Imagine being able to take every effects processor in your rack reverbs, delays, dynamics, and EQs and shoehorn them into one box. As long as we're dreaming,

Imagine being able to take every effects processor in your rack — reverbs, delays, dynamics, and EQs — and shoehorn them into one box. As long as we're dreaming, let's add a flexible software patch bay, dedicated 5.1 surround processing, quick hands-on editing, and great sound. That, in a nutshell, is the concept behind the Kurzweil KSP8.

With its brushed-aluminum surface, the KSP8 looks cool, calm, and ready for business (see Fig. 1). The faceplate is nicely laid out. On the left are the meters and a slot for a Smart Media card. In the center is a large display surrounded by function buttons. Next to the data wheel are buttons for cursor functions, data storage, a contextual bypass (depending on where you are in the interface, it works globally or selectively), and a keypad. All of these are duplicated on the optional RSP8 Remote (see the sidebar “The RSP8 Remote”).

Metering functions (located on the left, above the Smart Media slot) include eight tricolor LEDs, for viewing signal levels at four different gain stages (input, pre-FX, post-FX, and output), the Meter Stage selector, and LEDs that indicate the current selection and clipping. To meter from the display, hold down the Meter Stage button.

The six soft buttons below the display take their cues from the current display page, and the dedicated buttons are grouped according to function. The dark blue Edit and Exit buttons on either side of the display look and feel different from the other buttons, so you won't mistakenly press these two in the heat of a session.

The KSP8's basic I/O complement is four analog inputs and outputs and stereo digital I/O (see Fig. 2). The review unit came with the KANA8 option card, which adds another four analog ins and outs to the unit. Other options include 8-channel cards with AES/EBU, Lightpipe and TDIF, and mLAN connections.


My first task was to find a place for the KSP8. At over 15 inches deep, it wouldn't fit into the lower rack spaces in my studio desk. Then, like many musicians, I tried to see how far I could get with the new gear before having to reach for the manual. When I powered up the KSP8, I was stumped by the welcome screen. The manual says “the KSP8 offers a familiar interface for anyone who has used Kurzweil products before.” Just getting to where I could audition the effects required quite bit of head scratching and page turning. If you are new to Kurzweil gear, prepare to spend some time with the KSP8's manual. Once you get used to the interface, though, it's very easy and convenient to use.

The basic organizational unit in the KSP8 is the object, Kurzweil's name for a class of hierarchically arranged software parameters. All objects except the algorithms can be edited and stored in any of the 999 internal locations or on Smart Media cards. Understanding how objects relate to each other is crucial to using the KSP8.


Stored in ROM, algorithms are the signal-processing heart of the KSP8 system. The 249 algorithms includes single effects (reverbs, time-based and modulation effects, cabinet simulators, dynamics processors, EQ) and multiple-effects Combis (such as a stereo chorus followed by a delay and a reverb).

Algorithms are not just little snippets that you can string together to build an effect. Rather, each algorithm is a full-fledged effects block, complete with a set of eight Quicks (preselected, easily accessible parameters). The eight soft knobs on the RSP8 remote offer instantaneous hands-on control of the Quicks — that feature alone makes the remote essential. The complete list of algorithms and their specifications requires a 330-page PDF document, which is available on CD-ROM or from Kurzweil's Web site.

Algorithms consume differing amounts of processing power, measured in Processing Allocation Units, or Us. One of the strengths of the KSP8 is that it allocates DSP power dynamically. As long as you don't exceed a maximum of 16 Us, you can place an effect anywhere you want. Ample mono, stereo, and surround algorithms are available to handle most processing needs. The only way to audition an algorithm is to place it in a Preset.


Presets are made up of an effects algorithm and its associated parameter settings. For example, you can create variations of a single plate-reverb algorithm and store them as different Presets.


A Chain is a group of effects, each with its own editable parameters, modulation sources (MODs), and Quicks. Like presets, Chains are placed on an effects bus. A Chain can be of any length, as long as you respect the total DSP overhead of 16 Us.


Studios represent the complete signal path, from input to effects bus to output assignment. If an option card is installed, the KSP8 automatically knows which inputs and outputs you have.

The KSP8 excels at flexible routing. A Studio can have any combination of mono and stereo inputs — analog or digital — feeding as many as eight internal effects buses. The routing options allow you to submix internally or use one effect to modulate another.

Think of a Studio as a snapshot of all of your settings. For example, for a rough mix of an R&B song, I set up a Studio with one stereo and three mono inputs feeding four stereo effects buses. I configured a stereo Chain for the sax on effects buses 1 and 2 and placed a warm plate reverb on buses 3 and 4 for the vocal. Next I submixed all the bass and drum tracks to stereo and inserted a mastering effects Chain across buses 7 and 8 to pump up the low end and tame the dynamics. Last, I set up a basic club ambience for the entire mix.

The fact that I was able to process an entire mix of this complexity through a single device is amazing. Better still, it sounded great! If I could only have one piece of gear in my rack, this would be it. The KSP8 ships with a collection of default Studio templates in ROM that cover basic mono, stereo, and surround situations.

By the way, all of the inputs are routed through two EQ blocks on the way to the effects sends. The EQs come in a wide variety of flavors, from the simple (highpass, lowpass, bandpass, and notch filters) to the complex (with modulation effects and noise generators). Most of the common parametric-EQ effects do their job and stay out of the way sonically without using any effects resources.

The Master Page and Table

The Master Page in the Master Table is where you establish settings (for clock source, word length, digital format, and so on) that affect the entire device. Only one Master object at a time may be stored internally, but Master edits may be written and restored from Smart Media. This is useful if you move your KSP8 to a different studio.


Every editable parameter on the KSP8 can be controlled using MIDI. However, be prepared to spend time programming, because there are only a handful of default assignments. As with everything else, the KSP8 offers a wide variety of options at the Studio, Preset, and Chain levels.

The four studio modulation pages (SMODs) offer extensive options for controlling inputs, outputs, sends, EQs, and mix levels. The chain modulation pages (CMODs) let you configure real-time controls for effects parameters. MIDI Program Change messages can be used to select Studios, Chains, and Presets. For time-based effects, you can set tempo maps in bpm, with tap tempo, or by sending the KSP8 MIDI Clock data.

What really sets the KSP8 apart from the crowd of multi-effects processors are the software control sources: LFOs, envelope generators, and quirky mathematical equations called FUNs (short for Functions). FUNs combine two different control source inputs, such as an LFO, a MIDI controller, a numerical value, or another FUN.

For example, the equation sin (a+b), where a is an LFO and b a numeric value, either transforms a sawtooth wave into a smooth sine wave or an extremely complex waveform, depending on the input. You have 50 FUNs and a plethora of input sources to choose from, which gives the KSP8 some of the modulation power of a synthesizer.


I tested the KSP8 in a variety of configurations. For instance, I used it on a complete mix, on a drum submix, for vocal processing, and as a substitute for my usual selection of guitar stomp boxes. No matter what I threw at it — even complex arrangements of mono and stereo Chains — there was power to spare. Unlike some effects units that offer a handful of processor-intensive reverbs and then try to dazzle you with hundreds of wimpy patches, the KSP8 delivers nothing but terrific, usable effects. Once or twice I exceeded the 16-U limit when assigning presets, but each time I was able to find a substitute with little or no loss in audio quality.

Although some of the factory Presets were too over the top for my taste, many are usable just as they are. The KSP8's reverbs, in particular, fared very well in an A/B comparison with high-end dedicated stereo processors costing as much as or more than the KSP8. You can edit and overwrite any effect with confidence because the original is safely tucked away in ROM.

When you get past the standard effects, things really get interesting. The specialty effects that use FUNs, LFOs, and other modulation sources are amazing, especially when you add real-time MIDI control or use the RSP8's joystick. For example, from a single spoken word, I created an immense, swirling pad that seemed to last forever. Thanks to some creative use of LFOs and FUNs, the original vocal drifted in and out of the mix as it panned slowly from left to right over long intervals.


I took the KSP8 to Oregon Sound Recording to evaluate its surround effects. The unit supports a variety of input routing options before you get to the 5.1 bus: eight mono inputs can be submixed internally; a stereo input can be bused to the 5.1 and stereo buses simultaneously; or you can go 5.1 in and 5.1 out. Obviously only some of these options are available on the stock unit: you'll need to expand the I/O to get the most out of the surround routings.

For our first test, studio owner Sean McCoy and I processed a stereo source to simulate a live environment, which is a common mixing technique. By subtly adjusting the pan, diffusion, predelay, and other Quick parameters, we not only created a stunningly realistic concert hall, but we could select our seats. Next, we sent individual tracks from the mixer to each input. By adjusting settings in the individual FX Sends page, we could move each instrument around the room with the joystick.

The KSP8 lets you determine whether or not a sound skips the center channel as you pan in surround. That allows you to leave a hole for any dialogue that will be added to the mix. McCoy and I were amazed that a unit at this price point could produce such amazing effects with such high sound quality.


The KSP8 gives users unprecedented power and control of stereo and surround-sound processing. What's more, Kurzweil's unique tone-shaping FUN equations bring samplerlike modulation to any sound source, creating effects that are simply out of this world. Although it's an option, I consider the RSP8 remote a necessary component. I couldn't imagine using the KSP8 without it. Likewise, I'd suggest adding one of the optional I/O cards, particularly if you plan on doing surround-sound projects.

Whether or not you mix in surround, the KSP8 is an outstanding value. Once you get the hang of it, the flexible interface lets you instantly recall the perfect combination of routing, EQ, dynamics, and effects for just about every studio task imaginable. And the bottom line is that it sounds great.

Mark Nelsonlives and works in Southern Oregon's Applegate Valley. Thanks to Sean McCoy for help in this review.

KSP8 Specifications

Analog Inputs(4) ¼" TRSAnalog Outputs(4) ¼" TRSDigital I/OXLR (AES or S/PDIF)Word Length16, 20, or 24 bitsMIDI I/OIn, Out, ThruFrequency Response20 Hz-20 kHz, ±0.15 dBMaximum Input Level+22 dBuA/D/A Converters24-bit, 128× oversamplingDynamic Range> 110 dB unweighted @ 1 kHzCrosstalk< -100 dB @ 1 kHzTotal Harmonic Distortion + Noise< 0.002% @ 1 kHz, +19 dBuDisplay240×64 backlit LCDDimensions3U × 15.125" (D)Weight13.25 lb.


digital effects processor
RSP8 Remote Control $595
KANA4 Option Card $450


PROS: Flexible routing. Real-time control. Innovative tools for shaping effects. Supports for 5.1 surround effects.

CONS: Tough learning curve. Metering requires you to leave the editing screen.


Kurzweil Music Systems, Inc./Young Chang America (distributor)
tel. (800) 874-2880 or (253) 589-3200
Web www.kurzweilmusicsystems.com


The RSP8 remote features a set of buttons, LEDs, a display, and a data wheel that duplicate those found on the face of the KSP8 (see Fig. A). The remote adds eight soft knobs, for hands-on effects-tweaking, and a joystick, for panning or real-time control over any parameter you choose.

The RSP8 is about the size of a cigar box and has the same brushed-aluminum finish as the KSP8. Wooden side rails add a touch of class, and a soft rubber mat on the bottom keeps the remote from slipping around your desk. There's even an adapter that lets you mount the unit on a mic stand — handy for studios where flat space is at a premium — and it comes with a 52-foot cable. The RSP8 is powered by the KSP8, and with the HUB7, a single RSP8 can control up to seven KSP8s.