Key Features:

• CPR system for precise stereo image
• AOI system for superior impulse accuracy
• ALG system for ideal acoustic impedance adaptation
• Outstanding SPL @1m 119dB (peak/pair)
• Broad bandwidth 53 – 23’000 Hz
• Flat frequency response +/- 2.5dB
• Optimised phase coherent directivity
• Metal handle for easy handling, (mic.stand + wall mounting)
• Volume control on the front panel
• Magnetically shielded

PSI Audio Manufacturing
PSI Audio production is split between two manufacturing facilities. The cabinet making facility is located in St. Croix, a small town in the Swiss Jura mountains. A centre for the crafting of fine musical instruments and lavish music boxes since the 19th century, St. Croix's highly skilled craftsmen also have a rich history in the development of high-tech audio visual equipment. This combination of traditional and modern skills can be seen in the quality and finish of our speaker cabinets. 

Product development, electronics design, manufacture and assembly are executed at our Yverdon facility. Located at the foot of the Jura on Lake Neuchâtel, the facility also houses PSI Audio's commercial Headquarters and world-wide distribution centre. Built in 1989, the facility is designed around our huge anechoic chamber - the heart of PSI Audio.

A good speaker starts with a well-designed cabinet, carefully selected and tested materials, craftsmanship and attention to detail. Our skilled Cabinet Makers ensure that every step in the production process follows exact design tolerances and that the assembled cabinet is thoroughly checked for imperfections prior to being sent for finishing.

Our paint finishing workshop is kept absolutely dust free. The air is evacuated and recycled at the rate of 4,500m3 per hour and the room is kept under positive pressure. The cabinets are flatted down by hand between each application of paint or lacquer and are stringently checked for quality. The result of this process is a beautiful finish, unique to PSI Audio.The cabinets are now ready to go to Yverdon facility for electronics assembly, finishing and testing.

PSI Audio Company History
During he's studies at the EPFL in Lausanne back in 1975, Alain Roux, the founder of Relec SA, started producing the first speakers under the brand name PSI. Two years later, back in 1977 the production of PSI speakers became profitable and the company Roux Electroacoustique was founded. In 1988 after further successful development of Roux Electroacoustique the company changed its legal structure in to a Ltd. company and changed its name and location to Relec SA located in Yverdon. Finally in 1991 an analogue and digital electronics section was added to the acoustical laboratory. The development of these new competences was possible through the recruitment of Christian Martin, who has since then, successfully led that important part of PSI AUDIO.

During the past quarter of a century Alain Roux and he's team where to develop a huge variety of speakers for HI-Fi, PA and Professional Studio applications. A large part of the speakers built and developed by Relec SA where and still are produced under the OEM scheme for other famous, world wide renowned and respected companies who would then label and market the products under their own brand names. Many of these products have been apprised with some of the industries most desirable awards and even more have been blessed with the finest and most enthusiastic test reports by the professional press.

Today the former brand PSI has, in the field of professional studio monitors, evolved in to PSI AUDIO which will now be marketed worldwide. Finally customers will have the privilege to acquire a whole generation of pioneering and innovative know-how in speaker manufacturing under the original PSI AUDIO brand name outside of Switzerland. Enjoy our creations.

CPR - Compensated Phase Response System:
In a multi-way speaker system, the crossover filters as well as the transducers introduce distortion of phase and by consequence of the variations of group delays. The group delays in low frequencies are more important than in high frequency’s. They provoke a time related separation of the low and high frequencies which then is responsible for the hollow sound of multi-way speaker systems. In a limited frequency range, an all pass filter allows to intervene on the phase without influencing the amplitude. 
The CPR system consists of several all pass filters who each act in a specific range of frequency in order to obtain a wide area of Compensated Phase Response. This then provides a constant group delay. Thanks to the CPR system the placement of sound in the actual sound space is highly accurate. This technology allows designing of surround sound systems with different types of PSI Audio speakers while maintaining an accurate phase response.
 
Practical advantage of CPR and impact on stereo application
The human ear is very sensitive to group delays or phase irregularities of sounds. The human brain detects such irregularities easily and processes them in to space related information’s like the positioning of a sound source. All traditionally designed speaker systems suffer to a certain degree of such irregularities. These irregularities are the reason why some speakers produce a wider and deeper room perception hence a better-weaker reproduction of the sound image. Such phase irregularities are desirable on creative tools like equalizers, compressors, reverbs and delay units when creating a certain desired sound, whilst being an important part of the creative process of sound engineering. But as the speaker system represents the reference tool of every sound engineer, these irregularities represent a highly disturbing factor and should certainly not be present in the reference tool when trying to design specific sound or its positioning in the sound image. As a sound recording tends go through various processes (recording, mixing and mastering) in which maybe various people, locations and therefore speaker systems will be involved, it may well occur that corrections will be applied, due to phase irregularities, that may not even be present on the actual recording.

The PSI Audio speakers feature the unique CPR system that provides a Compensated Phase Response that removes such irregularities and therefore provides a much more accurate reference tool to the sound engineer. The stereo image and the projected room are of an extreme accuracy and therefore provide a more precise working tool.

CPR impact on surround sound applications
Unfortunately every traditional speaker design has a different phase response and therefore the phase inaccuracy phenomenon tends to get worse in surround sound applications, where the role of room information and positioning becomes an even higher priority and critical part of the sound engineering process. This is one of the reasons why speaker manufacturers strongly recommend using speakers of the same type when creating a surround sound system. The CPR system by PSI Audio will feature an extremely accurate and superior surround sound image and therefore a much improved working environment. One of the big advantages of the CPR system is also that for the first time a user can mix different types of speakers from one manufacturer (PSI Audio) in a surround sound system, whilst maintaining perfectly accurate phase response. Not only will the PSI Audio surround system sound much more accurate and therefore provide a superior working tool, but it can also introduce significant cost and space savings when investing in a new monitoring system.

AOI - Adaptive Output Impedanse System:
In low frequencies a loudspeaker behaves like a high-pass filter; therefore the damping depends on its mass, on compliances (mechanical and acoustical suspension) and of the source resistance. 
In high frequencies, the resonances correspond to the deformations of the membranes. The masses in movement are parts of the mobile mass. Compliances depend on the elasticity of the material. The resistances are the internal damping and the source resistance. For an ideal damping in a wide area of frequency, the source impedance must be adapted to every range of frequency for every transducer. 
The AOI system is constituted by a detection of the movement of the membrane and the moving coil, as well as by a counter reaction filtering. Therefore the damping rate is continuously ideally adjusted according to the frequency. The AOI system allows the reproduction of sound without transducer coloring over the whole frequency range.

Practical advantage
The PSI Audio speakers featuring the AOI system have much superior impulse behavior to traditional amplifier designs. Whilst the transducer travels to its intended position the AOI circuitry seamlessly adapts the amplifiers output impedance to insure ideal acceleration of the membrane to reproduce the desired impulse. Once the transducer reaches the end of the impulse the AOI circuitry provides a break in order to act against an overshooting of the transducer. The AOI circuitry is almost capable of reproducing a square wave and therefore increases accuracy by marring the transducer and the amplifier in to a perfect couple. A nice side effect of the AOI system is that the membranes of a PSI speaker do not produce parasite sounds when other speaker systems in the room are in use. When air pressure is produced by other sources than the PSI speakers the AOI will detect this and tighten the damping of its transducers in order not to produce parasite sounds not originating by the speaker system in use. 

In today’s times where much more importance is given to the low end reproduction of sounds especially when using sub woofer technology in surround sound systems the importance of a monitoring system that has an accurate and not a flattering reproduction becomes essential. The result of the AOI featured PSI Audio speaker range is a speaker family with a highly accurate impulse behavior with a minimum of transducer coloration. 

AOI - teknisk beskrivelse og forklaring

CPR - teknisk beskrivelse og forklaring

PSC - teknisk beskrivelse

PSI Monitorer - brukerveiledning