Floor-standing Speakers

B&W CM8 Tower Speakers

ARTICLE INDEX

Introduction

Bowers and Wilkins (B&W) recently made the bold move to sell their products through Magnolia and Best Buy. Adding big box retailers in addition to specialty retailers is quite a step from a brand surround by "audiophile" credentials. Few speakers have as much universal respect as B&W speakers. With this move to a wider distribution network (a welcome move in my book, it's becoming increasingly difficult to find good dealers, even in Los Angeles where I live) I wanted to listen to the new baby tower in the CM range. The CM8 is just the right size for many of us urban dwellers living in smaller spaces. Small towers promise the imaging of a good stand mount with better bass extension and a smaller foot print compared to a sub and monitor combo.

Specifications

  • Design: 3 -way, Ported, Tower Enclosure
  • Drivers: One 1" Aluminum Dome Tweeter, One 5" Kevlar FST Midrange, Two 5" Paper/Kevlar Woofers
  • MFR: 69 Hz - 22 kHz ± 3 dB
  • Nominal Impedance: 8 Ohms
  • Crossover Frequencies: 350 Hz, 4 kHz
  • Recommended Amplifier Power: 30W - 150W
  • Dimensions: 37.8" H x 6.5" W x 10.9" D
  • Weight: 43l Pounds/each
  • Finish Options: Wenge, Rosenut, Gloss Black
  • MSRP: $1099.99/each
  • Bowers & Wilkins

Design

Bowers and Wilkins has taken the configuration of the CM9 and scaled things down a tad. The recipe is the same. Nautilus tube loaded 1" aluminum tweeter as in the CM9 but with a smaller FST driver and dual 5" paper/Kevlar bass units rather than the 6" FST and 6.5" bass units for the larger and more expensive CM9. The overall profile and space occupied is markedly smaller in the CM8. Even with the plinth attached the CM8s took up less space than my stand mount speakers and sub combo. The speakers are sleek, attractive and exude a level of visual sophistication seldom seen in speakers at this price. Details such as the metal trim rings, contrast in textures and colors of the drivers, and the deep gloss black finish contribute to a perceived value much higher than the price would suggest.

B&W specifies the CM8 as having a 1st order cross over for the tweeter. The FST midrange driver uses a 2nd order high-pass in conjunction with a 1st order low-pass design. The dual bass units use a 3rd-order low pass filter.

A single port at the rear is placed above dual sets of binding posts. Both spikes and rubber feet are provided. Both can be attached to the plinth or for a sleeker look (though not as stable) you can attach the spikes/feet directly to the speaker cabinet.


Setup

Initial set up of the CM8s proved to be fairly simple. Using the factory terminal jumpers I wired up the CM8s using Kimber 8VS speaker cables to my Myryad MI-120 integrated amp. Signals to this combo were provided by an Audiolab 8200CDQ functioning primarily as a DAC.

The CM8's benefited from toe-in and maintained a consistent tonal balance regardless of toe-in. Toe-in just helped to tighten up imaging. The speakers were not overly sensitive to being placed close to rear walls. Lower mid bass energy was most affected by close proximity to the rear walls. I felt the included dual mode port bungs (fully closed, or a donut to lessen the diameter of the port) contributed little to my particular listening conditions. Fully closing the ports lessened bass extension with no other improvements to the sound. Using the hollow portion of the bung had no significant difference to bass response in my room. I chose to do all my listening with the bungs removed. Having hard wood floors I chose to use the adjustable rubber feet.

Once I found a sweet spot for the placement of the speakers, I set about adjusting the feet to level the speakers. Bowers and Wilkins provided the CM8s already broken in and I heard no changes to the speakers performance over time.

The two stars of the this show are the FST mid-range and the Nautilus loaded aluminum tweeter. Much has been written about Bowers and Wilkins revolutionary FST drivers.

To summarize, the role of a mid-range driver doesn't require substantial travel. The surround of a driver presents several problems. The mechanical movement of the cone is in fact a sum of two parts. The cone and the surround. The energy applied to the cone via the voice coil also generates sound through the surround. For various reasons the surround in fact colors the sound the cone produces. Human hearing is most sensitive to mid-range frequencies. Even minute reductions to distortion in this critical region can yield significant improvements. Removing the surround increases linearity and reduces distortion. Interestingly an infinitely rigid material would not work in an FST configuration. Which is where B&Ws expertise with Kevlar plays a role. A Fixed Surround Transducer requires the cone material to have some flexibility. The inherent self damping properties of Kevlar are the ideal material for an FST driver.

The next leading player is the 1" aluminum dome tweeter. Housed in a Nautilus tube, the tapered housing helps to cancel standing waves behind the dome. Essentially focusing the back wave down the tapered tube causes the energy to dissipate and also cancel itself out. The more energy that can be removed from the back wave of driver the purer and more accurate the reproduction. Drivers are semi-transparent (acoustically) and standing waves inside a cabinet are both transmitted through the cabinet and also out through the cone. Removing as much energy within the cabinet is critical. The Nautilus tube accomplishes this very well.

The combination of the FST mid-range and 1" aluminum Nautilus tweeter make wonderful music. This tweeter is one of the finest aluminum units I've heard. Strikingly fast, detailed, and lacking in distortion. The CM8's tonal balance tips upwards significantly. They're bright speakers. With any other tweeter this could prove a problem. A coarse tweeter would yield a speaker that is harsh or grating. The CM8s tweeter is so smooth, so refined, instead of being harsh or aggressive, the CM8 is gloriously detailed with an abundance of air and separation. Cymbals are embodied with clarity and all the metallic detail that soft dome tweeters usually gloss over. Harmonics extended smoothly into the highest reaches of the frequency domain with absolute clarity and purity of tone.

Combined with the stunning resolution and ease of the FST I've seldom heard a speaker at anywhere near this price posses such engaging resolution and imaging without sounding forced. The FST delves so deep into the mid-range it digs up gobs of detail never previously heard by me on extremely familiar recordings. Female vocals in particular ooze in clarity and intimacy. The subtlest nuance of a singers voice (and interaction with the mic) are rendered so effortlessly as to defy belief. The FST never fails to disappoint and this may be one of the best implementations I've yet to hear.


In Use

Recordings are presented in an astonishing new light. Subtlety of timbres and textures come forth along with an amazingly expansive and deep soundstage. For a relatively short speaker the CM8s also project a very tall soundstage, the acoustic image never localizes itself at tweeter height. The image is taller than the physical speaker and also extends far beyond the lateral location as well.

Well recorded music stopped me in my tracks. The B&Ws instantly grabbing my attention and drawing me deep into the soul and passion of the music. The very same qualities that make the CM8 so magical also render it unflattering to poor recordings. A bit heartbreaking, as previously loved music seemed almost unlistenable with the CM8s.

Punk albums from my youth are not enjoyed through the CM8s. The refined nature of the Bowers and Wilkins don't flatter these recordings. Which is probably ok, the CM8s are a bit too refined even for English punk.

One of the most enjoyable sessions with the CM8s involved listening to the dub influenced track Big Calm from Morcheeba's album of the same name. Kick drums possess an immediacy and transient attack that form a solid foundation to the rest of the music. Bass lines were both deep and agile. The music presented was rich, detailed and intimate. One can lock in on a given instrument and hear all the nuances and timbre or listen to the whole musical presentation.

I've yet to hear a speaker at this price without some short coming. In fact, the few short comings in performance revolve around the integration of the bass to the midrange and tweeter. Bass errors on the side of being slightly dry. I prefer a drier bass with good pitch definition and agility to outright force and impact. In general the quality of the bass is very good, deep, taught and dynamic. Yet, at times the bass struggles to keep up with the pace and speed of the FST and tweeter. Bass lines can lag ever so slightly behind the rest of the music. This was especially apparent when listening to Mark Ronson & The Business Intl. Listening to The Bike Song from the album Record Collection, the bass line struggles to keep pace and feels detached and aloof. It's not apparent on every recording, but it is there.

Unlike larger floor standers the CM8s prefer moderate listening levels. Pushing the speakers too hard results in an overly bright tonal balance. The output of the tweeter far exceeding the output of the FST and bass units. Kept at normal listening levels similar to those used for 2-way monitors brings everything back into line. Realistic listening levels of rock music are not the CM8s forte. They prefer more real world volumes. If you prefer to feel your music, the CM8 is not the speaker for you.

Frequency integration is better than most three way floorstanders I've heard at this price. Most full range speakers often sound to me as three distinct sections doing their own thing and not properly integrated. The CM8 manages to present one of the most cohesive frequency images from top to bottom I've heard, even if the B&Ws are not the most tonally neutral speaker.

Imaging while being ruthlessly precise and accurate, is also fairly narrow. I've owned many pairs of B&W speakers over the years and this seems to be a consistent trait. The sweet spot is fairly narrow and suitable to just one listener. Moving one's head eight or more inches away from center results in a near complete collapse of the stereo image. When in the sweet spot you will be treated to one of the most accurate and realistic imaging at this price. Instruments are anchored in space with a crystal clear picture of where every sound is emanating.

These are small limitations and far outweighed by everything the CM8s do right. After all I've yet to hear the perfect speaker. Of all the components in hi-fi, the speaker is still the most fundamentally difficult to perfect. The CM8s strike a great balance for those seeking a highly musical speaker at normal listening levels.


Conclusions

The CM8 is a beautiful example of English industrial design. Elegant, superbly finished and detailed, they are visually drool worthy and a welcome addition to a living space. Thankfully the gems from Bowers and Wilkins also have the sonic goods to back up their good looks. The CM8s are speakers for people who love music and also love design. Their footprint allows them to comfortably fit into smaller apartments and lofts and fit in aesthetically as well. Sound of this caliber seldom comes from such a small package.

Combined with the wide distribution afforded by Magnolia Audio Video, truly luxurious sound is available to the masses. Sure, 2,200 dollars isn't exactly an impulse buy but look at the CM8s as an investment in years of listening pleasure. Also, few speakers retain the resale value of B&Ws so should you feel the need to upgrade you'll be amazed at what you'll get for these years down the road. My extended listen with the CM8s has reinforced my respect for the engineering talents of Bowers & Wilkins. With the CM8s you essentially get a mini monitor with better dynamics and bass extension though not the substantial SPL capability of larger floorstanders. The CM8s are beguiling, seductive and good value, they deserve an audition.