impulse responses from other tools

In Room EQ

The Room EQ wizard can import your recorded IR files as measurements. This is the recommended path for room correction — it accounts for your actual in-room acoustics rather than relying solely on spinorama anechoic data.

Tips for Good Measurements

• Silence the room — turn off HVAC, fans, and background audio during recording
• Measure multiple seats — SotF can average several positions for a more robust correction
• Record each channel separately — mute all channels except the one you are measuring
• Check for clipping — peak level should stay below 0 dBFS; lower the sweep level if needed
• Repeat suspicious measurements — if SNR looks low (< 20 dB), try again