With over 120,000 units sold, it's a wonder Ohm Acoustics is not more of a household name. Founded in 1972 and based in Brooklyn, New York (where the speakers are manufactured), Ohm Acoustics designs and manufactures speakers utilizing the technology of Lincoln Walsh's Coherent Line Source (CLS) driver, which was patented in 1969. Since Ohm's inception, it has endured the cycles of our economy by evolving from its roots--distributing product to many typical and a few not-so-typical retailers--to its current online, consumer-direct business model, offering a long 120-day trial period.
According to the company, CLS technology covers the extensive frequency range of a full-range speaker with one single source driver and no crossovers, while emanating sound in 360 degrees. The design has been improved over time, and the company has now added a traditional tweeter to support frequencies both within and over the range of the Walsh driver.
I was fortunate to obtain the flagship production model, the Walsh Tall 5000 ($3,300 each), which will be the main focus of this review, along with a Walsh 5000 Center Channel Speaker ($3,300) and four Walsh 1000 Sat Omni speakers ($850 each) for the surround role, to make an entire CLS seven-channel surround sound system.
The entire driver design--the CLS driver and the super tweeter, as Ohm calls it--is encapsulated in a cylindrical black, metal mesh case, which impairs any visual inspection. However, on Ohm's website, you can see a cut-away representation of the design. As you will notice, it appears to be a traditional cone driver, mounted vertically and inverted.
The technology translates an electrical waveform into vibrations down the surface of the cone, bending and oscillating the cone, causing sound to emanate off the sides of the driver. Due to the convex shape of the CLS design and the fact that the waveform can travel faster along the cone's surface than through the air, all sound is in alignment at the rim of the driver. As a result, a single Walsh driver can play a broad frequency range without requiring the crossovers that can plague conventional speakers, with all sound being in perfect phase alignment.
The entire CLS driver design is mounted on the Walsh Tall 5000's ported, 13.25-inch square enclosure that stands 43 inches tall. This enclosure sits on four two-inch supports connected to a plinth, creating an air gap between the main enclosure and plinth that allows the port at the bottom to breath. A high-pass filter protects the tweeter, while the Walsh driver itself is allowed to play the full range. Given the speaker's sensitivity of 87 dB, it is not surprising that the manufacturer requires 100 to 300 watts per channel--with special notation that there is a greater chance of damaging the speaker with less power as opposed to more.
Ohm also claims that the speaker line has the ability to create a stereo image from various locations within the room by implementing a technique called Controlled Directivity. The level of sound is decreased in the back and around the sides in various levels so that, when listening off-axis, you are hearing a lower volume of sound from the speaker closest to you and a higher volume from the speaker that's farthest. This requires the speaker to be a matched right and left pair.
A variety of real-wood veneers (11 to be exact) are available for the speaker enclosure, and they come in a matte low-luster finish, which I prefer over common high-gloss finishes. My review samples all had the rosewood veneer option.
Worth pointing out is that the entire Ohm speaker line consists of models that are designed to deliver the same performance, with the only difference being optimization for room size. There's no good, better, and best product choices. However, the Walsh Tall 5000 benefits from four control switches located on the rear of the CLS driver that act as a four-band equalizer. Each control switch has three settings: the middle setting is neutral, and moving the switch up or down increases/decreases amplitude accordingly. To make it simple for us consumers, Ohm has labeled the four areas of control: Room Size (80 Hz and below), Location (60 to 150 Hz), Perspective (130 to 3,000 Hz), and Treble (above 3000 Hz). This creates an assortment of combinations to accommodate not only different room sizes but also different levels of depth and detail of the higher frequencies. This could be a truly important feature, as it would allow your speaker to be used in different rooms or different homes, as your needs change.
I had a conversation with John Strohbeen, President of Ohm Acoustics, in which he emphasized room acoustics as the single most important factor in sound quality in any room, for any speaker: It all boils down to acoustics; so, if your room isn't right, the sound won't be either. According to Ohm, the four-band equalization control helps with this issue. The speakers come with useful instructions, with an explanation of how the controls can be used; however, while discussing the issue with John Strohbeen, he clearly directed me to experiment, since each room is so different and tastes will vary.
As I unpacked the speakers, I was surprised by the box-within-a-box method for keeping the speakers safe--seven times over, if I counted correctly. I started with a huge box and ended up with a much smaller box by the time I reached the speaker. Within the boxes, the speaker was inside a plastic bag with a drawstring. Visually, it's not the most elegant style of protection, but it appears to be effective.
I set up shop in my living room with the 5000s as the right and left channels, along with the Ohm center/surrounds and a MartinLogan BalanceForce 210 subwoofer. I connected all speakers to an NAD M27 seven-channel amplifier, and I used the NAD M17 AV pre/pro for control. Sources included an Oppo BDP-105D Blu-ray player and a MacBook Pro for streaming audio from TIDAL.
Click over to Page Two for Performance, The Downside, Comparison & Competition, and Conclusion...