Calibrating Loudness

The user can fine-tune the amount of loudness compensation using the compensation adjustment slider and adjusting "by ear," or by measuring SPL levels in a particular room, then using the slider to adjust the loudness filter relative to the SPL of the room and system gain structure.

Before calibrating loudness, set up the system gain structure (see Optimizing Audio Levels on page 88). A pre-recorded track of pink noise or pink noise from a signal generator is preferable for this purpose. Program material can also be used (using familiar material is recommended).

If using a signal generator, set it to output -10 dBu. Tthen set the input gain of the DSP Configurator so the input meter reads -20 dBFS. If using a recorded source, the pink noise should be recorded at -20 dBFS and the player output level setting control set to maximum, or 0 dB of attenuation. For program material, set the input level to meter at approximately -15 dBFS, with peaks safely below 0 dBFS.

Unmute the mix-point from the pink noise source to the output connected to the room amplifier being calibrated. With the basic gain structure previously set up, loudness can be calibrated using an SPL meter or by ear. Loudness can also be set using an SPL meter, then fine-tuned by ear.

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

1.Set the Loudness processor to Bypass (Bypass button red).

2.Place the meter in an average (but somewhat prominent) listening location.

3.Generate pink noise, or start the program material playback.

4.Measure the SPL in the room.

5.In the loudness dialog, adjust the slider until the value in the SPL readout box matches the reading on the SPL meter.

NOTE: Theoretically, calibration can be performed with the output channel volume and post‑mixer gain level set to any comfortable listening level. But a relatively loud volume (well above the ambient noise in the room) that can be easily measured is preferred.

Loudness is now calibrated. Disengage Bypass to hear the compensation.

Alternate method to calibrate loudness:

1.Set up the procedure using step 1 through 3 of the previous procedure.

2.Set the compensation adjustment slider to its default center position

3.Set the output channel volume fader to 0 dB (100% volume),

4.Adjust the amplifier until the SPL meter reads 90 dB.

Loudness is now calibrated. This method works if 90 dB is an acceptable volume limit for the room.

Setting Loudness “By Ear”

When setting loudness by ear, it is essential the system gain structure be set up first. Sit in an average (but somewhat prominent) listening location.

1.Set the loudness processor to Bypass.

2.Set the output volume fader in the DSP Configurator to a relatively quiet listening level. Filter compensation from the loudness processor is most prominent at low listening levels. Use familiar program material set to the levels described earlier.

DMP 64 • Software Control

57

Page 62 Page 64
Page 63
Image 63
Extron electronic DMP 64 manual Calibrating Loudness, Setting Loudness By Ear, Alternate method to calibrate loudness
Page 62 Page 64

DMP 64 specifications

The Extron DMP 64 is a versatile digital matrix processor that is specifically designed for handling multi-channel audio signal distribution in a variety of applications. As a part of the Extron family of audio products, the DMP 64 is particularly well-suited for educational institutions, corporate environments, and other professional settings where high-quality audio management is paramount.

One of the standout features of the DMP 64 is its six inputs and four outputs configuration, allowing users to mix and route audio signals with ease. This flexibility is crucial in environments like lecture halls or corporate meeting rooms where multiple audio sources may need to be controlled simultaneously. The DMP 64 supports a wide range of audio formats and operates seamlessly with both balanced and unbalanced audio signals. This ensures compatibility with various microphones, speakers, and other audio devices.

The technology behind the DMP 64 includes Extron's innovative ProDSP, which enhances audio processing capabilities. ProDSP allows for high-quality sound processing through advanced algorithms that provide features such as equalization, compression, and limiting. The processor also includes preset recall functionality, enabling users to quickly switch between different audio setups as needed. This can be particularly beneficial in dynamic environments where quick adjustments are often required.

Another important characteristic of the DMP 64 is its user-friendly interface. With intuitive controls that are easy to navigate, users can quickly access and adjust audio settings without the need for extensive training. The device supports Extron's Global Configurator and GUI Designer software, allowing for remote control and customization of the audio system easily. This integration is essential for system integrators who want to create tailored solutions for their clients.

The DMP 64 also features an integrated web interface, providing a convenient way to manage the system from any connected device. This capability makes troubleshooting and system management straightforward and efficient, especially for tech support teams who may need to address issues remotely.

In addition, the unit is designed with robust connectivity options, including Ethernet for control and monitoring, as well as standard audio inputs and outputs. Built with reliability in mind, the DMP 64 is housed in a sturdy chassis, ensuring it can withstand the demands of everyday use in professional settings.

Overall, the Extron DMP 64 combines advanced audio processing technology with user-friendly design and features that cater to the needs of today’s audio/video environments. Its flexibility, reliability, and high-quality sound management make it an ideal choice for diverse applications, from classroom environments to corporate meeting spaces. Whether it’s for conferencing, presentations, or events, the DMP 64 stands out as a powerful tool in professional audio management.
Top Page Image Contents