Introduction

Tact-2.2 XP can perform room correction using PC software or automatically
from the 2.2 XP front panel user interface.PC based room correction requires that 2.2 XP is connected to RS232 port of a PC. The PC software is used just as a GUI (graphical user interface) to provide the user with graphical presentation of the correction process. After the room response measurement is completed room frequency response for all measured channels can be displayed on the screen. Crossover filters and actual correction filters can be viewed. The displayed graphs provide valuable information that helps users design their own optimum target curve.

Automatic room correction feature is designed to perform entire room correctionprocess without the PC interface. Tact-2.2 XP has sufficient DSP processing power to perform room measurement, crossover filter design and target curve generation and correction filter calculation. Entire process is controlled from 2.2 XP front panel DRCRCS menu. Target curve and crossover filter adjustments can be made on the fly while the music is playing. Users can, for example, specify a boost at low frequencies or a rolloff at high frequencies. Values of the ‘low’ and ‘high’ frequencies can also be adjusted.

Tact-2.2 XP memorizes two sets of target curves: computer generated and
automatically generated target curves. When automatic feature is turned OFF 2.2 XP will use computer generated set of target curves. When automatic feature is turned ON 2.2 XP uses target curves generated by 2.2 XP automatic correction feature. When 2.2 XP is connected to PC and automatic feature is enabled, automatically generated target curve will be uploaded into RCS/DRC screen. The curve can than be saved or modified. Modified curve can than be loaded back into 2.2 XP. However, uploaded curve will not take effect until automatic feature is disabled. Any target curve uploaded to 2.2 XP is saved as PC generated target curve and this target curve takes effect only when automatic feature is disabled. In another words, if target curve is to be
modified by the PC software automatic correction feature has to be disabled.

This paper describes automatic room correction process for all 2.2 XP operating modes.

2.2 Mode

This operating mode assumes a stereo system consisting of two main channelsand two subwoofers. To select the 2.2 mode, from the main screen, click on the MENU button to enter main menu screen and then select MODE menu. Click on STEREO 2.2 menu option to select 2.2 operating mode. Current operating mode is display it on top of the screen (1) Fig.1.

	Fig. 1. Mode menu. Selected 2.2 mode selection is displayed in the upper left corner (1).

To perform 2.2 mode automatic room correction implement the following steps.

1. Correction Bypass. Place 2.2 XP in correction bypass mode. You can place 2.2 XP in bypass mode by pressing on BP remote control button or by using front panel controls.

	Fig. 2. Tact-2.2 XP main screen. Note a ‘*’ next to BP. It indicates that BP – bypass mode is selected.

2. Crossover Filters OFF. Make sure that crossover filter option is set to OFF. It is important that all measurements are performed without any crossover filtering. If your loudspeakers have built in electronic crossover filters make sure that they are disabled. If crossover filters could not be disabled set the subwoofer crossover filter to its highest frequency and main channel to its lowest cut off frequency. To disable crossover filters enter RCS-DRC menu and select CRO-ON(OFF) option in Fig.3 to enter Crossover screen Fig. 4.

	Fig. 3. RCS-DRC screen.

	Fig. 4. Crossover menu. CRO: OFF indicates that crossover filters are disabled.

Crossover filters can be turned OFF from the front panel crossover menu (Fig. 4). Place screen cursor over CRO: ON menu option and then press enter button (click) until it displays CRO: OFF and then click on SET option. Please note that any change made on this screen does not take effect until you click on the SET option. Click on MENU button to go back to DRC-RCS screen Fig. 3.

3. Measurements. To perform room response measurement select MSR menu option to display measurement screen (Fig. 5).

	Fig. 5. Measurement screen.

2.2 XP is factory configured to measurement parameters as displayed in Fig. 5. MSR MIC CAL option should be turned ON and MIC FILE field should
display microphone serial number as printed on your microphone.

• MSR MIC CAL When this option is set to ON, the room correction algorithm will apply the microphone calibration file to the measurement data. When this option is set to OFF, the microphone calibration file is ignored.

• MIC FILE This field displays the microphone file name used to perform microphone calibration. The microphone calibration file data is saved in 2.2 XP internal memory. For more details on how to transfer microphone calibrations file to 2.2 XP memory, please refer to the Microphone section of the PC software manual.

• AVG This is a very important measurement parameter. It equals the number of measurements that are averaged prior to being saved. The averaging process reduces the effects of random environmental noise. Typical Average values go from 10 to 30.

• DELAY If you do not want to be in the room while measurement is in progress, set this parameter to a few seconds to allow you to exit the room. For example, if DELAY = 10 the system will wait for 10 seconds before it starts pulsing.

• PULSE This parameter sets the relative level of the output measurement
pulse. Minimum level is 1% and maximum level is 100%.

• FILE Use this option to assign a File number to the measurement you are just about to perform. At the end of the measurement process, the measurement data for all four channels will be saved in the selected File number. Tact-2.2 XP supports up to seven measurement files. In another words you can save up to seven different measurements in 2.2 XP internal memory.

• Use L, R, SL and SR options to select (enable) a channel for measurement. Channels are labeled as L for left, R for right, SL for subwoofer left and SR for subwoofer right channel. Selected (enabled) channels are marked by a rectangle. To select or deselect a channel place the cursor over
desired channel and press ENTER button. In most cases factory presets are optimum and users can proceed directly with performing actual measurements. To initiate the room measurement process click on START button. The following screen will be displayed:

	Fig. 6. Microphone calibration and measurement screen.

After the measurements are completed click on EXIT option and then click on
MENU button to go back to DRC-RCS screen (Fig. 3). At any time during the measurement process you can click on CANCEL option to cancel the process. After the measurement is completed or measurement was canceled
CANCEL option changes its name to EXIT.

4. Enable automatic room correction. In DRC-RCS screen (Fig. 3) select correction preset 1. Make sure that crossover filters are enabled and proper crossover frequency is selected. Crossover filters can be adjusted at any time even after you enable automatic feature. Click on AUTO-OFF menu option to enter Auto Correction screen (Fig. 5). Note that in bypass mode AUTO-OFF(ON) menu option is not displayed.

	Fig. 5 Auto Correction screen.

In the Auto Correction screen click on AUTO-OFF menu option to display AUTO-ON and then click on SET option to activate automatic room correction. In a split of a second 2.2 XP will calculate target curve based on LF, HF, crossover filter selection parameters and measurement data as saved in measurement file 1.

You are ready to perform your first listening test. Use LF parameters to add gain or attenuation at frequencies bellow the frequency as displayed in LF parameter bloc (1). Use HF parameters to add gain or attenuation to frequencies above the frequency as displayed in HF parameter block (2). In this way you can shape target curve to match your specific listening needs.

Please note that changes you make on this screen do not take effect until
you click on SET option.

2.1 Mode

This operating mode assumes a stereo system consisting of two main channels and one subwoofer. To select 2.1 mode, from the main screen, click on the MENU button to enter main menu screen and then select MODE menu. In the MODE menu click on STEREO 2.1 option. This will select 2.1 mode and display it on top of the screen (1).

	Fig. 6. Mode menu. 2.1 mode selection is displayed in the upper left corner (1).

The rest of the procedure is the same as in 2.2 mode. Note the change in the measurement screen in Fig. 7. Tact-2.2 XP will automatically select channels for measurements based on the mode selection.

	Fig. 7. Measurement screen for 2.1 mode. Note that SR does not have a rectangle around indicating that this channel is not set for measurement.

In 2.1 mode only Left, Right and Subwoofer Left channels will be measured. At the end of the measurement process Subwoofer right measurement data will be set to 0 dB flat response.

2.0 Mode

This operating mode assumes a stereo system consisting of two main channels only. To select 2.0 mode, from the main screen, click on the MENU button to enter main menu screen and then select MODE menu. In the MODE menu click on STEREO 2.0 option. This will select 2.0 mode and display it on top of the screen (1).

	Fig. 8. Mode menu. 2.0 mode selection is displayed in the upper left corner (1).

The rest of the procedure is the same as in 2.2 mode. Note the change in the measurement screen in Fig. 9. Tact-2.2 XP will automatically select channels for measurements based on the mode selection.

	Fig. 9. Measurement screen for 2.1 mode. Note that SR does not have a rectangle around indicating that this channel is not set for measurement.

In 2.0 mode only Left, and Right channels will be measured. At the end of the
measurement process Subwoofer Left and Subwoofer Right measurement data will be set to 0 dB flat response.