Update: Click here for a full review of Lionsgate's The Expendables 2 Blu-ray

The Expendables 2 Blu-ray is a world's first. Lionsgate has proudly boasted of its DTS-HD Master Audio 7.1 mix being 'optimised' for 11.1-channel playback via DTS Neo:X. Of course, while the majority of AV fans are using a regular 5.1 speaker array, or perhaps a traditional 7.1 array with rear back speakers, the chance to see/hear for ourselves what all the fuss is about was too good to miss. 

As sound tests go, this wasn’t the easiest to setup. Having got in Pioneer's flagship SC-LX86 AVR with Neo:X processing and outputs for 11 channels (pictured below), it should have been simple. But no. Outside of commercial surround sound processors there are still no true 11.1-channel AVRs on the market. Like many top-spec amps, the Pioneer is only a nine-channel model and even using its 11.1-channel analogue outputs, it won’t generate 11.1 sound. For reasons we haven’t got to the bottom of, the SC-LX86 happily sets up and EQs an 11-channel speaker system (with two subwoofers if you want), yet there is no way to output both Front Height and Front Wide simultaneously. It’s one or the other.

So, by our reckoning, the SC-LX86's refusal to play 11-channel ball (despite costing the best part of £2,000) leaves only Onkyo's TX-NR5010 and Denon's AVR-4520 as receivers that can drive such a setup. And with either of those, you'll need a stereo amp on-hand for the extra channels. As such, 11.1 audio is still not what you can call a mass-market proposition.

 

Anyway, we are not that easily beaten at HCC. Using the new Oppo BDP-105EU’s twin HDMI outputs with duplicated bitstream audio, we fed the SC-LX86 with one HDMI output and a Denon AVP-A1HDA processor with the other. We set up the SC-LX86 running 9.1 channels with height speakers and did the full-auto MCCAC EQ system. The Denon was set up running 9.1 with width channels, but all of its power amp channels were disconnected, save those driving the left and right width speakers. The helpful Neo X 11.1 optimizer lurking in the extras on The Expendables 2 Blu-ray, which sends signals to each channel in sequence, allowed level balancing between the Denon and Pioneer using the main volume controls. By setting both into DTS-HD MA with Neo:X Cinema mode, we managed to achieve full-fat 11.1-channel Neo:X sound. It’s not an elegant way of cracking the nut but it worked.

The Expendables 2's DTS-HD sound is actually a discrete 7.1-channel mix. Information for height and width channels is ‘matrix’ embedded into the main seven channels. This is similar to how rear and centre-channel information was matrix-encoded into Dolby Stereo back in the good old days of analogue cinema. With standard 5.1/7.1 movies, the Neo:X processor has a stab at pulling out ambient information for height and width channels even if there are no specific flags in the mix for them. In discs like The Expendables 2 the sound has been optimised for Neo:X (although studio Lionsgate hasn't yet managed to reveal to us exactly what that entails), with flags that allow the processor to pull out information that is almost discrete. Set up right and listening to the disc’s 11.1 optimiser playing sounds from each speaker in-sequence, it is very difficult to believe it’s not a properly discrete 11.1 format. It really is that remarkable.

The opening scenes of The Expendables 2 offer perhaps the most outrageously OTT action sequences yet to grace a silver screen and the sound is just as awesome. Every single channel gets a thorough workout from about half a nano-second into the movie, and the effect is utterly immersive. The height channels immediately pull the action up into the middle of the screen and create a much more three-dimensional soundstage. This is used to superb effect as Barney Ross's knackered sea-plane takes off and the camera angle is suddenly very low on the other side of the dam wall. The sound pans from high-front to rear-back, only losing height coming down towards the surround-back speakers, which are placed only just higher than the seating in our setup.

The extra width information is no less jaw-dropping, as it serves to de-locate the front speakers completely. Rather than the sound panning across three obvious hot-spots at the front of the room, it comes at you as a more cohesive and solid whole. Cross-camera bullets have a greater sense of distance and the sound is wider, but the real advantage comes with the additional ambience. The incidental sounds seem more present but less obtrusive, becoming more like realistic background sounds. Muting the Pioneer in our configuration revealed just how much information was being sent to the wide speakers, including forest sounds, explosions, background music and the plane’s engines. With main characters front of screen, the wide speakers have absolutely zero dialogue output and their relative volume in the mix has a wide dynamic range.

From end to end The Expendables 2 is an absolute poster-child for 11.1-channel surround sound, but it’s not without some flaws. The most noticeable is some fairly obvious compression. To make the sound ever ‘louder’, much of the action has been run through a compressor to bring up quieter elements. The effect is not overtly noticeable through much of the film, but when you want a real huge, extremely loud sequence to drive home the bacon, it just doesn’t happen. The epic opening sequence is a constant barrage of noise that in our cinema room tipped the digital scales at around 95-100dB, almost constantly from beginning to end. However, when the team put three tank shells into the floating bridge on the lake, the resulting explosion was also 100dB. The scene simply didn’t have the standout final punch it should have, as the rest of the mix is pushed to the limits anyway.

To a lesser extent this tends to make dialogue rather obvious in the mix, too. While I, like many, have sat through dozens of Sly Stallone films not hearing a single word he mumbled, in The Expendables 2 his voice, and those of all characters, is really thrust at you from the dialogue speaker. This doesn’t help the films’ suspension of disbelief (and let’s face it, that is a challenge with this film), as voices seem to cut through even the most epic background battle. In the end I knocked 1.5dB off of the measured centre-channel level to tame the effect and make things a little more natural overall.

So, the sound design on The Expendables 2 is not perfect, but it remains an absolute showcase for DTS-HD MA Neo:X in 11.1-channel surround sound. The additional dimension and ambience generated by using height and width channels simultaneously massively outweighs the rather compressed mix on this Blu-ray disc, resulting in a very big thumbs up  overall. The sooner AVR makers incorporate the format properly (by chucking in two more amplifier channels) and more movie studios put in the extra time and effort to optimise their Blu-ray mixes, the better home cinema sound will be.