Passive vs. Active Configuration – A Kudos Audio Guide

Passive or active? It’s one of the oldest and longest-running debates swirling around the world of high end HiFi. Which is better? Is there a right or wrong answer? Maybe you’re even wondering what on earth it all means in the first place!

All of these are valid questions, even for the most seasoned of music lovers. In this short article, we here at Kudos Audio are going to attempt to break down exactly what passive and active speaker setups are, how they differ from one another, and which might be better for your listening. Hopefully, by the end of this piece you’ll have a much clearer idea of the advantages and disadvantages of both approaches – especially when it comes to listening with Kudos.

The difference between a passive and active setup.

Let’s start with the absolute basics, by looking at how the two configurations work in practice, and how they might differ from one another. 

A passive speaker setup

SOURCE   ||   PREAMP   ||   POWER AMP   ||   PASSIVE CROSSOVER   ||   DRIVE UNITS

Whether passive or active, all audio systems start off looking relatively similar. To begin with, there’s a source component – a music streamer, CD player or turntable that plays the music. The signal is then sent on to a preamplifier that allows you to switch between your different source components, and control the overall volume level. Many manufacturers now choose to combine a music streamer with a preamplifier – these units are becoming incredibly popular on the market, and there’s some great ones available from many leading audio manufacturers.

At this stage, the signal is what we call ‘line-level’. We now need to increase this signal enough to drive a pair of speakers, and that’s where the power amplifier comes in. In a passive setup, however, the power amp isn’t directly connected to the speaker’s drive units. First, the power amp’s output has to pass through a crossover filter network commonly located inside the loudspeaker cabinet. 

The job of this crossover filter is to split the sound signal into different frequency bands, so that the right frequency reaches the right drive unit within the loudspeaker – ensuring bass frequencies are sent to the bass unit, treble frequencies to the treble unit, and so on. This crossover network doesn’t need a power source to operate, so in that sense it’s considered ‘passive’. 

And that is a basic outline of what a passive loudspeaker setup typically looks like.

The limitations with passive configuration

As far as signal purity is concerned, passive configurations present unavoidable limitations. After that original line-level signal is increased by the power amplifier, it reaches the passive crossover at a high strength ‘speaker level’. In order to handle and process this signal strength, passive crossovers are forced to employ large internal components like capacitors, inductors, and resistors to filter out any unwanted frequencies. This results in an unavoidable level of signal loss and energy wastage. 

Any signal loss or energy wastage is going to alter the sonic quality of our music by the time we hear it through our loudspeakers. What’s more, there exists another somewhat unavoidable side effect to a passive approach. As the impedances and capacitance change with frequency, a passive crossover will create a reactance that inevitably feeds back to the power amplifier. Once again, the result is reduced signal purity, and therefore reduced audio clarity. The more complicated the crossover, the more noticeable this effect will become. 

So how do loudspeaker engineers counteract these problems? One potential engineering solution is to remove the crossover altogether, and instead utilise what’s called a ‘full range drive unit’. However, (without getting too deep into the technical weeds) this approach can have many limiting factors for frequency bandwidth and power handling. 

Alternatively then, we can look at employing an ‘active’ crossover configuration. Let’s dive into that next.

An active loudspeaker setup

SOURCE   ||   PREAMP   ||   ACTIVE CROSSOVER   ||   AMPS (1 PER BAND)   ||   DRIVE UNITS

In an active speaker configuration, our system looks pretty much the same as the passive setup until the signal leaves the preamplifier. 

Rather than sending the signal straight to a power amp as we saw in the passive system, an active configuration instead sends the signal to an active crossover filter first. This means our audio signal reaches the crossover at ‘line-level’ – much smaller than the speaker level signal filtered by the passive crossover. This is very good news for the purity of our audio signal.

With the audio signal at such a significantly lower level, the components in an active crossover filter can instead be optimised for precision rather than pure power handling. Active crossovers can be built using small, simple, and super efficient internal filtering components, resulting in a filter network that is significantly more accurate and nuanced in its operation.

Each separate frequency band of our much smaller, pre-filtered line level signal is then sent on to a dedicated power amplifier, which are in turn connected directly to the loudspeaker’s respective drive units. This gives us much more control over gain levels for more precise signal tuning – something passive crossovers simply aren’t able to do. 

In short, active configuration creates a much more precise and responsive listening experience than its passive alternative. By connecting the amplifiers directly to the drive units, a whole level of signal variance and electrical reactance is removed from the signal path – making for a significantly enhanced listening experience on almost every level, whilst also giving the power amplifier a much easier task to achieve!

Passive vs Active with Kudos Audio loudspeakers

All this isn’t to say that a passive configuration is incapable of premium quality audio. There are many passive setup enthusiasts out there who love the sound their passive systems produce. And ultimately, the key is to find a sound and setup that works for you. 

At Kudos Audio, we’ve designed and built every single loudspeaker in our range to sound as good as practically possible in passive configuration. Whatever configuration you choose to use, our crossovers are engineered using the same masterfully simple methodology, utilising the fewest internal components possible. 

So if you opt for a passive system, Kudos Audio loudspeakers are very much equipped to furnish you with an incredible listening experience. However, choose or upgrade to active configuration, and your Kudos loudspeakers are elevated to a whole new level of sonic excellence.

Kudos Audio makes active configuration simple

Kudos Audio isn’t the only speaker brand to allow for conversion to active configuration, but few make it as easy and straightforward as we do. 

With Kudos Audio loudspeakers, there’s no unscrewing elements and manoeuvring (or in some cases resoldering!) internal components. There’s no need to cart your speakers back into the dealership or call out specialists. Switching to active configuration is as simple as plugging your cables into the correct inputs on the back panel. 

You can see a great example of an active Kudos Audio system in our first episode of The Listeners – where we met Harry. Harry owns a pair of Kudos Titan 808s employed in active configuration with a stunning Linn Klimax system – including the new next generation Linn Exaktbox. 

In Harry’s words, active configuration offers ‘more detail, more frequency range…there’s just more music available for you to hear.”

Kudos Audio’s active configuration works seamlessly with leading products from some of the world’s most revered audio brands. Employ active operation alongside system components like the Devialet Expert, Linn Exakt, NAIM Audio SNAXO and the Exposure VXN Crossover. 

It all means you can continue to create new and exciting iterations of your system for many years to come, whilst always keeping your Kudos Audio loudspeakers at its heart.