top of page

Becos CompIQ Twain Pro Compressor Review

If you feel like the compressor you have is lacking, the Becos CompIQ Twain might be for you. If you are the type that wants ultimate control, the Twain might be for you. If you play a 5-string bass and feel compression adversely squashes your B string, the Twain is definitely for you.

I have previously reviewed the Becos CompIQ Mini One Pro Compressor, the Becos CompIQ MINI Pro Compressor, and the mighty well-featured Becos CompIQ Pro Stella Compressor. Each model is impressive in its own right and satisfies a niche of buyer. From the simple two dial approach of the Mini One Pro to the loaded Stella which offerstape saturation, wet/dry blend, and side chain function, there is something for everyone in the Becos compressor lineup.

I've been impressed with each offering because each does what it does well and there is a lot of bang for the buck. I think anybody would appreciate thoughtful details like full LED gain reduction metering which is even included in the lower priced tiny Mini One Pro and Mini Pro.

Now Becos of Romania leaps forward with yet another device that is even more feature rich, more versatile, and might just be the Swiss Army knife of compressors.

Enter, the Becos CompIQ TWAIN Pro Compressor. There are a lot of dials, There are many switches. Many functions doesn't necessarily make for a useful device. So how does the Twain stack up? Is it overkill? Is each function even useful?

For those who are turned off by what appears to be complexity, I'd invite you to wait it out and keep reading.

I am well aware that a device like this is not for everyone, especially those that prefer utilitarian compressors.

The Becos Twain is a dual-band compressor. Inside are two independent 4320 THAT Analog Engines® coupled with Blackmer®VCA’s. Think of it like two compressor engines in one enclosure. The left side should be configured to compress your lows. The right side should be set to compress higher frequencies.

Notice the band of LEDs on the left and the band of LEDs on the right. They are there to help you dial in each compression engine.

With that said, the core controls for each compression engine are the dials marked:

  • Threshold

  • Ratio

  • Gain

You will see those controls for both sides.

There are also switches for Knee and Timing.

Threshold controls the signal level after which compression is applied. Compression is only applied to the portion of the signal that goes above the threshold. Set very low in the range, it makes compression kick in quickly, even for short amplitude input signals. Set higher in the range, it lets a good portion of the signal untouched.

Ratio sets how much the audio signal is compressed after it passes above the set threshold. It has a continuous range starting from 1:1 up to Infinite:1. At 9'clock, the control corresponds to 2:1 ratio ‐ a mild, musical and useful compression, which delicately evens out signal hikes. At 12'clock it sets 4:1 ratio. At 3'clock it corresponds to 10:1 ratio ‐ a rather aggressive setting, which may be desirable only when note sustain is needed. Inf:1 ratio means over 20dB amount of compression is applied. It makes a great limiter.

Gain is there to compensate for the fact that the more compression that is employed the more recovery gain has to be added to compensate. There is plenty of gain on hand. Note: the Twain has a stacked feature (discussed later in this review). Adjust gain carefully when in stacked mode so as not to add unnecessary noise.

The Twain offers Knee control (in the form of a switch) for each compression engine. With Hard Knee, compression kicks in with a sharp corner making it very audible. With higher compression ratios, it makes the limiting effect very clear. With lower ratios however, it provides a good and musical compression effect. The Soft Knee is more subtle and compression is applied progressively once signal passes above the Threshold. The effect is gentle and desirable when compression doesn't have to be explicit or used as an audio effect.

There is no control for Attack or Release on the Twain. Instead, there is an automatic engine that adjusts Attack & Release in real time, responding to playing dynamics. Two presets are available. Auto Fast (F) is 5‐7ms for Attack, 70ms for Release. Auto Slower (S) is 10‐15ms for Attack and 100‐220ms for Release. Both settings respond gracefully to any playing style.

In practice, you could set the either compression engine to fast timing which accentuates the compression feel and may sometime render pops, especially with higher ratios. Slower timing setting breaths more air into compression, making it feel more natural, even with higher ratios. It is easy hear the differences (especially at higher ratios with lower threshold) so just experiment. There is no right or wrong setting.

There you have the core controls of each compressor engine. Still with me?

Having two compression engines in one pedal is not necessarily all that useful unless you control which frequencies get what type of compression. Ahh, now the fun begins.

The crossover dial (marked X-Over) is the control you use to determine which frequencies are sent to which compression engine. The control ranges from 70Hz to 1 KHz, with around 150Hz in the middle. The input signal always passes the Crossover, from where it is split for compression processing. In Dual‐Band mode, what is below the Crossover’s set point is sent to the Lows engine (the left side of the pedal) and what is above is sent to the Highs engine (the right side of the pedal). In Stacked mode, the Crossover is active for the Dry Line only.

What's the point? Maybe you want to compress your lows more than highs to keep the lows tight and less boomy. No sweat. Once scenario to achieve this could be to dial in a lower threshold (to let the compression kick in sooner), maybe a little higher ratio (to squash a bit more), maybe hard knee, and fast timing (so the compression reacts quicker on the initial attack). On the high side, you might want to have a little higher threshold so more input signal gets through, a little lower ratio (so as not to squash as much), and soft knee for a smoother feel. Set knee to taste. Finally, set the X-Over dial at noon (or maybe even more counterclockwise) to send low frequencies to the left side while leaving the majority of frequencies delivered to the right side.

You can see there are virtually endless scenarios of how to manipulate both compression engines to tailor your sound. It is equally useful with guitar or bass (and probably any electric instrument).

Certainly one of the biggest complaints from antagonists of using compressors is the notion that compressors overly squash or suck the life out of an instrument. The Twain includes a Mix control which is very efficient at blending the amount of dry unaffected signal and wet compressed signal. Rotating the dial more clockwise brings in more unaffected signal and thereby restores transients at higher compression levels. It is very effective.

The fact that the Twain has a gain control for each compression engine opens up even more possibilities. For example, you can dial in lows on a 5-string bass guitar that are absolutely huge by creating a nice tight compressed output with the left compression engine and then dialing the gain higher than the right side. So much so that you must be careful.

Conversely, maybe you want to control your lows and balance with mids and highs but leave

the high end untouched. No problem.

Now is a good time to talk about the Side Chain Function which only works with the Lows processing engine (left side) and has three positions: Normal (N), Low (L) and Deep (D). In Normal position, the Side Chain Filter is set to accommodate a large range of audio signals and instruments. By design, the side‐chain’s signal is progressively compensated from highs to lows to balance the triggering potential of different signal amplitudes at different frequencies. This setting renders a natural response that is suitable for most instances. In Low (L) position, an additional ‐12dB@90Hz is freed up to prevent triggering the compressor too early. This is an intermediary position, and it lets more of the low end pass through at the output, while also lowering the amount of compression. In the Deep (D) position, even more of the lower frequency spectrum is freed with ‐12dB@200Hz.

Let me put it this way. Do you play a 5 string bass? Put the switch in Low or Deep position. The significance of this function cannot be underestimated because it opens up a world of opportunity for the "keepers of the low end." This control further refines how lows are managed and dispels the notion that compression sucks the life out of the bass guitar.

The Becos Twain is a killer compression device for 5-string bass players.

Oh, remember those independent gain controls mentioned earlier? When combined with the X-Over control you effectively have Tilt-EQ because you can increase or decrease the amount of highs and lows output. Nice!

Moving on, the Twain has an onboard preamp that should be used to trim the input stage to accommodate different processing level needs. It is highly useful if you use both passive instruments and instruments with higher outputs, like basses with onboard preamps.

Ranging from ‐9dB of attenuation to +6dB of gain, it can act as a compression driver or as a one‐knob balancer for the overall audio effect of the pedal. A PEAK level indicator will start to light faintly in Yellow once the signal level reaches +6dBu (1.54Vrms) and brighter, more consistent if signal passes over. The peak level indicator responds to positive gain trimmings and attenuating the signal turns the LED off. As peak LED turns on, clipping may occur and is advisable to trim down the signal.

I hit the preamp hard with Sadowsky basses (which are known to be "hot" active signals) and the Becos preamp Peak LED never illuminated. Of course my Fender Stratocaster posed no threat either.

With what we've discussed so far, you could stop reading and not mess with the rest of the controls. You'd have a killer compressor.

Yes there is more to this pedal.

The Tape Saturation circuit is available for both compression engines. Again, the controls on the left side of the pedal coordinate with the left compression engine and those on the right coordinate with the right compression engine.

With independent controls you can introduce different levels of saturation on each band, as separated by the Crossover (X-Over dial). It is an analog circuit used to saturate the Dry Line which you then mix with the Compressed Line, to fatten up the compressed sound with harmonic distortions. The Lows Saturation is more applied to note’s higher harmonics and less to the fundamentals, to prevent fuzziness with bass instruments. In practice, it works very well if that is your type of sound.

The dials marked Lo Sat and Hi Sat control the amount of saturation available. The signal is totally clean when dialed fully counterclockwise and mildly overdriven when fully clockwise. The dials marked Lo Cut and Hi Cut are there to help balance the saturation effect by controlling the amount of lows or highs introduced. The cut filters are passive first‐order filters (‐6dB), with a very gentle contribution. Think of it somewhat like a high pass filter (HPF) on the saturation line.

The dials marked Level are there to restore lost volume with higher saturation levels (which effectively reduce perceived volume).

An attentive reader might wonder whether these controls offer further control over dialing in the low end or high end, even with a clean signal. Absolutely! But remember, the saturation circuit reacts only to the Dry signal.

The whole point of the saturation circuit is to emulate vintage studio tape saturation compression effect of the '60s. This is a musical sort of distortion happening when high amplitude audio signals are recorded on magnetic tape. In practice, it works well for that type of feel. It is also great for adding in a bit of growl and is responsive to how hard you attack the strings.

One feature that really excites me is the Stacked operation of the entire circuit. There is a button on the right side of the pedal marked DB/STK which sets the operation mode of the Twain.

In Dual‐Band mode, the signal passes through the variable‐point Crossover and each frequency band is sent to its processing engine. In Stacked mode, the Crossover’s re‐combined signal is routed in series through each compression engine. Each operation mode delivers a different flavor. Stacking compressors feels more like an optical compressor. Dual‐Band processing is the more precise dynamics tool for the user wanting ultimate control. Dual-Band also offers tone enhancing possibilities.

No doubt there is a lot to the Becos CompIQ TWAIN Pro compressor. While it can seem complicated each feature is very useful. It certainly is not a device for the utilitarian but it is truly amazing what has been included in a device of this size, let alone something that is meant to be placed on a pedalboard.

Becos has produced a list of CompIQ Twain Dual Band / Stacked compressor setting examples and I would encourage you to take a look.

I tried each example and found them not only helpful, but spot on.

From light and airy to gritty and clamped to warm optical style compression, there is something for everyone and the Twain delivers.

You want sustain? It is here. You want all out limiting? No problem. Like a little grit? Yep. I can't think of another compressor currently on the market that offers as much as the Twain.

The first run of Twains shipped have the voltage printed on the enclosure as 9-12V. During the testing process with my prototype I encountered what turned out to be a bug. A cascade of mixings for the signal at the end of whole circuit is made in such a way that it clips with stronger signals and less headroom given by the 9-12V power. If you are using a passive bass or likely even with an active 4 string bass, you will probably never encounter the issue. But with an active 5-string bass you might. The fix is to run the device at 18 volts which Becos assures me is 100% safe. If you do encounter any type of headroom issue, run the pedal at 18 volts. The second run of pedals will be marked 9 - 18 volts on the enclosure. More information about a fix maybe found here.

Overall, it seems to be a quality device. All knobs are plastic though. The metal switches are tiny and not easy to access. I found myself adjusting dials sometimes when trying to flip a switch. It is all a tradeoff for the amount of controls yet trying to keep the pedal footprint as small as possible.

Input and output jacks are side mounted as is the power input.

There is a green LED that illuminates when the pedal is activated.

Footswitch is true bypass.

I think it is safe to assume the Twain is a little much for some. That's OK because there is probably another compressor in the Becos lineup to meet the need. The Twain takes the Stella several steps further which is commendable considering how robust the Stella is. No doubt the Stella offers more than what many rack mount studio compressors.

In some ways, the Twain simplifies things such as some manual timing controls are sacrificed for auto settings.

If you are into compression, the Becos CompIQ Twain Pro Compressor is in a league of its own. It forges a new path.

The price is right considering the technology inside. Might be the best fully-featured compressor for 5-string bassists.

I'm not sure what to directly compare it to. There are other multi-band compressors on the market including the EBS Multicomp and FEA DB-CL. The Twain is in an entirely different league than the EBS Multicomp. The Dual Band Compressor Limiter from FEA is probably the most similar but the Becos moves beyond it the amount of control. That said, the FEA is no slouch. It is an elite device for sure. Compared to the FEA the Becos Twain is brighter sounding overall. The LED metering is much better on the Twain than the single LED of the FEA. The Twain offers a wider Ratio range, though the FEA does offer a limiting mode with a flip switch. I do like the fact that the FEA offers independent control attack and release but frankly, the automatic timing engine in the Twain never really made me feel like I needed independent controls. It is important not to underestimate the wet/dry blend and side chain switch features in the Twain.

The Becos CompIQ Twain Pro Compressor is inherently a more neutral or uncolored compressor until you start inserting the tape saturation effect and adjust gains. It sounds really good. I'd be hard pressed to think of any compression type the Twain can't deliver. Is it too difficult to use? I would not recommend the Twain for those new to compression but I doubt that is the market Becos is targeting, nor is it the buyer who will be attracted to the Twain.

The folks at Becos sure are building an impressive pedal lineup and creating quite a name for themselves. I hope this review helps to further create awareness. Becos deserves more recognition.


  • Versatility

  • Dual LED metering

  • Dual engine compression

  • Stacked compression mode

  • Complete functionality

  • The "all-you-ever-need" compressor

  • Size

  • Price


  • Small switches

  • Complexity

  • Possibly power requirements (only if you you demand the 18v headroom and don't have that kind of pedalboard power supply).

Retail price: $329 USD


bottom of page