Onkyo has snagged the latest blip in the format wars and endowed its new midpriced receiver, the TX-SR600, with Dolby Digital EX. Yes, EX Surround has been on the market for a couple of years, but you could find it on only THX-certified receivers. Now, Dolby Digital EX is available on less expensive, non-THX models such as this Onkyo, which also offers a host of useful features and boasts above-average sound quality.

It's getting better all the time
For the uninitiated, the EX 6.1 format adds a rear-center channel to fill out surround effects in ways that standard 5.1 multichannel sound cannot. Beyond Digital EX, this receiver also supports DTS-ES and Dolby Pro Logic II processing, so it covers all current surround-format possibilities. On top of that, the SR600 is outfitted with six 80-watt, high-current power amplifiers that won't be fazed by tough-to-drive or inefficient speakers.

This receiver won't let you down when you're ready to move up to HDTV; its 50MHz component-video-switching capabilities are up to the job. The SR600's solid-aluminum front panel sports a complete set of composite and S-Video inputs, left/right audio inputs, and an optical digital-input jack for convenient connection to a video camera or a game system. Overall, however, the connectivity choices are only average; there's a smattering of A/V inputs, a 5.1 input for DVD-Audio/Super Audio CD, and four digital-audio inputs but no preamp outputs or phono input. Another small gripe: while the main-set speaker connectors are of reasonably good quality, Onkyo went with cheap spring clips for the B speakers.

As far as the remote goes, it's big and fairly easy to use. A few of the most frequently used buttons are backlit--no complaints here.

Getting surrounded with the SR600
We started our home-theater audition with The Others, a deliciously Gothic ghost story replete with screeching violins. We were impressed as the SR600 dredged up tension-filled, atmospheric effects, room ambiances, and low-level details from the DVD's 5.1 Dolby Digital soundtrack. EX processing can synthesize rear-center-channel information, so we experimented by switching the rear speaker on and off and heard only minor differences in the surrounds' spatiality. The rear speaker's contributions were more obvious and effective on a few 6.1-encoded DVDs such as The Stunt Man (The Others DVD doesn't have a 6.1 EX mix). If you have room to position the rear speaker at least a few feet behind your couch, the benefits of EX and DTS ES 6.1 processing will be worthwhile.

Stereo sound was awfully impressive; the SR600 uncovered every one of the deepest spaces in Chris Whitley's all-covers CD, Perfect Day. Billy Martin's nervous, crashing drums and percussion were set way back behind the plane of the front speakers. This Onkyo is a neutral-sounding receiver--it's not as warm as the rich Denon AVR-3802 or as bright and forward as the Yamaha receivers that we've heard of late.

Just a few months ago, we raved about the SR600's big brother, the $1,000 TX-DS797. And sure, the DS797 is still the better and more powerful-sounding unit. But the $530 SR600 is in the ballpark in terms of audio quality and costs much less. On a sound-quality-per-dollar basis, the SR600 is an absolute steal.