When looking for an audio interface to use with TrueRTA you have many choices due to the wide use of these interfaces for computer music and home recording. The maximum sampling frequency is important  because the maximum measurement bandwidth can never be more than half the sampling frequency. Thus a maximum sampling frequency of 48 kHz results in a maximum measurement bandwidth of no more than 24 kHz. TrueRTA provides measurement bandwidths up to 46 kHz with interfaces that can operate at 96 kHz sampling rates. Make sure the interface you select has the input and output connections that you need for your particular measurement requirements. When you order an interface review the setup with care to make sure you have the necessary cables and any required adapters. All interfaces shown here provide phantom power for microphones.

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This is a basic audio interface that provides all the capability you need to perform measurements up to 24 kHz with TrueRTA. It features only one mic input but two line level inputs. It's all you need to get started with TrueRTA. Line inputs use 1/4" phone plugs. Outputs are on stereo RCA jacks. A software bundle is included.

The Focusrite Scarlett Solo (3rd Gen) is a good unit or use with TrueRTA. It provides one phantom powered mic input and one line input with up to192 kHz sampling frequency for measurement bandwidth up to 46 kHz with TrueRTA. The unit is powered from the USB port so no other power supply is required. Line In/Out use 1/4 inch phone jacks. A software bundle is included.

The Focusrite Scarlett 2i2 (3rd Gen) is an upgrade from the Solo. It provides two phantom powered mic inputs and two line inputs with up to192 kHz sampling for measurement bandwidths up to 46 kHz with TrueRTA. Line In/Out use 1/4 inch phone jacks. The unit is powered from the USB port so no other power supply is required. Note that TrueRTA can select either the L or R signal for RTA analysis and can view both channels simultaneously at the oscilloscope. A software bundle is included.

The key differences between measurement microphones and microphones used for music performing and recording are that measurement mics are virtually always omnidirectional and employ a very small mic element mounted in the smallest possible casing with a somewhat long neck and no ornamental obstructions. Their tips are often designed for increased sound energy diffusion as seen in the EMM-6 close-up below. As professional grade electret-condenser microphones they require phantom power delivered by way of the balanced XLR connection.

This is a nice measurement mic that comes with individually measured calibration data. It requires phantom power.

This is a very good general-purpose measurement microphone. If in doubt, start with this one. I have an EMM-6 that I use regularly. jlm

This is a good measurement microphone that is widely available online and at many music stores. It requires phantom power.

The dbx measurement mic is often used with the dbx DriveRack systems. It is similar to the ECM8000 or the EMM-6 and requires phantom power.

  Mic Accessories

This is a basic 15' professional microphone cable suitable for acoustic measurement applications. Longer and shorter lengths are also available .

This is a basic microphone stand w/ boom suitable for acoustic measurement applications.