Measuring Time Delay in an Audio System Using Electroacoustics Toolbox Although Electroacoustics Toolbox is not limited to measuring audio systems, the measurement of audio systems is a common use that offers convenient ways to demonstrate the capabilities of the software. These examples can then be applied to other applications in which the Toolbox’s measurement capabilities may be considered useful. At times it is desirable to measure the delay of a signal through some component, or group of components, in an audio system. For example, when a digital signal processor (DSP) is employed in an audio system, to optimize or otherwise alter the listening experience, it may be desirable to measure the delay introduced by the DSP’s algorithms in the audio […]» Read more
Measuring Audio Unit Effects Plug-ins Using Electroacoustics Toolbox, Soundflower, and AU Lab A valuable use of Electroacoustics Toolbox is measuring Audio Unit effects. Measuring Audio Units can be useful to developers of such plug-ins, or to anyone employing Audio Unit effects in their digital audio recording, editing, or reproduction system. This tutorial requires two free software packages in addition to the Toolbox: Soundflower and AU Lab. AU Lab is distributed with Tiger (Mac OS X, 10.4). Soundflower is a free system extension for Mac OS X, version 10.2 or later, that allows for convenient routing of audio signals between applications on the Mac. More information regarding Soundflower, as well as a download link may be found at cycling74.com. (Version 1.2 […]» Read more
This article was originally published in the forums for version 2 of Electroacoustics Toolbox. Please visit the following link for an updated tutorial for version 3. Frequency Response Measurement with Electroacoustics Toolbox 3 Measuring the Frequency Response of Your Audio Device One of the most powerful tools in Electroacoustics Toolbox is the Dual FFT Analyzer, which is capable of measuring system transfer functions and even indicating the quality of the measurement. This tutorial focuses on using the Dual FFT Analyzer to measure the frequency response of the audio device that you use to measure other systems and devices. If you want to measure the frequency response, or impulse response, of a listening room for example, that measurement will be affected […]» Read more
One of the most obvious ways to get analog signals into an iPhone or 2nd generation iPod touch is through the headset connector. Several options exist for getting acoustic or electric signals into the headset input, which are discussed below. Any of these options will work with the iPhone, iPhone 3G, or iPod touch 2G. The original iPod touch does not have a headset connector with a mic input channel, so it is left out of this discussion. When making a decision about what to use the headset input for, or what to connect to it, you may want to take a look at the frequency response measurements of the various iPhone OS devices. Acoustic Signals Acquiring acoustic signals requires […]» Read more
Several options exist for getting audio signal into and out of iPhone OS devices via the dock connector. However, not all accessories are compatible with all iPhone OS devices. So, we put together this compatibility chart, based on our own tests with SignalScope/Pro and SignalSuite. Dock Audio Accessory Compatibility These devices were chosen for their ability to accept stereo audio input from external sources. Some dock connector devices simply feature built-in microphones, which are of limited use for test and measurement applications. It’s also important to remember that the iPhone OS automatically selects the current route for input audio signals (built-in mic, headset, dock connector, etc). iPhone iPhone 3G iPod touch iPod touch 2G Alesis ProTrack In/Out(1,2) In/Out(2) Out(3) In/Out(2) […]» Read more
Getting audio signals into and out of an iPhone OS device can sometimes be a bit tricky. The information presented below outlines the available means for getting audio signals into and out of each iPhone OS device.
Available Input Routes
Available Output Routes