Definitive Technology’s New Bipolar Dymension Series Promises Ultimate Home Theater Performance

Definitive Technology has been building speakers since 1990, with a focus on enormous dynamic range and surprisingly powerful bass, thanks to built-in powered subwoofers in many of the brand’s larger models. The first time I encountered Definitive Technology at a now-defunct AV store in my home town back in the 90s, an employee played a rock concert on LaserDisc, and I was blown away by the “live” sound and the raw power on display. One key design feature of many Definitive Technology tower speakers is that they are bipolar — they have drivers on the back of the cabinet firing in the opposite direction from (but in phase with) the “normal” set of drivers located on the front baffle. This design, as I learned during that first DefTech demo, contributes to an enveloping, wide sound stage with increased sound power and an engaging quality that can make music sound more “live” and less “Hi-Fi.” Now Definitive Technology has announced the Dymension Series, the next generation of its bipolar speakers, building on 25 years of experience. With prices topping out at $2,499 each for the flagship tower in the range, the Dymension Series enters a crowded segment of the market, but promises to be “the ultimate” home theater speaker system with “obsession-worthy performance and effortless room integration options,” according to the company.

Like their predecessors, the Definitive Technology Dymension speakers exude minimalism in their design, suggesting that the money spent to build them went more toward sound than toward aesthetics. A benefit of their “black sock” look (the speakers are wrapped in an acoustically transparent cloth) is that they will all but disappear in a darkened theater, and won’t reflect light from a TV or projector. The four tower speaker models all feature bipolar designs and should deliver the expansive bipolar sound fields for which the brand is famous. Three of the towers also include built-in powered subwoofers, as does the largest of the three center-channel speakers in the range. The Dymension Series also includes a wedge-shaped on-wall speaker for height/surround channels, and an Atmos-certified integrated height module that can attach to the top of the two larger tower models, accommodating those who must rely on the “bouncy house” (ceiling reflection) approach to Atmos. According to Definitive Technology, all Dymension Series speakers have been carefully timbre-matched so that customers can feel free to mix and match as needed.

The Dymension Series boasts an all-new tweeter, which Definitive Technology calls the Aluminum Oxide Dome Tweeter. It builds on the company’s experience using annealed aluminum tweeters, but reaches “new performance heights” thanks to a ceramic coating added to the aluminum diaphragm. The tweeter’s Teteron (cloth) suspension is impedance-matched, and reportedly helps to control resonant modes while ensuring pistonic motion of the dome. A newly-designed waveguide promises to deliver extended high frequencies and better dispersion than previous designs. This tweeter is just one of many technological developments employed across the lineup. The Dymension Series includes:

4 Floorstanding Speakers

DM80: Flagship active tower with a 12-inch powered woofer and dual passive radiators, $2,499 each.

DM70: Large active tower with a 10-inch powered woofer and dual passive radiators, $1,999 each.

DM60: Medium active tower with an 8-inch powered woofer and dual passive radiators, $1,499 each.

DM40: Small and slim all-passive tower, $999 each. 

3 Center-channel Speakers

DM30: Flagship active center-channel speaker with built-in 8-inch powered subwoofer, $1,499 each.

DM10: Passive center-channel speaker with a traditional form-factor, $699 each.

DM20: Slim passive on-wall LCR, $799 each.

2 Height/Surround Options (note that prices are per pair for these models)

DM95: Wedge-shaped on-wall speaker for height and/or surround channels, $799 per pair.

DM90: Atmos-certified integrated height module that attaches to the top of the DM80 or DM70 towers for “bouncy house” (ceiling reflection) Atmos, $999/pair.

The Towers

Definitive Technology’s announcement of the Dymension Series focused largely on the features and capabilities of the two flagship products, the DM80 tower speaker and the DM30 center-channel speaker. Let’s start with the DM80. The flagship of the Dymension Series offers a “fully balanced, adjustable bipolar array.” That means the drivers on the front baffle are mirrored on the rear, and that the bipolar effect can be adjusted to optimize for room placement (closer to the front wall or farther out into the room). In its default setting, the DM80 delivers a “balanced bipolar” effect, with equal output front and rear. The DM40, DM60 and DM70, all have a switch on the back panel allowing the user to choose between this balanced mode and a “Forward Focus” mode, which attenuates the rear tweeter by -6dB. The DM80 takes customization quite a bit further, however. There’s still the option to attenuate the tweeter (using a different binding post position, rather than a switch). But the DM80 can also provide continuously variable levels on its rear output for users taking advantage of the bi-amping option. This allows users to adjust the rear array to their tastes and speaker position relative to the wall. The DM80 achieves this flexibility thanks to a unique crossover that has separate crossover sections for the front and rear arrays. The bi-amping option allows the user to adjust the level of the rear array by using a volume control in front of the amplifier powering that array. Definitive Technology says that this level of customization is unprecedented in the brand’s decades of bipolar offerings.

Another first for the DM80 is the built-in amplifier powering the integrated 12-inch subwoofer. For this flagship model, Definitive Technology has designed an all-new, high-performance 400-watt GaNFET amplifier, which reportedly delivers “clean, detailed bass that perfectly blends with (the) mids and highs, and feels consistent no matter where you sit.” The GaNFET amplifier design boasts a higher damping factor, resulting in greater control over the transducer. The new amp also benefits from higher efficiency and up to 10 times lower distortion than previous designs, according to Definitive Technology. Output power is rated at 415 watts continuous, 500 watts peak. Again, only the DM80 features the GaNFET amplifier. The other active models in the Dymension Series use a 180-watt (250-watt peak) Class D MOSFET design with DSP.

The built-in active subwoofers are a significant part of the value proposition of the DM60, DM70, and DM80. The flagship DM80, with its 12-inch sub, offers real-world bass response down to 28Hz (-3dB), so separate subwoofers are truly optional — rather than necessary — even in the context of a home theater. Because each speaker has its own sub, the user automatically reaps the benefits of using dual subs, the most important of which is more consistent bass throughout the room. At the same time, the user doesn’t have to invest in separate subs and find available floor space for them to occupy. That’s a win-win in my book.

The bass level for each speaker is fully adjustable via a control knob on the back panel, and each gain position has its own DSP tuning to maximize bass performance without spoiling the tonal balance or muddying the higher frequencies near the crossover point. One thing to note is that, unlike the previous-generation 9000 Series, the Dymension Series speakers don’t have a separate LFE input for the “.1” channel in a surround mix. So if you plan to use the DM60, DM70, or DM80 in a home theater without a separate sub, you’ll need to make sure that your AV receiver or processor treats them as “Large” or “Full Range” speakers, and routes the LFE channel to them. This arrangement might offer a little less flexibility than using separate subwoofers in conjunction with a program like Dirac Live’s Multi-Sub Bass Control, but it should still be a cost-effective and space-efficient way to deliver the low-end goods.

Editorial Note About Bass Management by Gene DellaSala
If you're NOT running additional powered subwoofers with the DM60, 70 or 80 tower speakers, set the speakers to "large" and subwoofer to "off" in the bass management of your AVR. This will allow each of the Definitive Technology tower speakers built in subwoofers to get full range bass, plus the bass from bass managed speakers and LFE (front channels).

The Center Channels

The DM80 uses four 5.25-inch mid/bass woofers (two on the front, two on the rear) featuring DefTech’s patented Balanced Double Surround System technology (BDSS), which uses a set of specially-tuned soft rubber surrounds to lower distortion by ensuring pistonic motion of cone, while simultaneously helping to damp cone resonances, leading to a smoother response. The result is improved midrange driver excursion and a wide, uniform soundstage with seamless bass/mid integration, according to Definite Technology. The mid/bass woofers also feature the company’s Linear Response Waveguide, which is said to extend and smooth off-axis dispersion, delivering “great sound everywhere in the room.” The Linear Response Waveguide is a new design for the Dymension Series. Definitive Technology says that it “interferes with sound from the opposite side of the cone” to smooth the response and boost output in the critical midrange frequencies. The Flux Control Rings in the drivers deliver reduced inductance (for better highs), and reduced flux modulation and eddy currents (for lower distortion), according to the company. The deep bass is of course handled by the built-in powered subwoofer, with user-adjustable level. All of these technological developments might be wasted if the user’s selected bass level had the potential to distort the midrange, but Definitive Technology has a clever solution to this potential problem. The company’s patented Intelligent Bass Control feature uses “sophisticated digital processing (to) seamlessly blend subwoofer output with the mids and highs, to provide powerful deep-bass performance without sacrificing midrange clarity.” Definitive claims that the bass will “never get in the way of dialogue and other critical soundtrack elements.”

Speaking of dialogue, let’s turn to the DM30 flagship center-channel speaker and see what it has to offer. The DM30 uses an advanced five-driver array that combines four 5.25-inch mid/woofers with the new 1-inch Aluminum Oxide Dome tweeter to deliver “ultra-clear vocals with uncanny realism,” according to Definitive Technology. Like the DM80 described above, the DM30 features the BDSS system on the mid/woofers for improved excursion and superior midrange detail, while the patented Linear Response Waveguide extends off-axis dispersion “for total sonic immersion,” according to the company. The integrated 8-inch powered subwoofer isn’t something we see often in a center-channel speaker. But who doesn’t want clean, detailed bass from the most important speaker in a home theater? Definitive Technology says the powered subwoofer helps to draw you into the action by “anchoring voices and effects with rich, full-range sound,” while perfectly blending with the mids and highs. The DM30’s 3XR Architecture is a feature first introduced by DefTech in its flagship Descend Series subwoofers. It supports the active driver with dual passive radiators, resulting in “3X” the bass-radiating surface area compared to a similarly-sized ported design. The result in the case of the DM30 is “huge, impactful bass that’s unrivaled in a center channel speaker.”

Check Them Out!

The Definitive Technology Dymension Series loudspeakers are available now from your local Definitive Technology retailer, or from the Definitive Technology website. If you’ve never had the opportunity to hear bipolar speakers in action — especially ones with built-in powered subwoofers — I highly recommend seeking out the Dymension Series at your local dealer. Even if the black-sock aesthetics aren’t your thing, and even if you’re not in the market for new speakers, it’s worth checking them out just to see what makes bipolar speakers so effective and unique. While you’re at it, check out Theo Nicolakis’s review of the previous generation, the Definitive Technology 9000 Series bipolar speakers.

Have you heard this kind of speaker design, and if so, what did you think? Share your thoughts in the related forum thread below.

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