PMC active twenty5 23i

Those with good memories (or simply a grasp of how the website’s search function works) might be surprised to see this speaker pop up as a new review. You see, we’ve reviewed the PMC twenty5 23i before and we liked it a great deal. But our fondness for something doesn’t mean that we are in the habit of reviewing things twice - so why is this PMC back for seconds?

Ostensibly, nothing has changed on the outside. It is still a compact, two-way floorstanding speaker that makes use of a 19mm tweeter with a rolled surround (making it 34mm across in total) that hands over to a 140mm long-throw woofer for mid- and low-range duties. At first glance, the svelte cabinet doesn’t look like a recipe for much bass, but the 23i (like most PMC speakers) has a secret weapon in the form of a transmission line. Instead of reverberating in a fairly simple manner around the inside of the enclosure, sound from the back of the bass speaker is directed into a long, damped pathway within the speaker enclosure. This allows far greater control and use of speaker energy in the resulting sound.

So, what’s changed? Take a look around the back of a ‘normal’ 23i and you’ll see the ‘plate’ which mounts the terminals is a bit of a whopper. This means PMC can take exactly the same speaker and fit a different plate that allows the speaker to run as an active device. If you already own a pair of 23is, you can convert them to run as active speakers by removing the existing crossover plate and fitting this new one.

Changing to active configuration means that each speaker receives an unamplified signal which is split up via a powered crossover and then sent to amplifiers. Each driver has its own amplifier and, as there is much less loss in a powered crossover, the result is more efficient as well. In this case, the PMC uses a pair of 100-watt Class D amps, which ensures that each speaker runs cool and relatively efficiently. 

It's important to stress that the PMC is a different proposition from many active speakers currently on the market. Yes, it has amplifiers on board, but the PMC still needs both a source and something with a volume control to function correctly. This means it is not self-contained in the manner that some active speakers are - but equally, as long as you can supply it with pre-out signal via XLR or RCA cables, this speaker can be used in a wide spread of setups. 

Sound Quality 

Listening to the PMC in its active configuration is an interesting experience, because so many of the comments that apply to the passive version still apply… but it is indisputably a different device. This is still a speaker that can charm you with its ability to find the hook in a piece of music, regardless of whether it’s head-banging intensity or the gentlest of flows. So long as a little care is taken in positioning, it can deliver a soundstage that is wider and more expansive than the narrow frontage might suggest. 

The switch to active operation doesn’t change these traits, but it does tweak them. Because the relationship between the crossover and the amplifiers is exactly as PMC wants it to be, the active twenty5 23i enhances these positive qualities. The control and articulation that it demonstrates is hugely impressive, and ensures that even extremely fast and congested passages of music are dealt with in a manner that feels effortless. 

What’s more surprising is that this change has ensured the 23i has even more low-end impact. It’s able to hit that little bit harder, and it does this across the volume range rather than needing to be pushed hard. The result is an incredibly impressive level of heft for a speaker this svelte - and it’s not an isolated lump of bass stuck at the end of the frequency response, but the logical conclusion of a beautifully cohesive response. 

Some of the same quirks of PMC behaviour remain, though. The company has expended huge effort on its transmission line engineering over the years and the result is that, almost all the time you listen to it, you simply find yourself enjoying more bass than seems remotely achievable from a speaker of this size. Every now and again, though, I find myself feeling some fine detail in the bass is fractionally masked by the heft of the transmission line and the air being moved. It’s never pronounced - but some competitors can do a little better. 

Something that has improved, though, is the top end. It was already very good in the passive version, but the active variant balances crossover, amplifier and tweeter in a way that means it is now almost impossible to provoke this speaker into sounding hard or forward. But this happens without sounding dull or restrained - this unflappable refinement is the most notable step forward the active configuration achieves, and it turns the 23i into an even more accomplished all-rounder than it was before. 

Living with

The things that the passive 23i did so well have not been messed with in this active version. It is still a handsome, well-finished speaker that takes up less space than most standmount models on their stands. PMC paid a huge amount of attention to the spikes and mounts when developing these ‘i’ models, and it helps to make the 23i an exceptionally easy speaker to position and to live with. 

In terms of partnering the PMC, the company has played a bit of a blinder by releasing these speakers at this time. In a market where a vast (and at times surprising) selection of devices can be used as preamps, the PMC arrives as the device you need to complete your system. Yes, both speakers will need a signal cable, either RCA or XLR, and also need access to mains power - but it’s possible to build a formidably talented system with a significantly reduced box-count. I use the Bluesound Node ICON for a good deal of testing, and the scope of what this three-box system can achieve is enormous. 

All this performance comes at a price, though. At £6000 the PMC feels a little on the expensive side. It’s well made and attractive, but it is not hard to argue that there are amp-and-speaker combinations for the same sort of money that feel like more bang for your buck. It is only fair to point out, though, that other active rivals of this type (that is to say, those that have analogue inputs rather than a wireless module) will set you back a fair bit of cash too. 

Conclusion 

Stiff price aside, it’s hard not to be deeply impressed by what PMC has done here. The active version of the 23i hits harder, sounds sweeter - and opens up some intriguing system-building possibilities in its two svelte towers. 

Listening notes 

Scorpions Crazy World 

You can ponder the intriguing notion that the CIA really did write Wind of Change at the same time as enjoying just how good the PMC sounds while rocking out. 

Venus Hum Big Beautiful Sky 

A barnstorming collection of high energy electronic music that gives the 23i plenty of opportunity to show off its agile and hard-hitting low end.

Ghost Woman Ghost Woman

Play this lowest of lo-fi rock on the passive 23i and it runs the risk of sounding thin and harsh. The active version keeps the rawness and rough-and-ready energy that makes this album so cool - but you’ll be turning the volume up rather than down. 

Do you want to streamline your box-count without compromising on serious hi-fi credentials? The PMC is an absolutely peerless solution to those requirements.