Friday, March 17, 2017

THE GRIMANI FILES: Bringing Life to a Comatose Home Theater

This client was referred to us by the integrator, who completed this installation about 10 years ago.
The room was a dedicated three-row home theater in an upscale neighborhood of Detroit. All the gear was state-of-the-art for its time - from the studio-grade speakers, to the professional HD video projection system.
But the surround decoder finally gave up the ghost after several years of faithful service.
The client heard that Dolby Atmos® was the latest thing, so he sourced a new processor. He expected it to be an automatic upgrade, but wasn’t aware that he also needed to add speakers for the Top and Wide locations. At any rate, it was time to install, configure, and tune the system for the new processor. I took the job and carved out two days - right before Christmas - for a quick jaunt from my temperate San Francisco Bay Area home to frigid Detroit. (Who doesn't like a little cold for the holidays?) While planning the trip, I found out that the system didn’t include any equalization.  It's impossible to properly tune the frequency response, levels, time alignment, and phase relationships of the various speakers without a digital EQ, so I asked the client to add one. I specified a very good, cost-effective unit from Ashly, which was shipped to the site along with a few XLR M/F snakes to patch it into the system.
The end user was definitely a movie buff. He had a large collection of discs, a PRIMA Cinema server, and a good collection of source devices. He had set up a classy and comfortable dedicated environment to enjoy his movie viewing, and he had a lot of passion for proper presentation of the filmmaker’s intent.
But, as David Attenborough often says in the PBS series Planet Earth, the room and system had a few implementation issues that made it harder to achieve the optimal experience. I list these here not, so much, to criticize and point fingers, but to provide an opportunity to learn and improve the deployment of future systems.
1.    Acoustically Dead. The acoustical designer hired for the project specified that all the walls should be lined with two inches of high-density insulation, and he even showed some predictive calculations for the effect. Well, it has been known for a while now that a room should have a proper balance of reflection, scattering, and absorption. For typical residential home cinemas, the appropriate balance is about 20% absorptive surfaces, 25% scattering surfaces, and the rest reflective. The layout for these various types of surfaces needs to be strategically engineered so the sound reflections support the speakers' sound radiation. For a room this size, the resulting reflection decay time should land around 0.35 seconds across the full frequency range from 60 Hz to 10 kHz. In reality, the impulse response measurements for this room demonstrated it to have 0.15 second decay time down to 1 kHz, rising up to 0.3 seconds below 500 Hz.  That's pretty much what you would expect from a room packed with too much fuzz. The room sounded weird just walking into it; the sound was inconsistent from seat to seat, and the speaker interactions produced clearly audible comb filters. The solution is to peel back the decorative wall upholstery fabric that conceals the insulation, remove at least 60% of it, install some scattering diffuser panels at strategic locations, and retune the frequency response and levels - as they will clearly change.
2.    Seat Locations. The room was a bit too small for three comfortable rows. The back seats were up against the back wall. Bass was thick back there, and it was hard to get a proper immersive envelopment that far from the front speakers and so close to the back speakers. The solution is tough, here, since the room is already built. But every half foot of distance to the back wall helps. Scooting up all the rows a bit and reducing the aisles between them would probably help. Realistically, this would probably not happen given the high design values built into the existing room. It would have been better to properly lay out the room in the first place. Additionally, the left seats of each row were right up against the left wall, rendering them inappropriate for proper soundfield perception (although just OK for casual viewing of media).
3.    Subwoofer Placement.  The two subwoofers were in one corner. Bass standing waves, tightness, and coverage uniformity are all a major challenge in rooms under 50 feet long. Placing the subwoofers in one corner of the room is generally the worst option for good grades in the above performance areas, although you do get more sound level from this arrangement. Like they say, it’s junky but loud. Room EQ can somewhat mitigate the issues of amplitude response and resonances, but it won't ever solve the seat-to-seat uniformity issues.  The solution is to place the two subwoofers in different locations, preferably across the mid-points of the room. Better yet, conceal four smaller subwoofers in the four corners of the room and tune them each with a channel of digital EQ.  This reduces the response errors with judicious use of relative delays, levels, and frequency response tailoring. With a bit of time, you can get to tight, punchy, loud, and consistent bass that puts a smile on the face of anyone sitting in the room.
4.    Surround Speaker Placement.  The surround speakers were too low. Because of the location and size of the side wall lighting sconces, some of the side surround speakers were placed about a foot too low. This yielded insufficient immersion, and it called attention to the speaker locations since they drilled right at your ears. Turning them down a bit, reducing the higher frequencies, and delaying them a bit are all work-arounds, but the right solution is to reduce the sconce dimensions and place the speakers properly.
5.    LCR Speaker Coverage.  The LCR speakers were too beamy. The studio monitor-grade speakers used for Left/Center/Right were, in fact, a bit too inconsistent in dispersion across frequencies. As a result, the sound changed quite a bit from seat to seat, and it was hard to tune the room for reference-grade sound at all the seats.  The solution is to replace the speakers with more current versions that have broader horizontal directivity and smoother sound power (the net spectral response throughout the room). The sweet spot would get wider, and the overall sound quality would be smoother.
6.    Missing Equalization. As mentioned above, I requested that an equalizer system be added before I conducted the room calibration. I got half my wish: An EQ was sourced, but I had to install it into the rack and wire it up. The EQ had detachable three-pin screw connectors (Phoenix/Euroblock), and the decoder and amps all had balanced XLR connectors. So I had to create interface cables to go from XLR to Phoenix, cutting the newly acquired XLR cable snakes in the middle. A few hours later (which I spent in a cramped space at the back of the rack, equipped with my trusty cutters, strippers, utility knife, zip ties, headlight, and a bunch of patience and vigilance not to hit my balding cranium against the sharp corners of the projector base plate), I had taken care of this phase of work. Lacing up a rack cleanly and effectively is a matter of both art and science. You have to pre-think the best routing for all the runs, but you also have to consider noise interference, hum fields, ground loops, and much more. It takes a well-trained technician to do a good job. Even then it can require a few iterations to get right.
7.    Polarity Error. One of the surround speakers was connected out of polarity. The right side soundfield had both spatial and spectral errors as a result. It’s not unusual for a wiring error to creep into a system; this room, for example, had 15 speakers, and it’s understandable that a mistake can happen.  The solution is to painstakingly verify each speaker output with an acoustical polarity tester. Use the pulse test signals in the 5.1 Audio Toolkit test disc with a polarity checker like the Gold Line APT2. Remember to check the polarity of all the drivers in each speaker (one may have been wired wrong internally at the factory).
8.    Reference Level. Film soundtracks are designed to be heard at predetermined sound pressure levels. In cinemas, there is a reference detent setting for the volume control - often called “Fader 7” (position 7 out of a max of 10).  The same should apply to home theaters; the clients should have a way to set volume to reference if they want. In THX-certified decoders, this is known as 0dB reference. You can turn the level down or up from this baseline, and it is very cool to have the guidance of the target level. If you look at the on-screen or front panel volume display of one of these decoders, you will see values in dB +/- from reference. However, once the volume control is left up to a touchscreen, the user often sees a value that is not correlated to the reference scale. Feedback from an automation scheme (Crestron, Savant, Control4, etc.) should show the user the exact value on the reference scale - not some random number with a bar graph or % value. This is easy to say, but not always easy to do. Products don’t always report the volume control numbers in terms that correlate to the dB of attenuation or gain around reference level. Hmm. Food for thought for future iterations of products, firmware, and automation coding.
Despite the above issues, 15 hours of wiring, configuring, EQing, listening, and tuning finally yielded a sonic perspective that came close to ideal reference performance. I listened to my usual collection of music tracks and movie clips, and I tweaked a number of parameters until the sonic bubble came together. I also set up four presets in the digital EQ processor so that the user can listen to tracks in these modes:
a)    Reference – The Way the Director and Sound Designer Heard It in the Film Mix Stage
b)    Dialog Enhance – Level and Mid-frequency Boost in the Center Channel to Allow Dialog to Punch Through the Mix
c)    Enhance 1 - Added Bass and Surrounds to Sweeten the Track
d)    Enhance 2 - A Lot More Bass and Surrounds for When the User Really Wants to Have Fun
The four modes are recalled from a control pad on the Crestron touchscreen.

Thursday, September 22, 2016

A Techie's Dream Cinema - CEDIA 2016 Design Awards Winner

The life of an audiophile is driven by a relentless and unending pursuit of the idealized audio experience and the feeling of being transported to concert venues all over the world at the hit of the Play button. Sometimes this hobby also consumes the family living quarters and clutters them with large equipment, unsightly wiring, and seating arrangements that aren’t conducive to afternoon tea.
A living room in a luxurious Tuscan-style Southern California home was to be converted into a dedicated listening room and home cinema for an uncompromising audiophile client. It houses a concealed set of large Wisdom Audio LS4 speakers, matches the classical interiors of the residence, and serves as a soundproofed retreat. Exceptional picture quality with 4k UHD resolution and 2.35:1 projection screen, Dolby Atmos immersive audio playback, and fully integrated automation for access to the extensive collection of jazz, classical, and rock music, complement the stellar audio-video package.
Our client tried on his own to reach his dreams of audio excellence, swapping out several brands and models of speakers and amps, adding in tuning accessories, ultra-premium cabling, acoustical modules, changing rooms, and eventually throwing his hands up. When he reached out to our team, it was clear that he wanted it all: top-of-the-line audiophile sound; fully concealed loudspeakers that would give him back the beautiful ocean view from his living room window and the rustic Italian décor that permeates the whole residence; integrated and simple control; home theater functions with UHD video and Atmos immersive sound.
Our mission was to design and engineer an environment that could support and enhance the very sophisticated audiophile audio system, and instantly switch to movie studio-grade AV performance. The client wanted to spend a lot of time enjoying his passion for music and films, so the interior feel had to be comfortable and warm.
The project started with extensive engineering and planning six months before construction until all elements were carefully thought through. First off, the room itself was engineered for the right sound isolation and for interior acoustical sound reflection optimization. The room was closed off from the dining area with a resilient staggered stud sound isolation wall structure in the original archway. A front soffit system was built into the coffered ceiling in order to conceal the motorized screen and ductwork. We established the idealized speaker locations using computer modeling during the engineering phase and confirmed the locations of the front speakers and subwoofer with in-situ testing.
The theater was built as a remodel of this one wing of the home, and we had to do a lot of discovery and demolition to determine all the design and engineering parameters and specifications. Pre-wire from the equipment room to all the speakers had to include control of sound isolation leaks, vibration and rattles, and timing logistics. The project required some creative thinking from all in the team to figure out how to incorporate the drop down screen, conceal all the speakers, and apply acoustical tuning where there wasn’t stretched fabric. The front and back sections of the coffered ceiling were re-dimensioned so as to incorporate the screen mechanisms. A wideband absorber placed in front of the fireplace hearth is in fact dressed up as a fire screen. Artwork over the fireplace is in fact a LivingSound absorber module with custom artwork printing.
Aesthetic integration created the usual challenges for speaker placements, acoustical materials placements, etc. But the largest issue in this project was that the orientation of the room prevented easy integration of a Center speaker. The client wanted to be able to look out at the view at the front of the room between the Left and Right speakers, when listening to music. Also, the client picked a very large and effective speaker system, and concealing was tricky. We formulated the idea of recessing the L/R speakers in coves carved into the wall structures lateral to the large sliding glass doors. With proper baffling, acoustical damping of the cove surfaces, and carful tuning, we were able to achieve audiophile sound out of the pair of speakers, despite their location. Also, we were able to achieve a soundstage with a solid phantom center sound character and wide enough sweet spot, so as to forego the use of a Center speaker. We did prewire for a motorized unit in case it is decided to add it in per the plans.
The engineering team then specified a Dolby Atmos 6.4.2 speaker package, with large planar array LR speakers concealed behind stretched fabric coves flanking the acoustically transparent screen. The surround array consists of matched Side speakers along the lateral walls, two matching Back speakers, and four matching Top speakers to complete the immersive effect. Four highly efficient yet compact subwoofers were laid out in the Welti "four corner” configuration for smoothest response and maximum gain.
The display system features a 4K projector along with an acoustically transparent 2.35:1 screen. The projector was picked for appropriate light output and picture quality. The speaker package features a pair of large planar magnetic Wisdom Audio LS4 speakers, carefully integrated into acoustically damped coves and toed in for best imaging results. The speaker coves were essentially “carved out” of the false walls originally built out for the sliding section patio door system. We blocked out a portion of the slider travel limits, and appropriated the resulting space for the L/R speaker coves. A drop-down center speaker was planned into the design, and it was agreed that the client would first evaluate if he was happy enough with the phantom center character of the Wisdom LS4 speaker pair.
A Dimension4 Sonata acoustical tuning package was engineered, with the goal of achieving a target reflection decay time of 0.3 seconds across the audio spectrum - including appropriate 2D and 3D diffusion in the 500 Hz to  5 kHz region.
In this industry we often cater to clients that want nice audio and video, and understand the value of hiring a boutique operation. However, they don’t often have a reference of what is high performance sound or picture. So it is a thrill to work for real enthusiasts, and watch them be amazed at results that are so far beyond what they had ever expected.

The client now has a home cinema and audiophile listening room that rivals the best in the world and spends several hours a week enjoying it. He was so happy with the outcome, that he invited us to stay for an enjoyable evening of music listening paired with fine wines. Yum!

Tuesday, September 20, 2016

Dedicated High Performance -- CEDIA 2016 Design Awards Winner

In this industry, we regularly cater to “enthusiast” clients who are very enthralled with the idea of a fully engineered and commissioned private cinema. They may have played with speakers and receivers in their spare time. They may have preconceived notions about what makes speakers work or not work. They may even want to tell the crew how to go about doing the wiring and installation.
This client just built his Tuscan dream home in the rolling hills over Newport Beach, California. He wanted a great place to enjoy concert videos and movies from all around the world. He got that and a lot more in an acoustically treated and tuned room with appropriate sound isolation, Dolby Atmos immersive audio, 4K video, and a luxury-grade interior finish.
The room was to be laid out as a formal dedicated two-row theater, without many design frills, and with maximized return on investment for the equipment. The client decided not to adopt the customary stretched fabric dress in order to put more money into engineering, gear, and installation quality. In other words, budgets were very tightly controlled. There was no room for error in the engineering and commissioning.

Interior design was conspicuously absent. The client decided to focus all the available funds on engineering, equipment, and installation, so he did not budget in a stretched fabric wall decorative system. Since the room had an acoustical treatment package, we paid attention to laying out the absorbers and diffusers in a relatively even and consistent pattern, while preserving an optimal acoustical tuning balance. The walls, along with all the acoustical materials and speakers, are all flat black so as to disappear from view once the lights are dimmed.
Since the client is a techie, it was only appropriate to give him the latest technologies. The room had to have a very large 4K display and immersive audio for Dolby Atmos playback. First off, the room itself was engineered for the right sound isolation and for interior acoustical sound reflection optimization. The engineering team then specked in a Dolby Atmos 9.4.4 speaker package, with matched LCR speakers behind the huge acoustically transparent screen, Atmos Wide speakers brand-matched to the LCRs, dual Side speakers along the lateral walls, two matching Back speakers, and four matching Top speakers to complete the immersive effect. Four highly efficient yet compact subwoofers laid out in the Welti "four corner” configuration were selected to belt out the bottom octaves at the requisite peak sound pressure levels.
The picture end of the design was to present an image large enough to fully express what today's 4K Ultra HD video is meant to show, while not breaking the bank with a Digital Cinema-grade projection engine. Through careful matching of the screen gain, along with very dark colors in the room, we were able to achieve the maximum contrast ratio in that room - along with deepest blacks and satisfying peak white levels. The display system features a 4K projector along with an acoustically transparent 2.37:1 screen. The projector was picked for appropriate light output and picture quality. The screen was carefully evaluated for acoustical and optical performance so as not to lose any sonic or visual quality.
The speaker package features a matched set of Triad speakers. The Triad InWall Gold LCR speakers up front were baffle-mounted for better control of the bass response. The Wide channels in the Dolby Atmos format are handled by a pair of Triad InWall Silver LCR speakers, appropriately aimed back to the seating area for best coverage. The Side and Back channels are all handled by custom bipole Triad OnWall Bronze Surround speakers for best spatial integration and envelopment. The Top channels are handled by custom bipole Triad OnWall Silver Surround speakers for best coverage and immersion. The bottom octaves are handled by a set of four Triad InWall Bronze/6 subwoofers arrayed in the four corners of the ceiling for best balance between standing wave performance and room gain. They were resiliently mounted on rubber bushings in order to reduce sound transmission and rattles.
A Dimension4 acoustical tuning package was engineered with the goal of achieving a target reflection decay time of 0.3 seconds across the audio spectrum - including appropriate 2D and 3D diffusion in the 500 Hz to 5 kHz region. All the speakers were optimized through 15-band digital parametric equalization, carefully and lovingly tuned and voiced by a professional audio engineer - using a combination of impulse response measurements with spatial averaging, time varying windowing, and psychoacoustic smoothing.

In the end - after much patience and collaboration - it's a real thrill to witness the client's amazement at results that are so far beyond what they had ever experienced or expected. We spent several hours listening through every part of the Dolby Atmos demo disc, along with several of our favorite Blu-ray Disc demo sections. This project shows that - with careful engineering, equipment selection, optimized installation, and calibration - you can realize the full potential of the client's investment and produce a very exciting cinematic experience on a modest budget.

Friday, July 29, 2016

The Mysterious Case of the Turntable Hum

So there's this project down in SoCal; the client is a huge vinyl rock 'n roll and blues fan with what you'd call a multi-use media room. After the initial commissioning of his system, everything was groovy (pun intended) save for some serious hum and noise issues with the high-end turntable rig. Unfortunately, scheduling required us to knock off before we could track down all the issues. 
Over the next while, the installer's guys and some outside consultants gave it their best shot - to no avail. Eventually, I said, "Enough is enough; we've got to get this guy squared away."  

So, I loaded up my test gear, tossed in my trusty Technics SL1200 turntable with a basic preamp of my own, and headed south.
After a good bit of head banging (the bad kind) and hair-pulling, I replaced his turntable and phono pre with mine. Presto! Hum/noise gone. Taking systematic approach of slowly inserting the client’s gear into the scheme, I found a “perfect storm” of issues that caused the unacceptable levels of hum and buzz.
First off, a (much) closer look at his turntable revealed that the connector box that took the cartridge lead-in wires to the RCA connectors was powder-coated. Uh-oh. The ground lug, barrel connector for the lead-in, and the RCA connectors were all touching a powder coat finish instead of actual metal, and there was no ground contact anywhere. So there I was for an hour scraping off powder coat from the contact points with a tiny screwdriver. Good times! A reasonable person would expect that to fully fix all the issues, but no such luck. 
I then observed that the lead-in wire that looped up and out of the tone arm wasn't shielded and picked up RF interference. Also, we still had some oscillation and hum with his phono pre, but not mine. It was a vacuum tube device; lo and behold, one of the tubes was probably bad! We replaced the preamp with a fresh one from stock, thanks to some forward thinking on the part of the installer. Better, but still not perfect.
That's when I noticed the single-ended link between the phono preamp and the main pre-processor - a distance of about 25 feet - ran near lights and other EMI/RFI-spewing electronics. I don't want to point fingers, but that's kind of a no-no. Such a run needs to be balanced in order to reject the noise. Luckily, the wire used for the connection was actually a twisted pair with shield. So we upgraded the connection by inserting a Jensen transformer-based balanced converter after his phono pre and running the other end of the wires into a set of XLR balanced stereo inputs of the main system pre-processor.
There was still a tiny bit of noise audible when listening at a few inches from the tweeters, attributable to the non-shielded lead-in wire and noise floor of the tube-based phono preamp. The shield issue is simple enough to fix with a very flexible braided shield connected to the main ground lug. The quiescent phono stage noise floor is then probably low enough not ever be heard at the seating position.
The end result was a great improvement in the hum/noise problem - also some renewed lessons learned about verifying that gear actually comes from the factory working right!

Wednesday, November 18, 2015

Room Within a Room in Singapore

The second place CEDIA Awards winner this year is a room in a new luxury high-rise condo which was converted into a dedicated listening room and home cinema for an uncompromising audiophile client. The design brief included (1) housing the client’s five very large Meridian 25th anniversary edition DSP8000SE speakers, (2) matching the modern, slick and artsy interiors of the residence, and, (3) serving as a fully soundproofed retreat from Singapore’s hustle and bustle.

Our mission was to design and engineer an environment that could support and enhance a very sophisticated digital audiophile audio system, with full soundfield quality expectations, and instantly switch to movie studio-grade AV performance. The client wanted to spend a lot of time enjoying his passion for music and films, so the interior feel had to be comfortable and clean. This is probably the only room in the world with five of the large special edition Meridian speakers, and the resulting looks, sound and picture are all truly stunning. It is rare to be given the opportunity of creating a world-class dedicated room in a high-rise luxury building for a very exacting client. 

It all started with extensive engineering and planning a year before completion of the condo, with several planset iterations (eight to be exact) until all elements were carefully thought-through. A “room-within-a-room” structure with suspended ceiling, and resilient shock-mounted walls, along with floated floor was constructed by a builder team and supervised by our project managers. The interiors were precisely tailored to the speaker system and maximized the available dimensions of the room. The lighting was carefully selected for neutral colors and proper control of spill onto the screen. The list of minute elements goes on and on. Suffice it to say that every detail was considered in the design and implementation of this state-of-the-art room.

The combination of full sound isolation, low noise ventilation, clean power, ultra-high end audio gear, anamorphic projection, along with meticulous acoustics integrated into a slick décor, were all a challenge to assemble. The hallmark of CEDIA members is to deliver the level of service and planning that internet and box-mover stores can’t do, and this project is a stellar example of that exercise in a part of the world that isn’t yet used to investing in design and planning at such a high level. The client now has a Home Cinema that rivals the best in the world and spends several hours a week enjoying it.

When we heard that our client wanted to showcase his set of 5 gorgeous limited edition burgundy-colored anniversary edition Meridian 8000SE speakers in a dedicated theater in his new condo in Singapore, we knew that the first step was to ensure full-on sound isolation! Not a whisper could be heard in his daughter’s room next-door, or in his neighbors’ daughter’s room below. We brought in a world-renowned theater consultant and acoustician and designed a room with the right proportions, the right wall structures, the right acoustics and the right optics to support an ultra-high end experience.

The building’s wall-to wall window scheme had major flaws: All the supporting metalwork was connected from top to bottom. A light knock on the aluminum framing could be heard three stories up and down. And there were 1” gaps in the termination between the perimeter beams and the window frames, where sound leaked. This is obviously not a good thing at the extreme price per square foot of this high-rise, and much less for the development of a listening and screening room! Then we painted the window framing with visco-elastic damping compound, we sealed all the gaps were sealed with special gasketed brackets, and we installed a secondary window was planted 8” in front of the original window. After all this meticulous work, we verified that no sound leaves the room by running tests at 110 dB SPL inside the room, and verifying residual sound levels in all the adjacent spaces, using standardized ASTM methods.

The sound isolation envelope had to fit within the structural load limitations of the building. The room size is also a bit limited, so we needed to implement systems that didn’t reduce available space too much. We worked the building architect and structural engineering teams to establish the parameters and specifications. Extensive materials optimization eventually led us to the right design that wouldn’t cause a collapse of the residence! The floor system in a 2” deep Kinetics RIM scheme with mass-loaded layers for lowest resonance frequencies. The ceiling is a Kinetics ICC spring-based resilient scheme with multiple damped layers, and a 3Hz resonance frequency. The original concrete walls are amended with resiliently secured metal-stud framed walls in order to stop transmission of sound vibration through the vertical boundaries. The framed walls are finished with visco-elastic damped sheetrock, which offer higher impedance to bass sound waves, and therefore reduces bass standing wave resonances.

Most of the specialty materials had to be shipped over from the USA via boat and air, including a very special STC 55 sound-rated door. This door had to be sized and dressed so as to look like all the other ones in the hallway of this meticulously decorated condo. The homeowner is an art lover and collector, and he worked with a top interior design firm to select all the furnishings and finishes to complement his art collection. The client wanted leather seats, which we have found in the past to pose some problems with high-frequency reflections near the listeners’ ears. To avoid any issues, we micro-perforated the headrests to ensure proper sound absorption of reflected sounds!

The room proportions and materials were optimized for standing wave patterns with best distribution over the frequency range of 20 Hz to 150 Hz. A wall, floor and ceiling construction system was designed for an overall STC of 70 or better. The speaker and seating locations were optimized for best frequency response and soundstage. Two of the DSP8000 speakers were dedicated to the Back channels of 7.1 channel audio. A set of two on-wall Meridian Side speakers were added in, and a motorized Screen Excellence acoustically transparent screen was selected for its optimal picture and sound qualities. 

The DreamVision projector was concealed in a soffit at the back of the room that also served a ventilation plenum scheme. The picture shoots through an optically pure port glass so that noise and heat are all well controlled in the soffit. 

A full complement of MSR Dimension4 Sonata Symphony acoustical tuning modules including deep absorbers, tuned bass traps and solid wood deep 2D and 3D diffusers, bass traps, etc. were engineered into the room for the proper target reflection decay time of 0.28 sec, and concealed behind a deep stretched fabric wall decorative scheme. The fabric colors are all dark and neutral in the areas of the room close to the screen, so as to ensure best picture quality and contrast ratios. Brighter colors were used in other areas so that the room doesn’t feel to obscure for the client’s guests. The bright areas are also out of primary field of view during “screening” mode, so as to avoid any perceived color errors. All the lighting in the room is chosen for proximity to D65 color range. 

A set of tight-beam LEDS are over the seats to illuminate them with adjustable low level in case the client wants to preserve some visibility of drinks, remote controls, etc. A custom Eclipse acoustical diffusion drape controls the main speaker back-waves without over-damping the room, while ensuring total blackout from the bright tropical sun.

Speaking of tropics, an NC15 ventilation system able to cool down the room without adding any noise had to be engineered and retrofitted into very tight quarters. We installed an isolation transformer system for the power supply to the room so as to protect the sensitive digital electronics and ensure reliability.

The AV equipment is split into two racks. The Meridian gear that needs to be near the digital speakers and to the user is all mounted in a Sistrum-brand rack to the side of the seating area, while all the other components are neatly tucked away in a rack in the main equipment room of the residence. A Savant automation system integrates all the functions for ease of use. A Sooloos music server holds the client’s extensive music collection, and the occasional CD can be played through the local Meridian unit.

The ventilation system design and construction was a real chore, as it had to be squeezed into the limited soffit space between the top of the entry door and the concrete structure, and snake its way cleanly around the projector hush box and the room while ensuring the NC15 background noise specification required for this grade of audio performance, and cooling down the steamy Singapore ambient conditions.

Since the room is tightly sound-isolated from the residence an alarm annunciator was installed in the room, and was tied into the building fire and safety systems. From the photos submitted, the room does look small because of the combination of sound isolation and a deep stretched fabric dress. In fact the acoustical boundaries are 18” wider and 24” longer than the photos show. Also, the sheer size of the 5 Meridian DSP8000 speakers further tricks the eye when it comes to available space. However the actual audible character of the room appear much larger because of the space behind the fabric, and strategic use of high-quality sound scattering and diffusion modules on the walls and ceiling. Also, through the careful use of color work and lighting, the actual sense of space and comfort is again more ample than the photos would reveal.

We had to place the Back speakers further apart than ideal due to their size and space limitations. While a distance of about 4 feet would have been more ideal, the existing corner placement resulted in good overall soundfield results, once the bass build-up was equalized out of the speakers. Also, while we firmly believe in completely concealing all audio and video equipment in the room, the client wanted to showcase his beautiful red Meridan DSP8000 Special edition speakers. These are clearly a statement piece and we organized the décor, colors and lighting to properly show these amazing pieces of audio sculpture. 

The Meridian system includes an automated calibration system, but it was found not to perform adequately in this particular situation. There were several errors in bass response, and in the time-of arrival, based on the manual measurements and listening test. Bass management was set so that the five Meridian 8000 speakers handled the low frequencies in concert, to reduce standing wave effects. The room was then carefully measured using both impulse response and FFT analysis with spatial averaging. With the right setup you can override the set of biquad filters called up by the scheme, edit their frequency, gain and bandwidth, and painstakingly get to proper measured and results.

One annoying challenge is that spectral tailoring scheme only operates from 20Hz to 300Hz, and only in cut mode. That’s because Meridian conceived it as a device for only attenuating standing wave resonance peaks, based on an analysis of decay time of peaked signals. That was nice, but it ignores the fact that there are dozens of other elements in a room that affect the amplitude and time response of a speaker ( in my humble opinion). A strategic game of chess had to be played between the limited EQ range, the availability of bass and treble controls, and some degree of placement equalization of the speakers. Each iteration also took a “Save-and-Reboot” process of the decoder, making any cause-effect confirmation very tedious (are you laughing, or screaming yet?! Be patient Grasshopper; all good things take time, and who needs sleep anyway?) Extensive tests were used for fine-tuning of the room and speaker voicing.

Exceptional picture quality with 2.37:1 anamorphic projection, and fully integrated automation for access to the extensive collection of jazz, classical, and rock music complement the stellar audio package. The Dreamvision projector was carefully tuned to Rec709 standards, with gray scale at precisely 0.313. / 0.329 (D65). Video standards were SMPTE, ISF and CEDIA best practices. The gray scale was compared against a reference broadcast B&W monitor (Sony PVM96), and we made sure that our eyeballs actually liked the results by watching several known test patterns and movie clips. Black and white levels were carefully set for the balance of maximum dynamic range while avoiding clipping in either direction. Color settings were of course set to all the color bars standards (blue-filter method), and also by careful and extensive viewing tests. The resulting picture quality is stunning and makes the homeowner very happy to have invested in all the work.

The final touch was to perform a thorough and painstaking commissioning and calibration of the audio and video. No automated “push-the-button-and-pray” was allowed for this meticulous project. Multi-microphone analysis using FFT and Impulse response showed us what the room was doing to the speakers, and with override of the Meridian setup software we neutralized standing waves and boundary conditions. The stereo soundstage now extended at least two feet beyond the left and right speakers, and the multichannel music and film experience transcended the walls of the converted bedroom of this high-rise luxury private cinema!

Thursday, November 12, 2015

Modern Luxe Home Cinema in Nantucket

The first-place winner at the CEDIA Home Technology Professional Awards this year was a basement-level, ultra-high-end home cinema in a new house in Nantucket, Massachusetts. This project took two years of development as part of the overall construction of a gorgeous villa nestled among pine forest. The client is a detail-oriented audiophile and videophile who owns an aerospace engineering company, and demands nothing but the best. He had owned several systems before, and was familiar with the products and brands of our industry. He wanted absolute perfection in picture and sound reproduction, and after intently studying all the options, was willing to take the time it took for thorough engineering and project management; a rare privilege!

The interior architecture and design of the theater was to be “clean, slick, and modern”, and we completed the design work and lighting design in-house. After several months of deliberations and listening tests of various sound systems, we set to work on the design and development of the project, following an exact set of agreed-upon specifications and rules. Quite a rare process for this industry that really needs more of this type of exacting work flow. We learned a lot from the rigor of the aerospace world, and had great fun along the way!

The engineering, design, and integration effort for this project was outstanding, as was the meticulous wiring of the racks, and the programming of the fully automated house and cinema. Also, the fact that absolutely everything had to be brought in by ferry to this idyllic island location added challenge and complexities to this world-class project. We even commissioned a full electrical ground analysis since the soils in Nantucket are all sandy, causing us to fear high ground impedance. Proper grounding practices ensured low noise and low hum. And finally, state-of-the-art PMI 2.0 projection system with fully configurable aspect ratios and viewing angle selections, all property automated are still rare in this industry, but are essential for rooms with large screens.

The original architectural plans called for a flat floor for a two-row cinema. Of course that wouldn’t have worked for sightlines with a huge screen, so we re-configured the room entrance area, adding an elevated transition deck outside the room, to a re-positioned doorway in the middle of the back wall.

The room is fully sound-isolated and even at 115 dB you do not hear nothing anything anywhere else in the residence. We didn’t need to build heavy concrete walls/foundations to achieve these results – we developed innovative lighter weight materials and solutions expressly for this kind of application. The combination of properly engineered decoupled structures with resonance frequencies below 5Hz, along adequate visco-elastic damping ensure that the sound track sounds stay inside the theater.

An NC15 ventilation system able to condition the room without adding any noise was engineered and fitted into tight passages of the hallway and soffits. We installed a huge Torus isolation transformer system for the power supply to the room to protect the sensitive digital electronics and ensure reliability – this not only ensures very little variation in voltage but reduces noise, and lowers both signal and ground impedance to very low numbers.

The projector was located outside the room, hidden in a soffit above the entrance atrium, and it now shoots through an optical port glass in the back wall. The projector is suspended from vibration isolation springs and mass-loaded with a heavy metal plate, all tuned for a 3Hz resonance. We had to do all this just because the projector was set to be installed directly below the laundry room, and we needed to prevent any vibration effects of the washer spin cycles upon the floor ceiling structures – the last thing you need is your image vibrating during each spin cycle! Ventilation for the projector is timed to continue the cooling cycle well after the power-down command.

PMI engineered and designed a room with the right proportions, the right wall structures, the right internal sound reflection patterns, acoustics and the right optics to support the requisite ultra-high end experience. The room proportions and materials were optimized for standing wave patterns with best distribution over the frequency range of 20 Hz to 150 Hz. A wall and ceiling construction system was designed for an overall STC of 65 or better. The speaker and seating locations were optimized for best frequency response and soundstage.

A carefully engineered combination of Wisdom Audio front speakers, Triad bipole surround speakers, and ProAudio Technologies subwoofers produce clean and dynamic sound pressures. The audio package includes a Crestron Procise PSP-HD surround decoder, Ashly NE24.24 digital audio processor, and a full complement of LabGruppen studio-grade amplifiers.

The entire house is driven though Crestron for lighting, climate, security, and of course AV control. So it was only natural to also automate and outfit the cinema with Creston gear. All switching is conducted through substantial Crestron DM matrix units for flexibility of program sources.

A large Screen-Research woven acoustically-transparent screen was selected for its optimal picture and sound qualities, with PMI 2.0 4-way masking variable aspect ratio, and viewing angle adjustments. The Clearpix2 surface offers an acoustical transparency that is less than 1 dB attenuation across the entire range from 20 Hz to 10 kHz, and is barely 2 dB down at 16 kHz, so it behaves like a speaker grille cloth.

The video performance is also excellent, fully resolving the interpixel area of a DLP 1080x1920 projector, which corresponds to a resolution that is 10 times higher than what HD video requires. The Digital Projection Titan projector includes multiple lens zoom and focus pre-sets programmed for several aspect ratios including 2.35, 1.78, 1.33, in both high-definition and standard-definition viewing angles. All of this is automated through a Creston intelligent remote control system to help the client pick the best picture option for each movie with ease of use.

A full complement of MSR Dimension4 Sonata acoustical tuning modules including thick and deep absorbers, 2D and 3D diffusers, and bass traps, etc was engineered for the proper target reflection decay time of 0.3 seconds, and concealed behind a deep stretched fabric wall decorative scheme. We chose all dark and neutral fabric colors to ensure best picture quality and contrast ratios. The lighting in the room is chosen for proximity to D65 color range. A set of tight-beam LEDS are over the seats to illuminate them with adjustable low level in case the client wants to preserve some visibility of drinks, remote controls, etc.

The lighting scheme included the obligatory sconces and step lights, along with a set of tight-beam lights over the seating to illuminate them at low level without any spill onto the screen. The sconces were selected for both style fit and absence of rattles in conditions of loud bass sound pressure levels. Although this was designed as a dedicated 9.4 theater with multichannel sound, the 2-channel stereo performance of the aesthetically integrated speakers is absolutely stunning, and the four subwoofers crank up to 118 dB of clean bass with barely any variation from seat to seat. Imaging is deep and clear, and the sound stage clearly extends well beyond the Left and Right speakers.

Since the room is sound-isolated, an audible alarm annunciator was installed in case of emergencies. The automation system relays emergency conditions to the room as detected through the whole house Crestron system. The ventilation system is integrated through ducting, soffits, and plenums to keep the noise down to NC15. The supply is two long rattle-proofed vertical diffusers flanking the screen, and the return is a plenum silencer scheme built under the seating platform.

The final touch was to perform a thorough commissioning and calibration of the audio and video. No automated process could be allowed for this meticulous project! We implemented speaker control externally using the Ashly 8x16 digital audio processor. Settings in the surround decoder are all zeroed out; all delay and level settings are instead implemented in the Ashly EQ. This way, a change of decoder later is just an easy drop-in replacement, after enabling bass management. Any future replacement of the Ashly EQ would simply require a reload the configuration and settings program. We verified impedance and rub/buzz and distortion of the speakers. We initially found a few issues, and these were corrected after a factory replacement. The Ashly processing unit also ran the Wisdom Audio bi-amplified speaker crossovers and full room correction equalizations.

The final result is truly a marvel of premier picture and sound quality. The client’s comment after watching Flight of the Phoenix on opening night was “I loved it; I had to hold my breath through most of the movie!” Note that the client is a fully licensed IFR private jet airplane pilot, so the choice of movie was ironic!