Technology Showcase: In-ceiling Hi-fi Loudspeakers

Heightened expectations lead to higher quality overhead. 8/01/2007 8:00 AM Eastern

Technology Showcase: In-ceiling Hi-fi Loudspeakers

Aug 1, 2007 12:00 PM, By Bruce Borgerson

Heightened expectations lead to higher quality overhead.

QSC AD-C152ST and AD-C152T

Once upon a time — a few decades back — a studio monitor was a studio monitor and a ceiling loudspeaker was a ceiling loudspeaker. There was no way a competent audio professional possibly could confuse the two.

Today, however, if you stripped the guts out of a near-field monitor and a high-quality ceiling loudspeaker, and then piled the two side-by-side — look sharp! You might have difficulty telling which parts go over the mixing console and which go in the plenum.

It's a new ballgame overhead. Driven by heightened consumer expectations for quality foreground music, hi-fi has moved into ceilings with force. What started in upscale eateries has spread into hotels, retail stores, health clubs, shopping mall public areas, many professional offices, and even some fast-food outlets.

This accelerating trend has, in turn, fueled a whopping increase in the number of high-quality commercial loudspeakers on the market. There are so many, in fact, that this survey must impose restrictions to keep the subject matter under reasonable control. To be included here, a loudspeaker must be a true, two-way system — no whizzer cones allowed — with a frequency response (-3dB) extending below 100Hz and above 15kHz. Also, only models capable of 70V/100V operation out of the box (standard or factory option) in commercial installations are included; low-impedance ceiling speakers for the home market are not included.

Even with such restrictions, we're still looking at hundreds of loudspeakers. So, as a further limiting factor, only one premium model from each manufacturer will be profiled here.


In terms of both product availability and sales volume, the dominant hi-fi loudspeaker type would have to be the two-way coaxial with a high-compliance 5.25in. or 6.5in. woofer and a tweeter between 0.5in. and 1in. in diameter — usually a dome, although a few models have compression drivers. Most are supplied with a tuned back can and a front port to enhance low-frequency response. All have integrated transformers for both 70V and 100V operation, with at least three taps for each voltage plus 8Ω or 16Ω bypass, unless otherwise noted. Although they share the same basic design, differences in types and quality of materials (driver magnets, crossover components, etc.) will result in significant sonic variations. You should give a listen, if possible, before buying in bulk. Other criteria for evaluation include ceiling-mount systems, connector types, available transformer taps, and tweeter-aiming mechanisms, if any. Most systems will include a T-bar ceiling-mount kit in the package.

Leading off this big bunch is the Bogen HFCS1. The combination of a rubber-surround polypropylene woofer (6.5in.) and 0.75in. polycarbonate tweeter extends frequency response from 65Hz to 19kHz, with help from a 12in.-deep steel back can. Six power taps are provided (32W to 1W at 70V), plus a 16V input. Integral swing-out clamps speed installation, and plug-in connectors provide loop-through for the next loudspeaker. An alternate version, the HFCS1LP, has a low-profile 7.75in. back can, but bass response rolls off at 78Hz.

Because Canada is a major aluminum producer, it shouldn't be surprising that Ontario-based Enforcer Sound Products makes ample use of the metal. The G6 uses the material for the 0.75in. tweeter, the woofer basket, and the 6in. woofer cone. (The woofer surround, fortunately, remains rubber.) When pushed to maximum power, holes in the aluminum basket help dissipate heat from the voice coil.

Although it is better known for a full range of AV electronics, Extron Electronics also markets ceiling loudspeakers. In this category, we find the SI 26CT, which claims a frequency response from 70Hz to 20kHz. The 6.5in. long-throw woofer and tuned port enclosure (8in. deep) are coupled with a 1in. pivoting, ferro-fluid-cooled and titanium-coated dome tweeter. The 16V bypass mode features power protection limiting to prevent driver damage.

JBL fields a wide array of in-ceiling models, and here, we spotlight the relatively new Control 226C/T. The robust 6.5in. woofer is Kevlar-reinforced for extended LF response; the high-frequency driver is a true 1in.-exit, titanium-diaphragm compression driver; and the hefty crossover looks like it came out of, well, a JBL studio monitor. The overall result is an impressive 118dB peak SPL. This version is an all-in-one system with an integrated back can designed for blind-mount installations.

Over in the Klipsch corner, we have the IC-6T. The 6.5in. woofer has an injection-molded polymer cone, while the 1in. aluminum compression driver is mounted in a 90-degree Tractrix horn that can be swiveled up to 15 degrees. Maximum continuous output is rated at 106dB. The unit also features an integrated, zinc-plated steel back can and a rotary switch for tap selection behind the grille.

The All-N-One ICM6-730SET system from OWI uses a 6.5in. polypropylene-coated woofer along with a 1in. swiveling polyether imide (PEI) dome tweeter. Inputs are on a plug-in Phoenix connector, and Kwik Klamp mounting hardware speeds plenum installations.

The Posh Speaker Systems Solutions 6.0 incorporates a ported 6.5in. polypropylene-coated cone woofer (with butyl rubber surround) in a ported design along with a 0.75in. soft-dome swiveling tweeter. Taps are selectable between 3.75W and 30W at 70V and 7.5W and 30W at 100V.

QSC was obviously paying attention to the real world of contracting when it designed the AD-C152ST and AD-C152T systems. Both feature the same 5.25in. fiberglass cone woofer and 1in. titanium dome tweeter with a neodymium magnet structure. The difference is literally in the can. The AD-C152ST has a large-diameter (11.45in.) ported back can that's only 3.75in. deep, allowing mounting inside standard walls and very shallow ceilings. The companion AD-C152T has a deeper (9.25in.) sealed back can, but the front grille presents only a more discreet 8.5in. grille footprint.

Tannoy CMS401 DCe

The CMS401 DCe is a high-tech little marvel from Tannoy that almost opens up a category of its own. Tannoy calls it a “ceiling monitor,” and it does incorporate the same dual-concentric driver design as the company's studio products. (Unlike most coaxials, where the HF voice coil is in front of the LF voice coil, dual concentrics place the HF coil inside the LF coil to provide a true point source.) It's also unique in that the entire speaker “pod” pivots inside the ceiling mount — as with many light fixtures — to aim the sound as needed. Because it uses a 4in. LF driver (the only one in the group), the bass response rolls off just above 100Hz; however, the highs extend out to a claimed 50kHz.

TOA Electronics closes out this group with its F-2852C, another 6.5in. model with a ported bass-reflex design for extended bass response to 60Hz. A diffuser on the dome tweeter provides wide 120-degree dispersion. Other features include overload protection circuitry, 25V/70V/100V operation, a metal back can with safety cable, and a power tap selector on the front baffle.

Bose Freespace DS 100F


The following three manufacturers have eschewed the coaxial approach and placed the tweeters apart from the LF driver, rather than in the center of it. The reason for this is the inescapable fact that, apart from the rare dual-concentric approach, mounting the tweeter in front of the woofer causes some acoustical disruptions in the crossover region, however minor. The extent to which this is audible may be debatable, but in any case these three have chosen to give each driver its own space.

The Bose Freespace DS 100F follows the company tradition of doing things a bit differently. It has a typical 5.25in. low-mid driver, but instead of a dome or a compression driver, it has a 2.25in. Twiddler transducer for a smooth transition in the crossover range. Transformer taps, accessible on a front-mounted thumbwheel, range from 12.5W to a robust 100W at 70V. As with all Bose products, use of the company's dedicated processor (or a third-party unit programmed with the proper EQ curve) is recommended for best performance.

EAW also uses the term “ceiling monitor” for its CIS400, and with some justification. Here, the 1in. neodymium magnet soft-dome tweeter is mounted in a HF waveguide based on the HR824 studio monitors from sister company Mackie. The tweeter is paired with a 6.5in. carbon-fiber woofer, and both are enclosed in a zinc-coated steel back can. Connections are on a Euroblock connector, and two recessed front-panel switches access the 70V/100V taps and either a 16V bypass or 150Hz high-pass filter.

Martin Audio of England, also known for its arena-sized PA systems, now offers a full line of ceiling loudspeakers, as well. The C6.8T couples a 6.5in. carbon fiber and polypropylene woofer with a 0.8in. dome tweeter inside a steel back can. Dispersion is given as 150 degrees conical up to 7kHz, and claimed peak output is a healthy 106dB SPL at 3.3ft.

Architectural Acoustics by Peavey PHR 890


The loudspeakers in the following group all are based around coaxial design using 8in. LF drivers. Compared to the units above, they generally provide more power output and are designed for higher-ceiling applications.

The PHR 890 from Architectural Acoustics by Peavey employs an 8in. polypropylene woofer with a 1.2in. high-temperature voice coil and rubber surround to anchor low-mids. The high end is handled by a 0.75in. soft-dome tweeter. The molded polystyrene frame with locking installation arms mates to a formed-steel back can. Other installation aids include a conduit-capable wiring clamp and a wiring chamber with screw lock.

The FAP8CXT Strategy II system from Atlas Sound uses a polypropylene cone woofer in a tuned and ported enclosure for a low-frequency rolloff at 60Hz. The high-frequency section is a 1in.-exit true compression with a conical waveguide for a uniform 90-degree dispersion pattern. A front-mounted switch selects from four 70V/100V taps (7.5W to 60W) or 8V bypass.

Lowell has leveraged its strong position as a premier back can and accessory maker by offering its own ceiling loudspeaker series. In this category, Lowell offers the 8A50. Rated at 50W, the coaxial system incorporates an 8in. LF driver and 0.5in. HF driver with an integrated waveguide for a 110-degree dispersion pattern. The loudspeaker system is designed to mount inside the company's 0.8-cubic-foot back box for extended low-frequency performance.

Atlas Sound FAP8CXT Strategy II

For increased SPL and frequency response, SoundTube Entertainment is now offering its CMd series. The line includes the CM800d, the CM801d, and the CM890d. Features of the CMd models include dedicated high-SPL drivers, a 1in. compression horn (CM890d), a five-position tap switch for 120W applications with an 8-Ohm bypass, and a powder-coated steel grille for indoor/outdoor use. Other features include a rapid-installation blind-mount fixed-wing mounting system; a magnetic grille attachment available in white, black, or custom colors; and BroadBeam and BroadBeamHP high-frequency dispersion technology, which delivers a consistent dispersion across the frequency spectrum. Tile bridge, paint mask/installation guide and support cable are included.

The SP-CT8/T from Speco Technologies is modest in its power claims, but it does sport a different look. The 8in. coaxial loudspeaker (with 0.75in. Mylar dome tweeter) is fully integrated into a 2'×2' “ceiling tile” enclosure. The unit slides into the plenum space and drops onto the supplied support rail crossbar. Rear-panel switches select either 25V or 70V operation, with five power taps (1.25W to 20W) and an 8Ω bypass option provided.


Now we move into serious high-power territory for the loftiest of ceilings — in big hotel ballrooms, airports, convention centers, and the like. Here, the packaging rules change a bit, because some (here, the Electro-Voice) are supplied with back cans, bridge, and mounting ring; others (as with the Altec Lansing and Community) are sold separately for use with standard ceiling enclosures from the same company or third-party suppliers.

The Altec Lansing CD1012-60T is one of the largest loudspeakers in the survey, yet it shares fundamental technology with the smallest listed above: the Tannoy “eyeball” speaker. Both are point-source transducers with concentric voice coils, an approach Altec has trademarked as Duplex design. The voice coil for the 12in. cone woofer is nestled around the 1.4in.-exit compression driver, which is in turn coupled to a large flare 90-degree conical horn. To maintain the lowest possible profile, the crossover network is mounted doughnut-style around the back of the magnet structure.

The Cloud 12-99 from Community teams the 12in. cast-frame low driver with a 1in.-exit compression driver and a 90-degree horn. Mounting is on an integral baffle, tuned and ported for use in standard 3-cubic-foot back boxes. Additional features include adjustable HF attenuation, protection circuitry, and matching dual transformers for 70V/100V operation.

If you'd prefer the whole deal, installed as most systems above, Electro-Voice follows suit with the EVID C12.2 system. As with most of the smaller units, the HF driver is a dome type (1.5in.) rather than a compression driver, yet the output is a healthy 126dB peak SPL at 3.3ft., with frequency response from 85Hz to 18kHz. Input and loop-through is on a 4-pin Phoenix connector.

Electro-Voice EVID C12.2


The remaining ceiling loudspeakers defy easy categorization, either because they use different technologies or novel design approaches. Yet, because they mount in the ceiling and qualify as hi-fi, they merit inclusion here.

Armstrong is a company that certainly knows its way around ceilings, and when it came to do loudspeakers it decided it didn't like the idea of cutting any holes. So Armstrong has licensed flatpanel loudspeaker technology from NXT, and has come up with a line of ceiling tile speakers that blend in nicely with the rest of the silent product line. The Applause series A-50 is typical, with broad dispersion, a creditable 50Hz to 16kHz response (though stated as +/-6dB), and a maximum SPL of 98dB at 3.3ft. Here, you have your choice of pattern, grid face, and edge profile.

Pro Acoustics recognizes that, in some cases, it's better to have all sound originating from one point on the ceiling, and the novel SD4 Pro Omni series does the job in fairly large spaces. Sized to fit in a standard 2'×2' ceiling tile space, the system comprises four 6.5in. high-compliance aluminum woofers, each with a coaxially mounted dome tweeter. The fire-retardant ABS housing is tuned and ported for enhanced bass response. Even with four coaxes on board, the entire unit weighs in at a manageable 25lbs.

SLS Loudspeakers specializes in a full range of loudspeaker systems — for home, professional, and commercial use — incorporating ribbon high-frequency drivers. In the PRD8COM, a 3in. ribbon transducer is mounted coaxially with an 8in. Kevlar cone woofer. The coverage pattern is 120 degrees across the ribbon slot and 90 degrees in line with it. Two back can options are available: low-profile 0.5 cubic foot or 1 cubic foot for extended bass response. A baffle-front rotary switch selects transformer taps or 8Ω bypass.

Sound Advance takes a similar approach with its ST2432D speaker tile. Also designed as a flat-profile replacement for a 2'×2' tile, this unit incorporates a two-way patented Planar Diaphragm Technology transducer with dual voice coils crossed over at 1.2kHz. The stated frequency response is a noteworthy 40Hz to 19kHz (+/-4dB), with a near-hemispherical radiating pattern of 140 degrees for covering very broad, low-ceiling areas. Not to be outdone by the ceiling specialists, Sound Advance offers the front face of the unit in five ceiling textures that are strikingly similar to the real deal from “company A.”

There, that's the bottom of the crate. But, with hi-fi options abounding, there's no excuse for any ceiling not to at least make a stab at sounding like Abbey Road's Studio A.

For More Information

Altec Lansing

Architectural Acoustics by Peavey


Atlas Sound






Enforcer Sound Products

Extron Electronics




Martin Audio


Posh Speaker Systems

Pro Acoustics

QSC Audio

SLS Loudspeakers

Sound Advance

SoundTube Entertainment

Speco Technologies


TOA Electronics

Bruce Borgerson operates Wavelength Communications out of an office/studio (in Ashland, Ore.) where the monitors are not now, nor ever have been, mounted in the ceiling.

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