Denon AVR-2805 17ADDITIONAL INFORMATION

	Symptom		Cause	Measures	Page
unit			• Batteries dead.	• Replace with new batteries.	29
			• Remote control unit too far from this	• Move closer.	29
control
	This unit does not	operate	unit.		29
			• Obstacle between this unit and	• Remove obstacle.
	properly when remote	control
Remote	unit is used.		remote control unit.		—
			• Different button is being pressed.	• Press the proper button.
			• <and >ends of battery inserted in	• Insert batteries properly.	29
			reverse.

17ADDITIONAL INFORMATION

Optimum surround sound for different sources

There are currently various types of multi-channel signals (signals or formats with more than two channels).

2Types of multi-channel signals

Dolby Digital, Dolby Pro Logic, DTS, high definition 3-1 signals (Japan MUSE Hi-Vision audio), DVD-Audio, SACD (Super Audio CD), MPEG multi-channel audio, etc.

“Source” here does not refer to the type of signal (format) but the recorded content. Sources can be divided into two major categories.

Types of sources

•Movie audio Signals created to be played in movie theaters. In general sound is recorded to be played in movie theaters equipped with multiple surround speakers, regardless of the format (Dolby Digital, DTS, etc.).

ENGLISH

Surround back speakers

A 6.1-channel system is a conventional 5.1-channel system to which the “surround back” (SB) channel has been added. This makes it easy to achieve sound positioned directly behind the listener, something that was previously difficult with sources designed for conventional multi surround speakers. In addition, the acoustic image extending between the sides and the rear is narrowed, thus greatly improving the expression of the surround signals for sounds moving from the sides to the back and from the front to the point directly behind the listening position.

Change of positioning and acoustic image						Change of positioning and acoustic image
	with 5.1-channel systems						with 6.1-channel systems
		FL	SW	C	FR			FL	SW	C	FR

		SL ch	SR ch
SL ch	SR ch		SB ch
Movement of acoustic image from SR to SL		Movement of acoustic image from SR to SB to SL

With this set, speaker(s) for 1 or 2 channels are required to achieve a 6.1-channel system (DTS-ES, etc.). Adding these speakers, however, increases the surround effect not only with sources recorded in 6.1 channels but also with conventional 2- to 5.1-channel sources. The WIDE SCREEN mode is a mode for achieving surround sound with up to 7.1 channels using surround back speakers, for sources recorded in conventional Dolby Surround as well as Dolby Digital 5.1-channel and DTS Surround 5.1-channel sources. Furthermore, all the DENON original

Movie theater sound field
FL SW C	FR	Listening room sound field
SL	SR	FL	SW C	FR
		SL		SR
			SB

SB

Multiple surround speakers

(For 6.1-channel system)

In this case it is important to achieve the same sense of expansion as in a movie theater with the surround channels.

To do so, in some cases the number of surround speakers is increased (to four or eight) or speakers with bipolar or dipolar properties are used.

SL: Surround L channel

SR: Surround R channel

SB: Surround back channel

surround modes (see page 45) are compatible with 7.1-channel playback, so you can enjoy 7.1-channel sound with any signal source.

2 Number of surround back speakers

Though the surround back channel only consists of 1 channel of playback signals for 6.1-channel sources

(DTS-ES, etc.), we recommend using two speakers. When using speakers with dipolar characteristics in

particular, it is essential to use two speakers.

Using two speakers results in a smoother blend with the sound of the surround channels and better sound

positioning of the surround back channel when listening from a position other than the center.

2 Placement of the surround left and right channels when using surround back speakers

Using surround back speakers greatly improves the positioning of the sound at the rear. Because of this, the

surround left and right channels play an important role in achieving a smooth transition of the acoustic image

from the front to the back. As shown on the diagram above, in a movie theater the surround signals are also

produced from diagonally in front of the listeners, creating an acoustic image as if the sound were floating in

space.

•Other types of audio These signals are designed to recreate a 360° sound field using three to five speakers.

FL SW C FR

In this case the speakers should surround the listener from all sides to create a uniform sound field from 360°. Ideally the surround speakers should function as “point” sound sources in the same way as the front speakers.

SLSR

These two types of sources thus have different properties, and different speaker settings, particularly for the surround speakers, are required in order to achieve the ideal sound.

To achieve these effects, we recommend placing the speakers for the surround left and right channels slightly

more towards the front than with conventional surround systems. Doing so sometimes increases the

surround effect when playing conventional 5.1-channel sources in the 6.1 surround or DTS-ES Matrix 6.1

mode. Check the surround effects of the various modes before selecting the surround mode.

53