NI-Spektral Delay

Spektral Delay is a rarity. It's a delay that uses FFT to split the input signal into frequency bands (up to 160 adjustable bands, and up to 1024 bands internally for each channel). Each user adjustable band can have its own level, delay time, and delay feedback. You can link the left and right channels or edit them separately.
There's a global LFO for modulating almost any parameter, and there's various transform functions in a modulation section along the side of the GUI.

The nice thing about Spektral Delay is by using different delay times and/or feedback amounts, you get a lot of control over your imaging, and you're able to seat a part in the mix without resorting to track EQs. Because of the different adjustments per band, you're also able to simulate reverbs, comb filters and the like.
With up to 10 seconds of delay time available, you can also touch on a mild form of Frippertronics if you so wish. Of course, you can always set all bands the same and use it as a normal delay.

To adjust the bands, you use a pencil tool to draw in delay times and the like. Once again, the link button can be used for simultaneous editing of left and right channels if desired. Separate input and output sonographs show the results of the signal processing.

The preset handling is quirky to put it mildly- it's the one part of the whole that needs some serious attention. You have a file menu on the right that will show you the content of the bank you have loaded. However, the dropdown preset menu always has the default bank loaded, and usually only part of that.

The early versions of Spektral Delay were VERY buggy on Windows machines. The 1.5 update (released in 2002) improved it to the point where it was usable on a daily basis. The 1.57 update was mostly to fix bugs that the original Komplete version had. But, essentially it hasn't changed in three years.

Spektral Delay's only real competitor is Izotope's Spectron. While Spectron does some things that Spektral Delay won't such as spectral morphing, it comes at a much higher cost in CPU. Spektral Delay runs great with multiple instances on my humble PIII, while one instance of Spectron will bring it to its knees.

Spektral Delay isn't a plug for everybody. To some, it will appear utterly baffling. Others won't find it worth the price- NI raised the price by 50% about a year ago, and at about $300 list, it's not cheap. There also isn't a demo available at this time- there used to be a demo, but it was a very early version, and as such was prone to crashing.

I've been using it for over four years, and I really don't know what I'd do without it. I use it instead of normal delays in everything I do, and I quite often use it instead of reverb. If someone you know has it installed on their machine, ask if you can give it a test spin. There's nothing quite like it.