Martin Audio’s DD6 is an ultra-compact passive two-way speaker, uniquely adapted for a wide variety of specialized fill applications with a multi-angle enclosure and several specialized features. It employs a 6.5-inch neodymium woofer with a 1.75-inch voice coil, passively crossed over at 3700 Hz to a half-inch exit neodymium compression driver mounted on a unique Differential Dispersion horn (hence the name, DD6) with 60° of vertical coverage, transitioning from 120° at the bottom for a wide near throw, to 90° at the top for a gradually-narrowing further throw to minimize overlap and combing (or wall bounce) from its neighbor. The unique horn was designed using Martin’s proprietary Boundary Element Method (BEM) modeling tool, and the DD6 is just the first and smallest in a range of models that will offer Differential Dispersion and multi-angled enclosures.
The DD6 measures 7.5 by 14 by 8 inches deep and weighs about 14 pounds. While too small for proper handles, it does have a 2-inch hole by the rear connector plate that two fingers fit into, making it possible to easily “carry” a pair by pinching each between fingers and thumb. The multi-laminate birch-ply enclosure is finished with a textured black polyurethane coating, and each is rated for 150W AES, 600W peak, with a 91dB sensitivity and a max SPL of 111 dB and 117 dB peak. Typical of this type of fill speaker, its -10 dB point is 55 Hz, so a high-pass filter of 70 Hz, while not mentioned, would certainly be best practice.
For years, I’ve been a fan of Loud Technologies’ sister company EAW’s classic d’Appolito-configured JF80 — a staple of Broadway surround designs for decades and popular in regional vendors’ front-fill inventory — now replaced by their JF80z with its end-mounted tweeter. The Jacksonville Symphony’s sound company is Gainesville’s Everyman Sound, one of the original KF850 companies. They regularly provide a KF730 system supplemented by four JF80s across the front of Jacoby Hall’s 60-foot-wide stage: one for each side section of seats and two for the center section. For the purposes of our test, it was easy to simply replace those four JF80s, which we had been quite satisfied with until now, with four DD6 speakers, placing them at head height to the first row.
In Martin Audio’s attention to detail, they have provided not two, but four Neutrik NL-4 SpeakOn connectors: two on the woofer end for round-trip circuits up a pole, and two on the back beside the generous 40mm port, which has a two-way switch. Martin calls this feature Bi-Path,™ and it allows the installation technician to chose which pair of circuits in the 4-conductor Speakon cable the speaker is powered by. Since DD6 has a nominal impedance of 16 ohms, two sets of four can easily be run on a single stereo amplifier in one continuous run of NL-4, allowing left-right alternation or for delay purposes, inner-and-outer or near-and-far circuits.
Four optional accessories include a 14-inch swiveling yoke for ceiling, wall, or pole-mounting; a universal tilting bracket that fixes to either the top or bottom of the DD6 and either attaches to a scaffold clamp for Cheeseboro-style pipe or truss mounting (four pairs of M8 threaded inserts on the ends and sides); a simple 35mm tilting pole adaptor; and a compact swiveling, tilting wall-bracket with a locking mechanism for close-mounting to a vertical surface for more permanent installations (4x M6 threaded inserts). Pretty much everything you’d need if you weren’t simply laying them on the lip of a stage. Hello Broadway.
With the footprint of a legal pad, the DD6 has useful angles on four of its sides. Because it has a rotatable horn, the DD6 can stand on end — where it’s still only 14 inches tall — as well as lay horizontally like most front fills, reducing its height to half. Its other long side has a 7.5° angle designed to match the rake of most orchestra-level seating from the front lip of a stage, which is where this enclosure excels.
While a co-axial design would be smaller, you won’t get this type of HF pattern control from a co-ax. Because the rotatable horn is so small, it’s held in by screws that can be finger tightened or unscrewed, plus it has a magnetically-retained, quick-release perforated steel grille, so the rotation can be performed on the spot without tools in moments.
A 60° angle on the back allows the DD6 to be used as a floor monitor or, more precisely, a foldback loudspeaker — especially important in corporate Q&A sessions where a small Fostex 6301A might previously be used to feed questions to the rostrum. We tried the DD6 as a floor monitor, and it could work well for light house of worship applications or for jazz or light pop vocalists, or a pianist who just needs a little piano and high-hat fold-back, but the bottom line is that no matter how many DD6s you have, you won’t have enough.
Since it’s the best front-fill or near-fill I’ve ever heard, I would use them all there first, and then let the band have the usual single-twelve wedges. The angle also lets them be used as front fills on smaller stage platforms that transition in a series of steps or simply consist of one or two steps across the front, so that there’s no real front to the stage, also common in house of worship architectural designs.
Jacksonville’s Jacoby Hall has typically raked orchestra level seating that slowly rises towards the back. The same 10° angle that makes the JF80 a great front-fill is on one side of the DD6, providing just the right approach to the symphony’s seated patrons, except now coverage has been optimized to reach wide at the first row and deeper into the third, fourth and fifth rows.
Those familiar with symphony organizations know that front-row seats belong to patrons whose contributions go far beyond buying a season’s ticket. The flutes and percussion that get into every open mic on a reinforced symphony pops stage sound natural, as does the string section close-miked with DPA 4061s, and the reeds spot-miked with AKG 414s and the new Countryman condenser wand mics.
In a way, Martin has achieved two of the three goals that were JBL’s objectives with their new D2 driver (see Tech Preview, page 30). By reducing the HF driver’s size and raising the crossover point, they’ve increased high-frequency extension due to the diaphragm’s smaller moving mass as well as reduced distortion arising from dome breakup modes, resulting in clear, natural high frequency response.
My only recommendation is that you get plenty of these little DD6 fill speakers, because you’ll want to use them for more than front-fills. You’ll need them for a wide variety of fold-back and fill applications, from the conductor himself to high-dollar box seats and even the under-balcony at the hall’s rear (at the mix position). And if you take a pair home, your wife may not give them up.
