There's also support for THX's relatively new Neural Surround sound processing. Neural Surround processing encompasses several types of processing. First, it can act similarly to Dolby's Pro Logic processing in that it can take a standard stereo signal and process it into 5.1 or 7.1 channels, creating a faux-surround mix where none existed. For those with 7.1 systems, it can also make 7.1 audio out of a 5.1 soundtrack. Secondly, and perhaps more importantly, THX Neural Surround can take special acoustically watermarked stereo signals and decode them back to the original 5.1 mix. This makes it possible for you to get surround sound out of older gear if content providers properly encode the audio. THX Neural Surround is currently supported by XM Radio and some FM stations, but overall adoption is still relatively small.
The TX-SR805's rear panel is filled with ample connectivity. There are three HDMI inputs, each capable of receiving high-def video to as high as 1080p along with high-resolution audio. For analog video, there are three component video inputs capable of receiving 1080p signals, along with six total AV inputs with S-Video (five rear, one front).
For audio, there are the aforementioned HDMI inputs, plus six total digital audio inputs--two optical and three coaxial inputs on the back panel, and one front-panel optical input. Analog audio is covered by two stereo analog RCA jacks (including one recording loop for a tape player), a phono jack for turntables, plus a 7.1 multichannel analog input. Rounding out the rest of the connectivity are both XM and Sirius jacks, so you'll need only to connect an XM Mini Tuner for XM service, or the Sirius SCH1 Sirius Connect for Sirius access--with the appropriate subscriptions, of course.
Lots of high-def connectivity is great, but it's a whole lot less useful if there aren't enough source labels to assign components to. Luckily the TX-SR805 has six selectable high-def source names (DVD, VCR/DVR, CBL/SAT, Game/TV, AUX1, AUX2) that can be assigned to either HDMI or component-video inputs. That's pretty good, although we were disappointed that six is actually the total number of AV source labels available. That means that even though there are a total of 11 video inputs, only 6 video inputs can easily be connected at one time, without reassigning inputs when you want to watch certain devices. There are also additional source names for audio-only devices.
The TX-SR805 is capable of converting analog video signals to its HDMI output. This means that you can connect composite, S-Video, and component sources to the TX-SR805's inputs, then just a single HDMI cable from the receiver's HDMI output to the TV. This is a nice convenience, because it allows you to keep your TV tuned to one input when you change sources. Without video conversion, you need to change the inputs on the receiver and the TV each time you move from HDMI to analog sources and back again.
Along with allowing analog signals to be output over the HDMI output, the TX-SR805 converts standard-definition 480i signals to 480p, a process also known as deinterlacing. This is important because many HDTVs cannot accept a 480i signal via HDMI. On top of this, the TX-SR805 has some hidden functionality that allows you to upscale analog signals to 720p. The details to access the menu are in our Tips & Tricks section, but the short answer is that it's best to leave this feature off.
Like on the TX-SR605, there are a couple quirks regarding the analog-to-digital video conversion on the TX-SR805. For example, those planning to use the TX-SR805 with 1080i signals via a component-video input will be disappointed to find out that all 1080i signals via component are downconverted to 720p when output via the HDMI output. Furthermore, 1080p signals via the component-video input cannot be output via the HDMI output at all. There are certainly workarounds for these issues--see our Tips & Tricks section--but they involve complications that HDMI-equipped receivers were supposed to avoid.
Multiroom capabilities are pretty decent, supporting second and third zones. Zone 2 can be connected either using powered speaker cable or using the line-level RCA outputs to an additional receiver in the second zone. The third zone is limited to using line-level RCA outputs.
While the TX-SR805's is fully featured, we can't help but feel that it doesn't offer that much more over the step-down TX-SR705--at least in terms of features. The TX-SR805 has an additional AV input, more power, and a third zone, but the rest of the specs are very similar. The TX-SR605 is a bigger step down, with only two HDMI inputs, but it still offers many of the more important features at only $400 street price--and you can add HDMI inputs by using an HDMI switcher.
In this price range, Denon's most comparable receiver is the AVR-2808CI ($1,200), which has only two HDMI inputs but also has Dolby TrueHD and DTS-HD Master Audio decoding, upconversion, and three-zone capability. Sony's STR-DA330ES ($1,000) also has three inputs and features their excellent graphical user interface, but lacks Dolby TrueHD and DTS-HD Master Audio decoding--which may not be so bad for the reasons we stated earlier. Yamaha's RX-V1800 steps up to four HDMI inputs, but costs $1,300.
Given that many of the upgrades on the TX-SR805 are designed to improve audio performance, we were excited to sit down and listen to some music. We started off with The Derek Trucks Band's Joyful Noise and were not disappointed. Trucks' slide guitar was emotive as ever, and the TX-SR805 delivered rich, detailed sound. We switched gears and put on Charles Mingus' The Black Saint and the Sinner Lady, which sounded particularly lively, with the horns having a rich and textured quality. Overall, the TX-SR805 compared favorably with the more expensive STR-DA5300ES, although we'd give the slight nod to the STR-DA5300ES, which sounded just a tad cleaner and more detailed to our ears.
Although we're not generally fan of faux-surround mixes via surround processing modes such as Dolby Pro Logic II, we spent some time comparing the differences between Pro Logic II Music and THX Neural 5.1 processing. Overall, we still preferred plain, old stereo for CDs, but on some songs, the THX Neural provided an interesting experience. For example, on the title track of Joyful Noise, THX Neural firmly planted Trucks' guitar in the center channel during the breakdown section, while placing the keyboard in the rear-channel speakers. At times, it gives the feeling more that you're playing with the band, rather than watching a live performance, but at other times it sounds unnatural, putting too much emphasis on the center channel and actually sounding cramped when compared with the stereo track. Although we won't be switching out of stereo for CDs anytime soon, generally we found ourselves preferring THX Neural to the Dolby Pro Logic IIx Music mode.
The TX-SR805 didn't run out of steam when we watched Batman Begins on our HD DVD. Batman Begins features an excellent Dolby TrueHD soundtrack, which uses lossless compression, compared with the lossy compression on standard Dolby Digital soundtracks. Again, the TX-SR805 left us riveted; we could practically feel the ice under our feet during the training scene on the frozen pond. Dialogue was crisp and clear, and the TX-SR805 had no problems making us feel the subwoofer. Film fans won't be disappointed.
In terms of video performance, we ran into the same issues with the TX-SR805 that we did with the TX-SR605. We began our tests running the Toshiba HD-A20 via S-Video to the TX-SR805 connected to the Panasonic TH-50PHD9UK via HDMI. This tests the TXSR805's ability to deinterlace the incoming 480i signal. We took a look at Silicon Optix's HQV test suite, with the TX-SR805 failing to pass the initial resolution test, which means that it can't deliver all the detail of 480i sources when upconverting. Moving onto the jaggies tests, the TX-SR805 performed better, handling tests involving a rotating white line, three shifting lines and footage of a waving flag with ease.
Where the TX-SR805 struggled the most was with any test that required 2:3 pull-down processing. We first saw this on the racecar test on the HQV test disc, and we saw plenty of moire in the stands as its film processing never kicked in. The same behavior was confirmed in actual program material. For instance, on the introduction to Star Trek: Insurrection, there were jaggies on the hulls of the boats where there should have been a smooth, curved line. Similarly, the introduction to Seabiscuit was filled with tons of jaggies, and the image on the screen often seemed to pulsate because of how much the receiver was struggling. While many of the video-quality issues we mention are subtle, this is not and will bother anyone even mildly sensitive to video quality. To be fair, these artifacts will mostly show up only on video components that display film-based material, but we noticed them much less when using, for instance, an Xbox 360 in standard-def mode. However, while we were willing to overlook for the most part some of the video processing deficiencies of the TX-SR605 because of its low price, it's harder to overlook the same issues on a receiver that costs twice as much. Videophiles would be well advised to bite the bullet and consider one of the higher-priced receivers that offer built-in HQV video processing, such as the Onkyo TX-SR875 or the Denon AVR-3808CI.