Adding the £400 CS-3X Jr. brings Dolby Digital to your home cinema. But is it as good as using a dedicated EX amplifier? Bob Tomalski reports.

The advent of Dolby Digital EX and DTS ES brings a new dimension to cinema soundtracks. The director can now perfectly pan effects around the auditorium thanks to the addition of a matrixed rear centre-channel. In the home it means further sonic realism. Small rooms seem large because of the greater ambience spread around. Even movies not produced specifically for EX seem to sound more spacious.

In the past, HCC has applauded the latest breed of EX-equipped amplifiers including the Yamaha DSP AX1, Denon AVC-A10SE and Onkyo EX-DS909. All offer stunning performance plus the benefit of the extra decoding. The problem is, not everyone wants (or can afford!) to junk a perfectly good Dolby Digital model in favour of the new EX. Given that the only technical difference is the addition of a matrix decoder, surely there must be other ways of retrieving the extra information?

Indeed there is the £400 Smart Centre Surround - 3X Jr. has a decoder which retrieves rear centre information buried within the rear L/R signal of a Dolby Digital EX (or DTS ES) soundtrack. By hooking it up to an additional amplifier and speakers, you can upgrade your system.

The CS-3X Jr. doesn't look inspiring. It's a small steel box with two wonky buttons and rotary knob that sits uncomfortably in an oversized hole. The front panel also sports an LED marked 'presence' and a tawdry logo in blue and white.

At the back, the sockets look more professional; four pairs of gold plated phonos, a detachable plug for connecting an amplifiers speaker outputs, plus a bank of multiturn trimmers and a line/speaker switch. There's also a row of dip-switches to engage the onboard pink noise generator.

There are two ways of hooking this up. If your Dolby Digital amplifier has pre-amp outputs feed these to the centre surrounds line inputs. If not, use the speaker inputs - be careful to avoid and strands of the speaker wire crossing the terminals. The box has rear right, left and centre line outputs. Feed these to your rear channel amplification. You can use a separate external power amp for each channel or re-patch your integrated amplifiers rear left/right power/amps so they receive signals via the box, then add a single rear centre amplifier to complete outfit.

Frankly it's best to use three external amplifiers of the same brand as your main home cinema amp - thus keeping the rear tonality the same as the front. However, it's understandable that many will want to use their existing amplifier to keep costs down. In which case, try to use a centre-rear amplifier of the same brand at very least. The rear channel connections are completed by a rear sub woofer output plus two extra phono terminals marked SP1 and SP2. The makers explain that these are designed for future developments.

An internal test tone generator is provided for each channel. However, it's inconvenient because there's no remote control, so you can't set up the system from your armchair using an SPL (Sound Pressure Level) meter. Or can you? If you disregard the internal test generator, set the trimmers for maximum and then regulate the rear left/right outputs of your main amplifier using its test generator, you can balance these remotely.

Finally switch on the generator for rear centre and regulate the level via the trimpot, going back and forth to the listening position until it is the same value as rear right and left (we use 75db SPL for reference) once set, your ready to use the new world of EX surround.

PERFORMANCE

There are only two controls of consequence. The CS-3X Jr. switches between 'normal' and 3-channel (EX) rear surround. The Centre Fill control regulates how much audio (up to the preset maximum) comes from the rear centre.

For the test, we listened to DVD of The World Is Not Enough boat chase sequence (chapter 3) comparing regular Dolby Digital (DD) with EX. The sequence starts James Bond's amphibious vehicle flying from the Bond MI6 headquarters. At 02:19 the DD effect is panned from surround right to surround left. With EX engaged, the crescendo is rooted to rear centre, giving the effect that the underside has flipped right over the audience.

At 02:46, Bonds head is covered by water. The whoosh of the waves lapping his head first hits rear left/right. Then you hear the delayed sound at rear centre giving a much more realistic effect. At 04:53 the vehicle (literally) takes to the road crashing through a riverside bistro. With DD, you hear echoes of the splintered glass on the rear right and rear left. With EX each shard is precisely placed you hear the tinkle of every piece. It's awesome. To the finale and the dome sequence at 06:46. Again we hear the boat soaring into the air totally overhead using EX, but only vaguely rearward using regular DD.

The moral of the tale is that Dolby Digital, although brilliant, does not fully tell the story. This movie is mixed to be enjoyed using EX. Anything less and you miss some of the sonics.

The Smart Centre Surround 3X Jr. performs well. At £399 it's not exactly a bargain, but it lets you enjoy a new dimension with minimal fuss.

Could you do the same with a discarded Pro-Logic decoder from an old system? Probably. But this box is specifically designed for EX and lacks the technical clutter (surround delay, centre steering etc) of a Pro-Logic . In decoding terms it works as well a EX amplifier but is more complex to calibrate. It also lacks the auto EX DV detection offered by models from Yamaha and Denon.

That said, you pays your money and takes your choice. Get a demonstration. Chances are you'll hear things in Dolby Digital movies - and future EX releases - that you've never heard before.

RATINGS

Tonal response------------5 out of 5
Seperation------------------4 out of 5
Features---------------------3 out of 5
Overall------------------------41/2 out of 5

FOCUS

A useful accessory that endows any Dolby Digital amplifier with the extra dimension of EX. Simply add an extra amplifier plus a single (or two) rear centre speakers for totally encircling surround.

Model: Smart Centre Surround - 3X Jr.
Approximate price: £400
Tel: Cineware Limited. 020 7490 4970
Website: www.cineware.co.uk

FEATURES

Connections: L8/R8 inputs and outputs; rear centre output; rear subwoofer output
Other features: Decodes Dolby Digital EX and DTS ES; trimmer for all rear channels; test tone generator; manual rear/rear centre balance; over-ride switch
Dimensions: 210(w) by 42(h) by 135 (d) mm Weight: 1.6kg