Dirac Live® Theater Setup Guide Version 1.
Dirac Theater Setup Guide Version 1.01 Notices This product contains software proprietary to Dirac Research AB and Datasat Digital Entertainment and protected by US and International copyright law. Unauthorized reproduction or distribution, in whole or in part, is strictly prohibited. WARRANTY/LIMITATION OF LIABILITY EXCEPT FOR THE LIMITED WARRANTY PROVIDED HEREIN, THIS PRODUCT IS PROVIDED "AS IS" AND WITHOUT WARRANTY OF ANY KIND.
Dirac Theater Setup Guide Version 1.01 Table of Contents Limited Warranty .............................................................................................................................. iv Contact Information........................................................................................................................... iv Product Improvements and Upgrades................................................................................................ iv Introduction ..............
Dirac Theater Setup Guide Version 1.01 Limited Warranty Datasat Digital Entertainment software is warranted against defects for a period of 90 days from the date of the original purchase. AP20 hardware is warranted against defects in material and workmanship for a period of one year from the date of the original purchase. This warranty includes parts and labor.
Dirac Theater Setup Guide Version 1.01 Introduction This manual explains the procedure for optimizing the audio in a theater auditorium using Dirac Live® and the Datasat Digital Entertainment AP20 Audio Processor. It contains full instructions for setting up equipment and software, performing audio measurements, and performing optimization. One of the most compelling features of the AP20 is the inclusion of Dirac Live® room optimization technology.
Dirac Theater Setup Guide Version 1.01 Portable computer requirements A laptop computer (not supplied by Datasat) is used inside the theater auditorium that is being optimized. Both the AP20 Proxy and the Dirac Live® software will be installed onto the laptop and will run concurrently. The laptop will maintain wireless connectivity with the AP20 (which is installed in the projection booth).
Dirac Theater Setup Guide Version 1.01 Installation Checklist Use the checklist to make sure that important settings are completed before using the AP20. Table 1: Dirac Live® Installation and Setup Completed Task Refer to: Install Dirac Live Software on Laptop (if not installed already). Appendix A Projection room connections and setup -- Install wireless router onto AP20 (to communicate with laptop) Section 1.
Dirac Theater Setup Guide Version 1.01 ® 1. Dirac Live Setup The optimal approach to cinema audio tuning is to perform the procedure from inside the theater. The technician(s) are able to detect any faulty speakers or misdirected audio channels, as well as ensure that theater curtains and masking are properly opened. Technicians can also take note of any heating or air conditioning noise, or other extraneous noise that may interfere with audio quality. 1.1.
Dirac Theater Setup Guide Version 1.01 • Laptop with Dirac software installed and security dongle • Microphone and microphone stand • USB Pre amp • SPL meter • Cables for connecting microphone to preamp, preamp to laptop. • Hearing protection Find a comfortable spot to work in the Theater in which you will be performing the Dirac optimization. (Recommended) Locate an AC outlet for possible use if your laptop will require AC power during the setup.
Dirac Theater Setup Guide Version 1.01 The AP20 Proxy software is the wireless bridge between the Dirac Live® software and the AP20 hardware. If a single AP20 is found by the proxy software, the IP address of the AP20 on the network will be displayed in the upper left corner of the application. If more than one AP20 is found, the user must choose the target AP20 by selecting from the combo box as shown below in Figure 2. Once a target AP20 is selected, the application will look like Figure 3. Figure 2.
Dirac Theater Setup Guide Version 1.01 c. Sequence a noise burst across multiple channels. Declare a first and last channel. The noise will index from the first channel to the last channel in 3-second increments. d. Send a NetCmd to the target AP20 and see the returned message displayed in the AP20 Proxy debug window. Simply type the NetCmd into the Proxy and send it to the AP20. e. Enable/ Disable and bypass the Dirac Live® playback engine in the target AP20.
Dirac Theater Setup Guide Version 1.01 • Set the Fader to 7.0, which is the standard reference level. • On the laptop with the Dirac Live proxy software, run Pink Noise on the first channel. • Using the calibrated SPL meter in the auditorium, adjust the gain of the amplifiers to produce a nominal 85dB level. • Repeat for each channel. 2. Dirac optimization 2.1.
Dirac Theater Setup Guide Version 1.01 Important information about the choice of microphone positions The microphone positions should be spread out regularly (roughly evenly over the listening area), but somewhat randomly, in the various listening positions that will be used by the listeners. The microphone height should be consistent (the height of a seated listener’s ear) to capture all relevant variations that occur within the listening region.
Dirac Theater Setup Guide Version 1.01 2.2. Configure the Dirac Live® application Dirac Live®will take you through four steps to optimize a room. Each step has a separate and distinct user interface. The steps are: • Configure: Select the output channels on the AP20. For 5.1 audio (six channels), select the first six channels on this screen. If a given channel is actually routed to multiple speakers such as a surround array, you need to indicate this, by clicking the Multiple speakers checkbox.
Dirac Theater Setup Guide Version 1.01 2. Select the soundcard input that the microphone is connected to. See Figure 6. Be sure to select USB Preamp ASIO driver (if you have more than one ASIO driver installed on your computer) and be sure to declare which input channel your measurement microphone is plugged into. Select the ASIO driver for the USB Preamp. Select which soundcard input the microphone is connected to. Figure 6.
Dirac Theater Setup Guide Version 1.01 3. Select the output channels on the AP20 that are connected to speakers that you want to optimize. Only the selected channels are enabled and will be measured and optimized. See Figure 7. Check the output channels on the AP20 that are connected to speakers and that you want to optimize. Only channels that are checked become enabled and will be measured and optimized. Figure 7. Soundcard Setup Screen 9 Document # 9301H40300V1.
Dirac Theater Setup Guide Version 1.01 4. (Recommended) Select a name from the pulldown for each of the enabled channels, to assist in identifying the loudspeaker locations. See Figure 8. A Dirac Live® filter will be created for each of the selected channels. Optionally, select names for the enabled channels that correspond to the loudspeaker locations. Figure 8. Soundcard Setup Screen 10 Document # 9301H40300V1.
Dirac Theater Setup Guide Version 1.01 5. Check the Multiple speaker checkbox for any channel that services more than one loudspeaker. The Multiple speakers checkbox must be checked for loudspeakers that are horizontal arrays, such as the surround channels in many cinemas. Checking this box will skip the impulse response correction on those channels, and instead only apply magnitude response correction.
Dirac Theater Setup Guide Version 1.01 7. Press the Play button to start the test noise for that channel. Pressing the Play button outputs test noise on that channel and displays the sound level. (Press the Play button again to stop the test noise.) 8. Read the level in dB and make sure that each channel is measured at approximately -6 to -22 dB (normal listening levels), which corresponds to the green indicator. If the indicator is red, you need to adjust the recording level.
Dirac Theater Setup Guide Version 1.01 Click the Take new measurement button to begin recording. Figure 11. Record Samples Screen ® The Dirac Live interface will indicate which loudspeaker is currently being measured. See Figure 12. Do not disturb the measurement in any way. Do not adjust the recording and playback levels during measurement. Message indicates which loudspeaker is currently being measured. Figure 12. Make Recordings Screen 13 Document # 9301H40300V1.
Dirac Theater Setup Guide Version 1.01 When the measurement is completed, the measurement counter is updated, as shown in Figure 13. When the measurement is completed, the measurement counter is updated. Figure 13. Make Recordings Screen 4. Move the microphone to a different location and take a new reading. 5. Save the measurements when all measurements are complete. 2.4.
Dirac Theater Setup Guide Version 1.01 Blue plot = average magnitude response. Red plot = suggested target curve. Figure 14. Optimize System Screen 1. Click the Edit Target button to edit the target. See Figure 15. Note that the target response is a combination of a graphically editable curve and the cross-over filters that are edited separately. • Adjust the curve by clicking on a point and dragging it to a new location. • Double-click on a point to erase that point.
Dirac Theater Setup Guide Version 1.01 Click Edit Target. Then click on a point (on the red plot) and drag it to a new location. Adjust the cross-over settings and enable/disable the cross-overs as desired. Figure 15. Optimize System Screen The target curve and cross-over settings are all done on one channel at a time. Make sure you are satisfied with the target response on each channel. 3.
Dirac Theater Setup Guide Version 1.01 Click Copy target/xover. Then in the dialog box, select to copy the target, the crossover, or both, to any number of selected channels. Figure 16. Optimize System Screen Next, in the Optimization step, the Dirac Live® system analyzes the samples and the target for each channel, fixes the frequency alignment, and fixes the time alignment (also known as impulse correction). 4. Press the Optimize button.
Dirac Theater Setup Guide Version 1.01 Click Optimize. The lower plot (After) shows the target plot in red and the average magnitude response (in blue) after optimizing. Figure 17. Optimize System Screen ® Next, Dirac Live will perform impulse correction. The software will attempt to adjust for reflections or reverberations – “room modes” – coming off the auditorium wall, which cause portions of the spectrum to get reinforced.
Dirac Theater Setup Guide Version 1.01 Select Impulse response to view the average impulse response before and after optimization. Figure 18. Optimize System Screen The resulting system responses are shown in the lower panel on the Optimize screen. These are validation models computed by applying the filter to the system measurements. If the target response is not reached everywhere, it may be due to a filter gain limitation.
Dirac Theater Setup Guide Version 1.01 Downloading the filters to the AP20 will enable the newly computed filters in the sound chain. Click the Download button to download the Dirac Live filters to the AP20. Figure 19. Export Screen After the Dirac Live filters have been downloaded, it is possible to perform an optional gain and delay calibration of the optimized speakers. 2. Put the microphone in a central listening position where the distances and the levels of each speaker are desired to be equal.
Dirac Theater Setup Guide Version 1.01 2.6. Final Sound Level Adjustments After the Dirac Live® optimization procedure is complete, and Dirac Live® settings have been loaded, use the SPL meter and the Dirac Live® test noise as described previously to adjust the AP20 Analog Output Levels, if necessary, to match those shown in the table below. • By adjusting the amplifiers, try to achieve the baseline levels. Set the SPL levels according to the chart below.
Dirac Theater Setup Guide Version 1.01 Appendix A. Additional Installation Information USB Preamp, Setup 1 2 3 Figure 21. 4 USB Preamp, front view 1. Input gain controls – adjusts Mic input gain levels. 2. 48V Phantom power switch – push button to provide phantom power for both mic inputs, red LED will illuminate when power is ON. 3. Input level meter – meter shows the input level of each channel input. 4.
Dirac Theater Setup Guide Version 1.01 Loading the AP20 Proxy software and Dirac Live® software onto the laptop Note: Any virus protection applications and firewalls should be temporarily disabled before installing the Dirac software. The Dirac Live® software requires the following to be installed: 1. Matlab’s version 7.13 runtime library. To install this run MCRInstaller_2010a.exe which is found on the root of the “AP20 Dirac Live Configuration Software” disc. 2.
