REW Pro upgrade

The REW Pro Upgrade adds features for professional users. The first feature is support for capturing from multiple inputs simultaneously, further features will follow. The Pro Upgrade license unlocks multi-input capture and will also unlock all future pro features and is a one-time fee.

Multi-input capture

Multi-input capture is a Pro upgrade feature that allows REW to capture multiple inputs simultaneously for measurement or for the RTA. Each input can have its own calibration file. Individual SPL metering is available for the first four inputs, the level meters can show the input level for the first 16 inputs. Measurements made with multi-input capture will show an rms average of all the captured channel magnitudes with an underlay showing the span of the individual channels and can optionally include individual measurements for each channel.

Multi-input capture measurement result

The weighting of each input in the average can be configured and inputs can be aligned to a common SPL in a chosen frequency range before being averaged, useful for spatial averaging. Weighting and SPL alignment can be configured before the measurement is made (using the Configure averaging) button on the Measure dialog) or adjusted afterwards (using the Adjust average button in the SPL & Phase graph controls). Four preset weighting configurations can be saved.

Multi-input averaging adjustments

Multi-input RTA measurements

RTA measurements with multi-input capture show an rms average of the individual channel magnitudes and individual traces for the first 16 inputs. The maximum number of input traces to show is configured in the View settings, the processing and graphics capabilities of the computer may mean fewer than 16 can be displayed. RTA measurements are saved in the same format as sweep measurements allowing the same weighting and SPL alignment adjustments to be made to them.

If only two inputs are selected for a multi-input RTA measurement distortion and levels will be shown individually for each and stepped sine measurements can be made for both inputs simultaneously.

Multi-input channel selection

The first and last channels to be captured are selected on the Soundcard preferences, Measure dialog or RTA input dialog. The example below shows selection using ASIO drivers on the Soundcard preferences, a similar selection is offered for Java drivers. On Windows when using the Java drivers select the WASAPI exclusive device entries for multi-channel support (entries starting EXCL: in the device selectors). On macOS or Linux Java drivers offer as many channels as the interface supports.

Input selection

Multi-input microphones

Multi-input capture would typically be used with a mic array (such as the miniDSP UMIK-X) or a multi-channel interface with multiple analog microphones connected to it. REW captures a contiguous range of input channels. Whilst it is possible to use this feature with multiple USB microphones on Windows when using an ASIO wrapper, this is NOT recommended because:

The miniDSP UMIK-X multi-channel microphone system includes an REW Pro Upgrade license.

Multi-input license

A license is valid for a single user on any computer they use.

The miniDSP UMIK-X multi-channel microphone system includes an REW Pro Upgrade license.

The REW Pro Upgrade that unlocks multi-input capture is $100.
Multi-input capture requires REW V5.20 or later.
The license code is delivered by email to the address
registered with PayPal, usually within 24h of purchase. The
email will come from,
please add this address to your safe senders list to prevent
the email being diverted to your junk folder.

Before purchasing a license make sure that REW functions as required in its default single channel capture mode.

This upgrade is not required to access multi-channel outputs, to access multiple output channels on Windows use the WASAPI exclusive device entries with Java drivers or use ASIO drivers or an ASIO wrapper like FlexASIO or ASIO4All. On MacOS or Linux multi-channel outputs can be accessed with the Java drivers.

To enable your license, go to the REW Pro Upgrades menu and select Multi-input capture. Paste in your license code and click Verify license.

Multi-input capture license dialog

For support visit the REW Forum or email If you find multi-input capture does not meet your needs email within 30 days of purchase for a full refund. Please include your license email.