Interview - Procella Audio
Author: Chuck Back, Procella Audio
Procella came into the marketplace with a high-performance speaker system created not in a garage but as a solution for the European headquarters of one of the top audio companies in the world. Taking basic designs that come from a pro audio perspective that includes a strong cinema background, and seasoning them with studio/audiophile sensibilities, these speakers take a 'top down' approach to home theater, bringing the best performance characteristics of reference cinema systems into the home. Procella’s scalable concept enables enthusiasts to create systems capable of reproducing the full dynamic range of 96/24 recordings in any room size from a living room to a 40 seat cinema.
I understand that DTS was involved in the creation of Procella. Can you tell us about that?
The very first Procella speakers were created when the company’s founding partners, Anders Uggelberg and Gerben Van Duyl, were DTS directors working at the company’s headquarters near London. Anders, who is responsible for the design of over 300 cinemas (100+ THX certified), postproduction and mix studios, was head of the DTS Europe Cinema program. Gerben was responsible for DTS’s rapid marketing penetration in the European DVD market as DTS Director of Business Development for Consumer Content, where he was also actively engaged with leading music studios and record labels. The year was 2005, and at that time DTS was heavily involved not only in cinema, but in the promotion of multi-channel music recordings for both the DTS encoded and 24 bit/96KHz DVD-Audio formats. As they expanded their headquarters facility, DTS decided to build a 32-seat preview theater that could be used for presentation of DTS content that ranged from cinema to multichannel music and gaming.
Gerben and Anders were given responsibility for this theater, and finding the right loudspeaker system was undoubtedly their biggest challenge. They had no problem obtaining sample speakers from manufacturers – one and all were more than happy to provide samples for such a high-profile system. Yet as they evaluated a wide range of well-known consumer and professional audio systems, it became clear that there was no single speaker system that could meet the theater’s needs: it must reproduce the full dynamic range and impact of 24 bit/96 KHz film soundtracks and music recordings, and do it with sufficient resolution to enable music engineers and producers to hear all of the nuances and details in their own recordings – for all 32 seats. While some cinema speakers could deliver consistent and powerful sound to all the seats, none of them had the necessary musical resolution. And while many of the audiophile speakers and studio monitors produced reference audio quality, it was audible only in a narrow sweet spot of just a few seats, and none of them were capable of producing cinema reference level playback for all rows.
So, Gerben and Anders made the decision to design and build the speakers themselves. They turned to Italy, which is to pro audio driver manufacturing what Scandinavia was to consumer hi-fi speaker manufacturing, where they contacted several high-quality suppliers. From those companies they selected high-frequency compression drivers and pro woofer and subwoofer drivers, using them to create a three-way biamplified screen speaker, a two-way surround speaker and a dual 18” subwoofer (which eventually evolved into the P815, P8 and P18, respectively).
The high-performance and high-output woofer drivers helped ensure the necessary dynamic range and impact, but the key to achieving high-resolution audio performance throughout the seating area was Anders’ high frequency waveguide designs. In place of the horn used for cinema speakers, with its ‘honky’ coloration, his waveguides produce uncolored sound with the sweetness of a good dome tweeter, and directivity control that produces a smooth frequency response and good imaging across the entire listening area.
The system’s performance met with immediate acceptance and turned out to be a great success. On the music side, a parade of artists, engineers and producers from bands that include Queen and Depeche Mode spent many hours in the theater for demonstrations, evaluations and even multichannel music mixing. On the cinema side, the theater was a very effective demo for high-resolution 24bit/96KHz recordings – the format eventually adapted for Blu-ray discs. Time and again, Gerben and Anders were asked questions like ‘who makes these speakers?’ and ‘where can we buy them?’ After answering these questions for a year, they began to realize that the system just might be a viable commercial product. After leaving DTS, they joined together to create Procella Audio, and as they say, the rest is history.
Where is the company based, and where are the speakers built?
Our main office is in Stockholm, Sweden, and the speakers are built in a factory facility in Ljusdal, Sweden. Ljusdal is a small town in a beautiful setting in the Swedish countryside, about 3 hours north of Stockholm. We also have offices and warehousing in Los Angeles and in Sydney, Australia, making Procella a truly international company!
With hundreds of speaker companies in the world, why should anyone consider Procella?
Procella came into the marketplace with a high-performance speaker system created not in a garage but as a solution for the European headquarters of one of the top audio companies in the world. Taking basic designs that come from a pro audio perspective that includes a strong cinema background, and seasoning them with studio/audiophile sensibilities, these speakers take a 'top down' approach to home theater, bringing the best performance characteristics of reference cinema systems into the home. Procella’s scalable concept enables enthusiasts to create systems capable of reproducing the full dynamic range of 96/24 recordings in any room size from a living room to a 40 seat cinema, and Procella’s Identical Voices™ design concept ensures a seamless surround soundfield through timbre matching of all Procella models.By using pro audio components throughout the lineup, most notably high frequency compression drivers on proprietary constant directivity waveguides in place of dome tweeters, Procella speakers ensure life-like uncompressed dynamics and controlled high frequency dispersion, with pure, undistorted clarity and dialogue intelligibility. Integrators that have designed and built large home theaters are familiar with the limitations of consumer-grade components, and particularly appreciate the benefits of using speakers designed and built to pro cinema standards.
Procella takes a different design approach than the traditional hi-fi speaker company. What makes Procella different?
Virtually all hi-fi speaker companies use the same design elements in creating their speakers. While there are notable exceptions such as companies that make electrostatic and ribbon speakers, virtually all companies use cone woofers and dome tweeters, whether they are producing inexpensive speakers or very high quality music reproducers. These speaker components can give excellent performance in speakers used primarily for music in small to mid-sized rooms, and are well understood by many of the best speaker designers whose designs have always used these elements.
Coming from the cinema and pro audio side, Procella designers are experts in using the pro speaker components typically used for those applications. Our approach is towards the high end – we are not looking to compete in the mid or low priced speaker market, or for that matter, to offer expensive cabinet finishes so that we can compete on a fashion basis. There are many speakers in the market today that offer both good performance and good cosmetics – more than enough to satisfy listeners seeking such products. Our interest is not to compete with those speakers, but instead to provide the best possible high-performance speakers for larger rooms, especially for screening rooms, pro audio rooms and designed home theaters where consumer hi-fi speakers just don’t have the horsepower to perform to cinema (and in many cases, recording studio) specs.
You use compression drivers for high frequencies instead of dome tweeters. Why?
If you go back to the question about the first Procella system designed for the DTS headquarters, you’ll see that a wide variety of speakers were evaluated for their suitability in the 32-seat theater. The good audiophile and studio monitor speakers tested by Anders and Gerben used dome tweeters. Now, within its capabilities, a good dome tweeter can be a superb device for reproducing high frequencies. But in a large room, where most of the seats are more than a couple of meters away from the screen, a dome tweeter design simply cannot produce enough output to meet the dynamic range requirements for reference level playback throughout the seating area.
Cinema reference level playback, which is the proper playback level for film and the standard used for all film sound mixing, places the dialog level at 85 dB. With an additional 20 dB of headroom on digital film soundtracks above that level, each speaker must be able to produce a continuous level of 105 dB, not just at the speaker, but at the listener’s ears.
A good dome tweeter can produce only 105 dB at 1 or 2 meters before it reaches its limit, and it can also go into dynamic compression at lower levels with demanding program material. A dome is simply unable to produce enough output for reference level in large rooms.
Compression drivers, on the other hand, have significantly higher efficiency and vastly greater output capability, making them ideal devices for uncompressed, full dynamic range playback in large spaces. They have another important advantage when they are used with a well-designed waveguide. Waveguides give the designer the ability to control the directivity of the speaker, enabling delivery of smooth frequency response and good imaging to all seats across the width of the room. Dome tweeters tend to beam the sound, making their off-axis response significantly different than the on-axis response, which means that the sound will vary from seat to seat. Our constant directivity waveguides eliminate this problem and produce a predictable result that means good sound in every seat.
I thought that compression drivers required the use of horns, resulting in the honky coloration that many audiophiles dislike. Can you explain?
Historically, compression drivers have been used with horns, which are necessary to match the impedance of the driver to the air. Horns provide maximum efficiency, which is a primary reason that they are used in sound reinforcement and cinema systems. While horns have also been used for consumer speakers, those speakers have met with varying degrees of success. While many listeners enthusiastically embrace horn designs, others find them to have an objectionable coloration, and as a result only a limited number of brands have chosen to use horns for midrange or high frequency reproduction.
In the 1990s, however, new technology was developed that enabled the use of compression drivers without the acoustic tradeoffs of horns. This Waveguide technology, made possible by computer-aided design and manufacturing techniques, could be used to eliminate the ‘honky’ coloration of horns in speakers where accuracy rather than efficiency is the critical quality. While compression drivers on waveguides typically have less efficiency than those using horns, they produce better sound quality with less coloration because waveguides do not have the long throat of a horn and their design eliminates the internal reflections and diffraction of horns.
Anders Uggelberg is very familiar with waveguide design, having worked with them for many years before the DTS system was created. Given the high-resolution audio requirements of that system, using waveguides was the logical, if not the only choice.
Some of the Procella models are THX Approved. What does that mean, and how is that different than THX Certified?
THX has different standards for consumer products and professional products. To differentiate, THX consumer products receive Certification, and THX professional products receive Approval. Because THX’s goal is good audio and video in either the home and the studio, many of the standards are the same or very similar. However, achieving those standards is a very different matter in a large screening room or studio compared to a typical living room, especially considering the differences in room size and the number of listeners. Certified products fit into categories that include Ultra and Select, and these categories are defined by room size and listener distance from the screen. Approved products are also categorized according to room size and application, with a significant difference in that they must be able to meet THX standards in larger spaces and over a wider listening area than Certified products.
The Procella products that have received THX Approval were designed for large room sizes greater than those specified in the THX consumer product standards, so they really don’t fit into any of the Certified categories. Specifically, the P815, P8 and P18 are THX Approved for integration into professional rooms, including THX Certified Screening Rooms and THX pm3 Studios (professional Multichannel Mixing and Monitoring).
What new products do you have under development?
We are going to be showing several new products at the upcoming CEDIA Expo in September. First is a new single 10 inch subwoofer in the P10 family. This subwoofer has a very compact cabinet that can be built into the wall of custom-built theaters, and its primary purpose is to be used as a balancing subwoofer, located on the side and back walls of the room in combination with larger main subs like the P15 or P18.
We will also have two new three-way full-range main speaker systems designed for biamplification. One system will be moderately priced and based on our P6 with a single 10 inch woofer, and the other will be a true statement speaker with enough output for a mid-sized cinema! You’ll have to stay tuned to hear more details about these speakers.
Biography of Chuck Back
Procella Audio’s U.S.-based partner, Chuck Back, admits to being in the high-end audio and loudspeaker business back to the mid-70s, in the days when everyone had a turntable-based two-channel audio system. Spending over two decades as Executive Vice President of Miller & Kreisel Sound Corporation, he was in the middle of the action as the industry evolved towards the use of subwoofers and developing high-end multi-channel home theater speaker systems. He sees Procella as the next logical step, bringing the best of pro audio technology into the home.