DALI OPTICON WHITEPAPER
INTRODUCTION Designing a performance speaker series accessible to a wide audience is not just difficult – it is a huge challenge. Doing it the DALI way, with an unyielding focus on audio reproduction, construction quality and using the latest breakthrough technologies, only adds to the challenges. Nonetheless, this was exactly the task we set out to solve.
CABINET Cutting the MDF boards for OPTICON cabinet production. Rigid cabinet structure and separated chambers for the drivers. Placing V cuts along the MDF board before the folding of the final cabinet. Keeping the manufacturing of the OPTICON series firmly in the hands of DALI we utilize our large and efficient woodworking facility in Denmark to handle everything from cutting out the Medium Density Fibre board (MDF) cabinet to applying the vinyl.
BAFFLE The baffle sports a black or white high-gloss finish, for a more exclusive look and feel. The slim-line design of the front baffle contributes to the stereo perspective. And the ‘clean’ surface is not only pleasing to the eye; it reduces diffractions to an absolute minimum. The OPTICON series’ front baffle form a rigid base for the drivers, which are screw-mounted directly into the 25 mm thick MDF.
WOOFER The SMC pole piece set the OPTICON woofer apart for the competition with significant reduction of eddy currents and hysteresis. Design The OPTICON woofer is designed with a strong focus on DALI sound principles of low-loss, low distortion and low colouration of the reproduced sound. The ideal speaker plays just what the amplifier intented, with nothing added and nothing subtracted. Every part in the OPTICON woofer is carefully chosen for its low-loss abilities..
SMC Soft Magnetic Compound (SMC) is a coated magnet granule that can be shaped into any form that you would want. SMC has many advantages, and used in a speakers magnet motor system it result in a significant reduction of distortion from mechanical loss. SMC’s unique ability to deliver a high magnetic conductivity and a very low electrical conductivity delivers all the wanted qualities of a really good speaker magnet without the traditional downsides.
Hysteresis When using iron based magnets in speakers, the magnetization and demagnetization introduced by the shifting current directions doesn’t happen at the same pace. The demagnetization process is often slower than the magnetization. This phenomenon is called hysteresis, and is a known problem in almost all speaker magnet motor systems. The problem with hysteresis is that it introduces an unintended resistance Woofer optimisation to the voice coil, meaning unwanted distortion.
TWEETER DALI has a long and well proven tradition for using a hybrid tweeter module. It is a combination of a dome tweeter working together with a ribbon tweeter for an amazing rendering of the high frequencies, and a dispersion of high frequency sounds that outperform all other tweeter technologies. In the OPTICON series, DALI makes use of both the soft dome working alone, and the hybrid tweeter configuration.
RIBBON The ribbon tweeter features a broad frequency band and superb dispersion in the higher frequencies. Gently rolled in above 10 kHz, the ribbon reaches full contribution from 14 kHz to well beyond 30 kHz, far above the audible range. Equipped with a rear chamber fitted with rigid bracing, the ribbon is shielded from the disruptive influence of the woofers.
BASS REFLEX PORT All speakers in the OPTICON series rely on the bass reflex principle. The bass reflex port has been tuned to minimize distortion from the woofers, and to control the time response of the roll-off from the bass system. On the OPTICON LCR, DALI has taken bass port design to a new level. Wanting to maximize inner cabinet volume we moved the bass port to back of the speaker.
SIGNAL PATH The shorter the signal path, the better. That is why we have mounted the crossover directly onto the terminals – minimizing potential signal loss from the terminal to the crossover. Due to the high quality wideband drivers used in the OPTICON series, the crossover can be kept relative simple, pertaining as much of the original electrical signal as possible.
ACCESSORIES All floor standing OPTICON speakers come with spikes made of black chrome steel. These are mounted in the aluminium cast ‘feet’. For use on ‘sensitive’ floors, we have also included vibration absorbing feet which will leave soft surfaces - such as a wooden floor - untouched. DALI A/S www.dali-speakers.com Tools for mounting the aluminium feet and spikes are included.
PRODUCTS The DALI OPTICON series consist of no less than seven individual speakers. They are all build around a DALI manufactured SMC based woofer and uses either a soft dome tweeter or the hybrid tweeter module, which DALI is so well known for. The cabinets are available in three finishes, Silk matte White, Black, and Walnut. OPTICON 2 is a mid-sized stand mount speaker. The 6½” woofer and the more voluminous cabinet make this speaker a true 2-way compact performer.
OPTICON 6 has all the virtues of the OPTICON 5 with the added power of an extra 6½” woofer. Combined with the larger volume inside the cabinet, the OPTICON 6 reaches lower into the deep bass producing an even more impressive soundstage. Its high sensitivity and even impedance load together with its impressive ability to reproduce undistorted audio makes the OPTICON 6 the perfect balance between size and performance.
TABLE 2 - OPTICON TECHNICAL SPECIFICATIONS OPTICON 1 OPTICON 2 OPTICON 5 OPTICON 6 OPTICON 8 OPTICON LCR OPTICON VOKAL Frequency Range [+/- 3] dB [Hz] 62 - 26,000 59 - 27,000 51 - 32,000 49 - 32,000 38 - 32,000 72 - 32,000 47 - 32,000 Sensitivity [2.83V/1m] [dB] 86 87 88 89 88 90.5 89.
