Paul McGowan on Horn Loudspeakers

[Hear Here]

You wrote that you auditioned MBL and GP before. Were they auditioned in this room or in a regular room?

No, only at the dealer's demo room that was nothing like my own roon..

Have you thought about simply installing a second system for the dining area, instead? Maybe even in-ceiling speakers? This way you would not have to compromise for critical listening.

Yes, but they would be small speakers so the AG's bass enclosures might as well act as subs when the second set is working. I may give this more serious consideration, but frankly when I'm using the dinng area, I'm normally with friends so any music can be considered as background music where the lack of fidelity is probably an advantage if conversation is valued!

 

[Hornsolutions Swen]

Stimmt Pauls Geschichtsstunde, dass Hornlautsprecher als Lösung für das Problem entwickelt wurden, dass frühe Verstärker nur wenige Watt erzeugen konnten?

Hello Ron, even if the answer comes a little late.

In a period during the infancy of the gramophone, when it was universally employed, the horn loudspeaker gained increasing prominence, and its development advanced steadily. From 1887, when Emil Berliner invented the gramophone, to the golden era of the late 1920s, when Western Electric in the USA and Klangfilm in Europe began designing some of the most iconic horn loudspeakers in history, the pursuit of perfect sound was relentless.

However, after the heyday of cinema, the popularity of horn loudspeakers declined—likely due to their large size, the complexity of their manufacture, and consequently their high cost. The trend toward smaller living spaces certainly played a role as well. Today, while full-range horn systems are embraced only by a small circle of enthusiasts, most experts unanimously recognize their unparalleled virtues as loudspeaker enclosures, especially their exceptional realism and “presence.”



But let us take a look back at their origins.

The 1920s marked a period of unprecedented prosperity in the United States and Europe. Enormous resources were devoted to advancing sound reproduction technology across various domains: telephones, microphones, record-making processes, radio, and, most notably, talking motion pictures. Films were as central to daily life then as television and the internet are today. In major cities, newsreel theaters operated around the clock, much like 24/7 television channels. The invention of “talkies,” or movies with synchronized sound, was a groundbreaking event that permanently transformed film and media.

Two colossal corporations, RCA and Western Electric, dominated American and global communication technology for much of the 20th century. They were responsible for numerous innovations that underpin modern life, from the telephone system to record technology (pioneered by RCA under its Victrola brand), television, and even the VCR. Both companies played crucial roles in the foundational development of sound for motion pictures.

Theaters of that era were nothing like the multiplexes of today. They were grand, cavernous spaces, often seating thousands of patrons. With upholstered seats, heavy drapery, and audiences that absorbed significant sound, achieving effective sound reproduction posed a formidable challenge. The demand for loudness was immense, but the amplifiers of the time, relying on simple vacuum tube triodes, produced very limited power—typically no more than 10 watts per amplifier. Even with multiple amplifiers (which were large and expensive), the total power available to deliver credible sound in a vast theater was minuscule compared to even the most basic modern amplifiers. So how did they transform such modest power into impressive sound?


The answer was horns.

Horns themselves were not a new invention, but engineers at Bell Labs, Western Electric (notably Wente, Thuras, and Fletcher), and RCA (Volkman, Masa, and Olson) elevated horn technology to extraordinary heights. Their designs—such as Western Electric 15A or the 13A, and later the 22A—were monumental structures, typically positioned behind theater screens. These horn-loaded loudspeakers were so efficient that they could convert the limited power of triode amplifiers into plausible, realistic sound levels, even in the largest theaters.

In Europe, a few years later, Klangfilm achieved similar feats with systems like the Bionor and Eurodyn. Without the aid of computers, these engineers solved complex acoustical and psycho-acoustical challenges that remain difficult even with today’s advanced technology. Their achievements were nothing short of miraculous.

With the onset of the Great Depression and advances in amplifier technology, the necessity and popularity of large horn loudspeakers gradually diminished. By the mid-20th century, horns were nearly extinct, with few exceptions such as Klipsch. The development of the transistor by Bell Labs under Shockley, Bardeen, and Brattain in 1948 introduced new possibilities, though the sound quality of early transistor amplifiers was far from ideal. Even Klipsch eventually succumbed to market pressures, producing smaller, more economically viable designs. The once-proud kings of cinema were folded, both literally and figuratively, into compact horn systems suitable for living rooms.

However, these folded designs introduced unavoidable compromises, particularly above frequencies of 200 Hz. The misconception that greater excursion (x-max) and power can compensate for reduced cabinet volume remains one of the biggest obstacles to achieving perfect sound. Yet, shouldn’t perfect sound—the “holy grail” of audio—be our ultimate goal?

 

[Legolas]

Yes I agree 100%. I also love horns, and hear the things they do that other types of speakers struggle with IMO. Like all things, no single speaker is perfect.
Horns are making a comeback, albeit slowly, and not as much in the mainstream. Aries Cerat, HornSolutions, Cessaro, Tune Audio. And there are many more 'suede' horn such as the Supravox which uses a midrange horn and tradition cabinet for bass duties.
One thing that is a negative for horns, is they get grouped into a 'they are coloured' mindset. The subset of horns that don't work so well have done a lot of damage to a new market of people who may look at horns. IMO building a horn speaker is way more difficult than a traditional speaker. Though, I would personally encourage adventurous ones to have a go at DIY horns, if budget is an issue. There is a lot of info out there, with care IMO on what will work.

 

[Hornsolutions Swen]

Yes I agree 100%. I also love horns, and hear the things they do that other types of speakers struggle with IMO. Like all things, no single speaker is perfect.
Horns are making a comeback, albeit slowly, and not as much in the mainstream. Aries Cerat, HornSolutions, Cessaro, Tune Audio. And there are many more 'suede' horn such as the Supravox which uses a midrange horn and tradition cabinet for bass duties.
One thing that is a negative for horns, is they get grouped into a 'they are coloured' mindset. The subset of horns that don't work so well have done a lot of damage to a new market of people who may look at horns. IMO building a horn speaker is way more difficult than a traditional speaker. Though, I would personally encourage adventurous ones to have a go at DIY horns, if budget is an issue. There is a lot of info out there, with care IMO on what will work.

You hit the nail on the head. The well-known problem of so-called coloration is indeed the most recognized, but ultimately, it is just one of many, as horns are actually much more difficult to develop than conventional speakers. In today's world, developing conventional speakers is almost child's play. Calculation programs, AI simulations, and a few basic principles such as separating the chassis and stiffening the enclosure are often sufficient. If you also purchase high-quality chassis, almost nothing can go wrong. However, developing horns involves significantly more trial and error.

To return to the entirely justified prejudice about coloration: coloration is not an inherent property of horns but rather the result of poor development, often because design and suitability for living spaces are prioritized over physical laws. Horns start to beam (i.e., sound colored or nasal) after a certain range (usually after 2.5 to 3.5 octaves). This is simply a law of physics. So, if I want a horn that doesn't beam, I have to separate accordingly. This means either using multiple ways, resulting in several transitions and potentially causing further problems such as phase shifts, or I need to use larger horns that can separate at lower frequencies. Ultimately, uncompromising design means that the speaker will simply be larger.
Larger means lower sales.
This is the main reason why manufacturers are willing to compromise.

 

[Legolas]

This is a great topic.
I am trying to build a new horn speaker, with a midrange horn covering the 2K-20K. Do you think this is doable or advisable? It would be a 3 way in that case. The compression driver is a Radian 745NE which can go down to 800hz and up to 20K it is claimed. If I cross at 2K then 2k-16K is 3 Octaves, may work?

If will be fitted to a Circular Traitrix wooden horn 34cm diameter by 30cm deep, 1.4 inch throat.

I could later if required add a bullet tweeter or Ribbon maybe.

Back to what I like about horns. They are so fast, so detailed and yet can be so natural sounding, a huge feet - specially on piano, vocals etc. This is mid range and up. And seem to have a lot of headroom with less dynamic compression. This fools my ears to enjoy a more realistic presentation of music, as opposed to a very good speaker presentation for example. To get true bass extension and speed either a gigantic horn is required, or a well designed horn loaded bass cabinet. Great examples that work so well are IMO Aries Cerat Symphonies and Aurora, Living Voice Vox Olympian. Avante Garde, Tune Audio and Cessaro - bit mixed in the rooms I have heard over the years. I have not heard Hornsolutions yet, but if they have traits from the original WE Horns I can imagine they will do great things.

 

[Hornsolutions Swen]

Radian would certainly not be my first choice. Ultimately, it all comes down to budget. From 800 Hz onwards, I would always use the appropriate TAD driver. I believe I have heard just about every reasonably good compression driver, and for the specified frequency range, TAD drivers are still the benchmark. Of course there are a few others and also it depends on other things. Like passiv or activ

By the way, I wouldn’t classify this as midrange, but rather as upper midrange and high frequency. Over 80% of the entire music spectrum occurs between 160 and 700 Hz, where the soul of the music resides. Below that is for the heart and enjoyment, and above 2000 Hz, it’s purely about localization, to put it simply.

Interestingly, the most complicated part of your project would not be choosing the right driver, but rather the coupling of the bass to the midrange, or the right choice of bass solution. It needs to be fast enough, should go deep, and simultaneously play up to 800 Hz. This is extremely complicated to achieve.

BTW, you are welcome to visit us anytime you like.
It seems you are nearly around the corner....

Best Regards Swen

 

[Robh3606]

This is a great topic.
I am trying to build a new horn speaker, with a midrange horn covering the 2K-20K. Do you think this is doable or advisable? It would be a 3 way in that case. The compression driver is a Radian 745NE which can go down to 800hz and up to 20K it is claimed. If I cross at 2K then 2k-16K is 3 Octaves, may work?

Hello Legolas

You should be able to put together a nice system. I have 3 different set-up's using similar compression drivers that range from 700Hz-20K, 750- 8k with Tweeter up top and 1.5K-20K. They all work very well all 3 using different waveguides and horns.

The horn coverage being the issue going 700Hz and still giving reasonable coverage top octave and of course finding a compression driver that can actually cover the top octave without excessive roll-off. There are lot of options don't forget to give more modern horns/waveguides a listen. Take a look at CD horns and waveguides as well the flat power response make them more room friendly.

Rob

 

[Hornsolutions Swen]

Hello Legolas

You should be able to put together a nice system. I have 3 different set-up's using similar compression drivers that range from 700Hz-20K, 750- 8k with Tweeter up top and 1.5K-20K. They all work very well all 3 using different waveguides and horns.

The horn coverage being the issue going 700Hz and still giving reasonable coverage top octave and of course finding a compression driver that can actually cover the top octave without excessive roll-off. There are lot of options don't forget to give more modern horns/waveguides a listen. Take a look at CD horns and waveguides as well the flat power response make them more room friendly.

Rob

I mostly agree with your points. However, I would like to clarify that waveguides should not be categorized as horns. Waveguides have distinct characteristics that differentiate them from horns, particularly in their design and functionality. A horn is expected to provide a 6 dB gain, which is a fundamental aspect that defines its purpose and distinguishes it from waveguides and constant directivity (CD) horns. This is merely my personal opinion, and I certainly do not wish to spark an endless discussion on the topic.

Best regards,
Swen

 

[Robh3606]

mostly agree with your points. However, I would like to clarify that waveguides should not be categorized as horns. Waveguides have distinct characteristics that differentiate them from horns, particularly in their design and functionality. A horn is expected to provide a 6 dB gain, which is a fundamental aspect that defines its purpose and distinguishes it from waveguides and constant directivity (CD) horns.

Hello Swen

I have no issue with that. I will gladly give up 6db of gain for the advantages waveguides and CD horns can provide. It's all about compromises and loosing 6db of SPL is not a game changer. Especially at sensitivities above 100db

YMMV Rob

 

[Legolas]

Hello Legolas

You should be able to put together a nice system. I have 3 different set-up's using similar compression drivers that range from 700Hz-20K, 750- 8k with Tweeter up top and 1.5K-20K. They all work very well all 3 using different waveguides and horns.

The horn coverage being the issue going 700Hz and still giving reasonable coverage top octave and of course finding a compression driver that can actually cover the top octave without excessive roll-off. There are lot of options don't forget to give more modern horns/waveguides a listen. Take a look at CD horns and waveguides as well the flat power response make them more room friendly.

Rob

Thank you. I am hoping my 34cm circular exponential horn which crosses at 2Khz manages to go up to 16Khz at least. I won't know if it is beamy until I fully build it up. It that is an issue, I could add a super tweeter, but would prefer not to, keep it simpler.

 

[DasguteOhr]

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Ready is a top speaker 100db/ 1watt

 

[Robh3606]

Thank you. I am hoping my 34cm circular exponential horn which crosses at 2Khz manages to go up to 16Khz at least. I won't know if it is beamy until I fully build it up. It that is an issue, I could add a super tweeter, but would prefer not to, keep it simpler.

I have used a JBL 1" exponential 2391 and it beams, with a 1.4" throat it's going to beam. May not be an issue as long as you are on axis and what your tolerance is WRT sweet spot width. The 2391 could get you up there 15/16k so it may work out without a tweeter. In any case have fun and let us know how it works out.

Rob

 

[Legolas]

Thanks

I have used a JBL 1" exponential 2391 and it beams, with a 1.4" throat it's going to beam. May not be an issue as long as you are on axis and what your tolerance is WRT sweet spot width. The 2391 could get you up there 15/16k so it may work out without a tweeter. In any case have fun and let us know how it works out.

Rob

Thanks. I am on a horn like this:


34cm diamater, 30ck deep, 1.4inch throat.

 

[Robh3606]

Thanks

Thanks. I am on a horn like this:
View attachment 154026View attachment 154027

34cm diamater, 30ck deep, 1.4inch throat.

Nice! How are you planning of finishing it? That's a big horn why the 2K crossover point? Seam's it will be able to be crossed over lower. Going to find out once you get your compression driver mounted and tested.

You going active/passive/DSP?


Rob