Onkyo TX-NR906 £1399

13th Dec 2008 | 13:08

Onkyo TX-NR906

Onkyo's flagship AVR packs THX Ultra2 Plus certification, ISF calibration and seven chunky amplifiers

TechRadar rating:

5 stars

It might cost a small fortune, but this is a groundbreaking, feature-packed AV receiver with sensational audio performance and some top-notch 1080p video credentials


Excellent features and performance; ISF video calibration


Back-breakingly heavy; Not cheap

The Onkyo TX-NR906 is a potent, well-equipped and fully-featured flagship receiver – and it's yours for less that the price of a top-end Blu-ray player.

Full THX Ultra2 Plus specification heads up a features list that looks like a 'What's What' of AV receivers, including onboard processing for all your home cinema formats from Dolby Pro-Logic to DTS-HD Master Audio and everything in between; a real world measurement of 155W with five channels driven (jumping to a monstrous 180W in two-channel mode); and full networking abilities.

That's already peachy for this money – but there's so much more.

Receiver spec

Not only can you assign the rear-back power amplifier channels to Zone 2 or 3, you can put the NR906 in BTL (Bridged TransLess) mode to increase power to the front main stereo pair.

Interestingly, nowhere does Onkyo make any claim about exactly how much power is created by bridging channels in this way. I wouldn't want to lose seven-channel surround for a little extra headroom at the front end – but if you only have room for a 5.1 system and don't want multiroom, it's well worth giving a go.

Video processing is handled by HQV's Reon-VX engine which offers not only 1080p upscaling but fine-tuning of the picture output from any source. This includes individual RGB controls and adjustment for hue, saturation, gamma and a variety of noise reduction systems.

Picture control incorporates set-up and calibration standards established by the Imaging Science Foundation (ISF) – the first receiver of its kind to feature such enhancement. Onkyo recommends that a fully-qualified ISF technician performs the calibration for best results. If you don't have one of them to hand, just tweak the picture until it looks good.

Four v1.3a HDMI inputs are joined by a pair of switchable (not simultaneous) HDMI outputs. As well as offering auto lip-sync and x.v.Colour support, the HDMI inputs link to a DSD chipset that will convert incoming SACD signals.

There is also upscaling to 1080i via the component output.

Solid construction

The TX-NR906's THX and Audyssey implementation work hand-in-hand in several areas of sound.

THX Ultra2 Plus offers the usual THX Re-EQ, to re-balance the sound for the smaller listening environment of a living room, as well as THX Neural Surround.

This is probably of most use with new games that use 7.1-channel surround encoded in THX Neural, although the THX chaps are keen to point out that the system can be used to real-time encode live broadcast material in surround sound. Whether we see the BBC Proms broadcast in THX Neural, we will have to wait and see.

The Audyssey implementation is the full-fat MultEQ XT version including both Dynamic EQ Loudness Correction, to trim back over-loud commercials, and Dynamic Volume to keep soundtracks frisky and dynamic even at volumes your mother would approve of. So, there's a feature I won't be needing then. What I do love, however, is the excitingly chunky remote – weighty, solid, sculpted and well laid-out.

Much attention has been given internally to the block construction of the AVR and the fixtures and fittings look pretty good.

Power drain

Of course, you don't get this sort of feature count for this sort of money without a few compromises.

There is no second zone remote control and the overall feel is a little more plasticky that its higher-priced rivals. The speaker terminals in particular flex horribly if you have to shove in a tight banana plug.

Cosmetics and the small display look dated, and it's not exactly green either, drawing 20W in standby mode and a whopping 140W powered up without a source playing. Still, its 50˚c case temperature when idling keeps the room warm in wintry times.

Simple setup

The combination of the superb remote control and a really crisp and informative new GUI helps the TX-NR906 get off to a flying start.

Configuration and set-up are supremely easy. However, the initial measurements made by the Audyssey auto set-up in my room managed to set every channel bar the surround backs to the maximum decrease of -12dB – presumably due to my large, efficient speakers. This eliminated any relevant balancing between channels and made the centre speaker far too proud in the mix.

Reverting to manual set-up will cure the issue but probably upsets the Audyssey RoomEQ measurements. Unfortunately you can't tell if this is the case, as the Onkyo offers no way of displaying the Audyssey filtering results anyway.

Likewise there is no easy way to toggle Audyssey on/off without stopping playback and delving into the menus. So getting back to basics, the Audyssey was left off and I set the thing up manually. So much for technology.

Explosive sound

The epic zombie fight scene in a deserted Las Vegas strip in Resident Evil: Extinction (Blu-ray) is a tough test of any amp's dynamic capabilities and the Onkyo passes muster with ease.

A lack of overt background music gives the gun fights and roars of monsters real presence as they explode out of a creepy silence. The NR906 swells dramatically with the increasing sound pressure and puts you in the thick of the action. Gun shots ring out around the room, with a harsh metallic edge that makes them ever more realistic.

The overall balance is a little edgier and livelier than flat neutral but it certainly makes for edge-of-the-seat action entertainment. It also does wonders for the projection of dialogue, which manages to cut through the scene's chaos with excellent intelligibility.

Nudge the volume up a few notches and the Onkyo doesn't flinch, simply raising the bar across all channels without increasing the background noise or hiss levels. This further enhances its perceived dynamic capabilities and defines each effect into an individual facet.

Resident Evil is full of overt effects such as running water, electricity cables shorting out and jars dropping off of shelves, and the Onkyo pulls these right to the fore. Close your eyes and you are walking around deserted buildings or deep into the recesses of the underground research facility.

At high volumes you will jump out of your skin at the 'shock' FX – even when you know they are coming.

Detailed soundstage

At first this raw detail brought forward in the mix can sound a little chaotic but it's a definite grower. The more you watch films the more you appreciate the energy and up-front appeal that pushes every detail out into the soundstage.

Dialogue is ultra-clean, crisply portrayed, and blissfully free of the confines of the speaker. You can push the volume fairly hard before the dialogue becomes shouty; the Onkyo's power reserves are mighty although the natural balance means that things can get a little hard on the ears when the going gets tough.

Switching to a standard 576i DVD picture, the TX-NR906's high-tech processor works absolute wonders. Scaled to 1080p, lines are fairly free from jaggies, there are no visible artefacts and the scrolling is super-smooth.

Comparing Fifth Element on DVD and Blu-ray is no longer comparing apples with oranges. It's more tangerines with oranges, as this Onkyo seriously improves the lower-spec image.

Video tweaking

One word of warning, though: I spent a long time tweaking the video controls and after a while decided having an ISF engineer to hand might not be such a bad idea after all.

While there are several good DVDs out there with test patterns on, it would have been nice to have some built into the software of this machine. Either way there is no denying the power of the Reon-XV processor in making a 1080p silk purse out of a PAL DVD's pig's ear.

Just putting Fifth Element in the player wrote off an hour and half of my Sunday afternoon, but I didn't care. The swelling soundtrack and Latino rhythms soared into the room, Bruce Willis' voice was spot-on timbre perfect and the big action sequences veritably exploded across the room.

Having followed the smooth-as-silk Marantz SR6003 into my cinema room, the Onkyo was a supercharged joy-ride from start to finish.

Cinephile system

Supremely well-equipped but not without its foibles, and effortlessly exciting but perhaps a little up front and full-on for some, the Onkyo TX-NR609 is a must-hear for cinephiles.

Partner this beast with large speakers with a smooth top-end, and you are going to have a very serious AV system at a not-quite-so-serious price.

Onkyo Receiver Hi-Fi/audio Home cinema THX
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