The Acoustic Energy 309 floorstanding speakers have a sleek, minimalist design, but this minimalism is the result of years of Rodin-like practice in stripping away all unnecessary elements. The slightly tapered cabinet with smoothed upper edges and three dynamic drivers on the front panel are concealed by a black, magnetic fabric grille. Overall, they’re discreet and perfectly harmonious elements of a classic interior, as in our photo. For a more avant-garde setting, you can choose a black or white lacquer finish. The manufacturer emphasizes that the 300 series has a significantly higher quality finish than the budget “100th,” which we also couldn’t fault, even though it doesn’t look as sophisticated.
If you place the Acoustic Energy AE109 and AE309 floorstanders side by side, and choose the same color scheme, you might think they’re two models from the same series, just slightly different in size. Indeed, the enclosures are identical and feature the traditional Acoustic Energy shape—slim, deep, with rounded edges and a slotted bass reflex port. They’re made of 18mm MDF and feature internal bracing and baffles to dampen unwanted resonance. The enclosure contains a ballast compartment, which is filled at the factory, and spikes are included for vibration isolation from the floor. Therefore, the speakers arrive fully prepared; all that remains is proper installation.
The drivers of the AE109 and AE309 models also appear identical at first glance. But this is only a first glance. It’s the drivers that make the models completely different, as they use completely different materials in their construction. The tweeter is an aluminum dome, not a fabric one like the AE109. However, the larger 28mm diameter and signature WDT design with a wide horn, which makes high-frequency output less directional, remain unchanged.
But the most interesting thing about the Acoustic Energy 309 is, of course, its design. A pair of latest-generation 13-cm drivers feature cones with a sandwich structure composed of aluminum and ceramic. This composite offers increased resistance to bending deformation and eliminates high resonant peaks. The dust caps are cone-shaped, reducing interference in the midrange. Foamed polyurethane surrounds provide better reproduction of sonic nuances than the rubber surrounds used in the 100 series. Thanks to a reinforced magnetic system and effective voice-coil cooling, the speakers are capable of generating sound pressure of up to 115 dB, making them recommended for medium- and large-sized rooms.
The 2.5-way design allows for precise alignment of the system’s frequency response with minimal phase distortion and an extended polar pattern. One midbass driver covers the 38–296 Hz range, while the second extends all the way to the tweeter at 2560 Hz. Can you appreciate the precision of the crossover frequencies listed? They were clearly chosen deliberately and are the result of careful selection of crossover elements. The lower limit of 38 Hz is due to the presence of a bass reflex port, the slotted port of which is located at the top of the rear wall. The duct itself also has a fairly large rectangular cross-section, reducing the risk of turbulent overtones at high volumes.
The tweeter with a 28 mm dome was specially developed for the 300 series. It is placed in a short proprietary WDT (Wide Dispersion Technology) waveguide with a special profile that expands the directivity pattern. The emitter is protected from the outside with a fine metal mesh.
Acoustic Energy 309 Specifications
- Acoustic design: bass reflex
- HF driver: 28 mm, aluminum dome
- Mid/LF drivers: 130 mm, aluminum-ceramic cone
- Number of bands: 2.5
- Frequency range: 38-30000 Hz
- Crossover frequency: 296 and 2560 Hz
- Impedance: 6 Ohm
- Sensitivity: 89 dB
- Power: 175 W
- Dimensions: 900x175x280 mm
- Weight: 22 kg
