Gramophone Dreams #86: Harbeth P3ESR XD loudspeaker and Nelson subwoofer/stand

After lifelike timbres and speed-train momentum, how a loudspeaker projects its energy into my room is the main thing that determines how my sound system feels as I listen to it. When I review loudspeakers, I try to notice the unique tone and force of their "voice" as they speak into my room. Do they stand too close, stick out their chests, and brag loudly in third harmonics? Or do they have small voices that force me to lean in to make out what they're saying?

With a miniature box speaker like my reference Falcon Gold Badge LS3/5as or the similarly sized Harbeth P3ESR XDs, which I'm auditioning this month, I have to sit very close to experience any of their direct, "off-the-cone" energy. If my listening position gets too far away or the speakers are positioned too far apart or too far from the wall behind them, the sound thins and loses body.

I didn't need to sit close to those 1947 Altec A5 Voice of the Theatre horns I used to use. Their energy came out straight ahead and touched every corner of even a big room. Like they did in a movie theater.

In maximum contrast, each of my 83dB/W/m–sensitive LS3/5a's piston about 15 square inches of air. The 100+dB–sensitive A5 Altecs projected sound from about 1500 square inches of driver area. That's a sandbox shovel vs a snowplow.

To check that metaphor, consider that the soundboard of a Steinway A piano—a small grand—measures 2129 square inches (footnote 1); the whole piano might be emitting sound energy from 5000 square inches or more (footnote 2). When I think about squeezing all that energy through a 4.3" woofer and a 0.75" tweeter, I laugh at the impossibility, then quickly remember that the purpose of home audio is not to create realism per se but to present recordings in a manner that allows users to access the main pleasures the music and recording have to offer in a format suitable for domestic consumption.

With the perfectly undomesticated Altecs, the best part was not how much energy they put into the room or how believably they could materialize a piano, but how well their projected energy communicated the spirit of recorded performances. In dramatic contrast, my Falcon Gold Badge LS3/5a's and Harbeth P3ESR XDs present recordings in a perfectly domesticated manner: precisely articulated, fantastic to view, and conspicuously miniaturized. They were designed to work at close range in a small space like mine.

For me, the magic of mini speakers is that they present an endlessly fascinating spectacle, one that treats every music genre equally while giving me the engineer's view of what the microphones captured and how the album tracks were mixed—exactly what the BBC's LS3/5a was created to do: show engineers what the microphones were capturing.

Unlike the Voice of the Theatre, which made everything cinema-scaled, the LS3/5a shows off its location-monitor talents by depicting vocal recitals, large orchestras, and grand movie soundtracks in reduced size and loudness but in their original proportions! For me, this is key: The BBC's smallest monitor achieves its believability with proportionality and strict tone-truthfulness. And that makes for good long-term relationships.

I am recounting these observations in the hope that this notion of how speakers project energy will prepare your mind to grasp, first, Harbeth's latest version of their P3 minimonitor—the $3290/pair P3ESR XD—and, second, how the feel of that speaker's soundfield changed when I added Harbeth's new Nelson "bass extender + stand" (footnote 3).

Harbeth P3ESR XD
I used, studied, and enjoyed Harbeth's P3ESR 40th Anniversary Edition from the time of my review in 2018 (footnote 4) until it was replaced by the $3290/pair XD edition in 2022. Because I hadn't used the P3ESR in a couple of years, I took a few days to get a feel and see if I could notice what changed in the XD version.

I asked Harbeth's importer, Walter Swanbon of Fidelis Distribution, what the physical and design differences were between the P3ESR I reviewed and the latest XD version. "The difference is that Alan Shaw"—Harbeth's CEO and chief engineer—"reworked the crossover, ... and the result is greater resolution and transparency," Swanbon replied.

My initial impressions support that claim. The previous P3ESR was always a touch warmer than my LS3/5a, and if I remember right, better balanced but thicker than my 5a in the upper bass/lower midrange. This XD version is outstandingly clean in that region.

More than the physical difference between their tweeters and bass-mid cone materials, the most important difference between the Falcon Gold Badge LS3/5a and Harbeth's P3ESR XD is in their impedance characteristics. Both loudspeakers have nominal impedances higher than average; the Falcon is rated at 15 ohms, and the P3 is specified as "6 ohms, easy to drive." Both speakers stay above 5 ohms, allowing users to experiment with low-power tube amplifiers. In my studio, both versions cruised effortlessly with single-ended 300Bs, and both clipped easily with 2W 2A3s. Beyond that simple test, my experiments suggest Harbeth's 6 ohm P3ESR will make its best music with a wider range of solid state amplifiers than my Falcons; their very high impedance baffles some class-D amps.

Harbeth's P3ESR XDs produced their sharpest-focused detail and showcased their most solid piano realism using just a few watts from the 300Wpc (into 8 ohms) Parasound Halo A 21+ stereo amplifier, which drove the P3s with a clean, sweet-toned authority that, compared to my tube amps, put more push behind the sound. In daily use, the P3ESR XD–A 21+ pairing made recordings sound naturally reconstituted with no solid state grain, bite, or soullessness. A five-star combo.

Powered by Rogue Audio's 100W, tube-input/class-D output V3 Sphinx integrated, the P3ESRs came across as relaxed and naturally toned. The sound was rich and full, but jump and vigor were less than they had been with the A 21+. A three-point-five-star combo.

Most days during these auditions, I used my beloved Elekit 300B workhorse, the TU-8900. I never noticed any clipping or compression, and I enjoyed how its singular transparency made the P3s glow and sparkle. A four-star combo.

For more details about the P3ESR's history and construction and amplifier pairings, I'll refer you to my November 2018 review of Harbeth's 40th Anniversary Edition. Everything I wrote there still applies, including this quote: "I shall not forget the first time ... I played Harbeth's standard-edition P3ESR in my own system. ... it took me only 30 seconds to realize that the ... P3ESR ... was delivering more useful information in the 75–300Hz octaves than either my Rogers or Falcon Acoustics LS3/5a."

The P3ESR XD alone
Lately, I've been under the spell of German pianist/composer/record producer Nils Frahm's 2011 recording Felt, featuring his home piano with the strings covered in felt to keep the piano quiet when he played late at night (Erased Tapes LP ERATP033LP). "Originally, I wanted to do my neighbors a favor by damping the sound of my piano. If I want to play piano during the quiet of the night, the only respectful way is by layering thick felt in front of the strings and using very gentle fingers. It was then that I discovered that my piano sounds beautiful with the damper installed."

Captivated by his discovery, Frahm placed microphones inside the piano, almost touching the lightly damped strings. This radical close miking resulted in a recording that presents listeners with a brightly lit view inside Frahm's instrument, a view of an exceedingly corporeal landscape of steel, wood, and felt wherein I saw felt-on-wood hammers hitting piano strings. Because the P3ESR XD was so exceedingly clean and clear of tone, I could leisurely watch notes decay and feel dampers coming down. What I saw was bright, sharp-focused, and totally Alice in Wonderland.

In Autochrome color: Felt's sonic thrills come from the vibrancy of its reverb tails, so to bring out as much "'verb tail" as possible, and to see how the P3 XD would handle this symphony of energy, I used Dynavector's XX2 moving coil cartridge feeding Sculpture A's €790 "Mini Nano" nanocrystalline-core step-up transformer. This copper-wired SUT was designed by Zsolt Bognár for François Saint-Gérand, founder of Sculpture A and Ana Mighty Sound (footnote 5). More than cores of mu-metal or amorphous cobalt, the Mini Nano's nanocrystalline core plumps and juices music signals impressed on its primary. The XX2 + Mini Nano presented recordings with supersaturated tones that made Nils Frahm's Felt into a trippy, inside-the-piano adventure.

The rest of this "leans toward sensual" sound system consisted of Prima Luna's EVO 100 phono stage, HoloAudio's Serene preamp, and Elekit's TU-8900 amplifier with Brimar ECC82s and Cossor 300Bs. Wires were by Triode Wire Labs.

"Dear beloved listener": The liner notes for Felt are in the form of a personal letter from Frahm to record buyers, printed on an album-sized sheet of rag paper tucked inside the album sleeve. In it, Frahm explains how his next-to-the-strings miking technique brought "a host of external sounds into the recordings which most producers would try to hide: I hear myself breathing and panting, the scraping sound of the piano's action and the creaking of my wooden floorboards—all equally as loud as the music. The music becomes a contingency, a chance, an accident within all this rustling. My heart opens and I wonder what exactly it is that makes me feel so happy. Felt creates its own personal microcosm, offering a refuge of tender and honest beauty."

The P3ESR XDs presented Frahm's audio verité with a pristine clarity that exposed the high-tactility sound of wood hammers tapping steel strings veiled in felt, backed by screeching piano-hammer action and the world's longest reverb tails. In my system, this ability to peer deep into recordings was the P3ESR XD's defining trait.

Footnote 1: See

Footnote 2: See my discussion of the difference between sound pressure level and sound intensity in the March 2010 As We See It.—John Atkinson

Footnote 3: Harbeth Audio Ltd. US distributor: Fidelis 460 Amherst St. Nashua, NH 03063. Tel: (603) 880-4434. Web:

Footnote 4: Also see John Atkinson's review of the original P3ESR. At the bottom of that article, you'll find links to follow-ups by JA himself and by Brian Damkroger.

Footnote 5: Ana Mighty Sound. Web:


hemingway's picture

Hoping that Herb sent these speakers and the Nelsons to JA for measurement!

PeterG's picture

I'm not very technical, but I notice that you call them woofers, then compare them to subwoofers; and I wonder--are the Nelsons really subwoofers if they go down only to 35Hz?

Kal Rubinson's picture

What is a subwoofer?
Is it defined by a specific frequency range or is it defined as extending response below the range of the associated woofer?

zipzimzap's picture

I like your second description. If someone is shopping for a subwoofer and wants it to hit a specific frequency then they can easily limit their search to the ones that do that. Plenty of users wouldn't likely need anything that reaches below 35hz.

audiolab1962's picture

Well going back a good number of years, it would be for a device to fill in the bottom octave and a bit possibly. To fill in what a half decent floorstanded was missing. Now it seems to apply to just about whatever you want, almost a marketing tool and no more than that in a great deal of cases. Slightly surprised that they like this unit, bandpass designs are very critically tuned. Tend to display a slightly tubby sound quality. That the output below it's tuned frequency drops off like a cliff.

This is not the first time a solution like this has been offered.

It's Ultimate capabilities must clearly be limited, but then again look what it is supporting.

If it's your bag then great go for it.

Kal Rubinson's picture

I'm glad we cleared that up. :-)

argyle_mikey's picture

Herb - I think - is referring to “Nelson Riddle”, being Cockney rhyming slang for a visit to the toilet. Unless, of course, he’s thinking of Nelson Pass…

Herb Reichert's picture

I love pub slang


zimmer74's picture

but I want to comment on the various LS3/5A versions out there. I have several, including your favorite Falcon Gold Badge. But if you want to take it to the next level, you must try the Falcon 2024 limited edition. At $10K, most people will make the usual negative comments, but these are, by a considerable margin, the best speakers I have ever owned, regardless of price or size.

Herb Reichert's picture

stay tuned


justmeagain's picture

placing subwoofers directly beneath the primary stereo speakers rarely results in the most accurate bass reproduction. It's usually acceptable, but not ideal.

mSpot's picture

The P3ESR/Nelson combo effectively makes it a 3-way floorstanding speaker. The Nelson extends the bass of the P3ESR and capable of doing it in a very controlled way due to the fixed relative positions of the two units and the known output characteristics of the P3ESR. It is a plug-and-play enhancement, although for a given room, bass may not be as optimized as with freely positioned subwoofers.

Homer Theater's picture

How to make a HUGE slow-sounding speaker sound exactly like a small 2-way speaker... don't connect the woofer. Seriously. A giant "slow" speaker sounds EXACTLY like a small 2-way when the woofer(s) is inactive. Even without a tiny little box to put it in, the big speaker sounds like a tiny speaker without the woofer(s). The only thing people who "like" small speakers REALLY like is music without bass. Bass de-focuses your attention on mids and highs. It has NOTHING to do with the physical size of the speaker. It's 100% a question of bass being present or not. Bass DEMANDS your attention even if you try to ignore it. There is NOTHING special about the physical size nor is there anything magical about having 2 drivers sharing a tiny box. It's bass and nothing but bass that drives people to tiny speakers. They simply don't LIKE hearing all the sound that exists in the performance because they can hear the mids and highs better when there's little or no bass. The best sounding small speaker designed before the days of computer software optimization of everything, was the JR-149. Forget the LS-3/5a and it's "bass" bump and BBC "house sound". For accuracy, verve, imaging, detail, lack of noise from the "cabinet" and natural sound, nothing beat the JR-149... until computer-aided-speaker-design and modern analysis tools, and technically superior modern parts and materials allowed some well done modern designs to outperform anything possible from the 1980s and earlier. But big cabinets don't sound like big cabinets when you disconnect the woofers so the tweeter and midrange are the only operating drivers (and the midrange can work well down to 100 Hz or so). A giant speaker with no bass below 100 Hz sounds every bit as light and lively as a tiny 2-way--assuming the giant speaker is reasonably well-designed, of course. If you are going to rebut this and you have NEVER heard a great-sounding giant speaker without bass below 100 Hz-ish... don't bother, your opinion exits without a reference point. It would be like saying pancakes are better than waffles without ever having tried a waffle.

justmeagain's picture

who asked? Anyone?

Homer Theater's picture

It's a comment, nobody has to ask. Do I need to explain everything to you? Because I will...

MatthewT's picture

I do believe your post is the strangest yet.

Homer Theater's picture

Thanks. I'll take "strange" any day. People assign ridiculous magical properties to tiny (but well-made/designed) 2-way speakers. As though they do something NO larger speaker can do. Hogwash. Take away the bass and any larger speaker sounds exactly like a tiny 2-way.

justmeagain's picture

A. Obviously, a big speaker with a disconnected woofer sounds just like a small speaker that's incapable of reproducing bass frequencies. They're the same thing in different enclosures. Why anyone would do that is inexplicable, because having big speakers implies a desire to hear some bass. B. Hearing bass does not "de-focus" my attention to mids and highs, as splitting up the frequency range of human hearing in this fashion is strictly an arbitrary byproduct of component and speaker design. If you can't hear all the frequencies without being distracted by the bass, that's strictly your problem. C. Finally, your comment doesn't appear to have anything to do with the story it is attached to. You have every right to say whatever you want, wherever you want, but it's a bit of a head scratcher, that's all.

romath's picture

"Harbeth's P3ESR XDs produced their sharpest-focused detail and showcased their most solid piano realism using just a few watts from the 300Wpc (into 8 ohms) Parasound Halo A 21+ stereo amplifier,..."

At the first Pacific Audio Fest in 2022, the only audio show I've ever attended, the Louis Armstrong/Duke Ellington LP got a lot of play in the demo rooms. During my visits to virtually all of them, most more than once, I only heard two rooms where Ellington's piano sounded like the real thing. The one that truly stood out was the very modest sized hotel room that included Parasound, their amp if I recall correctly. Never forget that.

laxr5rs's picture

Because the measurements would show what is obvious. The only thing that these stands will change is any of the vibrations coming through a cabinet - that should already have been designed correctly. The cabinet vibrations from a multi-thousand dollar speakers, should be far below our ability to perceive them. If a $3000+ speaker isn't already designed with a mostly inert cabinet - why buy it? Not having measurements listed, allows the reviewer to - say anything they want. Why we need measurements here, is to eliminate flowery reviewer language, and get to the crux of the issue. Performance. Cars are complicated, but when you put a car on a dynamometer that's calibrated, everyone says, possibly, "hey, it's got 500 rear wheel horsepower." You don't see car guys saying, "but I really feel like it's closer to 501... maybe even 502. Then someone else - doesn't say, "my gut tells me it's 496." Speaker performance is not a mystery, and speakers are much less complicated than cars. Point.