Adcom GTP-860 Determining Delay Values, Speaker Settings, surround rear left front left, center

Scroll through the preset delay time options and select the desired time.

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

In Dolby Digital surround mode, the rear channel delay time can be set from 0ms to 15ms with 1ms increments. The center channel can also be delayed up to 5ms, in 1ms steps.

In Dolby Pro Logic surround mode, the rear channel delay time can be set from 15ms to 30ms and 1ms per step.

For other modes including DTS, the channel delay time cannot be adjusted.

Determining Delay Values:

surround

rear left

front left

surround back left

center

surround back right

front right

surround rear right

Measure the distance from the listening position to the center speaker and to one of the front speakers. Subtract the center channel distance from the front left or right 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 milliseconds or ms.

The GTP-860 can delay the center channel output up to

5 milliseconds and thus compensates for center channel speakers that are up to 5 feet (1.5 m) closer to the listen- ing position than the front left and right speakers.

In rare system setups, the center channel speaker is actu- ally further away than the front left and right speakers.

In these cases, set the center channel delay to 0ms. The center channel delay time adjustment is only available in Dolby Digital surround mode.

Now, measure the distance from the listening position to either the left or right rear speaker. Subtract the rear speaker distance from the front speaker distance. The resulting distance is equivalent to the delay in millisec- onds 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.

3.4 Speaker Settings

Four modes are available to the GTP-860’s setup: On or Off, and Large or Small.

The On mode is used when the speaker is present. The Off mode is used when a speaker is not present. Front speakers are assumed to be present, so they cannot be turned off. Center, Surround, and Subwoofer speakers are optional, and these are the speakers you must describe to the GTP-860. Audio signals intended for speakers which are not present are redirected to the main speakers.

When a speaker is On, it can be set as Large or Small. The Large mode is used when the speaker is full range and capable of reproducing the entire audible frequency spec- trum from 20Hz to 20kHz. The Small mode is used when the speaker is not capable of reproducing the deepest bass portion of the audio frequency 20Hz to 100Hz. When a speaker is set to small, the low frequencies intended for that speaker are redirected either to the Front speakers or the Subwoofer.

For best results, you should consider using a center speaker. Ideally it should be the same type as the left and right speakers. Using a separate center channel speaker will allow the dialogue to cut through even the biggest sound effects and musical scores. Having the sound spread across three front speakers also stabilizes the stereo image, making the usable listening area much bigger.

Installing surround speakers will greatly enhance the sur- round experience as these add considerably to the overall “ambiance.” Dolby Pro Logic encoded material is deliber-

28 ADCOM GTP-860 OWNER’S MANUAL