NextLevel Acoustics Reference Cinema In-Wall Speaker and CI-HV18 Subwoofer Review

When you need premium sound with no footprint, NextLevel Acoustics delivers its Reference Cinema In-Wall Speaker. With two eight-inch carbon cone woofers, a 4 x 4 compression horn tweeter and a heavy cabinet-style backbox, it can fill your theater or media room with super clean audio that plays at high volumes. Paired with the CI-HV18 18-inch Subwoofer, it’s easy to create a sound that rivals or exceeds a commercial cinema with speakers that are heard and not seen.

As much as I enjoy large cabinet speakers in my home theater, there is a part of me that wishes I could hide the speakers behind the screen the way commercial cinemas do. But I don’t have room behind my theater’s screen wall because there’s a room on the other side. I could, in my fantasy world, install in-wall speakers. But would I give up the quality of premium cabinet speakers? Not if I installed something like NextLevel Acoustics’ Reference Cinema In-Wall Speakers. These units are high-end all the way from their heavy back boxes to their carbon cone woofers and super-efficient compression horn tweeters.

NextLevel Acoustics is well known for its custom install products. I reviewed one of their passive soundbars and compact subs in 2018 and found them to be extremely well made with a premium sound that belied their convenient form factor. Usually, one must sacrifice some sound quality to go with a discrete solution like a soundbar or in-wall speaker. But NextLevel Acoustics says, “we can do better.” And they succeeded.

The Reference Cinema In-Wall Speakers have a wide frequency range (50 Hz-20 kHz) and mount flush to the wall. They can be installed behind an acoustically transparent projection screen or covered with magnetically attached fabric grills. To fill out the lowest frequencies, NextLevel sent me their 18-inch CI-HV18 Subwoofer with a 2,000-watt amp installed. On paper, this looks like a killer system for a custom-built theater. Let’s take a look.

The Reference Cinema In-Wall Speakers felt like premium parts the moment I unpacked them. Weighing 23 pounds each, I was struck by the heavy backboxes and thick front baffle. These aren’t open-driver in-walls with a backbox tacked on by any means. They are a sealed cabinet speaker that happens to go in the wall. To that end, they include wood retaining brackets with a metal flange surround in front to create a flush mount. They install in a standard six-inch wall with a 5.75-inch minimum depth required. The cutout is specified at 12 by 24.5 inches.

The drivers are arranged woofer-tweeter-woofer so you can run them vertically or horizontally if you wish. They are an ideal size and configuration to mount behind an acoustically transparent projection screen as an LCR array. My samples did not include grilles, but NextLevel can provide custom fabric colors to match any furniture, wall color, or décor. The grilles attach magnetically.

The woofer/midrange drivers are eight inches across, and feature cones made from carbon wool composite. They are extremely stiff and light which gives them a wide frequency range and quick response. Surrounds are made from butyl rubber.

The tweeters are the star here. They are 4 x 4-inch compression horns which give the speakers a high 96db (1w/1m) sensitivity. The large horn diameter, coupled with the woofers’ generous surface area means these speakers image like crazy. I was immediately surprised at how large the sound stage was when I set them up.

The Reference Cinema In-Wall Speakers are a sealed design which means no ports. In installer parlance, they have permanent backboxes installed but this is a bit misleading. Backboxes usually mean an optional part that often comes as a molded plastic shell. NextLevel Acoustics has created a traditional cabinet speaker here that just happens to have mounting hardware attached to it. You could feasibly attach them to stands and use them as traditional speakers.

The front baffle is ¾” MDF and the cabinet is also made from MDF. The surrounding frame that finishes the flush-mounting system is made from metal which is glued and screwed firmly in place. There are no parts to vibrate or buzz. The retainers are also made from solid wood and will keep the speakers firmly in place once installed. In back, there are a pair of gold-plated spring-loaded wire connectors. They are designed for bare wire, but I was able to fit banana plugs into them.

The CI-HV18 Subwoofer comes in passive or active versions. My sample was the latter with a 700-watt (2,000w peak) plate amp installed. The cabinet is a bandpass design which is something more commonly seen in the custom install world. The driver is fully enclosed in the cabinet, pointing downwards. At the bottom are two ports, tuned to pass frequencies between 17 and 120 Hz. The advantage of this configuration is that only the ports need to be exposed. Since they’re near the floor, you can hide the sub behind furniture or a decorative screen if you wish.

The US-made plate amplifier is rated for 700 watts continuous and 2,000 watts peak. It has the usual gain and crossover dials plus a low-frequency boost and delay from 0 to 20 milliseconds. LFE inputs are both RCA stereo and XLR and there’s an XLR loop output. The CI-HV18 can be set to automatically turn on when a signal is detected.

I wasn’t planning to cut holes in my walls, so I set up the three In-Wall Speakers by leaning them against the front wall of my theater. To isolate them, I used two-inch-thick mineral wool acoustic tiles. Their weight is toward the back, so I was able to set them almost vertically. To simulate the in-wall experience, I pointed them straight back, not toed in. Since NextLevel sent me three units, I put them in an LCR configuration in the same positions as my cabinet speakers.

The CI-HV18 sub was placed along the left side wall. My room is forgiving enough that I can put a sub just about anywhere and it will sound good. This position integrated it seamlessly. Everything was connected to an Anthem AVM-70 surround processor and Emotiva XPA amplifiers. With my Axiom QS8 surround speakers in the mix, I had a 5.1 setup, ideal for both music and movies.

Using a few test tracks from Blu-rays and my music library, I experimented with different crossover points starting at 60 Hz. The speakers are rated to 50 Hz, so this seemed logical. The movie sound was fine with a seamless transition and solid dialog rendering, but music seemed a bit too thin. Changing it to 80 Hz was the ticket. This took some load off the speakers and let the CI-HV18 sub flex its muscle. Despite an 18-inch driver, it is super precise throughout its range, most notably above 40 Hz. I couldn’t help but notice how acoustically inert the MDF back boxes were. Even at ear-splitting volumes, they barely vibrated when I put my hand on them.

I started with the best possible uncompressed soundtracks from three of my favorite home theater demos. No Time To Die, the latest Bond chapter, is filled with classic gunplay, explosions, fists striking flesh, cars crashing, the things we all love about these films. I was immediately drawn to the detail coming from the horn tweeters. They reminded me of fine ribbon units but with much wider dispersion. There was nowhere I could go in the room where they did not deliver amazing precision and clarity.

The dialog was delivered with a real sense of intimacy. Not only was it crystal clear, but it was also perfectly balanced and separated from the background. Whispers sounded like they were right in my ear. Male voices had just the right level of bass with no hint of chestiness.

In Transformers: Revenge of the Fallen, the opening sequence features a narrator with a very deep voice. This is one time when chestiness is appropriate, and the NextLevel Speakers delivered. His voice literally filled the room, even as other sound effects vied for attention. In the next scene where a mammoth Decepticon attacks a Chinese city, I could clearly hear the different robots’ voices. It’s usually hard to understand what they’re saying but those superb tweeters delivered every nuance.

The CI-HV18 sub shone here as well. Its presentation is very precise, much more so than typical ported cabinets. I’m spoiled by my Axiom EP-800 which is a large volume sealed sub with twin 12-inch drivers. The CI-HV18 is the only ported sub I’ve heard that is as precise as the Axiom. That it plays cleanly and loudly down to 17 Hz is pretty awesome too.

I finished my movie watching with U-571, the depth charge scene of course. I wound up watching most of the film after that because the sound was so compelling. This is an older Blu-ray release with just OK sound quality, but the NextLevel speakers and sub really mined all the detail in this movie. As the charges exploded, they sent huge geysers of water and spray that almost had me reaching for a towel.

I wanted to test the Reference Cinema In-Walls and HV18 sub with some more compressed fare, so I fired up Dolby Atmos encodes from Netflix’s Formula One: Drive to Survive. This is a dialog-driven show, and the familiar accents of the drivers and team principals were rendered beautifully. Screaming race cars moved across the screen and across the super-wide sound stage. Have I mentioned how incredibly well these speakers image?

To check out a more mundane stereo encode, I turned to Food Network’s The Julia Child Challenge. It’s stereo originally but I processed it using Anthem Logic Cinema to expand it to all channels. Voices were clean and clear with no signs of compression. Ambient sound effects were balanced and detailed without calling attention to themselves.

To get the HV18 sub rockin’, I turned to Five Finger Death Punch and their 2018 album And Justice For None. Modern metal has plenty of low drums, tuned-down guitar, and heavy bass. It was all on full display here. Ivan Moody’s vocals stood out from the mix without being too forward. Zoltan Bathory’s guitar solos screamed with his signature shredding style.

I turned the way-back machine to 1978 for a listen to Styx’s Pieces of Eight. This is a fairly compressed recording not only in volume but in frequency. It concentrates its energy on the higher guitar partials, wailing synthesizers, and Dennis DeYoung’s high vocals. Despite this, the sound filled the room. The tweeters get credit once again for their phenomenal dispersion and precise detail rendering.

When listening to classical music, I found the NextLevel speakers worked best with chamber music. They really separated the instruments and were extremely revealing. Jennifer Higdon’s Dark Wood calls for a unique combination of bassoon, violin, cello, and piano. Bassoonist Eric Stomberg’s sound had a nice richness with just a bit of edge. The string instruments floated above the mix while the piano kept everything grounded.

I listened to quite a bit of full orchestra performances, but my favorite was Murray Perahia’s Beethoven Piano Concerto No. 5 ‘Emperor’. The string section had a strident feel, but the piano’s percussive detail kept it to the fore. Woodwinds were solid in their supporting roles.

Through all my listening and watching time, I noted the terrific foundation provided by the CI-HV18 subwoofer. Its precision and cleanliness coupled with copious volume capability helped expand the sense of space in every direction. It’s amazing how well it worked when all I could see were the two ports near the floor. The CI-HV18 is truly a standout subwoofer.

The NEXTLEVEL ACOUSTICS REFERENCE CINEMA IN-WALL SPEAKERS AND HV18 SUBWOOFER produce better sound than any commercial cinema I’ve been to for less money than high-end cabinet speakers.

There is nothing negative I can say about the NextLevel Acoustics Reference Cinema In-Wall Speakers and CI-HV18 Subwoofer. The in-walls perform better than most cabinet speakers I’ve heard, and the sub delivers the extension and volume of a ported cabinet with the precision of a sealed one. NextLevel Acoustics has bent the laws of physics here, most definitely in a good way.

If you want a discrete speaker system that sounds better than any commercial cinema, the In-Walls can literally disappear behind an acoustically transparent screen or behind color-matched grills. They are a zero-footprint solution. The CI-HV18 sub is easy to hide too thanks to its bandpass design. Put it up front behind a partition or along a side wall and prepare to have your room shaken.

The NextLevel Acoustics Reference Cinema In-Wall Speakers and HV18 Subwoofer are a premium and convenient audio solution that doesn’t compromise sound quality in any way, shape, or form. They receive my highest recommendation.