TX-SR5805 Features

The TX-SR805 is a very flexible receiver with a number of features and functionality built in to allow a fair amount of control. The receiver has many of the typical installation control features, an RS-232 port for programming, IR input/output, Onkyo-RI System Control for use with other Onkyo components, and 12V triggers to daisy chain power up with other components.

The TX-SR805 features full HDMI 1.3a audio and video functionality. Signal bandwidth supports 1080p60 video and 36 bit Deep Color. Audio support is provided for bit rates of all the next generation codecs, DD+, DTHD, DTS HD, DTS MA, and uncompressed multi-channel LPCM. The TX-SR805 has three HDMI inputs as well as an output with an HDMI repeater to allow greater cable run lengths.

The receiver is capable of three zone operation with an optional powered zone 2 or zone 2 out and a zone 3 out. Combinations can include a main 7.1 surround zone with two stereo zone preamp outs or a main 5.1 with zone 2 powered by reassigning the main zone rear channel and the preamp out zone 3. The TX-SR805’s assignable audio amplifiers can also be used to bi-amp the main L/R channels.

The remote control is a standard Onkyo design that has been in use at least since the TX-SRxx2 generation, it is identical to what I recall of my TX-SR602 remote. It has a fairly standard feature set typical of most A/V receiver remotes. In addition to the obvious, it has programmable universal remote capability via a host of remote codes for various manufacturers and supports three programmable macros.

At the preamp switching level, each input channel allows for fully independent assignment of audio and video input types. Every video channel can be set to receive any input signal: HDMI, component, S-video, or composite video and each video source can then be assigned and switched between multiple audio input sources. In effect, the same video source can be assigned audio input via HDMI, SPDIF, and analog audio. For example, a DVD-V/DVD-A player would be allowed to use a single video input to switch between either HDMI or SPDIF digital input, for movies, and multi-channel analog, for use with DVD-A playback. With this feature, I was able to route HDMI video/audio from the HD-A2 and HDMI video with multi-channel analog from the HTPC.

The pre/pro section allows for independent crossover settings for each speaker group: main L/R, center, surround L/R, and back L/R channels. Surround setups, like my reference system, that use towers for the mains L/R can have a lower crossover frequency independent from bookshelf surrounds and back channels. All tone controls and manual equalizer settings allow independent settings for each speaker group as well.

Various volume control features can be setup though the OSD, such as setting the power up and maximum volume levels. Handy if little ones are about who like to twist knobs and press buttons. Volume control on the TX-SR805 is adjustable in 0.5 dB increments and can be switched between a relative and absolute display setting. The receiver also includes a feature for setting relative volume for different zone 1 source components that Onkyo calls IntelliVolume, which allows adjustment by input channel in 1dB increments up to + or – 12 dB maximum.

In addition to the TX-SR805 achieving THX Ultra2 certification, the receiver includes a number of other THX processing technologies: Neural Surround, Boundary Gain Compensation (BGC), and Advanced Speaker Array (ASA).

Neural Surround is a codec for embedding additional channels into audio signals with a limited number of channels. For radio broadcasts, a 5.1 mix can be encoded into a stereo signal for transmission, and then decoded back into 5.1 surround sound by any Neural Surround capable receiver. Another application for Neural Surround that THX promotes is for gaming where soundtracks are limited to 5.1 channels. The Neural Surround codec can embed playback for 7.1 channels into a 5.1 channel scheme.

Editorial Note on THX

Boundary Gain Compensation is exactly what it says. A common acoustic phenomenon, room boundary gain is sound reinforcement that occurs at bass frequencies due to wall reflections when in close proximity to a wall. The change from a three dimensional space, 4steradians, can boost bass by 6 dB. THX BGC is a filter that can be used to compensate for the effect to each channel.

THX Advanced Speaker Array is a calibration technique to approximate the different studio configurations used for mixing movie, music, and game soundtracks. Accurate recreation of the recorded sound field for each of these sources would require that speakers be physically relocated for every source change to match the original studio layout. ASA processing digitally compensates for use of a single speaker configuration in home theater settings to mimic the acoustical differences from the original mixing studio speaker arrangement for each source by use of a specific movie, music, and games mode setting.

The TX-SR805 includes Onkyo’s proprietary Theater Dimensional processing for virtual surround sound from stereo speaker arrays. This may seem like an unnecessary feature on an actual 7.1 channel surround receiver, but one possible use would be to mimic surround sound for use with zones, which are typically supplied stereo output from A/V receivers. Theater Dimensional processing, according to Onkyo, can also be used to doctor up near field performance of 5.1 speaker arrays in close quarters to increase the impression of space.

The audio processing on the TX-SR805 also includes Audyssey MultEQ XT acoustic room correction. MultEQ XT allows for correction of room acoustics issues using digital filters generated from up to eight in room measurements. These digital filters operate in the time domain but function as an equalizer that can smooth out frequency response without generating phase errors prevalent in typical frequency domain equalizers such as the ubiquitous graphic equalizer.

Editorial Note: Variations on Audyssey

Audyssey equalization is offered with various levels of room correction functionality, making this feature available for a wide range of product prices:

• EQ: Basic precalibrated system intended for HTiB that will eliminate the distortions caused by the speaker systems with room correction applied by assuming common room acoustics problems.
• 2EQ: Basic filter resolution applied to mid and upper frequencies based on two in room measurement positions.
• MultEQ: Moderate resolution filter applied to the full frequency response based on up to six in room measurements.
• MultEQ XT: Highest resolution using hundreds of points across the full frequency response for up to eight in room measurements.
• MultEQ Pro: Complete measurement software/hardware package used for professional system calibration.

Keep in mind that Audyssey can do a lot, but it is not panacea for all sonic shortcomings. The Audyssey system will correct for phase and frequency response errors introduced into playback by room acoustics and speaker coloration, but it cannot create recording detail lost by limits in audio system resolution and dynamic range. In a manner analogous to a video scalar, which can fill in the missing video lines, but can not recreate lost detail, Audyssey is simply another way to get the most out of the source material and electronics. Because there are compromises in using a digital filter to correct multiple listening positions, it is still good advice to make as much physical correction to the room as possible, leaving as much computational headroom for Audyssey in making the final touches.

Video Features

The TX-SR805 has modest video processing capabilities and it is clearly geared more for the audio side of the A/V equation. Considering that every other device in the video chain from source component to TV monitor has some form of video processing capabilities, including it in the receiver is another redundancy in an already overly redundant system. Onkyo’s offering in the TX-SR805 focuses the consumer’s dollar on audio, rather than another video scalar that may or may not be used.

Video processing for the TX-SR805 is provided by Faroudja DCDi, which will convert a 480i SD video signal to a 480p ED video signal. The TX-SR805 does provide HDMI switching between three inputs and one output in up to 1080p video resolution, but in does not provide any scaling capabilities between different resolutions.

DCDi is an older but a still viable deinterlacing/progressive scan technology. Even though DCDi does not scale to an HD resolution signal, it may still provide better deinterlacing than the embedded processing in other components. So, if one views at 720p or 1080p, test DCDi first before dismissing it as a SD/ED only technology and if it outperforms the deinterlacing capabilities of those other components, use it for generating a 480p signal and let the other system processor(s) scale to HD resolutions.

The TX-SR805 is capable of transcoding between various analog video inputs to digital output as well as between input and output of various analog signals, depending on what the monitor output setting is. When the TX-SR805 is set for an HDMI monitor, all analog signals will be transcoded to digital by the TX-SR805 as well as passes through signals in their native formats. With this setting, the OSD display will be routed to HDMI as well. Setting the HDMI monitor to off disables HDMI output, but will allow transcoding between analog composite and s-video input to any other analog output as well as pass through; component video will only pass through. Digital video input is never converted to analog by the TX-SR805.

One beef that I have with the TX-SR805 user manual is that it uses the terms upconvertion and downconvertion when describing transcoding; this is confusing and potentially misleading. Upconversion and downconversion are more appropriately applied to scaling to different display resolutions. When the signal format is changed between, say composite video to component video or to HDMI without any change in resolution, this is a translation of the signal encoding, hence transcoding. DCDi video processing is a deinterlacer, not a scalar as the video goes into it with 480 lines of vertical resolution and it comes out with 480 lines of resolution, the only difference is DCDi puts video frames split by interlacing back together into to a single, progressive frame.

One aspect of Onkyo’s implementation of DCDi in the TX-SR805 is that it is not applied to digital input signals, only to analog signals. I discovered this when I forced my HDMI connected HD-A2 to 480i output when attempting to look at the Onkyo’s video processing prowess but my TV was insisting that it was only getting 480i signal from the TX-SR805. So even if DCDi provides the best deinterlacing in a given system, it can not be used when the signal is kept digital.

For those consumers who do want full video processing in their A/V receiver, the TX-SR875 may be a better choice where it is clear from the shared owners manual that the TX-SR875 includes full scaling capabilities to 1080p. Direct comparison of features between the two receivers reveals that the extra $600 in price is mainly applied to improved video functionality, the TX-SR875 only sports 10 wpc more than the TX-SR805 but trades Faroudja DCDi video processing for HQV Reon-VX processing and an extra HDMI input.

As with audio, the TX-SR805 supports many of the latest video features and enhancements available through HDMI 1.3 and above such as Deep Color. Currently, digital video is encoded with 8 bits of data for each of the primary colors, red green, and blue in an RGB color space. The combined 24 bit color representation produces over 16.8 million color variations, which commonly is known as Truecolor. Many current DVD players specify a 10 bit video processor, which can be confusing as the color, is still represented as 8 bits in video encoding, while the extra 2 bits in the 10 bit processor amounts to digital headroom. Deep Color extends the color depth to true 10, 12, or 16 bits of data for a total of 30, 36, and 48 bit color representation. As this total color depth gets beyond the human eye’s ability to resolve distinct colors, the main advantage is that it will reduce posterization, which is the visible banding in an area of continuously varying color when not enough different colors are available for accurate representation.

Buying hardware that supports Deep Color is future proofing and the TX-SR805 supports up to 12 bit per color (36 bit RGB) Deep Color. When researching products, take care to look for specific features and functionality, because HDMI profiles are flexible not every product that states version HDMI 1.3 or greater is or has to be Deep Color capable. Any piece of equipment in the A/V chain that does not support the higher bit depth will limit the system to 8 bit performance, so choose wisely. The TX-SR805 may not provide another redundant scalar to 1080p resolution, but it will not choke it off the signal quality as it passes it along.