Real-time Analysis

IOScope performs real-time transfer function analysis, allowing you to monitor dynamic systems, even as their response changes with time. This makes IOScope a powerful tool for many applications. For example, it easy to apply an equalizer to a sound system and optimize the system's overall response on the fly.

Tools

• The frequency domain analyzer performs narrowband spectrum analysis of a single system or device under test (DUT).
• The time domain analyzer computes the impulse response or energy-time curve (ETC) of a single system or device under test (DUT), or the correlation function between the two input signals.
• The built-in signal generator can produce special excitation signals to excite the system or device under test (DUT), or a single tone for calibration purposes.

Each tool includes manual and automatic plot scaling, as well as a data cursor for obtaining precise signal information. Additionally, the current data in each tool can be saved to a tab-delimited text or MAT file. The analyzer display can also be saved to an image file within the device's photo library. (The image can later be retrieved from the built-in Photos app.)

Audio Input Path

The audio input path is automatically determined by the iPhone OS, according to the external audio hardware, if any, connected to your device. Some possible audio input and output scenarios are discussed on the audio routes help page.

On all devices, except the 1st generation iPhone, the audio input data is sampled at 48 kHz. On the 1st generation iPhone, the sample rate will be limited to 8 kHz when using any one of the built-in microphone, built-in speaker or receiver (the receiver is the internal speaker that is located near your ear when using the iPhone as a phone).

The three typical audio input paths are discussed in greater detail on the following pages:

• Dock Input (recommended for most measurements)
• Built-in Microphone (iPhone only)
• Headset Input (not available on 1st gen iPod touch)