Preprocessing Measurement Data

To visualize frequency response data using modernGraphTool, it’s necessary to preprocess the data appropriately.

This chapter explains how to preprocess measurement data so that modernGraphTool can understand it correctly.

Tip

modernGraphTool is designed to use the same data structure as CrinGraph. Therefore, users familiar with CrinGraph can skip this section.

Data Format

modernGraphTool supports measurement data saved in txt file format.

Freq (Hz)   SPL (dB)
--------------------
20          100
40          101
...

The txt file contains multiple rows, and each row includes two values. The first value is the frequency, and the second value is the SPL (Sound Pressure Level) corresponding to that frequency.

Depending on the export settings, a third value might exist in each row, which is the Phase value, indicating the direction of change for the SPL value at each frequency. This data is not used by modernGraphTool, regardless of its presence.

Most measurement software provides a feature to export data in txt file format. While there can be various ways to export data, it is recommended to preprocess the data as described below.

Exporting Data

REW

Here’s how to export data measured with REW (Room EQ Wizard) software:

1. With the measurement data to be exported selected, choose File - Export - Export measurement as Text.
2. Then, select the data export method as follows:

Item	Value
Use custom range	20 to 20000 Hz
Use custom resolution	96 PPO
Use custom smoothing	1/48 smoothing
Use REW export format	Selected
Export units	SPL
Export text delimiter	Tab

3. Click the Ok button to export the data.

Data exported this way can be processed normally by modernGraphTool.

Tip

modernGraphTool can also process non-smoothed original data that has not had Custom resolution / Custom smoothing settings applied.

However, modernGraphTool is designed to internally apply 1/48 smoothing to ensure adequate processing performance. Therefore, using data with a resolution higher than 1/48 oct will not affect the result.

ARTA

Here’s how to export data measured with ARTA software:

1. With the measurement data to be exported selected, choose File - Export - CSV file.
2. Run REW (Room EQ Wizard), and import the CSV data exported from ARTA via File - Import - Import frequency response.
3. Then, export the data using REW (Room EQ Wizard) as described in the REW tab.