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Komit™ Using & Applications

The Komit™ 500 series module is 100% compatible with older API Lunchbox™ modules and racks while being 'wired' to work with all of the extra features built into the advanced Workhorse 500 series rack and mixer. This short guide is written for those who are experienced with 500 series modules. Complete details on using the Komit and making connections to and from your 500 series rack can be found in the manual (PDF download).

The best thing about the Komit is that it is very easy to get great sounding compression. The Komit includes three sections, the compressor, an output gain stage and the unique limiter/clipper. The core function of each section works independently but the three parts can be used together as a whole to apply the unique character of the Komit upon the track.



For instance, the gain control is used to restore the gain lost through compression (make-up gain) but when combined with the clipper/limiter the gain control is used to "drive" the simulated diode-bridge clipper. Alternatively, when the limiter is set to BW (brick wall limiting) the compressor section is combined with the limiter turning the Komit into a super clean limiter for digital recording.


Using the Compressor


The compressor section is setup differently than most compressors. Lets start with just the compressor section active and later we will explore the limiter section. The limiter section has it's own bypass, or "OFF" setting, allowing only the compressor in the signal path.

Input +4/-10dB Switch

You will notice the absence of a threshold control. Normally, one sets the threshold or the point where compression begins using this control. But with the Komit, this has been replaced with a simple two position INPUT switch. The idea is simple. Since the Komit will be receiving the signal from a recorder or mic preamplifier, the signal will almost always be either +4dB professional line level or -10dB from an unbalanced source. You simply set the INPUT switch based on the operating level of the signal chain. This makes it easy and of course simplifies the front panel layout.

Time Constant Speed Switch

The Komit compressor is a VCA compressor with program dependent circuitry that reads what is happening and reacts accordingly. This means that you do not have to set an attack or release time, you simply set the 3 position time constant switch to slow, medium or fast based on the type of signal you are compressing, and adjust the compression ratio to suit. Although there are no hard set rules, the slower speed setting tends to be used on vocal tracks for smoother effect while the medium setting tends to be used on instruments. For dynamic control over percussive instruments, the fast setting of course is used.

Compression Ratio Control

The single ratio control is what makes the Komit's compressor section so easy to use. Start with the compression control set fully counter-clockwise to the 1:1 setting. This setting will produce no compression. Turn the control clockwise while observing the gain reduction meter. The higher the ratio setting the more gain reduction will occur.

Make-up Gain Control

Once you have set the desired amount of compression, you can increase the GAIN control to make-up for the gain lost through compression. As a rule, start by setting the control to unity (U) and then adjust as needed. The variable control will deliver up to +22dB of gain to compensate for any amount of compression.

The 10 segment meter

The Komit is equipped with a 10 segment meter that is split in two. The right side is dedicated to the output level of the compressor (-18dB ~ +6dB). The left side displays gain reduction (-4dB ~ -30dB). The meter is designed to give you a reference point and help you keep signals working within normal range.


Using the Limiter


The Komit's limiter is in fact a Dr. Jekyll & Mr. Hyde arrangement. At one end it can be used as a super clean brick wall limiter and at the other end it turns on the simulated diode-bridge Clipper™ effect. The limiter section is controlled by a simple 12 position rotary switch. The first ten positions of the limiter control are dedicated to the clipping effect. The second to last position (labeled OFF) bypasses the limiter section entirely for times when you want to use the compressor section alone. And the last position invokes the brick wall limiter.

The Clipper™ - Variable Clipping Limiter (Positions +21dB to -6dB )

The variable clipping limiter, or Clipper™ represents the dark Mr. Hyde side of the Komit's limiter. The Clipper is designed to simulate the effect of a diode-bridge limiter circuit. This type of circuit was used in vintage radio receivers. Although not a limiter in the usual sense of the word, the way this works is by limiting the gain in somewhat the same way as one 'unnaturally' limits the output of a device when pushed beyond its normal operating range. At one point, instead of getting louder, it basically distorts. The term of course is clipping, hence the name Clipper™.

The first ten positions of the limiter control is labeled in decibels representing the threshold of clipping. When the level exceeds the threshold the tops and bottoms of the waveform are clipped. The effect can range from subtle to extreme predicated by the setting of the 12 position LIMITER control. Use the Clipper™ to add character to bass, crush to kick drum and edge to vocals.



As you get to know the Komit, you will find that using the Clipper™ in a subtle way can increase the presence of a vocal track or add sizzle to a snare drum. By combining the compressor section with the Clipper™, you can unleash all kinds of new and exciting sounds that will surely please some and completely unnerve others. Not very nice but certainly loads of fun!

Driving the Clipper™ With Gain

The Komit's GAIN control serves two purposes. As described in the compression section it is used to make up the gain lost after the compressor is introduced. The second purpose is to overdrive the Clipper™ limiter allowing you to vary the amount of clipping produced at any given limiter setting.

In broad terms, you can think of this like the preamp stage of a guitar amp while the Clipper limiter acts like the master volume. The GAIN control can amplify the post compressor signal with up to +22dB of gain. With this much gain on tap you can dial-in varying degrees of clipping on any signal, from the softest whisper to the loudest kick drum.

Brick Wall Limiting (position BW)

The last position of the limiter control is labeled BW for brick wall. This position turns the Komit into a transparent "brick wall" limiter. It's the clinical and analytical Dr. Jeykle side compared to the Clipper™'s dark Mr. Hyde persona.

When the BW setting is selected the compressor's ratio is doubled (producing a 20:1 compression ratio when the control is turned fully clockwise) and the Clipper™ circuit is bypassed. Typically, the GAIN control is set to unity gain (fully counter-clockwise) when in brick wall limiter mode.

The BW limiter setting is ideally suited for digital recording where analog to digital converters must be protected from "overs". When you absolutely must keep the signal out of the red, reach for the Komit's brick wall limiting.


Sync & Link - Using the Komit In Stereo


The traditional way to link two compressors has been to share the control voltage between detector circuits in a master and slave configuration. The shortcoming with this approach is the inaccuracy of the attack and release characteristics between units due to part tolerances and voltage tracking lag time. To overcome the problem, the Komit employs an additional and innovative 'SYNC' function that allows both compressors to synchronize to one time constant circuit. The result is a more accurate stereo rendering, perfect for applications like a master stereo bus compressor.

Setting up two Komits for stereo use is easy. Some 500 series racks, like the Workhorse, are equipped with a LINK function that is designed to couple stereo modules together. Once the two detector units are linked via the 500 series rack a single front panel SYNC switch is engaged (inward position) on one Komit. Only one SYNC switch need to be engaged for the time constants to be synchronized.

Once linked in stereo, each Komit retains a certain degree of independence. In other words, although the time constant will be coupled, each side of the stereo signal will retain independent compression, limiting and gain control. Mostly you will want to set these controls to be the same on both compressors but variations can yield interesting effects. It's important to note that when linked in a stereo setup the loudest transient will ultimately determine the FlexKnee pivot point for both Komit's.


Omniport™ - Using The key Input


If you have a Workhorse, you can also control the Komit's dynamics from an external device by connecting it to the Omniport – which in this case is set as a key input. So instead of the Komit reacting to the program input signal, it will compress the signal following an external audio source. This can be used in a variety of ways.

Amplitude Dependent Compression or Ducking

Ducking is a term that refers to automatically reducing the level of one track when another is played. This is commonly used in video for dialogue replacement whereby when the orator speaks, the background music will automatically be shunted. You can also use ducking in music production. For instance you can automatically reduce the level of a rhythm guitar when the vocalist is singing. As soon as she stops, the guitar will automatically be brought back up to the previous level. To create these effects, simply take the vocal track output from your recorder or mic preamp and send it into the key input via the Omniport. Set the compressor to a relatively high setting like 5:1 and adjust the input level from the vocal track. Adjust to suit.



Another use for ducking is using the kick drum as the key to pull down the stereo track. This is popular with dance music and is used to accent the kick drum by automatically reducing the loudness of all the other tracks. To create this effect, set the Komit with fairly high compression and when the kick drum signal hits the Komit, the program will be reduced accordingly.

Frequency dependent compression or de-essing

Another popular application with a compressor is known as de-essing or controlling the sibilance of a vocal track that may have excessive 'S' sounds. To set this up, send the vocal track into an equalizer. The EQ will be used to accentuate the 'S' problem. The output from the EQ will then be sent to the Komit's key input. When excessive S frequencies are encountered, the Komit will pull down the track automatically smoothing out the track.



Some Practical Examples


Bass Guitar

Bass guitars tend to sound better when some compression is applied. Start by setting the compression ratio to 5:1 and time constant to medium speed. Then, depending on the dynamics try adjusting the ratio to suit. As you increase the compression, adjust the output to compensate.

Vocals

Setting a compressor for voice tend to be a bit trickier as some vocalists tend to drift all over the place while others have tremendous control over their instrument. As you increase the compression to compensate, the track can loose its dynamic appeal. Start with less compression – say 3:1 - as this will sound more natural.

Kick drum

Compressing the kick is usually done to even out the drummer's performance. Like a voice, some drummers are exceptionally consistent while others are not. Start by setting the compression ratio to about 3:1 using the fast time constant. If you want to create a more 'in your face' effect, increase the ratio to 6:1 or more.

Acoustic guitar

Acoustic guitars tend to sound 'poppy' unless compressed. A popular approach is to position a condenser mic about 6" away pointing between the neck and sound hole. Start with the compression ratio set to 3:1 with a medium time constant. This will eliminate the peaks without totally eliminating the dynamics. Adjust to suit.

Piano

Of all instruments, the piano has the widest frequency response and because it is very dynamic, one must be careful when applying compression. For solo performance, less works best such as setting a 1.5:1 ratio as this will tame the peaks without hampering the dynamics. When mixing the piano in an orchestrated track, a higher compression ratio would be used.