We recommend two interface solutions for WinMLS (one or two input channels maximum). Alternative 1 below is suited for room acoustics measurements that don't require very high sound pressure level if you are using a highly sensitive microphone, since the input may be clipping. Alternative 2 below does not have this limitation and input/output levels can be controlled directly from WinMLS. See more details below. Both alternatives are designed for measurement applications and can be used with the microphones we sell and other microphones that has XLR connectors.
Alternative 1: Customized Edirol UA-25
1. For "normal" measurements we recommend Edirol UA-25 USB powered stereo audio interface. For more information about the interface see: http://www.roland.com/products/en/UA-25/ The disadvantage with this interface is that it has too many buttons, to avoid this we sell a customized version that covers the buttons. This makes it much more user friendly and also suited for calibrated measurements. It will allow you to change the input and output gain using a screwdriver. See below.
Note:An issue with the operative system Windows XP is about measuring system delay (also called initial time delay or time-of-flight), this cannot always be measured accurately with the standard drivers unless you use the right channel as reference. However, this can be solved if you download driver version 1.0 (for Windows XP): http://www.rolandus.com/support/downloads_updates/eula.aspx?DownloadId=833. Then in WinMLS, select the MME input and output devices in Measurement->Sound Card.... Using this driver, you will then get sample accurate delay times even without using right channel as reference. A newer version of this sound car, UA-25EX, is also available. We have tested this but could not find any improvements useful for measurements.
Alternative 2: D-audio Reference Measurement Interface
One advantage with this card is that all settings (e.g. the phantom power and microphone amplifiers) are controlled from the WinMLS software. It also has a very high sensitivity range. We recommend that you purchase the D-audio from us because in future versions of WinMLS we might charge extra for the WinMLS-specific features for this sound card. For more information see: http://www.winmls.com/brochure/D-Audio_1.5_WinMLS.pdf
Note: If you need a sample accurate delay time for 2 input channels simultaneously, the internal loopback must be used. In case you need to measure delay times using both inputs (e.g. using two microphones) there is an internal loopback switch that handles this but it adds 3-5 seconds to each measurement.