PSI Audio aims for absolute fidelity in building their active studio monitor speakers. An often overlooked yet extremely important part of constructing speakers is the waveguide. PSI Audio has developed the Acoustic Load Guide, a special approach to waveguiding that is based mainly on the adaptation of acoustic load between the driver membrane and the air. In conjunction with other proprietary technologies like CPR and AOI, ALG waveguides contribute to the renowned Swiss precision that audio professionals around the world appreciate in PSI Audio speakers.

The contents of this press release

PSI Audio employs proprietary ALG technology

Waveguides: improving sound for multi-way speakers

Small horns optimize directivity and clarity

PSI Audio: Acoustic Load Guide technology

Swiss precision monitoring with ALG and more

Yverdon-les-Bains, XX March 2020 – In order to create perfectly accurate sound reproduction, every detail of a speaker must be finely tuned. Even the shape of the enclosure around the tweeter will have a significant impact on the audio performance. PSI Audio has developed its own approach to waveguiding – the Acoustic Load Guide ALG.

Waveguides: improving the sound of multi-way speakers

The ALG is the PSI Audio approach to building a waveguide. Most people who use professional monitor speakers are familiar with waveguided speakers, as most two-way or three-way studio monitors use waveguides to improve the performance of their tweeters. As a result, these monitors boast a more homogenous sound across the whole spectrum and a wider sweet spot.

Small horns optimize directivity

Technically, the PSI Audio ALG, like waveguides in general, is a very short horn (with no pressure chamber). One of its functions is to counteract the change in directivity that naturally occurs: a driver is not a point source, but a surface – the membrane. If the wavelength is short compared to the size of the membrane, the frequency emitted from one of its sides will counteract the same frequency emitted from the other side of the membrane at a certain angle from the driver. As a result, the shorter the wavelength, the more focussed it will be emitted by a given driver. This results in a driver’s distribution characteristics leaning towards an almost omnidirectional pattern in the low end while forming a more concise beam towards the front at higher frequencies. In a multi-way system, this principle applies to all drivers, which creates a problem at the crossover frequency: while the woofer is already focussing the sound, the much smaller tweeter membrane is still fairly omnidirectional. This inconsistency results in an often noticeable jump at the crossover point. The waveguide focuses the lower frequencies emitted by the tweeter, while not affecting higher frequencies, leading to an overall smoother directivity pattern and better handover from the woofer to the tweeter.

PSI Audio: Acoustic Load Guide technology

The primary function of the Acoustic Load Guide from PSI Audio is actually the adaptation of the acoustic loads between the transducer and the air in front of it. The optimized translation of membrane movement into air pressure makes the PSI Audio tweeters outstandingly efficient, so they can reach very high sound pressure levels at minimum distortion. In tandem with the improved directivity pattern and optimized coupling with other drivers, the ALG achieves a very clear and transparent sound image. Since the sound waves emitted to the sides are more evenly distributed across the spectrum, the same is true of the room reflections, which evens the overall sonic image even outside the sweet spot. The ALG waveguide thus plays an important role in providing the most accurate reproduction possible.

Swiss precision monitoring with ALG and more

The ALG waveguide is one of many PSI Audio technologies aimed at perfecting the sonic accuracy of all their fully analogue active monitor speakers. Along with the proprietary Compensated Phase Response, Adaptive Output Impedance and Class G/H amplifier technologies, the Acoustic Load Guide provides immaculate precision for making decisions in recording, mixing and mastering. Built by hand in the company’s own manufacture in Switzerland, each speaker is painstakingly measured and calibrated to perfection. The Acoustic Load Guide technology is employed in all PSI Audio monitor speakers from the compact A14-M to the large A25-M three-way system.