A new concept in speaker comparison.
Instead of speaker vs speaker...
Live versus...
Piano Waveform. Bass Drum Waveform.
If you were satisfied with conventional speaker sound, Technics would have made a conventional speaker. Then you could have compared our speaker to their speaker.
Instead, we developed Technics Linear Phase Speaker Systems and compared them to music. Live music. Look at the wave forms. On the left are oscilloscope readings (the fingerprints) of representative musical instruments. On the right, these instruments as reproduced by Technics Linear Phase SB-7000A. Waveform fidelity that could only be achieved by a drastic departure from conventional speaker design.
How did we do it?
Our engineers realized there were three conditions to be satisfied. First, the crossover network should be designed to provide an overall linear phase characteristic for the whole speaker system, while simultaneously compensating for the different acoustic pressures of the individual drivers. Second, each driver unit must be precisely located in the optimum acoustic position. Third, the driver units must be designed and manufactured with flat amplitude and a wide frequency response.
By using our unique new phase-controlled crossover network, which incorporates 6 dB and 18 dB/octave cut-off slopes and special phase-correcting circuits for each driver, Technics engineers have been able to achieve an overall phase response, linear between 00 and ,_45° between 100 Hz and 15 kHz. An incredible figure in a multi-range speaker system! The special phase -correcting circuits have also eliminated "audible dip" at crossover frequencies. These circuits assure excellent directional localization of the original sound source within the acoustic field.
To align the acoustic centers of the speaker units in precisely the same vertical plane, Technics engineers had to develop a new time-delay system using BBD (Bucket Brigade Device). After alignment, each unit was fine-tuned to assure precise linearity.
Additionally, each unit was positioned vertically for the best horizontal dispersion and then spaced as closely as possible for the best vertical dispersion of all sound frequencies.
Each of the wide frequency response/low distortion driver units was designed and manufactured by Technics after exhaustive amplitude and phase studies in anechoic chambers. It is this ability to both design and manufacture that has helped us become the world's largest speaker company. Supplying many of Europe's and America's finest speaker system designers with high -quality speaker units.
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Technics Linear Phase
Piano Waveform reproduced by SB-70001.
Bass Drum Waveform reproduced by SB-7030A.
The result: Waveform Fidelity
The diagrams show the phase and amplitude characteristics of Technics linear Phase and three other leading speaker systems.
The other speaker systems, including those promoted with "phase linearity," show severe phase shifts at different frequencies! But, as you can see, Technics Linear Phase Speaker Systems show an unprecedented flat and linear phase response. This results in more precise positioning of instruments in the stereo sound field.
What does all this mean to you? Waveform fidelity you can hear... and see. For the first time in audio history there is a speaker system with not only wide frequency response, but complete linearity: Flat amplitude/frequency response and linear phase/ frequency response.
Technics SB-7000A, SB-6000A and SB-5000A. The world's most linear phase speaker systems. No more wandering stereo imagery, no more bass loss at high volumes; just music, pure and simple, as it was originally played. Live.
And if specifications are music to your ears. Listen to these:
SB-7000A: 3-way speaker system with 13 3/4 "woofer, 4 3/4" mid-range and 1 1/4" dome tweeter. Output level (1M) of 90.5 dB/watt.
SB-6000A: 2 -way speaker system with 12" woofer and 1 1/4 " dome tweeter. Output level (1M) of 91.0 dB/watt.
SB-5000A: 2 -way speaker system with 10" woofer and 2 3/8" tweeter. Output level (1M) of 92.0 dB/watt.
The SB-7000A cone-type units are made from a new triple layer TC/aramid fiber.
This combines lightness with high Young's modulus (strength) for smooth piston motion and low distortion.
The high-efficiency dome type tweeters in the SB-7000A and SB-6000A use a diaphragm of heat molded expanded polyurethane on a silk cloth base.
Sounds great, doesn't it. But there's really only one way to be truly convinced.
Listen to Technics Linear Phase Speaker Systems. Now available for demonstration at selected audio dealers for very selective ears.
Test data and methodology available upon written request. Write Mr. James Parks, Technics Dept., One Panasonic Way, Secaucus, New Jersey 07094.
Technics by Panasonic.
(High Fidelity, Apr. 1977)
Also see:
Technics by Panasonic -- SL series turntables (ad, Nov. 1977)
Sony SSU series speakers (ad, Apr. 1977)