PMC twenty5.24i

PMC twenty5.24i

This is a review of the PMC twenty5.24i floorstanding loudspeakers. I reviewed the sibling PMC twenty5.22i standmount speakers recently and these 24is have the same tweeter and woofer configuration so one may expect the outcome to be similar? This, however, is not the case.

PMC twenty5i series

The full PMC twenty5i series includes two standmount, speakers, the 21i and the ‘Outstanding’ rated 22i, reviewed here recently. There is a compact floorstanding speaker, the two way 23i and this two way 24i. There is also a 3-way 26i floorstanding speaker at the top of this series that then graduates in specification, and price, to the PMC fact series. The speakers in this twenty5i series cost from £2,195 for the 22i to £8,995 for the 26i, these 24i are priced at £5,495 (current May 2021 RRP).

The twenty5i series has a matching centre and a subwoofer option if you are minded to apply them to a home cinema solution.


These PMC twenty5.24i have a SEAS/PMC custom 19mm SONOMEX fabric soft dome tweeter that is ferrofluid cooled, with a 34mm surround and dispersion grille and this is the same tweeter across the twenty5i series.

The 24i (as well as the aforementioned 22i and 26i) have a 170mm woofer made of long throw g-weave material with a cast alloy chassis.

PMC twenty5.24i

PMC twenty5.24i has Laminair vents derived using technology from F1

The speakers have that reclined trapezoidal shape that means the tweeter at the top of the cabinet is slightly behind the lower frequency driver.  This ensures accurate phase alignment from the cabinet to the listener.

The 24i benefits from a longer transmission line length over the 22i (see my description of the transmission line technology here ). With the 24i floorstanding design the effective advanced transmission line (ATL™) length increases by 50% to 3m. It is pretty clear to me that, as much as I enjoyed the 22i speakers, the extra length in the 24i is a game changer for me. The 24i feature the Laminair aerodynamic vent technology, of course, which is also described in the 22i review.

The claimed frequency response from the PMC twenty5.24i is a satisfying 27Hz – 25kHz, the reported impedance is 8 Ohms. The crossover is set at 1.7kHz, this is a lower setting from the previous 1.8kHz in the twenty5.24. The crossover has itself been upgraded with improved components and the use of these new elements are intended to offer an ‘immersive, all-enveloping sound field’.

The speakers are ‘light-heavy weights’, weighing in at 23kg each. They are 1015mm (+20mm spikes) x 192mm (or 275mm incl. plinth bars) x 419mm (+9mm with the grille) (HxWxD).


PMC twenty5.24i

If fingerprints are your only concern with the diamond black finish, you have few worries in life

The feel of the speakers is sumptuous. They are understated yet dynamic with the laid back look oozing all-out quality. I have a diamond black pair and the only let-down is that they are a fingerprint nightmare with this glossy finish. Happily, I always use gloves on unboxing, and anyway PMC supply you with a soft cloth for buffing purposes.

The slightly rounded edges of the cabinet offer that waxed supercar feel and over stroking is now a daily habit. The diamond black finish reflects most things in the room, from lamps and candles to TV flicker if you have the wrong angle. I had the walnut 22is last time and I suspect they may be more my preference. The 24is are available in walnut, oak, white silk, and diamond black.

Unboxing was a simple affair and fixing the plinth bars and sharp spikes to the base was a very satisfying process. The anti-vibration plinth bars are designed to minimise vibration from both floor to cabinet and vice versa. This added stability affects the performance of the crossover in a positive way.  This learning was derived from PMC’s incredible flagship Fenestria project.

PMC twenty5.24i

PMC twenty5.24i binding posts

The 4mm binding posts, just a pair, are a delight, being easy to access towards the base of the cabinet

There is a base to top grille provided that slips on magnetically, tantalisingly showing the PMC logo near the base, like an anklet on a Twenty5 year-old!


Set Up

I am listening to the PMC twenty5.24i driven by a Naim NAP 250 with a Naim NAC-N 272 preamplifier with a Naim XPS DR power supply. I am using Atlas Mavros speaker cables and power conditioners.


PMC twenty5.24i

PMC twenty5.24i with full length grille are delightfully understated

I have to say this review may go slightly over the top; I just absolutely love these speakers with this Naim based set up. Having lovingly unboxed and screwed on the feet and spikes I went straight to Hans Zimmer’s 2049 to see where the low end is. Immediately, like dark chocolate on the tongue, I was able to say to myself, “OK, I’m in good hands, this is heaven, relax”. These speakers are just so easy to listen to, the transmission line bass extension just breathes, and the music flows, endlessly.

Hotel California

When I came out of the Annapurna Range, west of the Himalayas, 25 years ago after a fulfilling 12 day trek I was picked up with a few other knackered trekkers by a minibus that was barely in one piece; I looked down to my feet and I could see the road through the floor. I was at the front and as we set off the driver fumbled about and pulled a cassette out of his pocket as we cornered on a terrifying cliffside corner. He gestured to me to put it in the radio cassette slot. It was a copy of Eagles’ Hotel California.

I have listened to this album a lot, it is often available as a 24 bit, 192kHz recording and I have a download of it on USB and my Server. It means a great deal to me, but I have rarely been taken back to that mountain drive in the minibus as I have been in the last week through these speakers. Not only is the title track revitalised for me but, Life in the Fast Lane and the orchestrated reprise, Wasted Time (Tidal Masters), comes across so perfectly in this rock opus. Such is the soundstage; the whole album is really consuming me, and I am very moved by the 24is.


I can only liken its character to that of a Merlin Engine on a Spitfire such is the distinctive tone generated. And I absolutely love it

As far as the character of these speakers is concerned, I would describe them as particularly easy to listen to, and I am running Naim Electronics! The high end accuracy from the tweeter is clear to hear and the presence and scale of these speakers will be the abiding memory of my time with them. If you ever want to clean out the transmission line in your speakers there is no better track than Billie Eilish’s collaboration with Rosalía from the TV Series Euphoria, called Lo Vas a Olvidar. Here the haunting sound is thunderous. The transmission line treatment of the low frequencies is acting as a third driver to the listener, I can only liken its character to that of a Merlin Engine on a Spitfire such is the distinctive tone generated. And I absolutely love it.

All Round Excellence

Each piece of music saturates the room, the clarity and separation of complementary instruments is such a striking feature of these loudspeakers

PMC twenty5.24i

The lad back trapezoidal shape of the PMC twenty5.24i

I have thrown everything I can think of, musically, at these speakers; from Nigel Kennedy’s violin (Tidal Masters, Vivaldi, The Four Seasons) and Yo-Yo Ma’s cello (Tidal Bach, Inspired by Bach: The Cello Suites). I have tried Ashkenazy’s piano (Tidal, Rachmaninov: Complete Works for Piano) and Bach’s organ driven Toccata and Fugue in D Minor (Tidal, Lehotka, JS Bach Organ Music). I have even gone from Jesus and Mary Chain’s April Skies (Tidal Masters, Darklands) to Jack Johnson’s wonderful Banana Pancakes (Tidal, All Acoustic 2019). Each piece of music saturates the room, the clarity and separation of complementary instruments is such a striking feature of these loudspeakers. The performance is absolutely breath-taking.

I cannot conclude without commenting on one of the most demanding pop songs of the last 40 years, Sledgehammer, by Peter Gabriel. With the 24is this song is magnificent, they deliver the attack and fabulous bass control at volume and it is effortless. It might be one of the most striking musical moments of my year so far. These speakers are beyond compare.

The full list of joy from these speakers is here on this specially curated 39 track playlist on Tidal, called HF&MS PMC twenty5i.


I have found my audio Nirvana, my idyllic state

I have wished to hear PMC speakers with my Naim electronics for a long time, the 22is I had earlier in the year gave me a glimpse of what was possible. Although I have the same tweeter and mid/bass driver, the greater transmission line treatment from these floorstanders is simply outstanding.

These speakers, like a Spitfire’s Merlin engine, simply breathe, that is all I can say, whether it is the transmission line technology, the Laminair aerodynamic vents, the improved stability or something else, I cannot explain it. I would quite happily end my HiFi journey here, I do not even need to hear the 26i or the fact series, I am perfectly happy I have found my audio Nirvana, my idyllic state.

Transmission Line response
Wonderful styling
Dynamic sound
Gloss black
For nothing else from PMC


Full details of the PMC twenty5.24i are on the company’s site.

PMC twenty5.24i are priced at £5,495 (current May 2021 RRP).

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