Odeon Omni downloads
Inverse filter for improved frequency response
To be used with the ODEON Sweep measuring system.
Download the file and paste it in the following folder:
ProgramData > Odeon > MeasurementFilters > Output.
You can access the ODEON’s program (application) data folder easily from within ODEON, as shown in the first screenshot below. You then navigate to MeasurementFilters > Output.
The file will become available to select from the Output Device -> Inverse filter drop down.
Pre-calibration file for G and STI parameters
A calibration procedure is required specifically for measuring Sound strength (G) and Speech Transmission Index (STI).
The full procedure is described in this Application note and it requires two steps:
- measurements inside a Reverberation or Anechoic chamber and
- in-situ correction measurements.
This tedious procedure can be greatly simplified by using Odeon Omni in combination with our pre-calibration file, which encompasses already the information of a Reverberation Chamber. The pre-calibration file is normally part of the default ODEON installation, and can be found in the Program data>Odeon>Calibrations folder as in the screenshot below.
You can also download the file manually (depending on the version of ODEON you use), unzip and copy-paste it in the folder above:
Important remarks:
- Use a cable when you perform calibrated measurements with Odeon Omni. The Bluetooth connection can occasionally become unstable, resulting in some variation of the levels in the final impulse response. Through large sets of measurements, we have seen that this does not affect the rest of the Room Acoustic Parameters, but it can affect G and STI which depend strictly on the actual level of the impulse response.
- Appart from your Odeon Omni, you can use any third-brand microphone and rest equipment (audio interface, amplifiers , cables etc.). The in-situ correction procedure ensures that levels are normalized automatically within ODEON.
- Make sure the entire setup with input/output device, cables, gains and any inverse filters remains fixed throughout the entire process, including the in-situ correction and rest measurements.
- For the in-situ correction measurement follow these guidelines:
- Place the microphone at the same height as the centre of the Odeon Omni source (approximately midway from the driver’s diaphragm and the bottom of the lens).
- Keep a distance of 70 cm between the microphone and the centre of Odeon Omni.
- It is recommended to measure at 4 to 8 points around the source, horizontally (at a radius of 70cm), to improve the reliability of the results.
Find detailed instructions about the process in the following links:
Publications
Sweep collections for deconvolution outside ODEON
Odeon Omni can be used with any software, like a normal loudspeaker. However, it is designed to perform best with sweep signals generated and processed in ODEON, using its deconvolution method (read more in Chapter 12 in the manual).
If you do not own ODEON, you can perform impulse response measurements by recording a sweep signal in the space and implementing your own deconvolution with the inverse sweep.
For this, you can use the following high-quality, optimized sweep files to playback through Odeon Omni. Each sweep speed varies with frequency, according to the source’s spectrum. This will favour a more even SNR across octave bands in your results. The changing speed is compensated for during the deconvolution of the signal. Read more about the sweep optimization method here.
Instructions for use
- Pick a sweep signal from the list. We provide different frequency ranges and durations, as indicated in the file name:
- Frequency range: 31 Hz-16 kHz, 63 Hz-8 kHz, 125 Hz-4 kHz, 125 Hz-8 kHz.
- Duration: 0.5 s, 1 s, 2 s, 4 s, 8 s, 16 s, 32 s, 64 s, 80 s.
- Play the sweep on your setup and record it as a .wav file.
- Find the corresponding InverseOdeonSweep in the folder, with the same frequency range and duration as the selected sweep.
- Deconvolve your recorded signal with the InverseOdeonSweep. We recommend performing this deconvolution in the time domain, in order to isolate harmonic distortion components.
- Truncate the obtained impulse response at the onset. Note that this step can be done automatically with ODEON.
- If needed, you can multiply the signal by the corresponding IRScale factor, found in the “Odeon sweep parameters.txt” file available in the same folder. This operation makes the obtained impulse response independent from the selected frequency range and duration.
