脉冲响应测量器演练
In this tutorial, explore key functionality of the脉冲响应测量器。这脉冲响应测量器应用程序使您能够
Configure your audio I/O system.
使用指数扫描正弦（ESS）或最大长度序列（MLS）方法获取脉冲响应（IR）测量。
查看和管理捕获的IR数据。
将数据导出到文件，工作区或其他应用程序以进行进一步研究。
To begin, open the脉冲响应测量器通过选择的应用程序
来自App Gallery的图标。
配置音频I / O系统
这脉冲响应测量器应用程序使您能够specify an audio device, sample rate, samples per frame, player channel, and recorder channel. The audio device must be a real or virtual device enabled for simultaneous playback and recording (full-duplex mode) and must use a supported driver. Supported drivers are platform-specific:
视窗®- asio™：点击
按钮打开ASIO驱动程序的设置面板。苹果–– CoreAudio
Linux®–– ALSA
每个帧的采样率和样本数的有效值取决于您指定的音频设备。
You can use the level monitor toverify the configuration of your audio I/O system。
配置IR采集方法
To configure your IR acquisition method, use theMethod和Method SettingsToolstrip的部分。
You can select the method to acquire IR measurements as either:
最大长度序列(MLS)指数席卷正弦(席卷正弦)
Both methods for IR acquisition have the same basic settings, including:
跑步数量–– Number of times the excitation signal is sent within a single capture. Multiple runs are used to average individual impulse response captures to reduce measurement noise.
每次运行持续时间–– Total time of each run in seconds.
Excitation Level (dBFS)- DBFS中激励信号的水平。
IR Acquisition的两种方法也具有相同的高级运行设置，包括：
第一次运行前等待- 开始前首次运行之前的延迟。延迟允许时间进行任何最后一刻任务，例如在测试其声学之前退出房间。
跑步之间的暂停- 运行之间暂停的持续时间。在暂停期间，未发送激励信号，并且未记录音频。使用时席卷正弦冰毒od, include a pause between runs to avoid buildup of reverberations. Pause between runs is always zero for theMLS方法。
预热运行数量–– Number of times to output the excitation signal before acquisition. TheMLS冰毒od assumes the signal it acquires is a combination of the excitation signal and its impulse response. Use warmup runs to remove transients.
总捕获时间是运行持续时间，暂停和初始等待的总和。
这席卷正弦冰毒od has additional高级设置to control the excitation signal, including:
Sweep start frequency
扫描频率停止
扫一段时间
End silence duration
使用时席卷正弦方法，备运行持续时间is divided into扫一段时间和End silence duration。During the end silence, the app continues to record audio, enabling acquisition of the response over the entire range of the frequency sweep.
Starting in R2022a, you can automatically save device, method, and advanced settings and use them in future measurement sessions.
获得IR测量
For this example, use theMLS默认设置的方法。设置音频设备设置后，单击Capture。A dialog box opens that displays the progress of your capture. IR measurements are captured twice.
Analyze and Manage IR Measurements
捕获后，脉冲响应测量器应用程序在本地存储捕获的数据。这数据浏览器显示捕获数据的标题，用于绘制的颜色，以及用于获取数据的设置的信息。您可以双击颜色数据浏览器选择您想要的颜色与每个脉冲响应相关联。您还可以双击标题以重命名捕获的数据。将捕获重命名为FirstCapture和第二种, and change the colors to pink and green. To make one impulse response plot appear on top of the other, select the title in the数据浏览器。选择您重新标记的捕获FirstCapture。
By default, the impulse response and magnitude response are plotted. You can view any combination of the impulse, magnitude, and phase response using theLayout按钮。最小化数据浏览器，然后选择Phase Response。
您可以通过移动分隔符来切换绘图的相对大小。您可以通过选择指针在绘图绘图时显示的图标来放大和缩小或在线性和对数频率轴之间切换或切换。更新幅度响应或阶段响应更新另一个。放大脉冲响应图以及频率响应图的0-20 Hz范围内。放大，你可以看到之间的小延迟FirstCapture和第二种。When the zoom level is high enough, line markers automatically appear.
导出红外线测量
要查看进一步分析或使用的导出选项，请单击出口。
出口the data to your workspace. The data is saved as a table. To inspect how the data is saved, display the table you exported.
irdata_111104
irdata_111104 = 2×16 table TimeOfCapture ImpulseResponse Device SampleRate SamplesPerFrame PlayerChannels RecorderChannel Method NumRuns DurationPerRun ExcitationLevel RawAudioData SamplesDropped OtherMetaData MagnitudeResponse PhaseResponse __________________________ _______________ ____________________ __________ _______________ ______________ _______________ ______ _______ ______________ _______________ ____________ ______________ _____________ _________________ _____________ FirstCapture 20-Oct-2021 11:01:22 -0400 1×1 struct "Focusrite USB ASIO" 44100 1024 {[1]} 1 "MLS" 2 0.5 -6 1×1 struct 0 1×1 struct 1×1 struct 1×1 struct SecondCapture 20-Oct-2021 11:01:29 -0400 1×1 struct "Focusrite USB ASIO" 44100 1024 {[1]} 1 "MLS" 2 0.5 -6 1×1 struct 0 1×1 struct 1×1 struct 1×1 struct
将数据导出为MAT文件时，将保存与导出到工作区时的相同表。当您选择将数据导出为WAV文件时，每个脉冲响应将保存为单独的WAV文件。捕获的标题是WAV文件的名称。在此示例中，选择将数据导出到音频WAV文件将两个WAV文件放在指定的文件夹中，firstcapture.wav.和第二种。wav。
要进一步分析捕获的数据，请查看数据Filter Visualization Tool要么信号分析仪应用程序。
See Also
脉冲响应测量器|audioPlayerRecorder|splMeter|reverberator
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