Getting Started with REW: A Step-by-Step Guide
(Rev 5.43, June 3, 2017)
Page 4 of 132
Introduction
The purpose of this document is to provide a step-by-step guide for novice users of Room Equalization
Wizard (REW), freeware audio measurement software authored by John Mulkahy. This guide focuses
on the recent enhancements to REW that support the use of USB microphones and HDMI
connectivity. You are encouraged to visit the REW forum, and to thoroughly read the REW Online Help
documents.
Hardware/Operating System
To conduct measurements with REW following this guide, you will need:
1. A computer (preferably a laptop or a netbook) running the Windows operating system or a
MacBook. While most of the examples given in this document pertain to Windows computers,
there are links to advice specific to Mac users.
2. A sound pressure level (SPL) meter (optional).
3. A USB microphone (currently either the UMM-6 or the UMIK-1).
4. A stand for the microphone (preferably a boom mic stand).
5. An appropriate suite of cables and connectors, as specified later in this document.
This document was developed using a typical Windows dual-core laptop. The chipset/video is an ATI
Radeon Mobile HD 4200, and the audio is a typical RealTeK chip. The laptop is patched current, which is
always important. Always check to make sure the chipset drivers are current, as well as the audio
drivers. Normally, running Windows Update will ensure the latest supported (i.e. non-beta) drivers are
installed.
Note: The two USB mic’s can be purchased directly from the vendor (MiniDSP for the UMIK-1, or
Dayton Audio for the UMM-6), in which case you can download a single calibration file from the
vendor’s web site. However, this calibration file is for a zero-degree orientation. Both mics are also
available from Cross-Spectrum Labs, which runs a custom calibration for each mic they sell. The mics
are provided with several calibration files, including a 90-degree calibration file, which is the angle used
for most REW measurements. Does it make a difference which type of calibration files you have?
Check out this post (post 4926), which provides measurement data comparing the various calibration
files available for the mic’s. Thanks to the research by AVS member Manni01, you can download a file
from the MiniDSP Forum here that will generate a 90-degree calibration file from your 0-degree file.
Tests have shown that the generated calibration file matches the custom files from CSL very closely. To
see a comparison showing the differences between the web-site calibration file and the CSL custom
calibration file for the UMIK-1, see this post (post 10185 in the MiniDSP DDRC-88A thread). Also, read
the special sections covering “USB Microphones with Sensitivity parameters: Special Considerations”
and “Notes on the accuracy of USB mic calibration files with sensitivity parameter” immediately
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