Dirac Live is an optional upgrade. This section applies only if Dirac Live has been purchased and activated. For information on how to upgrade, see Upgrade to Dirac Live.
The miniDSP Flex HT implements multichannel Dirac Live correction. That is, there are eight channels of Dirac Live correction. After Dirac Live correction, the audio signal is routed to the eight output channels for processing such as parametric EQ and crossovers.
Dirac Live overview¶
Dirac Live uses from 9 to 17 measurements made at different locations in your listening room to calculate correction filters for your speakers and subwoofer. You will take these measurements using the miniDSP processor, the Dirac Live application running on your computer, and a miniDSP UMIK-1 or UMIK-2 measurement microphone.
This software runs on Windows 10 or later and macOS 10.14 Mojave or later. Other versions of Windows or macOS/OS X are not supported.
Connections for Dirac Live calibration¶
The diagram below shows typical connections for acoustic measurement with the Dirac Live application. Usually, you do not need to change any of the audio connections, as the Dirac Live test signals are generated inside the miniDSP processor.
Connect the supplied USB cable (type A to type B) from the miniDSP Flex HT to a USB port on the computer.
Connect the supplied USB cable (type A to mini type B or type C, depending on version) from the UMIK-1 or UMIK-2 to a USB port on the computer.
Place the UMIK-1 microphone into a microphone stand and position the computer and cabling so that there is enough freedom of movement to move the microphone into the needed locations. A small tripod stand is supplied with the UMIK-1, but a larger stand with boom arm can be used if desired. If necessary, a USB extension (up to a total USB cable length of 5 meters) can be used. In larger spaces, an active USB repeater may be needed.
- For surround/multichannel applications, we recommend that the microphone be pointed at the ceiling and the "90 degree" calibration file used.
Loudspeaker and microphone positioning¶
Prior to performing acoustic measurements, loudspeaker and subwoofer positioning should be optimized. In particular, the location of the subwoofer will have a large impact on bass response. With Dirac Live®, you have more freedom with loudspeaker and subwoofer placement, but the best result will still be achieved if optimal placement is used together with Dirac Live®.
A total of nine, 13 or 17 measurements is recommended, with the microphone located in different positions in the room and pointed vertically (that is, at the floor or ceiling). The first measurement must be taken at the exact center of the listening area, so that Dirac Live can set the levels and delays of each speaker. Additional measurements are then taken at locations spread around the listening area and at different heights from the floor.
Note that all measurement positions should have acoustic "line of sight" i.e. the direct signal from the speaker to the microphone should not be obstructed by furniture or other objects.
Subwoofer settings for multichannel systems¶
When using a subwoofer in a multichannel system, we recommend that its low pass filter be disabled if possible, or set to its highest frequency if it cannot be disabled. Any EQ on the subwoofer should be disabled or set "flat." High pass filters used to protect the driver from over-excursion should be left in place.