Monitor Platinum In-Wall II Speakers Set Category Benchmark

The new Monitor Platinum In-Wall II loudspeaker utilizes proprietary drivers, along with a proprietary crossover network, and a three-way design to produce impecable sound quality.


Through many years of creative engineering and having the wherewithal to listen to its dealer base, Monitor Audio has grown from its roots as a traditional in-room, stereo speaker manufacturer, to a diverse audio company that offers everything from entry-level in-wall speakers to flagship floorstanding speakers.

Filling a void in the architectural market that few companies venture into, the respected British manufacturer has recently introduced a flagship in-wall product that it says rivals the performance of its premium in-room products.

Available through its American distributor Kevro, the newly announced PL In-Wall II loudspeakers has been developed by Monitor to provide homeowners with a premium, no-compromise in-wall loudspeaker that dealers can use as a room-friendly solution to complement dedicated stereo and home theater installations.

Features & Installation

Summarizing the speakers, Monitor utilized a considerable amount of its R&D team's resources to engineer this sealed box speaker that features a sturdy MDF enclosure augmented by a steel back and MDF cross bracing.

Internally the PL In-Wall II employs proprietary Monitor drivers. Reproducing low frequencies are a pair of RDT II 6.5-inch woofers, while a single 4-inch RDT II midrange driver handles the midrange. Rounding out the speaker’s driver array is a Monitor Micro Pleated Diaphragm (MPD) high-frequency transducer.

The speaker also incorporates a rotating midrange/high-frequency housing to help dealers align the speaker’s dispersion for vertical and horizontal installations. The speaker also incorporates three position (+1/0/-1) midrange and high-frequency adjustment switches.

In addition, the speaker employs Monitor’s latest crossover design, which includes metalized polypropylene capacitors and low-loss inductors.

The PL In-Wall II shipped in two large boxes. The well-thought out packaging allowed me to quickly unpack the speakers without much fuss. Unpacking the speakers in the CE Pro office required me to drive the speakers home via my little Volvo, but the speakers did fit in my car with little issue.

Carrying the speakers into my house did require some muscle however. They are big and heavy, and it did necessitate effort on my part not to whack the speakers while carrying them through my doorways.

Under most circumstances it would be impossible to review in-wall speakers in my traditional stereo system, but in this case I was able to because of the speakers’ sealed enclosure design and the speakers’ packaging that allowed me to stand the speakers up like traditional floorstanding units.

Photos: Monitor Audio's Platinum In-Wall II Speaker

Setting the speakers up next to my Monitor PL-100 monitors I had a pretty good idea on how the speakers should sound approximately nine feet from my listening position, but first I needed to connect my Straight Wire bi-amp/bi-wire cables to the speakers’ binding posts.

Using these speakers in tandem with a Bryston 9B-ST five-channel amplifier with four of its five channel in use as a stereo bi-amped configuration I found I that I was unable to connect the Straight Wire’s banana plugs. Cutting a pair of generic Monster 16/2 cables, stripping them and connecting them to Straight Wire banana plugs and the speakers’ binding posts served as a temporary solution.

Knowing this isn’t ideal, it allowed me to utilize my bi-amped Bryston amp and companion Bryston preamp without having to completely swap cables.The reason why I point this out is less to do with the measure I went to connect these speakers, but the lack of space and ability of the speakers to accept cabling termination easily.

I would guess that dealers selling thousands of dollars worth of speakers may have preferred cables they would like to use, but in the case of the Platinum In-Wall, those preferred cables may not work. For the sake of brevity, I’ll add that I set the speakers up in two positions: toed-in like traditional floorstanding speakers, and parallel to each other to mimic the installation of the products within a wall cavity.

Performance & Final Thoughts

Before I start any formal listening of a speaker I always like to sneak in a “first listen.” Popping in a Tommy Emmanuel CD in this case, I was immediately impressed with how big the speakers’ soundstage was and how airy the lively Emmanuel steel-string acoustic guitar playing resonated within that soundstage.

Digging into the speakers with about 20 hours of playback on them I listened to a handful of CDs from Lisa Loeb, Dave Matthews and Extreme. It was almost depressing to hear how much better these speakers sounded than my first-generation Monitor Platinum PL-100 speakers.

The PL In-Wall IIs were producing a deeper image, more detail and tighter mid-bass than my speakers, which I feel are a great sounding speaker too. Later with approximately 50 hours on the speakers I feel they are just about there in terms of break-in. Measuring the speaker’s frequency response with them toed in I was able to get the speakers to play down to 31.5Hz. Realistically the speaker's extension sits at 40Hz before noticeable roll off.

Getting into some other content from my network, which is a mix of AAC, Apple Lossless and AIFF files, I thought the speakers reproduced the clever mix of Lenny Kravitz’s “Believe” quite well. This song features vocal lines within the verses that are heavily compressed, as the song shifts to the pre-chorus, the vocals double with the mix panning these doubled vocals to the edges of the left and right channels.

Once the chorus hits the vocals are spread throughout the soundstage. The speakers were able to provide pinpoint imaging on this track, and all of its cool little tricks beyond the vocals that include the warble of tremolo and phasey modulation on the various guitar parts. The speakers also proved to be very kind to low-resolution content such as iTunes downloads. I loved how smooth and punchy my Train downloads sounded through the speakers.

After 60 hours I felt the speakers were broken in, and with them broken in I threw some vinyl at them via my restored Thorens TD-160 turntable and Cary Audio phono preamp. On LPs, like the Cars' first record, I thought the juxtaposition of Ric Ocasek’s smooth vocals and the heaviness/grittiness of Elliot Easton’s guitars provided a nice gamut of texture that was well communicated by the PL In-Walls. The speakers’ dynamics also conveyed the “drive” of the drums and bass line on the classics like “Bye Bye Love.”

Aligning the speakers parallel to each to mimic an in-wall installation revealed a few things to me: The speaker’s frequency response was smoother and a little more extended than when I had them in a toed-in alignment, which makes perfect sense. Also, the speaker’s soundstage is so wide that it provides some placement forgiveness to support placement flexibility.  

Having said all that, my takeaway is that the speakers are well engineered to produce a very involving listening experience from an in-wall mounting position. I found the speaker to deliver Monitor’s design goal, which is to offer a speaker that matches the sonic capabilities of its in-room products. Moreover, in doing so, Monitor has created a speaker that arguably sets new performance standards in the architectural speaker category.

Kevro will display Monitor Audio in booth #5142 during CEDIA 2016.


  • Sealed enclosure utilizes 25mm MDF, a steel back plate and thick MDF cross bracing.
  • Driver array features a pair of 6.5-inch RDT II woofers, a 4-inch RDT IImidrange driver, and a MPD high-frequency transducer specially built for the speaker .
  • Midrange and high-frequency adjustment switches.
  • A crossover network that features polypropylene capacitors and low-loss inductors.
  • Three-way design is 90dB sensitive, with a 4-ohm impedance, and it delivers a frequency response of 52Hz to 100kHz.

CE Pro Verdict



  • Impeccable build quality.
  • Sound quality meets audiophile criteria for imaging, soundstage, dynamics.
  • Versatility supports home theater and hidden two-channel, stereo applications.


  • Between the physical size and cost of the speakers, the Platinum In-Wall won’t be right for every system.
  • The size and weight of the speakers may require two people to install the speaker in order to maintain safety and to prevent any type of on-site accidents.
  • Binding posts are tough to access and preclude the use of commensurate cabling products.

About the Author

Robert Archer
Robert Archer:

Bob is an audio enthusiast who has written about consumer electronics for various publications within Massachusetts before joining the staff of CE Pro in 2000. Bob is THX Level I certified, and he's also taken classes from the Imaging Science Foundation (ISF) and Home Acoustics Alliance (HAA). Bob has also served as the technology editor for CE Pro's sister publication Commercial Integrator. In his personal time beyond his family, he's studied guitar and music theory at Sarrin Music Studios in Wakefield, Mass., and he also studies Kyokushin karate at 5 Dragons and Brazilian jiu-jitsu at Binda Brazilian Jiu Jitsu.


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