Description
Beyma CXK2 4-Ohm 4 kHz Passive 2-Way Crossover Pair
If you want to run a separate midrange and tweeter from one amplifier channel per side without turning the system into a fully active DSP build, the CXK2 gives you the frequency split and tweeter level control to make that architecture work.
This is a 4-ohm passive two-way crossover network sold as a pair, with a 4.0 kHz crossover frequency, 12 dB/octave filtering, 150 watts AES network capacity and selectable high-frequency attenuation at 0, -3 or -6 dB.
The key is not simply that it says “4 ohms.” A passive network only makes sense when the speakers on both sides of it are comfortable meeting at the network's fixed crossover point. The CXK2 is the right tool when the midrange can stay clean to the 4 kHz region and the tweeter can safely take over there with a 12 dB/octave electrical slope.
The problem it solves: a real two-way system without four amplifier channels
Take a normal left/right two-way front stage with one midrange and one tweeter per side. Run it fully active and you need four amplifier channels plus four DSP outputs: left mid, right mid, left tweeter and right tweeter.
That is the best route when we need independent crossover, delay, level and EQ for every driver. It is also more amplifier, more wiring and more tuning.
The CXK2 gives us the passive route. One full-range amplifier channel feeds each crossover. The crossover divides that signal so the midrange gets the lower portion and the tweeter gets the upper portion.
For the customer, that means a separate-driver two-way system can still be built from a conventional two-channel amplifier layout instead of doubling the required channel count.
Why 4 kHz matters more than the logo on the speakers
A passive crossover is fixed. We cannot decide during tuning that 2.5 kHz would have been better and simply drag a DSP crossover point lower. The 4.0 kHz handoff is part of the CXK2's design, so the drivers need to be chosen around it.
That makes some Beyma combinations more logical than others. A midrange with strong usable output through the upper mids has a better chance of meeting a 4 kHz network cleanly than a heavier midbass driver whose useful range is concentrated lower. On the tweeter side, the high-frequency driver needs to tolerate the 4 kHz handoff with the network's slope and the amplifier power being used.
This is why we do not sell passive crossovers by saying, “they're both 4 ohms, so it works.” Impedance tells the network what electrical load it sees. It does not tell us whether the acoustic crossover will make sense.
What the 12 dB/octave slope is doing
The CXK2 uses a second-order 12 dB/octave electrical filter. Around the 4 kHz crossover region, the network progressively removes high-frequency energy from the midrange and low-frequency energy from the tweeter instead of making an abrupt on/off switch.
That matters most on the tweeter side. Lower-frequency energy requires more excursion and can create heat quickly in a small high-frequency driver. The crossover is part of the tweeter's protection system.
But the slope is not a substitute for choosing the right tweeter. A driver that needs a substantially higher crossover does not become safe because a 12 dB/octave network is in front of it.
The 0 / -3 / -6 dB tweeter settings solve a real level-matching problem
High-efficiency tweeters often play louder than the midrange feeding them from the same amplifier voltage. Without some way to correct that difference, a technically correct two-way system can still sound like all horn and no body.
The CXK2 gives three published high-frequency level choices: 0 dB, -3 dB and -6 dB. That lets us pad the tweeter down at the crossover network instead of changing the entire amplifier level just to control the top end.
0 dB keeps the high-frequency output at the network's full reference level. -3 dB gives a moderate reduction when the tweeter is a little too efficient. -6 dB gives a larger reduction when the high-frequency section otherwise dominates the system.
That is not the same flexibility as an active DSP channel, but it is the feature that makes the CXK2 much more useful than a basic fixed passive filter.
CXK2 passive vs. active DSP
Use the CXK2 when the speakers already make sense at a 4 kHz handoff, amplifier-channel count matters, and the customer wants a clean two-way system without dedicating an amplifier channel to every individual driver.
Use active DSP when the system needs crossover frequencies chosen specifically around the installation, individual driver time alignment, independent EQ, steeper or different crossover slopes, or fine level control beyond the CXK2's three tweeter settings.
For example, a motorcycle build with limited amplifier space may benefit from one channel per side feeding a passive mid/tweeter pair. A serious sound-quality front stage where the tweeter sits in the pillar and the midrange sits much lower in the door will usually give us more tuning control when those drivers stay active on separate channels.
Neither architecture is automatically better. The system layout decides whether the simplicity of passive makes more sense than the control of active.
What the 150-watt AES rating means
The published 150-watt AES figure is the crossover network's power capacity. It does not turn every speaker connected to it into a 150-watt driver.
The midrange and tweeter still keep their own power limits. The tweeter also only receives the part of the spectrum above the network's crossover, so its thermal load is not the same as the amplifier's full-band rated output. That is exactly why comparing one amplifier wattage number directly to one tweeter wattage number can be misleading.
We design around the complete chain: amplifier, crossover, midrange, tweeter, impedance and intended volume. The weakest safe limit in that chain still matters.
Where the CXK2 makes sense in a real build
This crossover belongs in a 4-ohm two-way speaker system where the installation needs a separate midrange and tweeter but does not need—or does not have room for—a fully active channel layout.
That can be a pair of custom doors, motorcycle bags or fairings, a Jeep or powersports panel, or a straightforward component-style front stage. We would mount the crossover where it stays dry, secure it against vibration, and keep the input, mid and high-frequency wiring serviceable.
Before using it, we verify that the actual mid and tweeter can work around 4 kHz. After installation, we still listen and measure. A passive network establishes the electrical split; the vehicle and speaker placement determine the acoustic result.
The practical result: the CXK2 lets a properly matched Beyma midrange and tweeter behave like one two-way speaker system from a simpler amplifier layout, while still giving us useful control over the high-frequency level.
Manufacturer Specifications
| Model | CXK2 |
|---|---|
| Sold as | Pair |
| Network type | Passive 2-way crossover |
| Nominal system impedance | 4 ohms |
| Crossover frequency | 4.0 kHz |
| Filter slope | 12 dB/octave |
| Power capacity | 150 watts AES |
| High-frequency attenuation | 0 dB / -3 dB / -6 dB |
| PAC product code | 4FCKX2 |
Compatibility: use the CXK2 only with a 4-ohm midrange/tweeter combination that is appropriate for a 4 kHz crossover and 12 dB/octave electrical filter. Impedance by itself does not establish acoustic compatibility.
Where this fits in the build
Speaker choice should follow the listening goal and the location it has to work in. Factory replacement, sound quality, loud daily and high-output builds have different priorities.