The 1.5s chirp gives you a bit more resolution in the lower frequencies, which is useful if you are measuring large loudspeakers that have an extended low frequency response or subwoofers. The 0.5s chirp give you good resolution and a quick measurement time. You have two options for chirp lengths, which can be selected in the setup screen.
We will start with the first case where you wish to measure a small studio monitor in a close microphone configuration (as close to the transducer as possible), at the listening location and then at multiple locations in the diffuse field. The other is to make multiple spatially-averaged measurements of the same loudspeaker. The first is to make individual measurements of different loudspeakers or measurement locations around your room. There are two basic ways to use this module. Once that is set, as you move around your room and make other measurement, the delays and distance differences will be meaningful. If it is not, adjust your latency settings until your close mic is measuring 0 ms delay and distance. This time tap the 0.020s button on the ETC Curve graph, your new measurement’s peak should be 0 ms. Tap the wrench icon again, and type the time value you observe into the Latency field. This is the reference latency of your system. Use a single finger drag to slide the cursor to the peak of the impulse response and observe the time readout.
First, assure that the 1.00s option is selected in the ETC graph. The ETC, or energy time curve shows how energy is decaying in your room. To set the latency, switch from the Analysis Curves screen to the ETC Screen by tapping the second grey icon on the bottom middle of the module.
Tap the Measure button to take your first measurement, a log sine chirp signal will be recorded and through a process known as deconvolution, the resulting impulse will be generated. For complete calibration and gain adjustment instructions, please refer to the instructions in the Settings screen. Set the gain of your microphone preamp by tapping the Gear icon, and then Microphone Setup. Then tap done and place the microphone as close as you can to the transducer you wish to judge. Tap the wrench icon and in the ETC Graph setup screen you will see a Latency box. NOTE: This applies to Internal Trigger mode only.Įxternal trigger mode does not support delay measurements. The first step you need to perform is to take a reference measure to determine the latency of your system. Plot will still show the room decay, minus the initial arrival time of the Mode waits for an incoming signal, it cannot determine absolute time ofĪrrival, and therefore the speaker time delay cannot be computed. LARSA will wait until it detects a signal at the trigger level on the setup
Next, download the signal, eitherįrom our website on the Downloads page, or by using the Surround Generator on On the Setup page, select “External Chirp”.
In this case,Īfter downloading and installing Surround Generator on your Apple TV 4k, youĬan select the Atmos signals, and then choose LARSA as the signal type for any TV 4k app, “Surround Generator” as the source for the signal. You can use LARSA for example with a surround sound system, by using our Apple
That you do not need any connection from the iOS device to the sound system, so This allows you to use another sound source, rather than the iOSĭevice that is running LARSA, to generate the chirp signal. With our iTestMic, the configuration will be the same, except you will use the line output of your iOS device to feed the measurement signal into your system.įinally, you can use the internal microphone to capture the measurement signal, although for best results, a measurement microphone should be used.Īvailable. You will plug in your measurement microphone into the microphone input of the interface and set up the microphone in the location where you wish to measure the response. With our iAudioInterface2, you will plug in the line output of the interface into the input of the speaker you want to test. There are a number of ways to record this signal.