Yverdon-les-Bains, 14th April 2021 – When the market does not offer what you need, you have two options: you can change your requirements, or you can create the required component yourself. PSI Audio chose the latter option when the market did not provide a driver that would suit their needs – so they developed the Extended Dome driver (EXD).
A25-M equipped with all-new EXD driver
PSI Audio developed the EXD driver as an update for the large-format classic A25-M. The three-way monitor speaker was already a point of reference for acoustic precision and faithful reproduction. However, the engineers at PSI Audio found that the midrange driver could be improved, if only there was a driver that would suit the specifications. When the market offered no such component, PSI Audio decided to develop a new driver from scratch, so as not to compromise the quality of the speaker. The result is the EXD driver, an innovative combination of dome and cone constructions that boasts the strengths of both types while eliminating their weaknesses.
Cone drivers: powerful but heavy
When thinking of a speaker, most people will probably imagine a cone type driver as they are most commonly used for lower frequencies and significantly dominate the visual appearance of the respective speakers. Cones can generate a comparatively large bandwidth and still produce a lot of energy in low frequencies. Due to how a cone driver is constructed, it is quite heavy: consisting not only of the membrane, but also of a dust cap, spider and suspension, the overall weight severely impacts inertia and hence diminishes performance for higher frequencies, which require a fast-moving driver. The result is less output with more distortion – not helped by the fact that heavy basket designs restrict airflow and make the membrane even harder to move. For these reasons, cone drivers are generally well-prepared to reproduce lower frequencies, but do not fare too well in higher registers.
Dome drivers: fine but prone to distortion
Probably the most popular choice for high-frequency reproduction are dome type drivers. They are lighter systems – particularly in the sizes used for tweeters – and hence move more freely and easily. In lower registers, however, dome drivers cannot perform quite as well. Their bandwidth is limited and they tend to become unstable in the centre, introducing distortion. When more rigid material is used to counteract this effect, the driver gains weight, thus losing its most precious advantage. Consequently, dome drivers are and will probably continue to be popular for tweeters, but their midrange applicability is very limited.
EXD: the best of both worlds
Setting out to find the ideal mix of cone and dome type drivers, PSI Audio may well be said to have attempted to square the circle – but square it they did. The result is the Extended Dome driver, or EXD for short. This innovative hybrid driver type features a four-inch paper cone infused with latex and graphite as well as a polypropylene dome membrane. Both parts of the driver are directly connected to the voice coil. As a result, the dimensions of the driver and its weight are perfectly balanced with the coil to provide a performance unlike any other driver, with higher SPL and lower distortion figures. There is also no basket behind the membrane, so air can move freely without restrictions. Especially as a midrange driver in between a cone woofer and a dome tweeter, the EXD is the ultimate compound of both types, allowing for a particularly smooth transition between the ways.
Developing the future of precision speakers: PSI Audio
PSI Audio is uniquely qualified for innovations like the EXD, since the focus on absolutely perfect analogue technology and finest craftsmanship is deeply embedded in the company’s philosophy. Developed and built by hand in the Swiss manufacture, PSI Audio products are made to the highest quality standards without compromise. From the selection of perfectly matched components to the final calibration in the anechoic chamber, the experienced experts at PSI Audio ensure that unique sonic performance – the accurate reproduction of what the original source sounded like. This is not some acoustic representation, it’s the real thing.
About PSI Audio
For over 40 years, Swiss company Relec SA manufactures high- quality systems for professional audio reproduction. The company’s brand PSI Audio is firmly established in the field of studio speakers. The brand’s philosophy: 100 percent analogue circuitry without DSP, top quality through manufacturing in the company’s own facilities – and absolutely accurate reproduction. PSI Audio speakers play exactly what is present in the music, not adding anything to it or leaving anything out. With its active bass trap AVAA C20, PSI Audio also revolutionizes room acoustics.