The DD-2 K-Stereo Processor is referred to as an "ambience recovery device" in literature and on the Digital Domain website. The brainchild of mastering engineer Bob Katz, the DD-2 is built using K-Stereo technology, a patent-pending process that extracts ambience from a recording and allows the user to manipulate it. The DD-2 is rich in features. In addition to ambience processing, the unit can provide mono to stereo up-mixes, two bands of precision EQ, Mid/Side processing, and POW-R dithering. These functions are also MIDI programmable.
Despite being known as a "tech-head," Katz is also passionate about hardware usability. This fact is evident in the control design on the DD-2. All features are one knob or button away. There are no sub-submenus or convoluted controls. Owners can start using the DD-2 right out of the box (although the manual is very useful). It the heat of a session, usability can be critical, and I applaud Digital Domain for the elegance of this unit.
In terms of sound, I expected the DD-2 to be a really high quality version of a stereo plug-in. I was wrong. I've never heard a plug-in do the things the K-Stereo can do. The DD-2 creates very natural and believable sounding ambience. Where plug-ins can be extreme and overt, the DD-2 is reserved and subtle. At times, I was reminded of the Crane Song HEDD-192 in this respect. The HEDD, which can add harmonics to enhance perceived warmth, is another subtle unit. There isn't a big shocking change when you first turn on the HEDD or the DD-2. But if you bypass the unit after listening to it for a few bars, its absence is very noticeable. Defeating the DD-2 generated comments like, "I could hear the mix collapse," or, "Whoa, turn it back on." Clearly, the DD-2 might not be for everyone. It's a specialized tool that works really well in some situations. And it really depends on the material, not the genre, whether the DD-2 is appropriate.
On a wide range of performers, from mono 78's to a full rock band, the DD-2 was able to polish the final master in our tests. On an acoustic trio, the DD-2 enhanced an already decent stereo recording. Using the "wide" setting spread the trio across the sound field. It was like someone went back in time and moved the performers apart! I really started to appreciate the "ambience recovery" description for this unit. Adding the "deep" patch seemed to move the fiddle and guitar slightly to the back while pulling the vocalist forward. The effect really did seem to create a sonic illusion of a deeper soundstage, especially when compared to the original. Comments like, "How in the world does it do that?" and, "That's coooool," were common. I was pleasantly surprised when the DD-2 was able to help a rap mix's overall spaciousness. On this particular performer, the DD-2 brought out a slight sibilance that was lurking in the track. The built-in EQ came to the rescue. A few adjustments tamed the offending "essses" without hurting the overall high-end.
But on some things the DD-2 just didn't help. For example, a very dense rock mix that was recorded dry and drenched in tons of effects. (To be fair, one must wonder if there was any ambience to recover!) But, it all came down to taste, and there weren't any hard and fast rules. Of course, this is no different than any other processor when you think about it.
Some drawbacks include the fact that the unit requires external converters for input and output. I assume this a design choice to allow the users to pair the DD-2 with converters of their liking. Also, it's limited to mono or stereo processing (however, a stereo-to-surround processor that utilizes the K-Stereo process is available from Z-Systems). Finally, the unit is a bit pricey. At $3,500 it's a serious investment. For that reason, I want to strongly suggest that perspective buyers obtain a demo unit. However, if your client's music benefits from the DD-2, then the price doesn't sting that much. Because when this thing fits, it's smooth. Really smooth. ($3500 direct; www.digido.com)