The trend for invisible technology is clearly at play in JBL’s Conceal Range. Liam Power checks out the C83 Model and finds that the sound speaks for itself.

Looking for a speaker you can hide away in a wall or ceiling? The JBL Conceal C83s might be just what you’re looking for.

Living up to their name, the JBL Conceals are intended for invisible flush mounting in a wall or ceiling. They are rated for indoor or light outdoor use (as long as they are protected from the elements). The JBL Conceal C83 houses three elements attached to an acoustically conductive front baffle. Mounted against the rigid front panel are an 8” driver, 1.2” mid-range transducer and 1” high-frequency transducer.

The driver and transducers work in sync to deliver frequencies through the acoustically coupled front panel. This panel is made from JBL’s FidelityGlass, which reportedly enhances transfer between the speaker elements and the front panel. The driver uses acoustic lever technology to deliver sound energy through the compression-moulded front baffle. The C83’s have an impedance of 4Ω so driving them will depend on the amplifier you are using.

My review speakers came in a demo kit emulating wall installation, with a wooden box and clear back panel allowing full inspection of the drivers inside as well as a cutaway showing how the drivers would be covered by insulating material at the back.

The speakers have a power input of 50-160W RMS per panel and a rated frequency response of 45hz-20kHz. A tuned passive crossover network splits the incoming full-range signal into low, mid and high frequencies for delivery to the woofer and transducers.

Build and Aesthetics

The JBL Conceals are a product made to, unsurprisingly, be concealed behind a wall or ceiling. Therefore, their aesthetic qualities tend toward the utilitarian.

The front panel measures 403x559mm with a depth of 98mm. Their target audience would possibly be a home-theatre enthusiast, integrator or commercial client who was building or modifying a structure and wanted to integrate their speaker enclosures into their walls seamlessly.

By far the most impressive design qualities of the C83s lies in their transducer and woofer architecture. Ruggedness and longevity are of vital importance in an architectural application where a speaker failure or burnt-out component could lead to the expensive renovation of an existing wall or ceiling. With this in mind, the inclusion of a five-year warranty by JBL is a nice touch.

Installation and setup

When installing the C83s into a wall, the speakers work a little like a drywall patch: use drywall tape and compound to embed them into the wall cavity. An optional wooden jig can be used to mark out their location, then the speakers would be installed in a hole in your drywall or mudded in during the building of a purpose-built A/V space.

After installation the front surface can then be primed and painted over, making the speakers invisible to the naked eye. It must be noted that I did not install the speakers into the wall of my rental for testing, instead using an enclosure provided with my review units for testing. This came with speaker lead extensions mounted on the left of the case.

In an installation context, the gold-plated speaker connections are in the top middle, to the left of the crossover network. Plug in your speaker wires or banana jacks and you’re good to go.

Sound

The JBLs go loud and sound solid. The effect of the mid-range and high-frequency transducers in concert with the powerful woofer leads to an interesting acoustic phenomenon where the sound seems to emanate from the entire speaker panel instead of from the separate woofer and transducer elements.

Throughout the opening tracks of the Fleshtones’ Roman Gods (1981) the midrange vocals and fuzz guitar came through clearly during verses, with the snare punching into the low-mid-range. The Conceal C83s had a very unified sound, somewhat similar to high-end PA speakers in their tuning.

The C83s really came into their own when playing bass-heavy and live material. Drums are front and centre with these speakers, with kicks throbbing forward in the mix along with the meat of the snare drum. Adjustable low and high cuts would be useful for tuning the sound to your taste but would probably get little use once the speakers were installed into your wall.

Bush Tetras’ Too Many Creeps (1980) sounded especially weighty through the C83s, courtesy of a balanced mix, with the midrange-heavy guitars coming through front and centre.

Overall, the speakers have a pronounced bass-heavy sound, with my Rotel RA-10 driving them with more than enough power to hear their full range. The mid and high ranges are smooth and detailed, with no pronounced resonances. The C83 is in the middle of the Conceal line, with the flagship C86 breaking out the woofer and transducers for more separation of high/mid and low frequencies if that’s your preference.

The C83s give a unified sound throughout the entire panel, with low, mid and high frequencies seeming to appear equally from the front of the speaker. Sometimes during listening, it seems as if the various frequencies of the signal are competing for dominance, with the bass sounding more up-front with some material.

Note that in your architectural application the density and thickness of the building material in which the speakers are installed will have a large impact on their sound. Also, the frequency response of the speakers in a room would be largely dependent on their positioning, the furnishings and acoustic treatment within the space as well as the resonances of any material that they were embedded in.

As the speakers would most likely be placed within a wall, special care would need to be taken by the user to avoid standing waves and harsh reflections that could occur from the reflected sound being bounced directly back into the speakers.

However, as the market for these speakers is quite likely home theatre enthusiasts with an understanding of acoustics and with likely some acoustic treatment already installed in their space, this does not work to the C83’s detriment.

Stereo imaging is surprisingly wide, with the C83’s placed around 2m apart in my test environment there was a distinct separation between channels free from excessive smearing.

The Conceals seem tuned toward bass-heavy electronic or rock music, providing a large amount of bass extension for an 8” woofer. This is perhaps due to the increased surface area of the speaker via its acoustic transference with the front baffle. If even more bass is required, JBL stocks a subwoofer version in the same line named the C82W.

I conducted frequency response testing of the C83s with Room EQ Wizard. My test rig is a Sonarworks XREF20 calibrated measurement mic running into a Scarlett 6i6 audio interface. I ran sine-sweeps and pink noise through each speaker at a range of distances to analyse their frequency response.

In testing, the C83s showed a preference toward the lower frequencies, with a gentle ~3db peak between 70-150hz. The mid and high ranges were fairly flat with a small peak around the midrange at 1.5kHz, though this could be the resonance of the box enclosure provided with my review units and not the speakers themselves. These small peaks could explain the heft of the kick and the crack of the snare drum I heard in my reference tracks as these sounds usually reside in these ranges.

I was surprised by the lack of resonance in the rig, confirming that JBL has engineered the front baffle to reduce interference and crossover peaks.

Overall, the JBLs stood up well in testing despite a difficult design brief – to make a concealable, architectural speaker that sounds like a discrete one.

Conclusion

Whether you’re building a new space or modifying an existing one, the JBL Conceal C83s will provide a sturdy and high-quality solution for pumping sound through your walls or ceiling. A combination of weighty low end and clear, detailed highs make the C83s a solid choice for an architectural speaker free from interference and internal resonances.