The ISOLATOR section of the KLEMENTZ Dub Mixer is a three-band stereo filter that splits the sound into bass, midrange and treble, with a volume control per band, a backlit kill switch per band and two manually adjustable cut-off frequencies.
It’s this last point that makes all the difference. On most isolators, the boundaries between the bands are fixed at the design stage. Here, you can adjust them whilst you’re playing. This means the bass control doesn’t control the same frequencies depending on where you’ve set the cut-off.
What’s in the ISOLATOR section
The module comprises three groups of controls, all on the front panel, within easy reach during a set.
The three volume controls adjust the bass, midrange and treble levels separately. You can cut the bass without affecting the vocals. You can boost the treble without bringing the kick drum to the fore.
The three kills are illuminated switches. Pressing one cuts the band; pressing it again restores it. The action is crisp, and you can see the status out of the corner of your eye – which is crucial when you’re playing in the dark.
The two crossover settings adjust the boundaries between the frequency bands. One defines the separation between the low and mid-range, the other between the mid-range and high-range. On the front panel, they are labelled ‘X-OVER’. Details of the controls are listed in the article on the front and rear panel controls.
Kills, for a clean cut-off
A kill removes the frequency band from the mix in one go. This is the basic technique in dub: you remove the bass before a return, the bass comes back on a clear beat, and the tension comes from the silence rather than the volume.
Each of the three bands has its own kill switch. You can cut one, two, or keep only the middle one. Removing the bass and treble at the same time leaves just the midrange, which creates a very crisp ‘radio’ effect before bringing everything back in.
The indicator light serves as a status indicator. Whilst selecting tracks, you know which band is still muted without having to listen to guess.
The three volume controls, for balancing
The kill is binary; the volume is continuous. This is where the filter becomes musical rather than merely dramatic.
Cutting a band by half leaves the track intact, but shifts its centre of gravity. A little less midrange opens up a mix that becomes thick. A little less treble softens an old, slightly harsh pressing.
The reflex to avoid is the same as with all isolators: boosting all three bands doesn’t rebalance anything; it simply raises the overall level. If you want an element to stand out, first remove what’s masking it. The basic techniques are detailed in our article on isolator settings.
The two variable cut-off points: the real challenge
This is the feature that few isolators offer, and the one that requires the most careful listening. The video below demonstrates each setting in context, on the unit itself.
The high-cut filter determines what passes through the treble band. When set to maximum, it allows only a trickle of very high frequencies through: cymbals, breath sounds, and the tail end of delays. When turned down, it allows more midrange to bleed into the treble, and the top knob begins to affect the vocals.
The low-cut filter determines what is contained in the bass band. Set low, it reserves this control for the sub-bass, whilst the kick drum and the upper bass frequencies are routed into the midrange. When raised, it brings the upper bass and a little of the lower midrange back into this same band. The control then behaves like a low-pass filter that you’re sweeping by hand.
To hear exactly what each of these two settings does, first cut off a neighbouring band. Kill the midrange, then move the high-cut point: you’ll hear exactly where the filter draws its boundary. This is the quickest way to train your ear.
Table: where to set your two cut-off points
| Intent of the game | Low cut-off | High cut | What you get |
|---|---|---|---|
| Starting point | Midfield | Midfield | Three wide bands, a neutral setting to return to |
| Maintain a very fine high note | Midfield | High | The high end only carries the treble; the vocals remain in the mid-range |
| Isolate the sub | Bass | Midfield | The bass button only affects the sub; the kick drum is routed through the midrange |
| Wide bass cut-off | High | Midfield | The whole lower section disappears in one go, including the kick body |
| Notch effect | Bass | High | Cut the midrange: there’s still some bass and a hint of treble left |
| Low-pass filtering | Moving upwards | Midfield | The bass line gradually takes over the track |
These settings are guidelines, not fixed values to be copied. A system with powerful bass doesn’t require the same low-end cut-off as a pair of living-room speakers. First, listen to what’s in the track.
A three-way game that plays like a four-way game
On paper, the ISOLATOR has three bands. In practice, it covers more, because the boundaries shift.
Set the low-cut filter very low and the high-cut filter very high. You’ll get a sub-bass on one side, a crisp treble on the other, and the body of the track in the middle. You can then remove the two extremes and keep the heart of the track intact. Cut the midrange instead, and the same setting becomes a notch filter that leaves only the extremes.
These are two very different ways of playing, achieved using the same three buttons. It’s the position of the breaks that makes the difference.
Where the ISOLATOR is fitted in the machine
In the Dub Mixer, the isolator operates after the crossfader, on the entire mix, before the main bus.
CH 1 / CH 2 → Filters → Crossfader → Isolator → Main Mix Bus
Two practical implications. It affects both channels simultaneously, so it affects the track currently playing regardless of which deck it’s on. And it’s positioned after the channel filters, which gives you two levels of shaping: one per channel, and one for the mix as a whole. The full routing is detailed in Inside the Dub Mixer.
Bear one thing in mind: what goes in saturated doesn’t come out clean. Set your entry targets before looking for precise exit points.
Why is this section missing from a standard table?
A standard DJ mixer usually features three equaliser bands per channel, with fixed points and a limited range. These are for correction, not for performance.
An isolator works on the entire mix, with sharp cuts and wide bands. Add adjustable thresholds, and the filter becomes an instrument in its own right rather than a corrective tool. This is the shortcoming highlighted in our article on traditional DJ decks versus dub.
FAQ on the Dub Mixer’s isolator
How does this differ from an isolator with fixed breakpoints?
A conventional equaliser has its limits set by its design: the bass control always covers the same part of the spectrum. Here, you move the two crossover points, so you decide what each band covers. The same adjustment does not produce the same result depending on the position of the crossover points.
Does the kill really cut the tape?
Yes, it’s a sharp cut-off rather than just a gradual reduction in volume. That’s what creates the distinct silence before the bass comes back. The tape volume, on the other hand, is used for gradual adjustment.
Can you cut two strips at the same time?
Yes, the three cuts are independent. Cutting the bass and treble leaves only the midrange. Cutting the midrange leaves a notch between the low and high frequencies.
Should you adjust the cuts before the set or during it?
Both techniques are used. Many DJs set a parameter that suits their system, then leave it alone for the rest of the evening. Others adjust the cutoff in real time, which produces a sweep similar to a manually controlled low-pass filter.
Does the isolator replace the system shunt?
No. It’s used for playback and transitions, not for correcting a track or speaker placement. Calibration is carried out beforehand, during set-up.
How can you learn to use it quickly?
Isolate one variable at a time. Mute a track, then move just one fader and listen to what changes. Within a few minutes, you’ll know what each setting does, and the rest will come with practice.
It’s up to you to set your boundaries
Pick a track you know by heart, turn the midrange right down, and run both filters from one end of their range to the other. You’ll know where to set your limits before the track ends.
The ISOLATOR section is part of the Dub Mixer, housed in the same unit as the mixer, preamp, siren and delay.
