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ACOUSTICS - BACKGROUND INFO

Rear wall cancellation

When the monitor is set up at some distance in front of a wall, reflections from the wall may occur and influence the perceived frequency response. This could result in comb filtering if all frequencies produced by the monitor were radiated in all directions. But the monitors are typically only omni-directional at low frequencies.

The result of the reflection is a single or few dips in the frequency response perceived in front of the monitor.

This frequency is cancelled because of the oppositely phased reflection

The frequency response may look like this: one cancellation at the frequency that has a wave length of four times the distance to the rear wall.

The dip - or cancellation frequency - is dependent on the distance to the wall. If the distance is 1 m, the first dip frequency will occur at a frequency with a wavelength of 4 m.

l = c / f where

l = wavelength [m] (or ft.)

c = speed of sound [m/sec] (or ft./sec.) f = frequency [Hz]

Hence

4 = 344 / f f = 86 Hz

A closer position will result in a cancellation at a higher frequency. This is then limited by the frequency where the monitor becomes directional and does rot radiate sound to the rear.

A farther position will result in cancellation at a lower frequency. This is limited by the distance being so long, that the reflected sound is attenuated due to the long extra path travel.

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Dynaudio pmn manual Rear wall cancellation
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pmn specifications

Dynaudio, a company renowned for its high-fidelity audio products, has made significant strides in the field of professional monitoring through its PPM (Professional Precision Monitoring) series. Among the standout models in this series is the Dynaudio PMN (Professional Monitoring Nearfield), which has garnered attention for its outstanding sound quality, precise technical performance, and sophisticated design.

One of the key features of the Dynaudio PMN monitors is their advanced driver technology. Equipped with proprietary drivers, the PMN series employs custom-designed woofers and tweeters that deliver an incredibly accurate frequency response. The woofers utilize a lightweight diaphragm, ensuring that low frequencies are produced with power while maintaining clarity. The tweeters, known for their soft dome design, excel in reproducing high frequencies with exquisite detail and minimal distortion, making the listening experience both immersive and enjoyable.

In terms of design, the PMN monitors boast a sleek and modern aesthetic that fits seamlessly into any studio environment. The cabinet construction employs advanced materials and techniques that minimize resonance, thus reducing unwanted coloration in sound. The unique curved shape of the cabinets is not only visually appealing but also supports optimal acoustic performance by enhancing sound dispersion.

Another notable characteristic of the Dynaudio PMN is its versatility. The monitors are equipped with multiple inputs, allowing for seamless integration into various set-ups, whether in a professional studio or a home listening environment. This flexibility is further complemented by adjustable bass and treble controls, empowering users to tailor the sound profile to their specific requirements.

Dynaudio has also incorporated advanced technologies such as room correction in certain PMN models, which enables precise calibration according to the acoustics of the room. This feature ensures that audio professionals can rely on consistent and accurate sound reproduction regardless of their monitoring environment.

Overall, the Dynaudio PMN series represents a blend of pioneering audio technology, meticulous craftsmanship, and user-focused design. For professionals seeking precise monitoring solutions for music production, film scoring, or any audio-related projects, the Dynaudio PMN monitors provide an exceptional listening experience that stands the test of time. With their stellar performance and innovative features, these monitors have become a top choice for sound engineers, musicians, and audio enthusiasts alike.
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