PSB Speakers of America Overview History & Research

Brand Development The Lenbrook Group owns 2 specialty brands: PSB Speakers & NAD Electronics Technology Development The Lenbrook Group has developed new wireless technology - products with emerging service revenue opportunities including Clearnet Communications, ComSpace Corporation and AirIQ Inc. Distribution Management Lenbrook’s original core business now operates in Canada, the USA, Asia and the UK as well as independent distributors worldwide.

PSB Int’l Head Office Pickering, Canada Lenbrook A/V Canada Pickering, ON Lenbrook America Boston, MA Lenbrook UK Milton Keynes Lenbrook Asia Singapore PSB Independent Distributors - PSB is sold in 25 countries a r o u n d t h e w o r l d

In 1972, violinist/engineer Paul Barton, at just 21, founded PSB Speakers as a work/study program. “As a symphony musician, and also through my involvement in sound engineering in the recording studio, I came to the realization in 1971 that live music and recorded music, for the most part did not accurately resemble each other.” h i s t o r y The Early Years…

Performance Exceptionally accurate tonality, tremendous dynamic range and superb clarity and detail. Value Sets the standard for speaker designs that deliver the best sound per dollar. Appearance Strikingly simple, slim, elegant lines. Exceptional fit and finish quality. Reliability High quality proprietary drivers, crossovers and enclosures assure a good investment. Backed by a comprehensive 5 year warranty. p h i l o s o p h y PSB Goals

r e s e a r c h Canada’s National Research Council (NRC) PSB gathers extensive acoustic research knowledge on sound reproduction and perception. PSB Research

Canada’s National Research Council (NRC) Campus PSB Research r e s e a r c h

"How do Measurements Relate to Listening Preferences?" r e s e a r c h

Listening Tests Listening is the final analysis of loudspeaker quality and is the basis for selecting loudspeakers for domestic applications. How measurements relate to listening perceptions. Evaluations had relied on subjective and unrepeatable judgments. Standard testing parameters had not been established. r e s e a r c h

Challenges: Controlling the Variables Listening Environments - Real World Source Material Aesthetics Listening Levels Establishing Evaluation Vocabulary and Evaluation Methods Choosing Speakers for Testing Selecting Subjects and Eliminating Bias r e s e a r c h

The Listening Environment Major Factor in evaluations Identifying and designing a typical real world listening room 22’ x 13.5’ x 9.2’ - Ratio (1 x 1.46 x 2.39 / LxWxH) Reverberation Time Speaker Placement - Driver Height Seating Arrangements r e s e a r c h

Sound Levels All listening levels must be equalized. Program Materials Source selections will alter listener opinions. Recording techniques will enhance or detract from loudspeaker performance. All recordings were standardized using consistent high fidelity studio equipment and recording environments. r e s e a r c h

Listener Variables Eliminated product identities and aesthetics by placing loudspeakers behind an acoustically transparent screen. Listeners were chosen from a broad range in age and experience. (New listeners were given rehearsal rounds) Each program tape was limited to short intervals and contained considerable redundant material. Communication between subjects had to be controlled. A numbering system of evaluation produces the most consistent and reliable judgments. r e s e a r c h

Controlling Experiment Variables Standardizing assessments of different individuals. Loudspeakers can influence opinions of other loudspeakers - even the order of listening. Individual products chosen in grouping should not display any strong idiosyncrasies. (colorations/directionality) The order of speakers tested were randomized Changing loudspeakers being tested was instantaneous and auditioned an equal number of times. All experiments utilized double blind testing. r e s e a r c h

Controlling Experiment Variables Listeners instructed to avoid high pressure sounds for 12 hours Listener’s hearing was tested Hz (measurements loose precision above 8kHz) Standardized Evaluation were given in verbal and written form Listeners were seated in numbered locations and rotated seats to average room position effects Loudspeakers were picked in sets of four and positions rotated 30 minute rest period between sessions/ 6 sessions daily No verbal discussion between tests r e s e a r c h

Scaling Listener Responses Overall Sound Quality Responses - Pleasantness and Fidelity Fidelity was intended to reflect the extent to which the reproduced sound resembles reality. Pleasantness was used to describe musicality Comments Section was used regularly on these two evaluations Further ratings were required to force listeners to evaluate several important aspects before arriving at an overall assessment (see next slide) Inexperienced listeners may tend to concentrate on only the most obvious features Overall Ratings were scaled numerically on a scale of 0-10 with one decimal place (5.3 etc.) r e s e a r c h

Detailed Analysis Included: Sound Quality Clarity and Definition. Softness. Fullness. Spaciousness Presence. Distortions. Loudness. Frequency Response. Coloration Spatial Quality Definition of Sound Images. Continuity of Sound Stage. Width of Sound Stage. Depth. Abnormal Effects. Ambience, Spaciousness and Reverberation Presence You are there. Close but still looking on. Outside looking in They are here. Artificial/Contrived. Other (describe) r e s e a r c h

Testing Results: The majority of listeners consistently endorsed the same loudspeakers. Testing was repeated to confirm results. Listening data was converted to measurements. Design criteria was developed to relate directly to true to life reproduction. Challenge - Interpreting the results r e s e a r c h

Interpreting Results (PSB) in order of listener and design priority 1.Spectral Balance - The ability of a loudspeaker to respond with equal output volume from lowest to highest frequencies 2.Dispersion - The ability of a system to produce flat frequency response both in front of the speaker and off axis. 3.A) Distortion (Harmonic) - Is most audible in the middle frequencies - It occurs when harmonics are not produced at the same aptitude as the primary frequency. B) Distortion (Intermodulation) - Occurs when the driver is reproducing a low and high frequency at the same time, causing the high frequency to modulate on the lower frequency. (higher volume) 4.Transient Response - The ability of a loudspeaker to start and stop exactly without any overshoot causing ringing and resonances. 5.Dynamic Power Range - Occurs when the loudspeaker displays extremes in efficiency. Either extreme will result in problems with the first four points. Balancing dynamic power range is a priority. 6.Phase Response - The ability of a system to produce music in an equal time base as received in the recording. r e s e a r c h

Paul Barton was involved in designing the testing experimentation and was the first engineer to design loudspeakers using this data. Paul Barton uses this criteria extensively to design all loudspeaker systems. Properly interpreted set of measurements correlates closely with listener preferences. PSB speakers have consistently chosen as a top choice in ongoing testing. (see brochure) Paul’s musical experience allows for proper interpretation of the gathered data. Materials and system designs are chosen as a means to achieve the desired results. r e s e a r c h

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