At the 2014 CEDIA, I went to at least a half dozen Dolby Atmos demonstrations organized by companies like Yamaha, Denon, Lyngdorf, Pioneer and even one by Dolby Labs itself. My involvement with Dolby Atmos is not new. By the time this article is in your hands, I will have 53 Dolby Atmos commercial theatres under my design belt.
The problem with Atmos for home is that by using direct radiating speakers above the listener, in too many cases, the atmospheric layer (i.e. the second speaker layer), sounds too jarring and gimmicky – at least based on my findings during the aforementioned trade event.
The only way thus far to eliminate the in-your-face effect is by using Atmos-enabled speakers angled by approximately 30 degrees combined with special crossover within the speakers, and Digital Signal Processing in the processor to shoot the Atmos atmospheric sound to the ceiling and reflect it back to the listeners’ ears. However, this method also washes out the directional sound cues.
To borrow the As Seen On TV’s phrase: “There must be a better way.” And there is: you just need to find in-ceiling speakers with an exceptionally wide radiation pattern, with tweeters that can be angled towards the listeners.
After a lot of reading, testing, and measuring, I found the speakers that, at least on paper, can meet this criteria: the Monitor Audio CT-265IDC has a wide dispersion angle, a boundary compensation switch so the lower frequency sounds clear and not bloated, and can easily go down to 80 Hz as per THX criteria.
With the guidance of Kevro International, Monitor Audio’s Canadian distributor, I combined this with the company’s Silver Series speakers.
For this review, then, I had a pair of Monitor Audio Silver 6 floorstanders, a Silver Centre, a pair of Silver 1 bookshelfs, and Silver W12 subwoofer to do the duties of the ear-level surround, plus four CT-265IDC in-ceiling speakers for the Atmos layer. Ideally, one should go with the Silver 10 floorstanders as they will produce improved bass response and wider sound dispersion for a better overall sonic experience. However, considering the small size of my viewing room (10’ x 16’ x 7.5’), the Silver 6 was more than enough to create an ideal sonic balance without any bloat and/or excessive unwanted reflections. Remember, bigger is only better if the room acoustics allow it.
In terms of aesthetics, I chose gloss black to make the speakers “disappear” into the darkness when all the lights are turned off – they also come in walnut, rosenut or white.
The Silver Series Speakers
Monitor Audio has long used a material they call C-CAM—a thin, light, and rigid alloy of aluminum and magnesium with a layer of ceramic coating for added rigidity. The C-CAM cones in the Silvers are dimpled to further strengthen the cone and minimize air resistance during playback, a technique the company calls RST, or Rigid Surface Technology. The Silvers’ tweeter domes are also made of C-CAM in glossy gold finish. The speaker grilles are held in place by magnets hidden beneath the veneer. It’s very classy indeed, with or without the grille. But again, because I didn’t want to be distracted by the look of the speakers in my home theatre, I kept the grilles on at all times.
Further, in a technique now used in most Monitor speakers, threaded rods are fastened to the back of the Silvers’ drivers and extend through the rear of the cabinet, where they are tightened down by visible bolts with hexagonal slot (Allen Key included with each speaker). Each individual rod holds the drivers securely to the cabinet, providing a clean appearance without the need for visible screws, and perhaps most importantly, drastically increase the cabinet’s front-to-back rigidity.
Foam plugs (or as Monitor Audio calls it: Port Bungs) are provided for blocking the ports. According to the manual, “If the loudspeaker is to be installed in a small room, typically 80 square feet, or a room known to reproduce accentuated bass response, it may be desirable to fit port bungs.” In my case, where the Silver 6 are corner mounted, I filled the bass reflex port with the provided foam to prevent bass overhang (boominess). Regardless, I always prefer an enclosed cabinet as opposed to bass reflex as the latter tends to have the side effect of bass bloat (boominess). In fact, Monitor Audio even includes an explanation of bass boom in the manual. “Bass ‘Boom’ (sometimes termed as overhang,)” it reads, “is generally caused when bass energy from the loudspeaker ‘excites’ room modes and causes an accentuation at a particular frequency, or number of frequencies. When fitting port bungs, the overall bass extension will not be reduced, however bass energy/output around the port tuning frequency will be reduced. This has the effect of reducing bass ‘boom’ while increasing bass clarity and apparent agility.” (Their manual is not the most consumer friendly and sometimes one will ponder “is that even in English? ” – Especially since this is a British brand) In other words, plugging in the foam plugs will not affect the fundamental frequencies of the bass response and only reduce the harmonics in order to prevent the bass from sounding like car stereos of the 1990s.
The In-Ceiling CT-265IDC
The CT-265IDC in-ceiling speakers use various award-winning features from Monitor Audio, including a 6.5-inch C-CAM bass driver and a pivoting IDC module housing a 4-inch C-CAM RST inverted midrange driver and a 1-inch C-CAM gold coloured dome tweeter.
These in-ceiling speakers employ a unique pivoting Inverted Dual Concentric midrange/tweeter module offering up to 18 degrees of play, (The IDC module can be tilted by +/- 18 degrees) which allows for the speakers to have a wide dispersion angle. They can also be positioned so the localized sound within the Dolby Atmos soundtrack can be directed toward the listening zone by pivoting the IDC driver module.
Within the proprietary IDC module, an inverted 4″ midrange driver provides superior dispersion while enabling the midrange cone and tweeter dome assembly to be set as far forward as possible, allowing a clear acoustic “line-of-sight” of the desired listening zone and reducing undesirable diffraction effects.
With the IDC module installed, these speakers become true 3-way designs, offering superior performance and flexibility over typical 2-way or fixed angle speakers; something that is needed for Dolby Atmos installation. To obtain the proper angle is easy is you are using the Atmos Enabled speakers. However, as the new THX standards require direct-radiating speakers, the ability to position the ceiling speakers’ angles properly becomes very crucial.
There are two very important switches to customize these speakers even further. One controls the high frequency (+3dB /0dB / -3dB) level adjustment – which is necessary if your room acoustics is either too “dead” or too “live.” And, most important, there’s boundary compensation (on/off) controls to eliminate, or at least minimize boundary gain effects (read: boomy bass).
To control unwanted reflections of midrange and high frequencies is actually very easy. Slap some sound absorbers and you’re done. For the lower frequencies, however, it’s a very different story. Any room almost inevitably plays havoc, no matter how good the speaker is an anechoic measurement.
Below 100 Hz, the speaker’s sound is being reflected around the room and the direct sound arrives to your ear in one big lump with the room effects. The phenomenon of a boom somewhere below 100Hz and a large dip between 100Hz and 200Hz is far too common. To fix the room effects (also known as Room Modes), Monitor Audio employs Automatic Position Correction (APC) to the W-12 subwoofer providing a degree of automated DSP room equalization.
The subwoofer’s 12-inch cone is also made of C-CAM. It’s driven by a 500-watt (continuous) Class D amplifier. Despite the W-12’s small size – barely larger than the driver itself – it offers everything you would expect in a full-featured powered sub including 12V trigger, phase control, et cetera. The level control is positioned on top, along with the control buttons and microphone connector for the W-12’s Automatic Position Correction (APC) feature. I prefer the volume control to be at the back to make the subwoofer appears “cleaner.” It also has three operating modes: Music, Movies, and Impact. From my Real Time Analyzer, I found that Music is the most neutral of the three whereas Movies tend to add some bass harmonics and Impact uses some kind of boost in select frequencies.
After running all speakers using white-noise for 100 hours non-stop, I started my listening test. I used a Pioneer Elite SC-85 AV receiver (reviewed in the January 2015 issue), my oldie-but-goodie Pioneer Elite BDP-09 Blu-ray player, a Panasonic PT-AE7000U projector, and Stewart Filmscreen StudioTek 130 screen. Content was played from the Dolby Atmos 2015 demonstration disc, supplied by Dolby Labs, which I can only assume to be the best representation of Atmos.
Choosing the sound-only tracks, which goes back and forth between Dolby TrueHD and Dolby Atmos, the sound quality difference is immense, to say the least. The sound of rain changed from only surrounding me to a truly immersive experience. Thanks to Monitor Audio in-ceiling speakers, I did not feel as if the sound came from the speakers at all – the imaging was amazing and the speakers disappeared. However, when the thunder struck, I could clearly locate the source of the thunder, but still, not the speaker itself.
The same goes when I played the track filled with percussions and insects buzzing around. I could not spot the in-ceiling speakers, or any speaker for that matter. This can only mean one thing: all of the speakers (and especially the CT-265IDC) are amazing in terms of dispersion angle, yet they all sound very controlled at the same time. On the other hand, imaging is still very close to perfection. I still can locate every single sound queue within the spherical sound envelope, even though some of the sounds didn’t come directly from the speakers. Most interesting, when I played the sound-only track called “Abduction,” all I had to do was to close my eyes, listen to the soundtrack, and I felt like I’d been “abducted” by the aliens.
From the demo disc, I moved to Shania Twain’s “Still The One – Live in Vegas” concert which is recorded natively in 5.1. This is done not only to showcase how great the Dolby Surround Upmixer capability is in creating faux-Atmos, but serves as a torture test of dispersion angle. I’ve played the disc a couple of times using Atmos-enabled speakers and the result was impressive, albeit a given considering the nature of reflected sound. So how do these in-ceiling speakers fare? Quite well. In fact, in too many cases, I forgot I was using the in-ceiling speakers instead of the Atmos-enabled speakers. Yes, the dispersion angle is that wide.
The speakers were impressive overall, and much better than I had expected. It turns out that the 18-degree angling capability makes a whole lot of difference for an Atmos experience. The Silver series and especially the CT-265IDC truly create an amazing enveloping sound. Thus far, this set of speakers with proper calibration performed the closest to a true Dolby Atmos commercial theatre than any others I’ve tried out, and they do that without breaking the bank.