• Very impartial on-axis reaction
  • Excellent imaging capacity
  • Very precise build first-rate
  • Good dynamic variety
  • Extremely proper business design


  • Average low-frequency extension of 39 Hz
  • Relatively insensitive for floor-status speaker

D15 Tower Speaker | Definitive Technology released their ‘Demand’ series loudspeakers returned in past due 2017 with 3 one-of-a-kind bookshelf audio system. Two and a half of years later they’ve eventually expanded their Demand series line with two floor-standing audio system and a center speaker with the D15, D17, and D5C respectively. The distinction among the 2 ground-standing speakers is that the D17 uses slightly larger drivers which must provide it a chunk extra bass extension and barely greater dynamic variety. In for evaluation nowadays, we’ve the D15. The Demand towers are unusual in that they occupy a similar charge range as other ground-status speakers from Definitive Technology, specifically the BP-9000 series. It is not often that loudspeaker producers have traces similarly priced in the identical employer.

There are two key differences between the BP-9000 and Demand product traces. One distinction is that the BP-9000 collection use a bipolar design where sound is projected from the rear of the loudspeaker. This should make for a valid infused with more overdue reflections which have been proven to growth listener envelopment, despite the fact that that may come on the cost of a extensive soundstage and specific stereo imaging. Another distinction is that the BP-9000 series uses built-in powered subwoofers. That takes a load off of the consumer-furnished amplifier. However, with the prevalence and versatility of powerful and low priced subwoofers, integrated powered subwoofers are extra of an attraction to folks that do no longer want to devote ground space to stand-alone subs.

In comparison, the Demand collection is a much greater conventional loudspeaker layout. The exclusion of rear audio system may make for a greater acoustically predictable speaker with finer imaging and a much broader the front soundstage. The absence of a powered subwoofer phase makes integration with outboard subs much less complicated. So while Definitive Technology has two unique strains occupying a similar fee variety, in my view, they are distinctive sufficient to justify their availability. Definitive Technology seemed to need to offer a more traditional opportunity to their BP-9000 series, consequently the motive for the creation of the Demand tower audio system.

Let’s consciousness at the Demand D15 itself for a moment. At $3,400 a pair, they genuinely are not reasonably-priced but nor are they extravagantly expensive both. It’s a less difficult loudspeaker layout than Definitive Technology’s different floor-status speakers, and if this simplicity is an exchange of complexity for better excellent, that can be a welcome alternate. This isn’t to say that the design is straightforward, and we can get into the diverse components of its construction in our ‘design evaluation’ phase, however it is lots more of a conventional loudspeaker than the BP-9000s. There are lots of traditional ground-standing loudspeakers in its price variety, but, so what does the Demand D15 do to split itself from the relaxation? Let’s find out…


Upon arrival, the D15 speakers do want a moderate quantity of assembly with the aid of screwing in a steel plinth to the bottom and screwing ft into the plinth, however that is straightforward and takes less than five minutes. Following guidelines on the field, this must be completed earlier than unpacking the audio system. Unboxing the D15’s exhibits them to be a strikingly modern layout. The boxiness of the cabinet is not at all softened by means of corner rounding, and, in fact, the layout embraces it with tough right angles at all corners. This is an effort to contrast the various circles of the drivers which might be emphasized with black cones towards the light aluminum front baffle. The all-aluminum front baffle offers a very appealing and excessive-quit detail to the appearance, and, to be sincere, I am amazed to discover something like that in a speaker at a charge this low. While the economic layout right here is hanging, I don’t assume it is ‘loud’ in that it becomes the center of interest in maximum rooms. For folks that need a tamer look, the grille hides the the front baffle with a mild-silver fabric and gives the speaker a much more minimalist appearance. The grille makes use of magnetic adhesion, so it has no grille publications to break the smooth look of the the front baffle. With the gloss white end (a gloss black end can also be had), the grille’d D15 is so minimum that it appears almost like a bit of summary artwork. Normally, I think grilles make the audio system simply appearance dull, however that is not the case right here. Strangely, there are few pix of the D15’s with the grille on published to Definitive Technology’s product web page.

D15 Tower Speaker

There are eight” passive radiators on each sides of the speaker that have a gloss white cone and are easily the nicest-looking passive radiators I actually have ever visible. The tweeter is an aluminum dome that is partially obscured through a segment lens and has a mirror-photograph offset in a huge black faceplate. It nearly resembles an eye this is looking off to the side. The midrange driving force has a huge phase plug that Definitive Technology has utilized in beyond designs. I even have by no means cared for the manner it appears inside the beyond, but by hook or by crook it isn’t as visually obtrusive right here. The bass drivers have a sleek-looking carbon fiber cone. Altogether, I suppose it is an interesting searching speaker without or with the grille. I am guessing that even those who generally item to the appearance of audio system will get in conjunction with those when the grille is in vicinity. In the Gloss White finish, they could fit right in any brightly colored decor. All-in-all, the Demand D15 audio system look quite nice.

Design Analysis

The Definitive Technology Demand D15 loudspeakers are a three-manner ground-status design that makes use of passive radiators to enhance low frequencies. In such broad strokes, that isn’t a in particular unusual design, however there are a number of design improvements that do set the D15s aside from other tower speakers in its class.

Let’s start our discussion starting from the pinnacle and happening, so let’s talk about the tweeters. The D15 tweeters use a 1” aluminum dome established in a shallow waveguide. The aluminum of the tweeter dome is annealed, which means that it has been softened through bringing the aluminum near its melting factor after which allowing it to cool slowly. This method dissolves the crystalline structure of the metal, and, in its recrystallization, it turns into softer. In its softer nation, it has increased the damping that can tame wreck-up modes in higher frequencies. It ought to make for a smoother sound, especially with those individuals who are sensitive to better treble frequencies. There is a plastic piece with partly covers the front of the tweeter that may be a segment lens that Definitive technology calls the ‘20/20 Wave Alignment Lens.’ Its purpose is to block sound from the end of the tweeter dome from interfering with sound emanating from the sides. It can also function safety for the fragile diaphragm of the tweeter dome.

The midrange driver is a five.25” polypropylene design that is quite particular to Definitive Technology that they name the ‘BDSS Woofer,’ which stands for ‘Balanced Double Surround System.’ It gets that call because the cone makes use of two surrounds: one surround on the outer edge of the cone and one inside the internal part that attaches it to the section plug. Definitive Technology claims that this double surround gadget permits greater linear excursion. In theory, it ought to be viable that surrounds may want to provide a more managed tour from the suspension additives, despite the fact that I can’t believe that could provide a huge increase in excursion. This particular midrange section plug is also some thing simplest seen in Definitive Technology loudspeakers, and they call it the ‘Linear Response Waveguide.’ It’s the biggest section plug I have seen, and that is probably why Definitive Technology calls it a waveguide, even though it surely does no longer feature as a traditional waveguide. It seems to me find it irresistible just does what everyday phase plugs do that is blocking wavefronts from the distinct areas of the cone from colliding and interfering with each different. It simply does it loads more than everyday section plugs.

For the bass drivers, the D15 makes use of five.25” carbon-fiber cones. They look best and have a beefy surround and in order that they must be pretty succesful in bass frequencies. They are also used to power the 2 eight” passive radiators on the side of the speaker. Definitive Technology claims a decrease -3dB restrict of 48 Hz for the D15, so those radiators need to be very able right down to 50 Hz as a minimum. I wasn’t capable of get a near study the naked drivers considering the fact that a trim ring covers the frame screws, and getting rid of the trim ring may be a piece unstable for the reason that it’s miles glued on.

The crossover circuit is a quite formidable piece that uses a large number of higher-great additives along with steel-movie capacitors and air-core inductors. There is a 2d-order acoustical crossover among the bass driver and midrange driving force at 450 Hz and a third-order crossover among the midrange and tweeter at 2.5 kHz. The D15 has units of five-manner nickel-plated binding posts for people who want to bi-twine or bi-amp the audio system. This is a feature that maximum upscale speakers are supposed to have however in reality, it isn’t very useful. The advantages of bi-wiring or bi-amping a speaker like this are negligible and not well worth the potential for issues which can arise for those who try the ones types of connections.

All of this generation is about in a completely slick MDF cabinet with the aforementioned aluminum front baffle this is 6mm thick. The facet panels and bracing are all 18mm with the bracing designed and positioned with FEA analysis for most fulfilling stiffness of the cabinet. The midrange is enclosed inside its own heavily-damped compartment inside the cabinet in order that again waves from the bass drivers do not have an effect on the cone role. A correct amount of polyfill stuffing is positioned in the cabinet for inner damping. The speaker is about on a rectangular aluminum bass with the choice of spiked ft or rubber feet. The cupboard feels stable and inert.

The Demand D15 audio system seem like a well-designed and equipped loudspeaker, but, as with any high-end loudspeaker, its objective is in the long run to sound right. Let’s in the end deliver it a listen to look how it achieves that goal…

Listening Sessions

In my 24’ through thirteen’ (about) listening room, I installation the audio system with stand-off distances among the back wall and sidewall, and same distance among speakers and listening position. The speakers had been installation to face the listening function directly. Listening distance from the audio system turned into about 9 ft. Amplification and processing have been handled by way of a Pioneer Elite SC-55. No room correction equalization changed into used. Subwoofers were used for some content that contained deep bass frequencies.

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