NAD T 751751 owner manual Channel Delays, Channel Balance

GB

Dolby Digital uses a dedicated Low Frequency Effects (LFE) channel. If a subwoofer has been selected, the LFE channel will be fed to the sub- woofer output.

Channel Delays:

For the best surround sound performance it is important that sound from all speakers reach the lis- tener’s ears at the same time. Because the sur- round/rear speakers are usually closer to the listener than the front speakers, there is tendency for the ear to localise sounds to the rear, because the ear takes most notice of the sounds that arrive at the head first. Similarly, the center speaker is often closer to the lis- tener than the front left and right speakers. To com- pensate for this, the T 751 can slightly delay the audio sent to the center and rear (closer) speakers. In this way, when playing Dolby Digital or Dolby Pro logic soundtracks, the sound from all speakers arrives uniformly at the listening position as intended by the film’s producer.

Each millisecond corresponds approximately with 1 foot or 30.5 centimeters.

NOTE:

The channel delay option is not available in DTS surround mode.

To set the center channel delay time,

•Call up the SETUP menu of the On Screen Display (Fig. 7).

•Select the CHANNEL DELAYS menu (Fig. 10).

•Choose CENTER and select the desired delay time (1, 2, 3, 4 or 5ms).

channel speakers that are up to 5 feet (1.5 m) closer to the listening position than the front left and right speakers.

NOTES:

In rare system setups, the center channel speaker is actually further away than the front left and right speakers. In these cases, set the center channel delay to 0mS. The center channel delay time adjust- ment is only available in Dolby Digital surround mode.

To set the rear channel delay time,

•Use the 3 or 4 cursor button (No. 7) to highlight the REAR.

•Scroll the preset delay time options by 1 and 2 cursor buttons.

Measure the distance from the listening position to either the left or right rear speaker (dLS or dRS). Subtract the rear speaker distance from the front speaker distance (dFL or dFR). The resulting dis- tance is equivalent to the delay in milliseconds for the rear delay setting. For example, if your rear speaker distance is 6 feet (1.8 m) and the front distance is 12 feet (3.7 m), the correct rear channel delay setting is 6 milliseconds. Again, set the rear channel delay to 0mS if the rear channels are further from the listening position than the front speakers.

In Dolby Digital surround mode, the rear channel delay time can be set from 0ms to 15ms with 1ms increments.

In Dolby Pro logic surround mode, the rear channel delay time can be set from 15ms to 30ms and 1ms per step. In DTS surround mode, the channel delay time cannot be adjusted.

FRONT

LEFT

REAR

LEFT

dFL

dFS

CENTER

dC

LISTENING POSITION

FRONT

RIGHT

dFR

dRS	REAR
	RIGHT

•When both delays have been entered, choose “SAVE & EXIT” to save the settings and return to the Main Menu.

Channel Balance:

The output levels of each of the speakers connect- ed to the T 751 may need to be adjusted so that there is an even balance of sound from all the speakers in the system. If, for instance, the relative volume level

Measure the distance from the listening position to the center speaker (dC) and to one of the front speakers (dFL or dFR). Subtract the center channel distance from the front L or R channel distance. For example, if the front speakers are 12 feet (3.7 m) from the listening position and the center speaker is 10 feet (3.0 m), the difference is 2 feet (0.6 m). For this example the center channel delay is set to 2 mil- liseconds or ms.

The T 751 can delay the center channel output up to 5 milliseconds and thus compensates for center

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to the Left and Right speakers and the center speak- er is set too low, most of dialogue may be difficult to follow. If, on the other hand it is set too loud, the over- all balance will sound unnatural.

To adjust the channel balance the T 751 is equipped with a TEST button (No. 6) to help assess the loudness levels of each speaker. Before adjusting the channel balance level make sure the master vol- ume is turned down to a normal listening level.

Pressing the TEST button engages the Test signal