MEDIA ROOM INSIDER: APARTMENT THEATER
This Tel Aviv penthouse apartment fits a no-compromise 7.4.4 Dolby Atmos system into a cozy 10 x 18-foot space
AN ISRAELI A/V enthusiast faced a quandary not uncommon among home theater builders: Is the space I’ve set aside big enough for a no-compromise audio solution? The question loomed large as he pondered the entertainment options for a new luxury penthouse he was planning to buy in the heart of Tel Aviv. Making the situation even more challenging, the space had to be acoustically isolated.
His concerns were understandable, considering the highend home theater he built in his previous home was more than three times the size of what would be possible in his new digs. A die-hard lover of movies and music, he wasn’t about to settle for a run-of-the-mill setup, especially since blueprints would need to be modified to accommodate an entertainment space—and a modestly sized one at that. He wanted something special. So much so, he held off on buying the condo until he could confirm it was possible to achieve the level of audio performance he demanded.
The client (first name: Yair) reached out to Dan Nagar, owner of the high-end audio/video and home automation company Cinemart in the nearby coastal resort city Netanya. He was quite familiar with Nagar’s work, having hired him to handle a number of A/V projects over the years, including the spacious theater he enjoyed in his previous home.
The home theater Yair envisioned would be the linchpin of an elaborate whole-house audio system with more than 30 speakers. “He wanted a “no compromise, full surround solution,” Nagar recalls, but was worried that he wouldn’t be able to achieve a true cinema experience in the limited space he had to work with. “I remember his call asking me if it’s possible to have a decent cinema experience in a comparatively small room. I told him that with the right system, yes, it was possible.”
“Dan knows audio is a big part of my life and how important having a cinema room is to me,” Yair observes. “He calmed me down and said, with the right gear and careful planning, we can make it work. I trusted him based on the other projects he did for me so I decided to pull the trigger and we bought the apartment.”
Nagar proposed a Dolby Atmos surroundsound system comprising a full suite of speakers and amplification provided by Netherlandsbased manufacturer Alcons Audio with processing from France’s Stormaudio. But Yair was still a bit leery because he had never heard of either brand, so Nagar arranged for an audition. A full surround setup wasn’t available so he demonstrated a pair of the Alcons CRMSC-SRHV speakers with two CRMS-LFE18 subwoofers— both models he planned to use in Yair’s new home theater.
The demo did the trick. Yair left the session feeling confident and enthusiastic about Nagar’s
plan, especially the Alcons speakers he was proposing.
The Plan
“We wanted to ensure every seat received the same 3D audio quality, with no gaps between seats,” Nagar explains, noting that achieving a smooth, low-frequency response at every seat in a small room isn’t easy. “We wanted headroom and as much lowfrequency extension as possible, but we also wanted the sound to be accurate and consistent throughout the room.”
Nagar settled on a 7.4.4 Dolby Atmos speaker layout for the 10 x 18-foot space. There would be three speakers across the front, two side-surround speakers, two rear surrounds, four height speakers, and four subwoofers. “There was no point in adding more top speakers because ceiling space was limited,” Nagar advises. “They wouldn’t provide a better experience.”
There were other challenges to achieving Yair’s uncompromising desire for sonic realism.
In a small room, proximity to speakers can shatter the illusion that you’re in the middle of the action. “The sound has less tendency to develop into a coherent diffused sound field,” Nagar explains. He had to really pay attention to room acoustics— especially absorption and room modes, which can “obscure bass response and affect our perception of higher frequencies.”
Making matters worse, room modes if left untreated can lead to the dreaded situation where bass is weak and thin for one listener and loud and boomy for another. “You can’t fix that with roomcorrection software,” Nagar says. “You have to start with multiple subwoofers and passive acoustic treatment before you apply digital correction to achieve perfection.”
Nagar’s plan called for four subwoofers—two in the front of the room and two in the back—to “achieve smooth and even amplitude response throughout the seating area. We actually brought the subwoofers in during the concrete stage of construction because we had to decide on their exact positions.” There was no room for error— once the locations were set, they couldn’t be changed. “Every element had to be calculated and tested before the installation, both in simulation software and, finally, in the field.” The whole process coupled with the small size of the room required a lot more planning than usual.
Serious Soundproofing
Keeping the peace with his new neighbors— especially the one directly below him—was one of Yair’s key concerns. And beyond wanting to isolate the theater from the building, he also wanted sound from the space to be isolated from the rest of the apartment. Nagar brought in Omer Karni of Omer K. Acoustic Design, a Tel Aviv-based firm with expertise in treating recording studios, to devise and implement an acoustical treatment plan that would include a heavy dose of soundproofing.
The acoustician made it clear from the get-go that the only way to achieve the level of containment Yair wanted was to “create a floating room—a room within a room, fully detached from the original space and the rest of the apartment.” The first step in Karni’s elaborate soundproofing plan was to construct a floating floor in a shallow recess, or “pool,” in what would be the floor of the theater.
Karni’s team started by spreading acoustic matting on the floor and shallow walls of the recess. The next step was to cover the damping material with plastic and fill the “pool” with 3 inches of concrete. The acoustic matting would prevent physical contact between the structural foundation of the apartment and the new concrete floor. “This floating floor was designed to attenuate the spread of vibrations caused by shocks and impacts of the speaker system and its four massive subwoofers,” Karni says. “We definitely do not want the downstairs neighbor knocking on Yair’s door.”
During this early stage of construction, two windows had to be sealed to create a space that would be dark and sonically isolated. Once the windows were closed up, Karni’s team built the walls of the theater on the floating floor and, for the ceiling, created a grid structure that attached to the original room with special acoustic springs to provide damping. The walls were a double-stud construction with acoustic springs in between, two layers of mineral wool, and two layers of drywall. “This system is very effective, not only for isolation, but to reduce bass buildup caused by room modes,” Karni advises. Or as Nagar put it, “It creates a resilient structure that acts like a resonant bass-trap system.” An acoustic door was installed as the final touch to the soundproofing.
Acoustic Ambitions
The overarching goal of Karni’s acoustical treatment plan was to facilitate huge, evenly dispersed sound throughout the room. In addition to building multi-layered walls and filling them with insulation, Karni’s team constructed an elaborate (and very heavy) wood baffle wall in the front of the theater to house the three front speakers and two front subwoofers, which are situated above the main speakers and separated from the baffle with sheets of rubber. The 19 or so inches of space behind the baffle was filled with high-density acoustic foam, and 0.7-inch-thick birch panels were installed around the speaker openings with a final layer of acoustic foam to prevent any comb filtering effects from the screen that would be placed in front of the speakers.
The theater’s back wall comprises what Nagar calls a custom designed “equipment cupboard” with space for an A/V rack, two subwoofers, the two surround speakers, vents with silencers for the dedicated AC system, and the video projector. Like the front baffle wall, the cupboad was filled with acoustic foam. “This acoustic treatment resulted in evenly dispersed bass with a 0.2 second reverberation time under 500Hz,” Karni says, which translates into “very tight and detailed bass.”
The next step involved strategically affixing a number of large Quadratic Residue Diffusers (QRDS) on the side walls and ceiling to disperse reflected sound. “The mathematical sequence of the diffuser creates diffraction of the
mid frequencies to make the room, psychoacoustically, sound bigger than it actually is,” Karni explains. “In this case, our small room felt huge!” Some of the panels were covered with acoustically transparent fabric in burgundy or muted pink to complement the plush red Moovia theater seating; others were left exposed to achieve the classic-meets-modern design Yair was going for.
Final touches to the theater include a beautiful hardwood floor with a strategically placed throw rug in the front of the room and a stretched black-fabric ceiling, designed and installed by France’s Barrisol. To ensure the ultimate in comfort, the theater seats are motorized and equipped with two gold-plated cupholders.
The System
Knowing Yair wanted quick, easy access to high-quality 4K content featuring high dynamic range (HDR) and immersive Dolby Atmos sound, Nagar started with what he considered to be the “best AV solution possible:” the Pro 4K HDR media player from Paris-based Zappiti. The player was reviewed as part of a complete Zappiti system that received a Sound & Vision Top Pick in 2019.
The Zappiti feeds Sony’s award winning VPL-VW760ES 4K laser projector, selected for its HDR compatibility and “superb video processing.” The projector sits in a hush box built into theater’s custom back wall and projects majestic images onto a 106-inch (diagonal) screen from Norway’s Dreamscreen. The acoustically transparent screen was chosen because it “provides the lowest attenuation available on the market, even at very high frequencies,” Nagar insists.
A Stormaudio ISP preamp/processor sits just below the Zappiti media player at the top of the audio chain. Chosen for its wide dynamic range, excellent room-correction software, and Dirac Live bass management, which Nagar considers to be the best, the processor feeds AES3 digital signals at 96khz to all channels and provides immersive surround decoding for the Dolby Atmos, DTS:X Pro, and Auro-3d formats, and also has IMAX Enhanced support.
The ISP hands the signal off to five Alcons amplified loudspeaker controllers running at 4 ohms. Four Sentinel3 amps, rated to deliver 4 x 750 watts, drive three front speakers and eight surrounds, while one 4 x 2,500-watt Sentinel10 powers the system’s four subwoofers. The amps were mounted in a rollable rack, hidden behind a magnetically latched door in a custom alcove on the right side of the rear wall. The door concealing the rack is soundproofed to prevent fan noise from entering the theater space. We wanted the room to be dead quiet,”
Nagar explains. To prevent heat buildup in the small cavity, Nagar’s crew also installed a damped pipe that vents heat outside of the theater.
“Alcons Audio delivers a complete ‘eco system’ with speakers, amplification, and dedicated speaker processing,” Nagar says, explaining his decision to go Alcons all the way. “The Sentinel gives you an active solution with a built-in DSP for each speaker. The filters linearize the response and avoid any anomalies the passive crossover presents while protecting the speakers to ensure maximum reliability.”
Leading the suite of 15 Alcons speakers are the three Crmscompact monitors used for the front left, center, and right channels. Each is a biamped, three-way speaker that comes in two pieces: a bass module housing a 12-inch woofer and a mid/high section that mates a 6.5-inch midrange with one of the patented proribbon drivers Alcons is known for.
From there, eight compact CRMSC-SRHV speakers create the cohesive surround bubble that make this theater so special: two on the sidewalls, two on the back walls, and four firing down from the ceiling at a precise angle. Each speaker mates a 6.5-inch woofer with the same pro-ribbon driver used in the front LCRS to ensure a seamless blend between the mains and surrounds.
The surrounds were mounted higher than “text book” position and aimed toward the seating area to achieve a greater distance to the listener, Nagar explains, adding that knowing the SRHV’S exact dispersion pattern and having the ability to rotate the ribbon drivers’ waveguides was key to achieving surround-sound success.
“The Alcons pro-ribbon high-frequency drivers are amazingly fast, which translates into remarkable transient response,” Nagar observes. “Combine this with almost nonexistent distortion and you get a solution guaranteed to trigger emotions and create the you-are-there experience everyone is after.
The dispersion pattern is also unique and evenly spread. The constant directivity up to the highest frequencies guarantees a wide and even sound field that can be easily controlled with room-correction software to achieve an in-room target response.”
Four enormous CRMS-LFE18 reference subwoofers complete the speaker lineup. Two are built into the bottom of the front baffle wall and two into the custom wall at the rear of the theater—all concealed behind acoustically transparent fabric. Ready to deliver thunderous bass below 10Hz (in-room response), each LFE18 houses a beefy 18-inch woofer in a spacious 29 x 34 x 18-inch cabinet.
“Alcons speakers provide tremendous 1:15 Rms-to-peak dynamic range, which is a key for any cinema,” Nagar advises. “And they do so without sounding harsh, thanks to the proprietary pro-ribbon drivers, which always operate in their ‘comfort zone’— even at crazy high SPL levels.”
Tiny But Mighty
When all was said and done, everyone involved with the project was thrilled with Yair’s tiny but mighty apartment home theater installation. Says Karni: “We’ve been building recording studios and home theaters for the past 10 years and I can definitely say the Alcons
CRMS system and the Storm Audio immersive AV processor in this room deliver, by far, the best theater experience I’ve ever heard!”
Nagar chimes in: “People get excited when magic happens and audio sounds like the real thing. It makes them smile, be excited in the moment, and forget everything else. For us, this is the most important thing.”
Yair now knows with certainty that it is, indeed, possible to achieve uncompromised surround sound in a small home theater space. “The sound is so crisp, detailed, and coherent,” he offers eagerly. “When you play an Atmos soundtrack, the experience becomes so vivid and precise you can pinpoint the location of every sound. It’s a heavenly experience.”