Date: 2024-12-30
Active or powered speakers are finally having their hay day, the demand for smaller wireless audio systems is largely why this is happening now but incorporating amplifiers and electronic crossovers into the speaker cabinet has advantages way beyond space and cost saving. The main advantage and the one for which active systems have long been used in studios is that the amplifier is connected directly to the drive unit, there is no crossover network in between to suck power and screw up phase. This makes genuine active speakers seem expensive as, unlike their powered wireless cousins which merely build the amp into the cabinet and use a regular passive crossover, they have an electronic crossover and one amplifier per driver which is naturally more costly. Yet rarely is it more costly than building a nice box for the amplifier and one for the loudspeaker which is what most of us buy.
PMC is long established in the pro audio world and the list of top class studios that use their speaker systems is long, the company even has its own facilities for mixing in multi-channel with Dolby Atmos being a speciality. They are very well versed in what it takes to make an active loudspeaker and have offered such models in their more ambitious ranges for some time. This year they added a range of active models to the entry level twenty5i range. From the front the new active models look exactly like their passive counterparts, the change is on the back where the stainless steel back panel now has line level and power inlets instead of the usual binding posts.
The active board can be used with any twenty5 or twenty5i series two-way loudspeaker, so owners of passive examples from the current and previous series can upgrade with the minimum of palaver and at a reasonable price (£1,795). This panel contains an analogue electronic crossover and a pair of 100 Watt amplifiers, one for each driver. It’s worth noting that the crossover is an analogue example because this is a luxury rarely afforded to less expensive active speakers which rely on DSP (digital signal processing). DSP has its uses and gives a range of set up options but rarely sounds as good as analogue circuitry in this situation.
The amplification modules in the active twenty5.22i are the latest from ICEpower, a Class D technology that was originally pioneered by Bang & Olufsen but which has since become an independent organisation. PMC chose these modules because of the experience that they have with them in pro monitors; if they meet the heavy demands of studio usage they are more than appropriate for end users.
The the larger of two bookshelf models in the twenty5i range, the active twenty5.22i is has a six and a half inch main driver and 19mm tweeter. The other two ways in the active range are the smaller 21i bookshelf and the 23i and 24i floorstanders, PMC describes the active twenty5.22i as the choice for those looking to fill a larger space with a bookshelf speaker, one that stands 41cm (16 inch) high in its leant back cabinet and weighs in at just over 10 kilos (22 lbs). I was surprised to see that the active twenty5.22i is weighs only slightly more than its passive counterpart, this is because the crossover components are so meaty on the latter and Class D amplifiers are not so big.
The active twenty5.22i driver array consists of a 19mm tweeter in a 34mm surround built by SEAS in conjunction with PMC, it uses ferrofluid to aid cooling when the speaker is used ‘in anger’ for extended periods. This has a fixed metal grille that aids dispersion and protects the soft dome. The mid/bass driver is a long throw type for greater extension and power with a g-weave cone in a cast alloy chassis. G-weave is PMC’s proprietary woven cone material and described as a resin-bound, fine-weave glass fibre. It’s interesting to note that Bowers & Wilkins also have a proprietary woven cone in their midrange drivers, maybe there is something in this tech after all.
The cabinet is PMC’s favoured advanced transmission line type, these are more complex than the common reflex loaded variety with a transmission line that takes frequency energy from the back of the main driver to the vent at the bottom of the front baffle, filtering out higher frequencies in the process. This provides low bass reinforcement that is in phase with the output of the driver itself and tends to result in excellent low frequency performance.
Sound quality
I experimented with stands under these speakers and found that wooden 58cm Hifi Racks ones sounded better than a 60cm steel example, quite possibly because the Hifi Racks have foam decoupling pads on them. I assumed that the active twenty5.22i is would work better with an active preamplifier than the passive one I usually use, so I brought in an ATC CA2 for the purpose, later experimentation revealed that the passive Townshend Allegri gave a more refined result but that it couldn’t match the dynamics provided by the powered preamplifier.
And as dynamics is one of the main benefits of active operation it is worth giving up a degree of finesse for. I suspect that you could get close to the latter with a better preamplifier of course and as you will read I did find an alternative which seemed to offer the best of both worlds. There was an awful lot to enjoy with the ATC in the driving seat however, not least a soundstage that totally escaped the cabinets when the level was raised. This occurred with a number of recordings and sources albeit some sources proved better than others, but when it happened the effect was quite thrilling and not one that you encounter with separate amp/speaker combinations at this price. It’s almost like the speaker disappears and the sound takes over with a degree of three dimensionality that is uncanny.
The active twenty5.22i’s bass extension is very impressive for the box size too, put on something meaty and you know all about it, the weight and crunch that Amon Tobin’s mix of Nepalese Bliss (The Irresistible Force) inspired the active twenty5.22is to deliver was pretty damn monstrous. With the more sophisticated vibes of great acoustic jazz recordings you get a transparency and vitality that is equally enthralling. These speakers have a monitor like ability to reveal detail and this combined with PMC’s long established ability to create loudspeakers that time with unerring precision, this makes for considerable musical appeal with decent recordings. Heavily compressed examples will sound that way of course but it’s worth remembering that this is the way that the artist/producer wanted them to sound. These speakers tell it like it is in an unusually coherent fashion.
I have a pair of twenty5.22s from a few years back which are also very good and when partnered with a decent amplifier can deliver a more relaxed sound than the active twenty5.22i. But the key work there is ‘decent’, which means £3k plus, and that combined with the price of a passive twenty5.22i (£3,875) takes you well above the £5,275 asking price here. And even then you wouldn’t get the imaging and dynamic capabilities of the active version. I also managed to get a much more refined result out of the actives by using an Icon5 passive preamplifier with them, this has a buffer option which drives the long cables being used rather well and produced a beautifully smooth and finely detailed result.
Pricewise the ATC CA2 is a more appropriate partner however so I went back to that and revelled in Kendrick Lamarr’s Alright (To Pimp a Butterfly) and enjoyed the taut, solid delivery combined with clearly defined vocals that makes this track so engaging. It inspired a bass fest and the selection of Nils Petter Molvaer’s Quiet Corners, this really plumbs the depths and its brooding menace sprinkled with diamond dust from the trumpet came across with a degree of torque that few passive speakers can match. Bigger examples will go lower of course but the active twenty5.22i can certainly rumble.
These speakers revel in great recordings and those made in the last decade or so frequently seem to be of that ilk, one such is the rather dark Bvdub whose In Iron Houses managed to create a sound that swirled around each speaker in full 360 degrees. Mingus at Carnegie Hall is by no means recent but also manages to escape the cabinets, the sound describing the venue as well as it delivered the groove that the bandleader manages to create. Here I contrasted a remaster with the original (streamed) and was surprised to find that the bass line was more prominent on the older cut. I also really enjoyed some steel string acoustic guitar on a more recent vinyl release, the way that the active twenty5.22i is produce the immediacy and zing of the instrument made the instrument sound very real indeed.
Conclusion
The active twenty5.22i might look expensive for a bookshelf two-way but it is an extremely capable and superbly executed loudspeaker that is way more capable than might be expected. The active factor brings the ability to play at higher levels without effort and delivers dynamics and imaging that cannot be matched by a passive speaker with a separate amp for the price. If you like a revealing, powerful and engaging sound these PMCs are going to be hard to beat.
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