Adjusting the post-matrix trim

Adjusting the post-matrix trim is a bit of a balancing act. This section provides guidelines, but it may take a bit of going back and forth to set levels just right. For example, the output level can be controlled and kept below clipping using a compressor or limiter in the output dynamics block. However, adjusting the post- matrix trim affects how the compressor or limiter works.

1.	Open the output volume dialog box and the post-matrix trim dialog box.
2.	Set output volume to 100% (if the audio is too loud or distracting, mute the
	output).
3.	With program material or pink noise present at the input, adjust the post-
	matrix trim until the output volume dialog box’s meter level is below clipping
	(or ideally, matches the level at the input gain meter). This maintains the

audio at an optimal level in the output signal chain, and prevents clipping at the output.

Setting the volume control for the amplifier stage

The switcher’s maximum output is +22 dBu. Assume that you have a power amp with a maximum input level of +4 dBu when the input attenuator is fully open. If you want to control volume levels using the switcher’s non-DSP output volume controls and at the same time ensure that clipping does not occur at the amplifier, you need to turn down the power amp’s input attenuator the equivalent of 18 dB (18 + 4 = 22 dB), which puts the amp’s input level at -14 dB (+4 minus 18 = -14). If you find that the amp setting (when the DSP Configurator’s output volume controls are at 100%) is too loud for the room, you can turn it down further. If the amp is not loud enough for the room, you will need a more powerful amplifier.

On the other hand, if you wish to control volume levels using the power amplifier’s input attenuation control, (using the same power amp max input level) you can set the DSP Configurator’s output volume control to -18 dB. This is another way that clip points of the two devices will be matched, ensuring that clipping will not occur.

However, Extron recommends using the matrix switcher’s output volume control for controlling output volume. If you are using loudness processing on the unit, it works only in conjunction with the output volume control.

Calibrating loudness

The basic gain structure is now set up. From this point, loudness can be calibrated using an SPL meter, a critical ear, or a combination of the two.

Setting loudness using a meter

To calibrate loudness, use a sound pressure level meter set to “C” weighting.

1.	Open the post-matrix loudness processor dialog box.
2.	Bypass the loudness processor.
3.	Place the meter in an average listening location.
4.	Start your program material playback or generate pink noise.
5.	Measure the SPL in the room.

PRELIMINARY

MPX Plus 866 A Media Presentation Matrix Switcher • Switcher Software 5-39

MPX Plus 866 A specifications

The Extron MPX Plus 866 A is a powerful multimedia presentation switcher designed to meet the needs of modern AV environments. This advanced device simplifies the management of multiple audio and video sources, providing seamless control and connectivity in various settings such as conference rooms, classrooms, and auditoriums.

One of the key features of the MPX Plus 866 A is its ability to handle a wide range of video formats. It supports both HDMI and analog video, allowing for compatibility with different devices. This versatility ensures users can connect laptops, projectors, and other AV equipment without any issues, making it ideal for mixed-use environments where various technologies coexist.

With an 8x8 matrix design, the MPX Plus 866 A can route up to eight different input sources to eight output destinations. This feature enables users to select and switch between sources quickly and efficiently, enhancing the overall presentation experience. Additionally, the device incorporates Extron's high-performance scaling technology, which ensures that video signals are processed with exceptional clarity and detail, regardless of resolution.

Another noteworthy characteristic of the MPX Plus 866 A is its built-in audio capabilities. The switcher includes a comprehensive audio mixer with support for both analog and digital audio signals. This allows users to integrate and control audio sources effectively, ensuring that sound quality matches the visual experience. Furthermore, it features advanced audio processing tools, including equalization and filtering functions, to enhance audio output in any environment.

The MPX Plus 866 A also emphasizes ease of use and accessibility. Its user-friendly interface, combined with an intuitive control system, allows operators to navigate the device with minimal training. Additionally, the switcher supports various control options, including RS-232 and Ethernet, enabling integration into larger AV control systems for centralized management.

In summary, the Extron MPX Plus 866 A stands out as a versatile and reliable multimedia presentation switcher. Its extensive range of input and output options, advanced scaling and audio processing technologies, and emphasis on user-friendly design make it an exceptional choice for any professional AV installation. Whether in an educational setting or corporate environment, the MPX Plus 866 A ensures seamless connectivity and high-quality performance, meeting the demands of today’s multimedia presentations.

Extron electronic MPX Plus 866 A manual Adjusting the post-matrix trim, Calibrating loudness

Models: MPX Plus 866 A