output levels from 0.1 mV to 5 V and offsets from 0 to ±5 V, and delivers up to 100 mA of current.

Arbitrary waveform capability is standard with the SR785. Use the arbitrary source to playback a section of a captured waveform, play a selected FFT time record or upload your own custom waveform from your computer.

User Math

Create your own measurement in each of the SR785's measurement groups using the math menu. Enter any equation involving RMS averaged, vector averaged or unaveraged time or frequency data, stored files, constants, or a rich array of supplied operations including arithmetic functions, FFT, inverse FFT, jω , d/dω , exp, ln x, and many others. Because all the averaging modes are available as user math operands, non-repeatable runout measurements (used in analyzing disk drives) can be performed in a single pass by entering the equation MAG(RMS<F1>)-MAG(Vec<F1>). Unlike many other analyzers, the SR785's measurement rate is virtually unaffected when user math is selected. For instance, the function exp(ln(conj(FFT2/FFT1))) can be calculated with a 100 kHz real-time bandwidth.

The SR785 doesn’t limit you to a few preselected measurements. With user math you can create an infinite variety of measurements.

Waterfall

Waterfall plots are a convenient way of viewing a time history of your data. Each successive measurement record is plotted along the z-axis making it easy to see trends in the data. All

Two 2k deep waterfall buffers ensure you’ll never miss important waterfall data.

FFT, octave and order tracking measurements can be stored in the SR785's waterfall buffer memory. You can choose to save all measurements and averaging modes or just the current measurement to conserve memory. Waterfall traces can be stored every n time records for FFT and order tracking measurements. For order tracking measurements new records can be acquired at a specific time interval or change in RPM. In octave measurements, the storage interval is in seconds (as fast as every 4 ms). While displaying waterfall plots, you can adjust the skew angle to reveal important features, or change the baseline threshold to eliminate low-level clutter. Any z-axis slice or x-axis record can be saved to disk or displayed separately for analysis.

Analysis

The SR785 includes a wide variety of built-in analysis features. Marker analysis lets you easily measure the power contained in harmonics, sidebands or within a given band of frequencies. Important information such as THD, THD+N, sideband power relative to a carrier, or total integrated power are calculated in real-time and displayed on the screen. The front/back display feature allows you to display live data from both signal inputs on one graph. You can also simultaneously display saved traces and live data. The peak-find marker allows you to quickly locate frequency peaks with the click of a button. The marker statistics feature calculates the maximum, minimum, mean and standard deviation of data in any section of the display. For modal analysis, the cursor can be configured to display the resonant frequency and damping of a single selected mode.

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SRS Labs SR785 manual User Math, Waterfall, Analysis
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SR785 specifications

The SRS Labs SR785 is a powerful and versatile audio analysis tool designed for audio engineers, researchers, and manufacturers. This instrument is renowned for its ability to perform a wide array of measurements, making it an essential asset for anyone involved in audio testing and development. With its cutting-edge features and technologies, the SR785 stands out in the competitive field of audio analysis.

One of the main features of the SR785 is its dual-channel capability, which allows users to analyze both input and output signals simultaneously. This is particularly useful for applications such as loudspeaker testing, where comparing the input signal against the output can provide valuable insights into the performance and fidelity of audio systems. The device supports a wide dynamic range and can capture audio signals from an impressive range of frequencies, ensuring accurate representations of even the most nuanced sounds.

The SR785 employs state-of-the-art Fast Fourier Transform (FFT) technology, enabling users to switch between time-domain and frequency-domain analysis with ease. This flexibility allows engineers to tailor their measurements based on specific requirements, whether they are evaluating distortion levels, frequency response, or impulse response. The instrument’s high-resolution display provides clear visual representations of the analyzed data, making it easier to identify trends and anomalies.

Another notable feature of the SR785 is its built-in automation capabilities. This technology allows for automated testing sequences, streamlining the analysis process and reducing the potential for human error. Users can pre-program a series of tests to run automatically, ensuring consistency in measurements and saving valuable time during testing and analysis.

Additionally, the SR785 offers extensive data storage options, allowing users to save measurement results for future reference or comparison. This is particularly beneficial for long-term studies or for manufacturers conducting quality control checks on production lines. The device is also equipped with a range of connectivity options, including USB and GPIB, facilitating easy integration into existing test setups and enhancing its versatility.

The combination of advanced features, robust technologies, and user-friendly design makes the SRS Labs SR785 a top choice for audio professionals seeking a reliable and efficient audio analysis solution. Whether for research, development, or quality assurance, the SR785 delivers precise and actionable insights that drive sound performance to new heights.
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