How robust is the sound in today’s cinemas? What should theatre owners be doing to make sure their sound is as good as it can be? Film Journal International turned to a distinguished group of audio experts for their observations and “sound” advice. Participants in our forum are: John F. Allen, Founder & President, High Performance Stereo; Chapin Cutler, President, Boston Light & Sound Inc.; John Durliat, Senior Director, Technical Services, Regal Entertainment Group; Louis Eales, Senior Director, Worldwide Technical Operations, Products and Services, Dolby Laboratories; Barry Ferrell, Senior Director of Product Strategy, QSC Audio Products; Kirk Griffin, Director of Engineering, Harkins Theatres; and Mike Skrzat, Field Engineer, Datasat Digital Entertainment (formerly DTS). We thank them all for their expertise and valuable contributions.

What are the most common problems you’ve observed in cinema audio performance?
Cutler: The simple act of adjusting sound levels in an auditorium. It often appears as though no one in a cinema complex is checking sound levels at all. Beyond that, obvious lack of maintenance, such as blown or defective speaker components and dead amplifier channels, are also frequent culprits. And faulty sound pickup, causing constant or frequent sound reversions from digital to analog, particularly when the bypass levels have not been properly adjusted.

Griffin: Movies presented at too low a volume level. This is usually caused by preview trailers that are recorded at elevated levels. Their presentation prompts the movie patrons to come out and complain about the excessive volume level, at which point the projectionist lowers the volume. When the feature comes on, it is quieter than it should be and inevitably the movie is presented this way.

Allen: Because the speaker systems in most movie theatres are too small and surround speakers haphazardly located, poor dynamics, phony bass and excessive distortion result. When added to incorrect tuning as well as poor coverage, audiences are deprived of the full impact and often beautiful soundtracks of modern films.
Ferrell: Under-specification of speakers for a given theatre size is a very common problem. We often see an inadequate number of subwoofers and surround speakers used in many theatres.

Durliat: With the introduction of 35mm digital soundtracks and new AES sound technology as a component of digital-cinema systems, the need for additional headroom (or power handling) has become apparent. Audio systems designed for monaural and SVA 35mm recordings will not handle the dynamic range provided by these soundtracks. We are continually upgrading older systems to handle the new audio horsepower required today.

Eales: One of the most common problems associated with audio performance is misalignment or poor alignment in the soundtrack reader, room equalization and crossovers usually caused by lack of maintenance or time to set up and calibrate. Although there are standards and specifications for room tuning, sometimes the room design requires a modification to these parameters. It takes a person with a trained ear and known reference material such as Dolby Listen or Dolby Jiffy film to know when this is necessary.

Skrzat: The two that bother me the most are lack of maintenance and EQ.

The lack of regular maintenance of the system can be a real problem. The audience rarely complains about audio issues—mostly because they don't really know what's wrong, or that what's wrong can be fixed. But audiences aren't completely clueless—they know that something wasn't really right, and they likely walk away thinking it just wasn't a very well-made film when the theatre's playback equipment was the culprit. Recently I attended a local cinema where one of the films was playing with no left channel. I was the only one to inform them of the problem. Issues like these take away from the experience even if no one realizes something is wrong.

I don't know whether this story is funny or sad, but about 10 years ago I was at a well-known, respectable cinema in Los Angles to support a press screening that was running in DTS. I was doing a complete set-up and alignment which wasn't going well, so I went to check the subwoofer—there was no driver in it. I went to borrow one from another house to find that none of their subs were working; all of them had either been stolen or blown. It was a 15-house theatre. Obviously, nobody was checking the sound, and hadn't been in quite some time. The point I'm making here is that a little maintenance goes a long way.

My pet peeve is over-EQing, or rather, overuse of the EQ—specifically, adjacent EQ bands diametrically apposed. The techs, even some supposedly knowledgeable professionals who should know better, will set adjacent bands: one to full boost, the other to full cut. It may look good on an RTA to have a perfectly smooth curve, but it sounds unnatural and may have a detrimental effect on intelligibility; it causes phase distortion. There's no substitute for a good ear, and even a good ear gets saturated, so the X-curve is a useful tool to make a room sound good, as long as it's used properly. I cover this in detail in my classes because I have strong feelings about it. Don’t overdo the EQ!



What fundamental practices should exhibitors follow to maintain the best possible sound?
Durliat: Listen! Does the voice intelligibility remain during loud effects? Can you hear and understand a whisper? Are there rattles or buzzes? If a movie can’t be heard, it won’t be understood. Are your customers asking each other, “What did he just say?” A properly tuned auditorium reproducing the soundtrack at the proper level is as important as a focused and bright image on the screen.

Ferrell: Do the math. Cinema sound practices are very standardized. It is easy to do the math and specify a system correctly. Cutting corners results in distortion and poor sound at best and blown speakers at worst. It is cheaper to do it right once than to do it wrong over and over again. Service calls and refunds are very expensive. Dissatisfied customers rarely complain, they just don’t come back.

Eales: Exhibitors are recommended to hire a qualified installer with the latest calibration equipment and who has proper training. In addition, exhibitors should purchase the correct speakers based on the dimensions of the room. Only purchase equipment that is designed for cinemas, manufactured by companies that spend time and money on research and not companies that just copy other products. You get what you pay for.

Griffin: Simple inspection and maintenance. This starts with regular auditorium checks during performances, listening for problems with the sound system and disturbances to the presentation. Institute a program with your projection personnel where they regularly run known program material that exercises all audio channels, so that they can verify all the speakers are present and performing as expected. Set up simple preventive maintenance schedules with your operators, so that things like vents on amplifiers and soundhead optics on projectors get cleaned regularly. Make sure problems that are noted are communicated to your service organization so they can be repaired.

Allen: The motion picture recording organizations have made spectacular soundtracks for over 50 years. By seriously evaluating and upgrading every aspect of the way they deal with sound, exhibitors could deliver a sound quality in theatres that matches the sound quality of the films they play.

Cutler: At the very least, a quick run of the Dolby Jiffy film periodically will point out sound system deficiencies very quickly. This is an inexpensive tool that can make a huge difference in sound presentation. And it does not require a technician to make the observations. It is self-instructive as to what the symptoms are that it is pointing out. It also helps for quick picture checks. Service personnel should do an “A chain” alignment quarterly.

Skrzat: I realize the days of the professional projectionist are gone. There are a few specialty houses that have a projectionist, and some of those only bring them in for high-profile screenings. Shows in the local theatre are run by kids still in high school who are only trained to thread the projector or push the start button for digital. This is because the cinemas can't afford projectionists, and because the equipment is becoming increasingly easier to operate. However, most of the kids I have met are happy to learn how to make sure all channels are working and check optical levels. Theatre techs are spread so thin, if problems aren’t caught by theatre staff it could be a very long time before they are corrected. This directly affects sales, and the exhibitors are losing revenue to it, and aren't even noticing.

It ties into the maintenance issues I’ve discussed. Poor maintenance is exacerbated by the fact there is a high turnover rate in these kinds of jobs, so it doesn't make sense for every kid who gets hired to be trained. But the theatres can certainly do a better job of identifying those in their management team who would enjoy being responsible for playing a test loop/disc, checking to see that each channel is working, and checking the optical level. This is as easy as learning to thread a projector, it takes about 10 minutes per house, and should be done once a week. In DTS houses it's even easier—because they don't have to thread the projector (except to check the optical), they just need to pop in a test disc or play the file off our newer XD10/20 systems.

What is the single most important part of the audio chain?
Allen: Transducers. If one is looking at the sound reproduction end of the chain, it’s the loudspeakers. At the recording end, it is the microphones. Of course, there's also everything in between.

Durliat: The volume control. If the sound level is too high, the customer will be fatigued and feel as though they have had an unpleasant experience with the performance. If it is too low, they will be a spectator instead of a participant with the movie experience.

Griffin: I’d have to say the speakers. Others may tout the sonic superiority of a certain amplifier or sound processor, but I doubt that this can be heard by your everyday patron. On the other hand, I have experienced some poorly designed and/or implemented speaker systems that truly sounded bad.

Ferrell: The auditorium. We like to start with the right speakers for the room and then design the amps and DSP to suit. The system is only as good as its weakest link.

Skrzat: The cinema processor is the brains of the audio chain. Everything goes through it and it's the interface between the projectionist and the sound system. It's the thing that provides the majority of the adjustments of the system—all the EQ and delays.

Cutler: The sound pickup. If it is out of whack, no matter what you do down the line, it won’t improve sound quality.

Eales: The single most important part of the audio chain is room acoustics and design. Case in point is that many mixing stages use the exact same sound playback equipment that can be found in cinemas, but they pay a lot of attention to the room design and acoustic treatment.



What are the new audio challenges of today’s digital-cinema presentations?
Cutler: The same as those that exist from the continuing film-based systems: poorly designed systems that are underpowered. Systems that are designed to meet a price point rather than performance. There are now sound components that have made their way into the commercial sound marketplace that are totally ignored in the design and installation of cinema sound systems, most notably line-array loudspeaker systems. Use of these types of innovations could improve intelligibility (always a problem), dynamic range and even sound field coverage, particularly in large, stadium-seated theatres.

Skrzat: Up front, the biggest stumbling block for exhibitors in the digital age is cost. The systems are more expensive to buy, and it's not likely that a server will last 50 years, like a projector, and even if it does it will be obsolete. However, the sound produced by these systems is more dynamic and detailed.

Most cinema servers output a digital AES/EBU signal with up to 16 channels. It's also uncompressed. Older cinema processors can only handle six channels and need an external D-to-A converter to receive the digital audio. In other words, cinemas need equipment upgrades in order to bring in the digital sound.

Fortunately, it doesn't require any more maintenance on the audio end of it, but the servers and projectors require that the techs have an IT background to service them.
Having a digital projector opens the door for new revenue streams—remote concerts and sporting events, to name just a few. Today’s cinema processors need to handle a much wider array of audio inputs to play back other types of events—for instance, the Olympics. To accommodate the new marketplace, exhibitors should consider processor upgrades when upgrading to digital cinema.

Ferrell: Alternative content presents a tremendous challenge and opportunity. A live concert broadcast has the potential for high sound levels well above that of movies. Opera brings in a potentially critical audience that is used to high-fidelity live performances in a concert hall. Upping the sound system quality for these presentations gives the theatre owner a chance to stand out from the competition and develop a loyal following that knows where to go for these presentations.

Allen: We have to be totally honest about this. It’s the human factor. By that I mean those responsible for purchasing, installing and maintaining the sound systems in movie theatres. Great sound is something human beings respond to in many ways. The uncompressed digital soundtracks d-cinema offers are technically the best possible. Exhibition can and should take full advantage of this fact. But too often politics and deal-making trump what should be engineering decisions.

Durliat: We must maintain a standard for audio level from one studio and director to another. This standard then must be adhered to when adjusting playback in each theatre. This is the only industry that has an established audio reference level that I am aware of. It should be our industry goal to preserve and maintain this important standard.

Eales: Digital-cinema audio is plain PCM. There is no metadata carried in the bit stream to help with dropouts, splicing, channel mapping, etc. PCM is not frame-based and there is no backup audio track.

Griffin: Dynamic range is a challenge. The specifications for digital-cinema sound, with its increased frequency response and dynamic range, open up a Pandora’s Box in the exhibition environment. Not only does the sound system have to be engineered to handle the more rigorous requirements, but the facility also needs to meet the criteria. This means the HVAC system needs to be quiet enough to hear a whisper and the demising wall’s structure heavy enough to keep an explosion from being heard in the neighboring auditorium. Far too often, I see exhibitors installing digital-cinema systems in theatres where the sonic benefits cannot be realized, because the building is not up to par.

What’s the most significant improvement in cinema sound of the past few years?
Griffin: Digital cinema sound. Pure, uncompressed, 20-20kHz, 24-bit audio. The first time I heard a movie soundtrack on an auditorium’s sound system that was engineered from the ground up for digital cinema, I was blown away! The clarity and trueness of the sound, especially in the upper midrange, is unbelievable.

Ferrell: Uncompressed digital audio that is available from d-cinema servers is identical to the audio that was recorded in the studio. The recording media is no longer a limiting factor in cinema sound reproduction.

Cutler: Probably the improvement in mid-range and high-frequency horn designs and speakers designed for stadium-seating installations. And there have been improvements in electronic crossovers used in three-way and four-way speaker systems.

Eales: Using screen-array stage speaker systems is a huge improvement for cinema sound. They offer better coverage, which gives you an improved response from every seat in the house.

Allen: Digital recording, production and mixing techniques have made it possible to produce vastly more complex and beautiful soundtracks with many more elements. These can now be played in their original quality in every theatre if properly equipped.

Skrzat: Digital cinema gives us up to 16 channels of uncompressed 24/96 sound. That's a lot of information. A rich soundtrack is really enhanced by this type of resolution. In a well-tuned theatre, soundtracks that have been lovingly, beautifully mixed sound incredible. I hate to keep harping on this, but theatre owners who spend big bucks to install this kind of high-end equipment should make sure that they keep it maintained, and properly EQ'd if they want to get the playback they're paying for.

Durliat: Digital 35mm soundtracks were a significant improvement over monaural and SVA recordings. Now, AES audio has surpassed even the best film audio by supplying higher sampling rates, additional tracks, and higher dynamic range. Each audio channel now provides for full-range dynamic sound; therefore, audio speaker components need to be carefully selected to assure full bandwidth, power handling and clarity.



Ideally, what should the audience be getting from a cinema sound experience that they can’t get at home?
Griffin: Good bass. The size of most home-viewing environments precludes the development and resonance of lower-frequency sounds. A 20-Hz bass wave is over 55 feet long. For it to fully form and then resonate takes a decent-sized auditorium. Loud subwoofers in a home A/V system will certainly shake the couch and rattle the windows, but the viewer will never really hear the sound that’s causing all that vibration.

Another benefit of the cinema experience does not come from the movie’s soundtrack, but from the patrons around you. The reaction of an audience is something unique to public performance and can never really be recreated in a home environment.

Cutler: Big sound in a big room. It is easy to get big sound in a little room. However, consumers that frequent our theatres are spending more on their home sound systems than many exhibitors.

Allen: Sound quality in the home can be just as good as the best movie theatres. Two things that cannot be found in the home are the pleasures resulting from the acoustics of the large space of the theatre and the communal experience. All the more reason for theatres to take better advantage of their size than they presently are.

Ferrell: Big pictures and big sound are incredibly compelling and involving. Properly designed sound systems are “transparent” and lure the audience into the world that the director creates. Small screens and tiny speakers used in many home systems just can’t re-create the mood of a movie the way a top-performing cinema can.

Skrzat: Cinemas offer complete immersion. Few home theatres can provide the dynamics available at most cinemas and even fewer have been aligned using an RTA by a professional installer. I spend time in some amazing home theatres that are better rooms than your local theatre—but these belong to celebrities who don't think twice about paying between a quarter to a half a million dollars for a home theatre. The rest of us have a different experience.

The days of a family sitting around a 27-inch television every Thursday to catch their favorite show are gone, as most people have fairly sophisticated recording and playback systems in their homes. Some even have home-theatre systems that offer adequate sound, certainly better than anything we had even a decade ago. Still, these rooms are usually shared with other family activities, so the acoustics aren't optimal, most home owners aren't trained to tune them, and even if they can there are always easily annoyed neighbors. Most home theatres can't reproduce the dynamics of a theatre system.

Aside from sound, the group experience you get at the cinema can’t be reproduced at home. I watch movies for living. Often I sit alone, usually at a studio in an immaculately tuned screening room and watch a movie. I can't count the times that I've told my wife that a comedy wasn't funny, to find out when I saw it again with my family I felt differently. There’s really something to be said for the experience of sharing a laugh with a group of other theatre-goers. Additionally, those of us not lucky enough to be on the Bel Air circuit don't get to see current releases at home. We go to movies to see the latest release.

Eales: In general, the cinema is a more controlled environment and the engineers tuning the sound system are using sophisticated test equipment and adjusting everything to the same standard that is used for the soundstage the soundtracks are mixed on. Also, the size of the room allows for better-quality speakers coupled with the use of surround arrays instead of single surround speakers that have been used in the past.

Durliat: Cinema sound continues to be the touchstone for home audio system design. Whereas a home-theatre room will typically have only one localized “sweet spot” to listen to the content, a cinema audio system strives to encompass the complete seating area with the finest reproduction. This is possible due to the fact that the listener is in the far field of the speaker radiation area, with the auditorium adding to the complement of audio reproduction quality.

What’s the most impressive sound mix you’ve heard in a theatre recently?
Ferrell: I was quite impressed with the subwoofer track in Terminator Salvation.
Allen: Star Trek.

Skrzat: Pixar’s Up. From the quiet ambiance of the fog-cloaked mesa and jungle scenes to being inside an old house floating through a thunderstorm, the mix was outstanding. The soundtrack made this implausible movie real without making me feel pummeled.

Durliat: I recently visited an IMAX digital performance of Transformers at our Regal Entertainment Group location in Orlando, Florida. The sound was superb, with excellent intelligibility, discrete rear-channel audio and well-balanced EQ. The volume level was matched to the content and action of the movie. The audio presentation enhanced the visual experience.

Eales: There are too many to list, but a good place to start is the 2009 Academy Awards nominations for sound mixing. They were all excellent mixes. One of my personal favorites was The Dark Knight.

Griffin: To be honest, no recent movies come to mind. Last year’s Iron Man was a great mix. The dialogue was clear and the effects, though loud, were at a good volume level. The first Transformers movie also had a good sound mix. Some of the low-frequency effects were literally spine-tingling! Even in the midst of full-blown chaos on the screen (and in the sound), the actors’ lines could still be heard.

Cutler: The “impressive” mix needs to go with the quality of the sound system. I am fortunate as most of the sound systems I hear are designed for performance not price, such as at ShoWest. Based upon that, Miami Vice, American Gangster and Memoirs of a Geisha top my list. In a movie theatre environment, it would be Mongol at the State Theatre in Traverse City, Michigan. A well-designed and installed sound system lets you hear not only the big things but the little noises and whispered words as well.

Overall, how does today’s theatre sound compare with that of ten years ago?
Eales: There have been a lot of improvements in the mixing of the soundtracks. They are now mixing completely in the digital domain. No more analog tape and better sound consoles.

Ferrell: D-cinema offers the best possible audio source and current DSP and speaker technology are far better than a decade ago. We have more dynamic systems that can play louder without distortion. Today’s subwoofers can play lower and louder and screen-channel speakers feature advanced high-frequency driver technology that produces far less distortion.

Allen: The source material is much better, but the sound in too many of the theatres is about the same as ten years ago. Sadly, the weaknesses of motion picture sound systems are chronic. Major improvements and standardization resulted from Dolby's introduction into the business 35 years ago. Things would be better today had their guidelines and those that came after from others been more faithfully followed.

Cutler: If anything, it has gotten worse. Back in the days when THX was driving awareness of audio quality upwards, it carried the bulk of the industry up with it. Since then, there has only been the drive towards digital cinema as a technology which has taken much of the focus off sound system improvements. As the drive for digital technology and its cost are argued in the marketplace, money spent on the core technologies of film delivery and sound systems have taken a back seat.

Durliat: Audio improvements have maintained the same pace as the visual experience. Improved film stock has evolved, and so has the reliability and quality of analog and digital 35mm soundtracks. Now, with the advent of digital cinema, AES has also improved the overall sound quality with bandwidth and larger digital audio storage capability on the server. The next challenge: additional audio channels in the theatre and placement of these new discrete soundtracks within the environment.

Griffin: The major adoption of digital sound, both on film and now in digital cinema, has allowed the film sound designers and directors to take advantage of the full dynamic range available in today’s movie theatres. This translates not only into more visceral explosions, but also greater intelligibility of the barely audible whisper.

Skrzat: I haven’t seen a drastic improvement in the high-end cinemas in the past 10 years; the technology being used has been around a while: Dolby came out in 1990, and DTS in 1993. However…more cinemas fall into the high-end category than 10 years ago. You had to drive across town to hear a film in digital in 1995. Now, it's hard to find even an art house without digital sound. Most older theatres have upgraded their equipment fairly recently, and most new theatres have been built incorporating high-end digital systems from the beginning. As the equipment keeps improving, the changes have been incremental, but the big changes are coming with digital cinema.

There are a handful of really high-end houses that are a step above anything the average theatre-goer has access to. I sit on the Theater Standards Committee for AMPAS, which, along with the DGA, the Ross on the Warner lot and a few others are unsurpassed in their playback systems, partially because they have a team of the industry's best engineers setting the rooms up and keeping them in perfect shape. They also spare no expense in the equipment. The Sam Goldwyn or Academy Theater, for instance, has equipment that can play back anything—from 16mm nitrate from the early 1900s to 3D digital cinema. The Academy has many screenings that are open to the public. If an audiophile wants to have a consummate moviegoing experience, they should take the time and effort to see a film in the Sam Goldwyn. Short of that, almost all local cinemas are offering a digital surround experience that will make most moviegoers happy.