FLASH - SYMPOSIUM ROOM RECEIVES OUTSTANDING CRITICAL NOTICE AT RMAF 2007!
Click HERE to see the on-line report from The Absolute Sound's AV Guide
Click HERE for a run down and description of ALL the equipment used in the Symposium Room at RMAF 2007.
Introduction
The Panorama is the result of more than 12 years of development of a true state-of-the-art ribbon / planar magnetic / dynamic hybrid speaker system, and features new techniques of diaphragm treatment, design and suspension, combined with no-compromise frame and magnet motor construction which benefits from well-known Symposium isolation, damping, and mechanical grounding technology. The Panorama achieves effortless transparency, speed and fidelity to the input signal, with room-filling image width, height and depth on appropriately recorded stereophonic recordings, yet will not "bloat" or exaggerate the size of sonic images. Its outboard passive crossover system employs low-distortion, phase-correct slope filters in order to preserve transient response across the audible range; each driver has been carefully designed, sized and positioned in order to preserve these proper imaging and virtual size characteristics.The first demonstration of early Panorama technology was made in 1994 in Los Angeles with a bi-amplified, line-source system which included a full-range ribbon-drive HF line source section and a separately powered, planar "ribbon bass" driver (see photo at bottom of page). The prototype displayed at the 2007 Rocky Mountain Audio Fest (shown in the pictures immediately above and below) employs newly designed lower midrange, upper midrange high frequency planar drivers, and true ribbon dipolar tweeters combined with a matching transmission line bass system that uses high quality cone drivers. Future versions will offer an optional planar dynamic "magnetostatic" bass unit with response to below 30 Hz.
Description
The Panorama is a four-way, quasi-point source loudspeaker consisting of proprietary ribbon and planar magnetic drivers and an aperiodic transmission line bass unit. Response covers the entire range of human hearing and the entire speaker is driven with only one amplifier - the bass towers are NOT separately powered or biamped. Amplifiers of 20 watts power or less (estimated efficiency is in the range of 93-94 dB) are recommended as a minimum; 60 watts per channel is plenty of power to give satisfying room-filling sound with powerful bass. Efficiency, frequency response, transient response and power response (which describes the loudspeaker's ability to evenly distribute all frequencies throughout the entire room, and not just in one directed sector) are excellent, and are a result of the Panorama's design which preserves a fairly constant ratio of wavelength to driver size throughout the range from the lower midrange up. The Panorama's midrange-through-tweeter drivers are arranged for optimum dispersion in a modified MTM (midrange-tweeter-midrange) array in order to preserve accurate reproduction of the virtual sound source "image." To our knowledge, the Panorama is the first loudspeaker to utilize disparate planar magnetic and ribbon drivers which cover different frequency ranges in an all-planar MTM configuration. Further, the Upper Midrange and Ribbon Tweeter drivers are mounted on a separate baffle which "floats" independently of the main frame Lower Midrange drivers in a proprietary isolation scheme.
The Planar Drivers
The heart of the Panorama is its planar magnetic, "ribbon drive" elements designed and manufactured exclusively by Symposium, and benefit from new, proprietary technologies. The drivers are constructed with no-compromise materials to achieve extreme rigidity and very low chassis resonance, and team extremely powerful neodymium iron boron magnet motors with extremely light, specially suspended diaphragms in order to achieve fast transient response, flat frequency response, realistic imaging, and unparalleled transparency and musicality. In addition, each lower midrange driver may be tilted at a precise angle of the owner's choice in order to tailor the directive pattern of the speaker to individual room characteristics. This gives the owner the ability to "dial in" imaging and thus precisely match the Panorama to his or her individual personal preferences for virtual imaging characteristics.
The Bass
The Panorama prototype's bass cabinet utilizes an aperiodic transmission line design, and is the only part of the Panorama with conventional dynamic cone drivers. Transmission line bass systems have long been admired for their superior transient response and extended low frequency response, but are difficult to realize due to various, seemingly intractable problems related to transmission line tube resonance. In order to tame these problems, the Panorama's transmission line is aperiodic; that is, its twin 8" drivers are staggered along the line to create three different line lengths in the same cabinet in order to smooth out response. In addition, the port exhaust has been given a unique 6 foot long mouth taper which improves impedance matching to the air. These and other techniques preserve transient speed and efficiency while minimizing frequency response fluctuations (due to the combining adding or cancelling of the front wave by the rear wave), the traditional bane of transmission lines. The result is that the Panorama's bass drivers blend in seamlessly with the high frequency section, yet provide realistic, authoritative bass which is at once nimble and powerful.The Crossover Network
The crossover may be likened to the "brain" of any multi-way loudspeaker system, and orchestrates each element's contribution to the reassemblage of the original signal. Crossover network design is as important as any other aspect of loudspeaker design: it doesn't matter how good the speaker drivers are if the crossover isn't correctly designed.The Panorama crossover is the result of decades of study and experimentation. Constructed of the highest quality individual components available, each crossover element is tuned and each channel element matched to within a percent of its corresponding sibling element. Housed immediately behind the HF Section, the crossover is assembled on a special edition Ultra Platform which isolates the crossover elements from the speaker and also damps the speaker frame at the same time. All wiring and connections to speaker drivers are made by high quality silver wire, and ground and positive signal busses inside the crossover consist of solid rectangular silver bar. In addition, all coils in the crossover units are arranged in optimum positions in order to minimize "crosstalk" from coil-radiated magnetic fields, a known source of coloration in passive crossover networks.
Absolute Phase control
The resolving power of the Panorama is such that it was decided that an absolute phase control should be incorporated in the crossover network, since the difference between absolute phase is plainly audible with good recordings, and not all active electronics components or systems have a "phase" switching capability. Therefore, a high quality switching system with "inaudible" silver/gold contacts is incorporated in the Panorama crossover network and is controllable from a remotely located control box. The system is bypassable.Driver Compound Isolation and chassis Vibration Control
The Panorama benefits from Symposium isolation and vibration control techniques, with constrained-layer damped solid aircraft aluminum frame support bars which simultaneously damp spurious vibration while providing an unimpeded, non-reactive mechanical ground path. The specially designed side panels of the latest version Panorama affords additional damping of frame vibrations and shapes rear wave radiation to improve imaging characteristics. Rollerblock isolation is used under both HF and Bass units to reduce intermodulation distortion, and the upper midrange and tweeter planar drivers are additionally compound-isolated from the main frame of the HF section with a floating, damped spring suspension system. Due to the addition of isolation systems in series (as oppposed to merely in parallel), the extremely critical upper midrange and tweeter units benefit from Compound isolation, patented by Symposium USA, Inc.The Immediate Future
The Panorama will exist in several versions ranging from the "Reference" versions with either separate transmission line box or full-sized "ribbon" bass driver to smaller, "single-box" units which will combine conventional cone drivers with Symposium planar magnetic drivers. Availability will be limited, since these loudspeakers will be constructed individually to the exacting standards of Symposium products, and pricing will be announced. Please contact Symposium direct for more information.
Press Reactions
The Panorama has attracted positive reactions and attention from many sources, but perhaps none as prestigious as The Absolute Sound, America's most respected high end audio magazine. You can link to their show report here.
The first Symposium product was this loudspeaker, dubbed The Symposium, and demonstrated to members of the high end audio press in Los Angeles in 1994. It represented the beginning of the basic driver design technology and acoustic principles embodied in the current Panorama. The original Symposium was a biamplified line source that featured "full range," crossoverless midrange to treble line source and matching planar dynamic bass drivers. Bass response was fast, dynamic, and detailed, and extended into the 20 Hz range.
