Harbeth Super HL5plus XD loudspeaker

What Were Once Vices Are Now Habits—the 1974 album by those San Jose yacht-rock sages the Doobie Brothers—could also describe an audiophile's life.

The journey begins with booze and bong money spent instead on an entry-level turntable and cartridge; it did for me anyway. Then starts the churn, through many components and configurations seeking that elusive, blissful audio fix until finally we find our audio oasis, our own sonic peace, our gearhead nirvana. We achieve a system that satisfies our listening indulgences, whether it be based on streaming or spinning, class-D or tubes, with Belden wire or 0.999999% pure-silver single-strand wire that costs more than a Range Rover. It doesn't last.

My audio evolution began in the late 1970s, with a Garrard 42M Automatic Record Changer, a skanky, toneless Lafayette LA-25 solid state integrated amplifier with fake woodgrain wrap on its yucky tin shell, and a Utah Radio Products A-70A speaker system. Not pretty. Soon enough, a Bang & Olufsen Beogram RX turntable joined the mix; that led to a pair of Cary Audio Design CAD-300SE monoblock amplifiers—progress—an Oracle Alexandria turntable, a chunky Audio Research SP-9 preamplifier, and an Art Audio Diavolo SET 300B amplifier. More recently, I've locked down my jones with B&W, ProAc, Gallo, DeVore Fidelity, Shindo Labs, Thorens, Kuzma, and VPI.

Good stuff, it makes me happy, but satisfaction is fleeting and soon I—we—need another new fix. You find yourself exploring again, dodging hurricanes and meteorites to reach new audio vistas. It would be wise advice not to listen to those urges. We know this, but we do it anyway because we know in time we'll stumble onto something new that rocks our world.

More than one audiophile has found hi-fi contentment in a pair of Harbeth loudspeakers. Founded by former BBC engineer Dudley Harwood and based in West Sussex, England, Harbeth Audio Ltd. has sold thousands of loudspeakers to people who cherish clean musical expression, luminous tone, and exceptional midrange lucidity, achieved with the company's unusual thin-walled cabinetry. Though generally requiring more than flea watts to drive, Harbeths work well with a wide range of amplification: solid state, reasonably powerful, push-pull tubes—even, probably, high-performance class-D. Harbeths have this reputation: That they can put an end to audiophilia nervosa, becoming one's final loudspeaker purchase.

I've never owned Harbeth, but the brand has enjoyed much love from my Stereophile brethren. In the March 2018 Stereophile, Herb Reichert wrote, "Harbeth's Monitor 30.2 [Anniversary Edition] is the most neutral, accurate, tuneful, fun, and music-loving stand-mounted two-way speaker I've heard."

Writing in our May 2015 issue, Art Dudley wrote, "With both of the amplifiers I used, ... the Harbeth Super HL5plus sounded conspicuously, even startlingly, clear. The Super HL5plus simply emanated a greater amount of sonic detail and musical information, especially in terms of pitch and timing, than I hear from most speakers, and did so with ease, beauty, and an utter lack of artifice or strain." He concluded, "For the listener who wants a loudspeaker that is both explicit and truthfully beautiful, the Harbeth Super HL5plus is an excellent choice."

The hallowed halls of Harbeth
The roots of the Super HL5plus XD can be found in the late 1960s with BBC engineer Spencer Hughes's Rogers LS3/6. Upon leaving the BBC, Hughes developed the Spendor BC1; I own a pair. That speaker's success inspired the Rogers Export Monitor, which set the stage for the Harbeth H.L. Monitor developed by Harwood. The H.L. Monitor was the first speaker to use a polypropylene-cone woofer, which Harwood developed and held the patent on. After a 24-month study in the early '90s, under Alan Shaw's leadership, Harbeth created its RADIAL (Research and Development into Advanced Loudspeakers) driver technology. The SHL5plus XD incorporates the latest formula of Harbeth's exclusive cone material.

The HL5 series is based on the very first Harbeth, the HB-1, which was introduced in the year of the company's founding, 1977. The latest in that series, the Harbeth SHL5plus XD ($7995/pair), is two generations beyond the version Art reviewed. It upholds tradition while adding Harbeth's XD upgrades, which span the whole Harbeth line. Though the cabinet size, driver dimensions, sensitivity rating, and frequency response closely resemble those of the Super HL5plus, several upgrades make the SHL5plus XD rather different and, one hopes, better.

"The standard circuit diagram dates from 2016," Harbeth designer Alan Shaw wrote in a note to importer/distributor Walter Swanbon of New Hampshire's Fidelis Distribution, the US Harbeth distributor; Swanbon then shared it with me. "Looking at the standard versus XD crossovers, there are five component-value changes, all of which improved the overall balance of the speaker to give it a more modern, open, even presentation across the audio range, which suits the contemporary listener with a more diverse range of musical tastes."

The Super HL5plus XD's stout, stylish, front-ported cabinet is made of thin layers of birch MDF. Each speaker measures 28" high × 13" wide × 12" deep and weighs 40lb. Behind a fabric grille is one 200mm (7.87") RADIAL2 polymeric composite-cone bass/mid driver, a 25mm (0.984") ferrofluid-cooled aluminum tweeter, and a 20mm (0.787") aluminum dome super tweeter, both made by SEAS to Harbeth specs. ("Super" in the product name indicates the use of a super tweeter.) Specifications include a frequency response of 40Hz–20kHz, ±3dB, a nominal impedance of 6 ohms, and a sensitivity of 86dB/2.83V/m. All Harbeth speakers are handmade at the factory in Lindfield, a village in West Sussex, England.

"All woofers are handmade in-house, using injection-molded proprietary cones (a mix of 5 compounds)," Swanbon explained via email. "The tweeters are made by SEAS according to Harbeth specifications. Both tweeters in the Super HL5plus XD [use] treated/coated low-mass aluminum domes. Crossover points are 3.5k and 10k, with response out to 40kHz."

"XD" upgrades in the SHL5plus include VanDamme internal wiring, new damping material, new binding posts, more tightly spec'd tweeters, and that new crossover design, which in addition to those component-value changes includes upgraded capacitors. Amid all this newness, the basic thin-walled, MDF-comprised Harbeth box follows time-tested BBC principles. "The cabinet utilizes specifically damped, lossy panel construction based on 50+ years of BBC research," Swanbon said. "The Super HL5plus XD uses the tried-and-true, classic BBC 2-cubic-ft. box, ideal for this woofer-cone size. This model is historically the biggest seller in the Harbeth line and has quite a legacy."

"The backs of all Harbeth speakers except the P3 are removable," Shaw told Hi-Fi News for its November 2007 issue. "A bell cast with no cracks: Hit it and it rings forever. Introduce even a hairline crack into the bell, and it resists resonating. And that's exactly the same principle. The sound waves have to work through the less-than-perfect joint. It's a BBC idea. If you were to take the same box, remove the front and back, and then PVA them back on (footnote 1), you'd get a totally different sound.

"Let's accept that we cannot dispose of all that energy," Shaw continued. "Instead, let's steer it away from where it's acoustically objectionable—the mid frequencies—down to where it's not objectionable—the very low frequencies—and make the box [walls] thin, and manipulate those resonances by adding mass and damping the panels, and pull it all down to the bottom. So, you've got this extremely clean midband and this sort of warm, involving low end, which is ideal for some music."

Harbeth's finishes are almost as revered as their sound. Everyone visiting my Manhattan listening den during the review period was knocked out by the review pair's rosewood boxes even before they started making music. Equally lovely were the German-made TonTräger stands, built especially for the SHL5plus XD. "Using solid wood from FSC-certified local forests" with surfaces "coated with natural oils and pigments in several processing steps," the stands employ "extended tenons" atop each column, which are said to "allow direct absorption of cabinet resonances and decouple the speaker from the ground." (The quotes are from fidelisav.com.) Individual "ToneBeds"—oval hollows on top of the tenons—are said to "prevent vibration bridges"; so says the TonTräger website. The stands are lightweight but, at $1650/ pair, they're not cheap. They fit the SHL5plus XD perfectly and sounded better than the old pair of all-wood stands I use with my Spendor BC1s.

Footnote 1: PVA, polyvinyl acetate, is your basic wood glue.

Harbeth Audio, Ltd.
3 Enterprise Park, Lindfield
Haywards Heath, West Sussex RH16 2LH
England, UK
(44) (0)1444-484371

donnedonne's picture

Would be interested to read your take on the Graham LS8/1, their updated version of the Spendor BC1, as designed by Derek Hughes. I have found contentment with those (famous last words). I have owned other speakers that do this or that thing better, but when I listen to the LS8/1, I am grateful for the music and don't want anything else.

hemingway's picture

It is interesting that Ken did not find the cabinet resonances to disturb/alter the sound profile, though it is somewhat unclear from the review ("decay tails were ... off the charts"). I read that to mean the box sound did not deteriorate performance from this subjective perspective. The measurements section implies the resonances may alter this speaker's sound, as does the quote of the the manufacturer himself - "you've got this extremely clean midband and this sort of warm, involving low end, which is ideal for some music.""

I wonder why the reviewer measured the frequency output from the supertweeter, and whether it interfered with the output of the 'regular' tweeter, to create the dip from 10-15kHz? If it was measured on axis, would the response be flat? It seems like it has to be an anomaly considering Harbeth's focus on even frequency response, and not a deliberate design choice, to utilize a tweeter system that would create a significant dip in an area where many users can still hear (10-15kHz), but then a high amount of energy above that, where most buyers of this speaker will not be able to hear... I wonder if Ken noticed this.*

Take it for what it is worth, this review lacks comparison to other speakers, outside of "magical, life force, beauty." Such comparisons are usually in other reviews and are very helpful to the reader who might not have the opportunity to audition this speaker in person against competitors. It also gives no hints at what the sound of the speaker actually is. How does a speaker have "life force"? Maybe that means it does not exhibit dynamic compression. But compared to what? Respectfully this could be more helpful to the reader.

*P.s. is this academic for most readers of this magazine, who will likely experience some hearing loss in this region?

georgehifi's picture

These speakers with an EPDR of 3.02ohms in the bass were a far better speakers to use to review the Audio Research I/50 integrated tube amplifier with last week, than 2 x pairs that had an EPDR's less than 2ohms.

Cheers George

Nirodha352's picture

So…” the Harbeth Super HL5plus XD is easily the finest standmount speaker I've heard..” is actually a limited, old-fashioned looking loudspeaker for 8K which doesn’t do Led Zep. Interesting.

MhtLion's picture

Thanks for great review. The retail price of $7995 is 50% premium over U.K retail price of $5335 in current exchange rate. Please note I deducted the VAT in the calculation because the consumer in U.S. is not subject to it. Just because U.S. consumers are not aware of the facts a U.K. price already includes 20% of VAT (sales tax) importers always charge more to U.S. consumers. Ex) a typical U.S consumer will think this speaker’s U.K. price is $6700 in USD just because the tax system are different between two countries. With shipping and import process, a U.S. consumer is fooled as if they are paying a reasonable price. But, the importer knows about this very well and takes advantages of it. Call it what you think, but I personally am disgusted by it. It’s your money so please spend it however you want. Also, bringing a pair of loudspeakers overseas isn’t easy. So, if you like this brand, you really don’t have a choice. Now you read this, I hope you can get over the fact you paid 50% more just because you live in U.S. and the same importer may charge only 20% premium in other part of Europe. Depending on the exchange rate, sometimes you can pay as much as 80% premium over U.K for this brand for no reason really. So, at least now you can feel happy you are only paying 50% more as of now.

donnedonne's picture

This is very true in regards to BBC or BBC inspired speakers, and also European gear generally -- unfortunately. American retail mark-ups are often absurd, even after accounting for shipping cost, currency fluctuation cushion, customs, etc. It's not uncommon to see a mark-up approaching 100% (over suggested retail abroad) . It appears that in the U.S., distributors/dealers charge what they think they can get away with, whereas in Europe, they charge what they think is fair (there are exceptions of course -- some U.S. dealers are not trying to make a living off hifi, and charge more reasonable prices).

This is true as well when roles are reversed (check out what American gear costs in the UK/Europe...yes it needs to be marked-up, but the spread isn't as absurd as it is in the other direction, when UK/European gear is imported into the U.S.)

bhkat's picture

People have to decide for themselves if it is worth it to pay the premium. For me, there are plenty of US speaker companies that make great speakers for which I don't have to pay import fees etc..

MhtLion's picture

I agree with both of you. I think it's important to discuss things like this in public when a distributor profits 2x or 3x compared to other distributors over Europe hurting both consumers and manufactures from the lost sale due to the higher price. Like we all said, consumers will decide for themselves. At the end of the day, I wish more people know about it to help making a right decision, and I wish this kind of practice will diminish as time goes.

Kursun's picture

An 8” mid-woofer crossovered to tweeter at 3500 Hz invites some problems.

Mid-woofer diaphragm diameter is almost twice the wavelength of sound at 3500 Hz.
This results in beaming, starting just below 2000 Hz up to the crossover frequency.
This is clearly seen on polar response graphics.

No loudspeaker design engineer would probably start with a design like this.
But does it sound good? Probably yes. (But can’t do Led Zeppelin, or Yes :)

avanti1960's picture

SHL5 Plus version (tested in Stereophile May, 2015 and that I owned and enjoyed for several years) has more to do with an incredible reduction in cabinet resonance than new crossover components.
The non XD Plus has an abundance of cabinet resonance while the new HD has cabinet resonance that is much lower in amplitude, has a huge decrease bandwidth and decays much more quickly.
Not a bad thing but definitely not text book Harbeth lossy design either.

Anton's picture

Herb has been noted to describe speaker sound by noting that drivers sound like the material they are made of. (Pardon me if I paraphrased poorly.)

In my experience with Harbeth speakers I have found that to be stone cold true, but it doesn't seem to get mentioned much.

Thanks for a great read, by the way!


I like this part: "Good stuff, it makes me happy, but satisfaction is fleeting and soon I—we—need another new fix. You find yourself exploring again..."

In matters of romance and Hi Fi... ;-D

I am never surprised when I meet someone listening to vintage gear and hear them say, "I had those. Man, I wish I hadn't sold them." There is a season for each speaker, under Heaven...but we know seasons are cyclic. Hi Fi works that way, too.

I have found a great way to stay fresh: I keep all my old stuff and when I get that "New is better" urge, I rotate something I already own and get 99% as much joy, on the cheap.

hemingway's picture

Harbeth says its drivers are made of a "bespoke plastic compound"(https://harbeth.co.uk/harbeth-about-us-harbeth-technology/). So these speakers sound like bespoke plastic compound? Even if yes, I have no concept of what bespoke plastic compound sounds like. Again with respect to the reviewers, this is not helpful to those reading to understand the sound of these or any speakers. My constructive criticism with this review is it doesn't really answer the question of what the speaker sounds like.

Anton's picture

Imagine whacking the material in question, or bending and quickly releasing it, or the sound of mylar snapping in air. I think Herb makes a great point to think about.

Thump a plastic cone versus paper or metal....different materials seem to have an intrinsic sound.

Herb could audiophile-splain it better. Check his columns and reviews, this pops up from time to time.

RH's picture

I think the concept of "speaker drivers, when playing music, sound like what they are made of" is based more on a sort of intuition, a folk notion of "how things would work" more than actual engineering principles.

First, it wouldn't make sense that speaker drivers could produce the vast array of sounds they could, if you were likely to hear the sound of the driver materials overlayed. And I'm not sure there are good engineering/psycho-acoustic reasons to expect it either. Yes in principle you can get audible break up or cone resonances, but they can be controlled to below audibility.

I used to have that intuition, e.g. "metal dome tweeters sound like metal..they do cymbals great, but add a metallic bite to other sounds." But even anecdotally I've heard speakers with metal drivers sound organic, and speakers with paper drivers sound more metallic (which I think has more to do with dispersion/frequency response characteristics).

I have owned many speakers (and still own a variety), that use paper drivers, plastic, metal, carbon fibre, etc. I currently own Thiel 2.7 speakers, all metal drivers, driven by CJ amps, and I detect no metallic character overlayed at all. Even compared to my Spendor S3/5 speakers, or older speakers I have using paper drivers.

hemingway's picture

I read those articles to describe the sound of enclosures more than drivers, if I remember right, but maybe I don't. It is one thing to say that it "sounds like a paper driver," or "it sounds like a plastic driver," or even, "it sounds like a thin-walled wooden box enclosure," and another to describe what the sound of a paper driver or thin walled box enclosure sounds like. Rambling off topic.

Anyway I was just wondering about the high frequency response and wanting to understand how/if the cabinet resonances impacted the sound to the listener, if noticed at all. On re-read, I suppose they were not noticed

Gojira's picture

You wrote that the Harbeths had not played satisfactorily with ZZ Top and Led Zepelin. At this point, I would like to point out that you can never exclusively test a loudspeaker or any component and then evaluate it afterwards. When you test, and this applies equally to all situations, you are always testing one component, within an existing system of other components that have an enormous influence. A loudspeaker can only give out what has been put into it. If one tests, one never tests only one component alone, it is always also the sum of the further devices involved, which lead to the result. Only if one would get to the bottom of this loudspeaker in many other systems, a more complete impression would be achieved. This is not to say that your system would not be able to do this, but rather that the combination of the various elements can lead to this impression. I wouldn't be surprised that these speakers could definitely rock in another system.

Ortofan's picture

... high-power solid-state amplifier with the Harbeths.
At UK hi-fi shows, where Alan Shaw can choose the amp, his speakers are driven by a Hegel amp that can supply over 350W continuous and 400W peak power into a 6 ohm load.
For rock music, consider adding a pair of REL S/812 subwoofers.

hemingway's picture

A full review should utilize different amplifiers to report how the speakers respond. I appreciate people like tube amplifiers, but there is no disputing that tubes alter the response of the speaker. I think he used PrimaLuna, and the measurements of those amplifiers change the response significantly and more than many of the other tube amplifiers this magazine reviews and measures. Best to have a 'fair fight' with a clean solid state amp to describe how the speaker actually sounds.

orfeo_monteverdi's picture

[please forgive my poor English]

Tube amps are passionately discouraged by the manufacturer (too much interactions with the impedance curve, which is rarely flat).

My Harbeth M30.2 Anniversary in a 2nd system work (very) well with a NuPrime AMG pre+power combo: AMG-PRA preamp (class A amplification) + AMG-STA power amp (class A + D), approx. $3500?

Back to the Super HL5 XD:
on a hifi show in Brussels, my audiophile buddy (who owns a pair of TAD ME-1) and I listened to a pair of Super HL5 XD powered by ultra high-end solid state Swiss electronics FM-Acoustics, Resolution Series. We looked at each other, shaking our heads, amazed by the both the flow and the transparency, along with the body and flesh that speaker could deliver.
(I am not suggesting that he was ready to sell his TAD ME-1 for a pair of SHL5 - instead, he is thinking about upgrading from TAD ME-1 to TAD CE-1 TX).
Please note that we both listen to classical and jazz. Last season I attended 37 live, un-amplified performances (mainly classical), in various concert halls, so I know how it sounds in real life.
We heard some convincing modern, jazzy, streamed music too during that demo (not just classical), but no rock.

FM-Acoustics Resolution Series.

Of course, that fancy setup was just for fun (but genuinely impressive!).

But very good results can be achieved with "modest" class A/B SS amplifiers. For instance, a €3900 integrated that the Harbeth Brussels dealer praises very much (Italian Audio Analogue AA Cento). Plenty of affordable good solid state amplifiers can be found in the US too.

Important: always listen to Harbeth near- or midfield. They are monitors. They act more like "convergent lenses". Never expect they will fill a large room like "divergent lenses", spreading the music in a very open way: you have to sit close, and look inside. Otherwise, if Harbeths are listened to from too far away, in too big a room, they can give the impression that they sound like a "big radio gear" (these were the words of my used pair's first owner...). Don't do that awful mistake (he did it...).

My audiophile life began quite early in life, in the late 90's. I was like a kid in a toy store.
As I obsessively protected my ears with earplugs when I used to go in clubs (and I never attended rock concerts), I think my hearing is still good enough to enjoy the best tweeters.
I did not spontaneously noticed anything wrong with the SLH5 XD's highs (cf. unevenness of the tweeter response beyond 10KHz), BUT I admit I did not focused specifically on that part of the spectrum either (and this last point matters; so to be confirmed; everyone will decide for himself anyway; I would suggest to try different heights for the seat: for instance, my M30.2 Anniversary sound best approx. 10° above the tweeter, which may seem surprising).