Various spectral enhancers, which are devices designed to impart hyper-realism to full mixes but also to individual tracks, have been available for more than a decade. Typically, enhancers contain two or more processors — for example, one for lower frequencies and another for processing highs. One possible approach to low-end enhancement is to generate bass-frequency subharmonics (frequencies that are an octave lower than the source signal). Another approach, which affects the upper end of the audio spectrum more, is to expand the stereo image into a wider plane or even a three-dimensional perceptual field, typically by employing digital-signal processing (DSP) algorithms that manipulate signal phase.
The Peavey Kosmos, described as a “low-frequency energy and stereo image enhancement system,” puts both of those types of processes into one inexpensive box. The dual-channel, 1U rackmountable Kosmos can be used in the studio to beef up individual tracks or an entire mix, or live to enhance the sound of a P.A. system.
The Kosmos's rear panel is not stingy with I/O. Each channel provides two balanced inputs and outputs, wired in parallel, one on XLR and the other on ¼-inch TRS jacks. (The TRS jacks can accept unbalanced lines.) In addition, the unit has a Sub Woofer output on a fifth balanced ¼-inch TRS jack. An IEC power receptacle and a detachable AC cord round out Kosmos's rear-panel connections.
The unit's front panel is divided into three sections: Input, Seismic Activity, and Sub Woofer. In the Input section, a continuously variable Level knob provides 10 dB of additional gain (plenty for processing -10 dBV signals) and “infinite” attenuation (off or muted output). The knob's unity-gain position, marked U, is detented. Two LEDs next to the Level knob indicate signal levels: a green LED, labeled 0, lights when the input level exceeds 0 dBu, and both the green and a red LED (labeled +10) light when the signal level exceeds +10 dBu. (Output levels should nominally be +4 dBu, though the unit's maximum output levels are specified as +22 dBu.) The Input section also provides a Global Bypass button and a corresponding red status LED (labeled By). The bypass disables all controls except those that adjust input for the unit and levels for the Sub Woofer output.
There are three continuously variable knobs in the Seismic Activity section: Quake, Thud, and Xpanse. Each knob is marked “min” in the fully counterclockwise position and “max” in the fully clockwise position, with nine hash marks between. To the left of the knobs are the Cut Sub Bass from Main and the Sub-Terranean Shift buttons. The Kosmos Operating Guide is cryptic as to what exactly most of the unit's controls do. That is in part to safeguard Peavey's trade secrets; fortunately, however, I did manage to wrestle some details from the company.
The Kosmos's Quake control takes bass-frequency content present in the input signal and shifts it down an octave to generate subharmonics. As you turn the Quake knob from its off position, you increase the volume of subharmonics in all of the Kosmos's output signals. A yellow LED lights when the subharmonic levels exceed -20 dBu. The frequencies that Quake adds to the output signal(s) are determined by the position of the Sub-Terranean Shift button. With that button disengaged (out), Quake processes a narrow band of frequencies in the 100 Hz area, shifting them down to the 50 Hz zone. When the button is engaged (in), Quake shifts frequencies in the 70 Hz region to about 35 Hz. Leaving the button out thus makes the Quake effect more audible on smaller speakers.
The Thud control knob boosts an unspecified band of bass frequencies that lies roughly an octave above the subharmonics the Quake function produces. This control is also off at the “min” position.
The Xpanse control produces two effects at once. As you turn its knob up from “min,” the Kosmos simultaneously boosts high frequencies and expands the perceived stereo width of its left and right output signals. But Xpanse doesn't employ equalization per se; the high-frequency boost and stereo-width enhancement are instead produced by the Kosmos's phase manipulation of the input signal(s).
BASS IN YOUR FACE
The Sub Woofer section contains a lone, continuously variable Level knob. With its nine hash marks and its “max” label at the fully clockwise position, the Level knob is identical to the others, except that it is, curiously, marked “off” (as opposed to “min”) in the fully counterclockwise position. The knob raises the level of the signal presented at the rear-panel Sub Woofer — output jack. The Sub Woofer output's 90 Hz lowpass filter remains operational even with the unit bypassed. The Kosmos's Power button and accompanying blue status LED reside to the right of the Sub Woofer section.
IT TAKES CONNECTIONS
When cutting tracks in the studio, you can route them to the Kosmos's left and right inputs and feed the unit's processed output signals to your MDM or digital audio workstation (DAW). You can feed your mixer's main stereo outputs to the Kosmos to process an entire mix (connecting the unit's outputs to your mixdown deck or DAW to record the processed mix).
For live-sound applications, you can route the Kosmos's left and right outputs to an amplifier that feeds the house monitors. The Kosmos's Sub Woofer output jack, which accommodates balanced and unbalanced connections, puts out a line-level signal that can be patched into a subwoofer. The subwoofer will receive the sum of three bass-range signals derived from the unit's separate processing blocks: the input signal filtered by an 18 dB — per-octave lowpass filter with 90 Hz corner frequency and the outputs of the unit's thunderous Quake and Thud circuitry. If, in a live-sound setup, the Kosmos's beefy bass output is clipping the house monitors, you can engage the Cut Sub Bass from Main button on the front panel to remove low frequencies from the unit's main outputs and then feed them to a subwoofer through the Sub Woofer output jack.
You wouldn't want to use that setup in the studio, because it would hype your subwoofer's bass response and thus skew your perception of bass content in the mix or on individual tracks. However, you could simply print the subwoofer output to a separate track and combine it with the original during mixdown. That strategy would allow you the flexibility to adjust the balance between the original signal and the Kosmos's low-frequency output.
QUAKE, RATTLE, AND ROLL
One difficulty in using the Kosmos stems from the somewhat deficient Operating Guide. The manual is too cute for its own good — it offers plenty of playful earthquake metaphors but falls short on critical application notes and other useful information. Although Peavey has since expanded the Kosmos Operating Guide to include three pages of helpful diagrams that illustrate various studio and live setups, if you are planning to buy the Kosmos, save this review for a better understanding of what the controls do and ways you can put the unit to use.
I began my tests by using the Kosmos to process a stereo mix. At 0 dBFS meter readings, my Yamaha 02R's +4 dB stereo analog outputs dish out +26 dBu levels, exceeding the Kosmos's maximum input spec of +22 dBu. Yet even with its Input Level knob in the unity position, the Kosmos handled all but my hottest (most compressed) mixes without distorting them.
On stereo mixes, I liked the Quake function the most of the three Seismic Activity processes the Kosmos offers. You should be aware that a little bit of the Quake function goes a long way — cranking the control too high could damage unprotected speakers. (I recommend putting fuses on passive speaker leads to protect the drivers.) Moderate Quake settings can add thunderous bottom to mixes, imparting a quality that cannot be achieved using EQ. You probably won't want to use Quake on every mix and musical style — although it worked great on some R&B and techno mixes, it just sounded weird when I tried it on country and folk stuff.
The Kosmos's Thud function can provide flattering midbass EQ boost. However, you can't adjust its bandwidth or center frequency, so its usefulness on stereo mixes proved a hit-or-miss proposition. The same held true when using Thud on individual tracks.
As for the Xpanse process, anything more than moderate settings changed the stereo material's spectral balance too much for my taste. The Xpanse function can open up the sound of a mix considerably, but the cost is often a thin or brittle sound. Unfortunately, there's no way to avoid the resulting EQ boost — and you also can't tweak the affected frequency range — as you turn up the Xpanse control to enhance stereo width, because both of those effects are irrevocably tied to the same control knob in a proportional relationship (that is, increasing one effect increases the other).
The Kosmos generated mixed results on individual tracks. The Quake and Thud processes gave me wonderfully beefy kick-drum tracks; indeed, that turned out to be my favorite application for the Kosmos. I could detect no processing delay, and the groove remained tight.
The Kosmos also delivered some extremely deep tones on electric-bass tracks. That worked well for some musical styles, but for others, it sounded like unwanted rumble. As with any processor, judicious and artistic use of the Kosmos's abilities must be prime considerations.
The Kosmos's Xpanse effect made hard-panned stereo acoustic-guitar tracks sound wider, but it also made them sound exceedingly bright. I obtained similar results using the Xpanse effect on drum-overhead tracks. Remember that simply boosting highs on hard-panned tracks will result in a wider-sounding mix. For example, I was able to duplicate the width enhancement and change in timbre produced by the Kosmos (with the Xpanse knob set to 11 o'clock) fairly closely by using simple EQ. I gave the hard-panned, dry tracks a +6 dB shelving boost at 5.04 kHz and a 5 dB shelving cut at 157 Hz. The tracks processed through the Kosmos still sounded slightly wider, but not dramatically so. In either case, the resulting brighter timbre was not desirable. Moreover, after I turned down the Xpanse knob to a point at which the timbre was acceptable, little stereo-width enhancement remained.
At Peavey's suggestion, I multed a mono vocal track to the Kosmos's left and right inputs, turned up the Xpanse process, and listened to the unit's stereo outputs, hard-panned in the stereo field. Contrary to what I had been led to expect, I heard virtually no stereo-width enhancement in the processed signals.
The Kosmos can deliver great sounds on stereo mixes and individual tracks; however, its fixed frequency bands and interaction of imaging and timbral effects often require compromised settings. Peavey is aware of the Kosmos's limitations and plans to offer an advanced model, tentatively dubbed the Kosmos II, that will grant greater control and flexibility.
For the time being, other devices on the market can deliver more dramatic 3-D effects than the Kosmos and do so with fewer timbral compromises. That said, the Kosmos is fully mono compatible, something many other 3-D devices cannot claim. Moreover, few other enhancers can compete with the Kosmos's low price. Finally, the Kosmos provides more than just stereo-width enhancement — indeed, its Quake function alone might be worth the price of admission. If urban and techno music are your specialties, the Kosmos could be your low-cost ticket to bone-shaking nirvana.
Inputs(2) balanced XLR; (2) balanced ¼" TRSOutputs(2) balanced XLR; (2) balanced ¼" TRS; (1) balanced ¼" TRS (subwoofer)Maximum Input+22 dBuMaximum Output+22 dBuFrequency Response (in Bypass mode)<10 Hz-40 kHz (+0, -1 dB)Total Harmonic Distortion + Noise0.003% (Process mode); •0.002% (Bypass mode)Signal-to-Noise Ratio-101 dBuCrosstalk•75 dB (@ 1 kHz)Dimensions1U × 9" (D)Weight7.1 lb.
low-frequency and stereo-image enhancer
FEATURES3.0EASE OF USE4.0AUDIO QUALITY3.5VALUE3.5
RATING PRODUCTS FROM 1 TO 5
PROS: Affordable. Mono-compatible. Plug-and-play operation. Quake function can beef up the bottom end of tracks and mixes in a way that EQ can't. Balanced I/O can handle unbalanced signals.
CONS: Needs more parameter control. Xpanse function can make audio sound thin or brittle, even at moderate settings. Scant documentation.