EP 061 Harbeth Audio Interview. Behind the scenes of a quiet revolution 50 years on.

Aug 25

6 min read

Updated: Sep 1

The Harbeth Audio revealed in an exclusive interview with Alan Shaw in Episode 061 is not a company simply repeating successful passive loudspeaker designs.

It is a company with:

A £100,000 laser vibration scanning system
A new church-based acoustic research facility in development
Active loudspeakers and DSP engineered largely in-house
Ongoing passive loudspeaker development
An undisclosed future project linked to Alan Shaw’s 60-year ambition
A determination to preserve control of its own technology
A clear awareness that younger listeners consume music differently

Harbeth’s passive loudspeakers remain central to its identity and commercial success. But the research taking place behind the scenes shows that its heritage is being treated as a foundation rather than a restriction.

Harbeth Audio P3 speaker in Cherry — Harbeth Audio P3 Model

The quiet revolution at Harbeth is not about discarding the past. It is about using modern measurement, digital processing and decades of accumulated loudspeaker knowledge to determine what should come next.

Best known for passive loudspeakers

In this interview for Episode 061 of Not An Audiophile, Harbeth Audio Managing Director and Head Designer Alan Shaw takes Andrew Hutchison inside this less familiar side of the company. Their conversation reveals a heritage HiFi brand preparing for its next 50 years without walking away from the passive loudspeakers upon which its reputation was built.

Why Harbeth bought a church?

Harbeth plans to use a disused church as a large acoustic measurement and loudspeaker research centre – in short an anechoic chamber.

At the time of the interview, Alan Shaw said Harbeth’s offer on the church had been accepted and the company was proceeding with the purchase. The large interior will allow Harbeth to conduct more reliable full-range loudspeaker measurements, particularly at low frequencies.

A sufficiently large acoustic space should allow Harbeth to make more dependable full-range measurements and better understand a loudspeaker’s true low-frequency performance.

Line drawing of an old English Church similar to the one Harbeth Audio bought to set up as an anechoic chamber — Harbeth Audio creating an anechoic chamber in a disused church

The church will use movable acoustic treatment rather than permanently covering its historic interior. A six-year-old member of the extended Harbeth family also suggested the facility’s remarkably appropriate name: the “Rechurch Centre.”

Harbeth’s £100,000 laser vibration scanner

The church is only one part of Harbeth’s expanding research program. The company has also invested approximately £100,000 in a Polytec laser vibration scanning system.

The scanner allows Harbeth’s engineers to see how the different parts of a loudspeaker move while it is operating. It can be used to investigate cabinet panels, drive units and other mechanical structures without attaching a contact probe that could influence the object being measured.

Harbeth’s scanning system is commonly used in automotive and aerospace development to locate unwanted vibrations, buzzes and rattles. Harbeth intends to apply the same level of analysis to loudspeaker cabinets and drive units. The scanner will also help confirm research already conducted using slower, more traditional methods and contribute to future development projects.

Is Harbeth moving away from passive loudspeakers?

Despite its investment in active loudspeakers and digital technology, Harbeth is not abandoning passive loudspeaker design. Shaw states clearly in the episode that Harbeth remains fundamentally a passive loudspeaker manufacturer. The company has almost 50 years of history in passive design, an approximately 18-month rolling order book and no commercial reason to discard products that continue to be strongly supported by customers.

The traditional Harbeth range and the company’s new active loudspeakers should therefore not be interpreted as one replacing the other. They address different requirements while allowing Harbeth to investigate technologies that could play a larger role in its future.

Harbeth Audio speaker M40-5 in walnut — Harbeth Audio M40-5 Speaker in Walnut

Why Harbeth still believes in BBC loudspeaker principles

Shaw remains deeply respectful of the BBC engineers who investigated loudspeaker design from the 1930s through to the 1970s.

from the Harbeth Audio website an image from the BBC studios mixing room — Harbeth Audio - BBC history

From Harbeth Audio It all started as a way to seel radio receivers. Over forty years, a handful of talented engineers at the BBC’s Research Department conceived and undertook the world’s most comprehensive and sustained loudspeaker investigation project. Their contribution to driving-up the standard of hi-fi speakers was and remains immense.– Alan Shaw – Designer, Harbeth Audio Ltd –

Harbeth continues to use the broad principles of the BBC thin-wall or “lossy cabinet” approach. Instead of attempting to make a loudspeaker enclosure completely inert through extreme mass and bracing, cabinet behaviour is carefully controlled so that unwanted energy does not intrude upon the reproduced sound.

Harbeth’s new laser scanner will allow the company to examine that behaviour in far greater detail. The purpose is not necessarily to prove the original BBC engineers wrong, but to understand more precisely why their principles worked—and how they might be developed further.

Harbeth active loudspeakers and in-house DSP l

Harbeth Audio the full NLE active series of loudspeakers NLE-1 and NLE-3 in multiple colours — Harbeth Audio NLE Series Active Loudspeakers - the latest in technology from Harbeth

Harbeth’s active NLE loudspeakers represent more than the addition of amplification to a conventional passive design. They have allowed the company to develop expertise in digital signal processing, electronics, software and active crossover design.

To retain complete control over the future of the DSP design into the future, Harbeth decided to bring most of the work in-house rather than use an external development company. Programming its own controller chips and keeping a close hold on DSP development means the ability to correct bugs, update code and add features directly.

Why DSP has changed what is possible for Harbeth.

Alan Shaw describes the processing power available through DSP as “utterly seductive.” Unlike a passive crossover, digital processing allows engineers to make precise changes quickly and investigate ideas not possible with passive crossovers.

The NLE controller includes a “Presentation” adjustment that can alter the listener’s perception of how close or distant the performers appear. It works by making subtle changes through the presence region rather than simply increasing or reducing the overall volume.

This reflects a recurring theme throughout the interview: the most important parts of loudspeaker design are not always at the extreme top or bottom of the frequency range. Shaw considers the region between approximately 1kHz and 4kHz particularly important to realism, intelligibility and listening fatigue.

Why Alan Shaw does not have a HiFi system at home

One of the episode’s most surprising moments has nothing to do with churches, lasers or active loudspeakers.

QUOTE from Alan Shaw Managing Director & Head Designer Harbeth Audio

"I don't have HiFi at home... I have a dozen portable radios....and that's quite deliberate. You become seduced by whatever you're listening to and your critical listening acuity degrades...So when I'm hearing them (Harbeth speakers) I'm hearing them as a consumer would on the point of first encounter" Alan Shaw

His reason raises an uncomfortable question for loudspeaker designers and audiophiles alike: does a familiar system sound good because it is genuinely accurate, or because the listener’s brain has adapted to it?

For audiophiles, this suggests that familiarity and quality are not always the same thing. Our brains can learn to compensate for problems, making objective judgement of a system we know intimately more difficult than we might assume.

https://youtube.com/shorts/Zx9muafUBRY?feature=share

A secret Harbeth project and a 60-year ambition

One of the most intriguing revelations in Episode 061 concerns a future Harbeth project that Shaw is not yet ready to describe in detail.

He says the project is more advanced than simple brainstorming and that the laser scanner was purchased partly to confirm work Harbeth had already completed using more laborious methods.

Alan Shaw suggests that the future concept will probably benefit from being active because DSP gives the designer extraordinary freedom, although he stops short of confirming exactly what form the project will take.

Harbeth at 50 may look different to 60 and beyond

2027 is the Harbeth Audio 50 year anniversary. Many brands spend their anniversary year harking back to the past. Instead, it seems Harbeth has decided that 50 years will be a jump-off point for the next exciting period of technology and innovation. Where other long-lived successful brands may be taking their foot off the gas at this point – Harbeth is guaranteeing that the brand will continue to address the needs and desires of HiFi enthusiasts far into the future.

Thanks to these fine Global HiFi Brands for their Support.