Definitive Technology SR9040 Bipolar Surround Speaker

Definitive Technology SR9040 – The Bipolar Surround Speaker Built for BP9000 Systems

The Definitive Technology SR9040 is a bipolar surround speaker: drive units on both faces of the cabinet fire in opposite directions, creating the diffuse, enveloping soundfield that makes surround effects feel as though they are happening around you rather than at you. It is voiced to match Definitive Technology BP9000-series tower speakers, so a system built from that family sounds seamless from front to back.

Each face of the SR9040 carries a 1-inch aluminium dome tweeter and a 3.5-inch BDSS midrange and woofer driver, giving the speaker a total frequency response of 50 Hz to 40 kHz and sensitivity of 92 dB. Mounted on the wall beside or behind the listening position, it spreads rain, crowd noise and ambience across the rear of the room instead of beaming them from two obvious points.

Key features

• Bipolar surround speaker with drivers on both cabinet faces
• Two 1-inch aluminium dome tweeters, one per face
• Two 3.5-inch BDSS midrange and woofer drivers
• Frequency response of 50 Hz to 40 kHz
• Sensitivity of 92 dB for easy amplification
• Nominal impedance of 8 ohms
• Recommended amplifier power of 20 to 150 W
• Voiced to match BP9000-series front speakers
• Diffuse soundfield ideal for film surround effects
• Compact wall-mountable cabinet in black

Why bipolar surrounds work for film

A conventional direct-radiating surround points its output at the listener, which is excellent for pinpoint effects and poor for atmosphere. Most of what a surround channel carries is atmosphere: weather, crowds, room tone and the tails of music. A bipolar design fires along the wall in both directions, so that information arrives as a spread of reflected and direct sound. The rear of the room feels larger, effects move without drawing attention to the speaker, and listeners sitting off-centre still hear a convincing surround field.

Placement and system matching

Mount a pair of SR9040 speakers on the side walls slightly behind the seats, or on the rear wall in narrower rooms, at a height that puts the drivers above ear level when seated. The 92 dB sensitivity and 8-ohm load make no special demands of an AV receiver, and the voicing match with BP9000 towers and the CS9000 centre speakers keeps pans consistent as sounds cross from the front stage into the surrounds. Set the crossover in your receiver around the usual small-speaker range and let a subwoofer handle the deepest bass.

Who the SR9040 suits

Choose the SR9040 if you are completing a Definitive Technology home theatre, or any system where film immersion matters more than pinpoint rear effects. It suits dedicated theatre rooms and living-room cinemas alike, and it is the natural surround partner for BP9000-series owners who want the rear soundfield the range was designed around.