What is stereo?




There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.




H.H. Scott '59





Pioneer PL-540 turntable

 

Auto-Return Quartz-PLL DC Direct-Drive Turntable

Now that you know to look for in a turntable, look at the PL-540 from Pioneer. If you've ever owned a good manual single-play turntable without automatic return, you know how desirable the latter can be - if only it doesn't compromise tone arm sensitivity.

The auto-return system in the Pl-540 doesn't harm sensitivity. If you've ever wished your turntable had the accuracy of a professional studio type - but without a studio-standard high price. The DC Hall motor and Quartz -PLL in the PL-540 deliver the same accuracy - 0,025% or less wow and fluter - as monitor turntables used in record-cutting studios. But its price is considerably less. If you've suspected that the boxy cabinet and shaky little feel on yesterday's best turntable are not  enough to be called "best" today, and if the latest improvements in tone arm suspension and platter design have set you thinking about replacing your favorite noisy old faithful; look at the Pioneer Pl-540.  And as you do, remember to ask for an audition of its superb tonal quality. Your ears will see that it's the turntable you've been listening for.

 


Our Own Quartz-PLL Servosystem

There are 200 evenly-spaced magnetic "bits" on the bottom of the rotor of the DC motor, and each has two poles; the north pole of one is opposite the south pole of the next, and so on. Then positioned below is a circular circuit board on which is a printed coil with 200 poles. A current proportional to the actual speed of the direct-drive motor is generated in the coil circuit as the magnets rotate above, and that current is sent to the PLL or Phase-Locked Loop circuit and Sampling & Hold Circuit in the servo. There phase is compared with that of an ultra-accurate reference signal from the built-in Quartz oscillator. Differences in phase if any, are converted into control voltages which in turn "tell" the motor to speed up  or slow down to achieve absolutely accurate rotational accuracy in far less time than it takes your eye or ear even to begin to detect even the slightest error.

 


Specifications

Drive System:  Quartz PLL direct-drive system

Motor:  Quartz PLL Hall-motor

Speeds:  33-⅓ and 45 rpm

Wow and Flutter:  no more than 0,025% (WRMS)

Signal-to-Noise Ratio:  more than 73 dB (DIN-B)

Tone Arm

Type:  Static-balanced S-shaped pipe arm

Effective Arm Length:  221 mm (8-11/16")

Overhang:  15,5 mm (5/8")

Usable Cartridge Wight:  4 g - 10 g

Power Requirements:  110/ 120/ 220/ 240 V 50/60 Hz

Power Consumption:  8 watts

Dimensions (W x H x D):  440 x 145 x 365 mm (17-5/16" x 5-11/16" x 14-3/8")

Weight:  10 kg (22 lb 1 oz)

Pioneer PL-520 turntable

 

Dual-Motor Direct-Drive Full Automatic Turntable with Brushless DC Servo and Front-Control Design, Low Howling

 

Precision mechanisms. Precision speed control. Pioneer has combined the best of both in a turntable which, not surprisingly, delivers precision performance. What will surprise you, pleasantly, is the price. Where elaborate, costly devices in other turntables are needed to drive the platter and the arm from one motor, we use independent motors for each and save the expense. Where uncomfortably bulky cabinets are used by other manufacturers to disguise internal vibrations and shut out howling, we use a high-mass base and wrap-around SPC steel plate to achieve good looks and the highest anti-howling characteristics of any competing model. On the PL-520, all controls for the fully automatic/manual operations and speed adjustment are up front, outside the dust cover. On the PL-520, a newly-designed Pioneer tone arm with direct stylus pressure adjustment and special anti-resonance features ensures precision performance where it counts most.

 

PL-520 Features

Brushless DC Servomotor with Hall Elements

The PL-520 incorporates a high-precision phonomotor combining control circuitry composed of semiconductors with Hall elements in the brushless DC motor. The speed of the platter is smooth since the Hall elements guarantee accurate position detection and the motor's winding current is controlled by transistors. Another feature is the high inertia platter. Altogether, these attractive features make for a Signal-to-Noise Ratio of more than 73 dB (DIN-B) and wow and flutter of less than 0,03% (WRMS).

 


Two-motor, Full-automatic Turntable with Precision Geared Motor Mechanism

The lead-in and return of the tonearm are performed by a special precision geared motor mechanism which does not affect the speed of the platter at all. Furthermore, a speed detection-type auto-return mechanism controls the tonearm for accurate and stable operation every time it is returned to the arm rest.

 

Switches and Controls are Located at the Front for Easy Operation

The two-speed fine-adjustment knob for adjusting the speed of the platter, the push-button speed selector switch, the size selector for selecting the size of the records, the stop button, repeat button and start button are all located on the front panel. This means that you don't have to lift the dust cover every time you want to make an adjustment. It also means that it is much easier to use this turntable on a shelf or audio rack.

 

High-sensitivity Tonearm with Excellent Trackability.

The newly developed, high-sensitivity S-shaped tonearm comes with built-in lateral balance and anti-skating mechanisms and it displays excellent tracking performance with a light tracking force cartridge. There is a separate tracking force weight in front so that you can easily change the tracking force even if you have mounted your turntable in an audio rack.

 

Wide Selection of Accessory Mechanisms

There is a plentiful variety of accessory mechanisms including an independent arm-elevation mechanism, a headshell stand for conveniently storing a spare cartridge, a free stop-hinged dust cover which allows easy attachment and removal, and large-sized insulator feet.

 


Specifications

Drive System:  Direct-drive

Motors:  Brushless 8-pole 24-slot DC Servo controlled motor (for platter drive), Warren motor (for automatic functions)

Turntable platter:  330 mm diam. Aluminum alloy die-cast

Inertial Mass:  200 kg-cm² (including platter mat)

Speeds:  33-⅓ and 45 rpm

Speed Control Range:  within ±2%

Wow and Flutter:  no more than 0,03% (WRMS)

Signal-to-Noise Ratio:  more than 73 dB (DIN-B0, 60 dB (JIS)

Tone Arm

Type:  Static-balanced S shaped pipe arm

Effective Arm Length:  221 mm (8-11/16")

Overhang:  15,5 mm (5/8 ")

Tracking Error:   0,21 deg./cm (0,525 deg./in)

Usable Cartridge Weight:  4 g - 10 g

Cartridge Specifications

Type:  Moving Magnet

Stylus:  0,5 mil diamond (PN-400)

Output Voltage:  2,5 mV (1 kHz, 50 mm/s peak Velocity, LAT)

Tracking Force:  1,0 g to 1,8 g (proper 1,5 g)

Frequency Response:  10 to 40,000 Hz

Power Requirements:  110/120/220/240 V 50/60 Hz

Power Consumption:  8 watts

Dimensions (W x H x D):  460 x 171 x 395 mm (18-1/8" x 6-3/4" x 15-9/16")

Weight:  8,5 kg (18 lb 12 oz)

JVC QL-7 turntable

 

 The QL-7 is nearly identical to the QL-A7, though it lacks the end-of-play arm liftup/stop convenience and is correspondingly less expensive. Specifications are identical, including less than 0,025% WRMS wow/flutter , and a Signal-to-Noise Ratio of beter than 73 dB (DIN-B). Other performance parameters are equally superb, and intentionally superior to those of conventional direct-drive turntables in the same price range.

 

JVC Quartz and JVC Motor

jVC Quartz Technology is pleasantly apparent in the QL-7 , achieving the most uncanny speed accuracy. This accuracy is in no way compromised by our use of a DC direct-drive motor that spins the heavy 2,2 kg (4,8 lbs) platter - including rubber mat - with powerful torque (over 1kg-cm). Exceptionally low wow and flutter of 1,125% (WRMS) and speed drift of no more than 0,0001%/hour are other prominent features you can count on to bring you Closer to the Musical Truth.

 


Quick Start and Quick Stop

The QL-7A, like every JVC Quartz Turntable in this brochure, has a quick start feature; in no more than 1,4 seconds after you turn on the turntable, the platter rotates precisely at 33 rpm or 45 rpm. It also has a quick stop feature using a low-wear mechanical brake, which stops the platter in less than 1,6 second. For ease of operation, three buttons - one each for 33 rpm, 45 rpm speeds and Stop - use Touch Sensors; a simple brush of one with your finger selects speed or stops the platter.

 

Quartz-Synchronized Strobe

Since the strobe is illuminated by the neon lamp whose pulses are synchronized by the Quartz servo, just one row of strobe dots is required. The pattern is sharply contrasted and always clear. Other features of the QL-7 include; New Gimbal Support, Parallel Isolator Suspension, Oil-Damped Cueing, solid cabinet, and more.

 


Specifications

Type:  DC servomotor

Drive System:  Direct-drive

Speeds:  33-⅓ and 45 rpm

Speed Detection System:  Integrated Frequency Generator

Servosystem:  Quartz Servosystem

Speed Change:  Touch Sensor

Start-up Time:  less than 1,4 sec

Wow and Flutter:  less than 0,025% (WRMS); 0,045% (DIN)

Signal-to-Noise Ratio:  better than 73 dB (DIN-B); 63 dB (IEC-B)

Start-up Torque:  better than 1 kg-cm

Speed Deviation:  less than 0,002%

Load Characteristics:  0% (under 120 gram loads)

Drift (hour):  0,0001%/H

Voltage Drift (±10V):  0%

Thermal Drift:  0,00005%/°C

Quick-Stop Time:  less than 1,6 sec

Platter

Type:  313 mm aluminum die-cast

Tonearm

Type:  Statically-balanced arm with New Gimbal Support on TH (Tracing Hold) System

Effective Lenght:  245 mm

Tracking Error:  +1°48'  -1°31'

Overhang:  15 mm

Applicable Tracking Force:  0 - 3 grams (0,25 gram steps)

Applicable cartridge Weight:  14,5 - 23,5 grams

Arm Elevation Range:  43,5 - 54,5 mm

Operation Mode:  manual

Dimensions (W x H x D):  477 x 152 x 401 mm ( 18-3/4" x 6-3/8" x 15-3/4")

Weight:  10,8 kg (23,8 lbs)

JVC QL-5 turntable

JVC Quartz technology

JVC Super Servo Frequency Generator

Highly Sensitive New Gimbal Support

Quick Start and Quick Stop

 

The QL-5 has all that's needed for your musical enjoyment including, of course JVC Quartz servo. It's the "no-frills" model in our lineup of Quartz Turntables, and its balanced electrical and mechanical construction makes it a particularly good buy.

 


JVC Technical Knowhow

To produce expensive state-of-the-art. Equipment is not our only virtue, our knowhow accumulated during a half century of work, permits us to use the best of electronics and machining technique to offer reasonably priced equipment for serious audiophiles JVC Quartz Turntable are no exception. In the medium-priced QL-5 for instance we;ve designed a special C-MOS IC which incorporates all necessary circuits for the servo system. This configuration not only simplifies the circuit-board layout but improves overall dependability.

 

jVC Quartz and Super Servo FG

With its simplified circuitry and mechanisms, none of the JVC Quartz Technology has been omitted from the QL-5. the precision Quartz oscillator, responsive servo system, JVC Super Servo Frequency Generator, accurate direct drive DC servo motor, etc., are all part of this attractive and supremely reliable turntable package. All superb basic parameters are all included.

 

Heavyweight Platter

To absorb all miniscule vibrations, the platter must be heavy and accurately concentric. The dynamically balanced one used on the QL-5 is heavy weighing 2 kg (4,4 lbs) rubber mat included. Wow and flutter is thus virtually eliminated, while speed accuracy is maintained against suddenly increased loads. Among other QL-5 features are the Quick Stop, New Gimbal Support, newly designed One-Row Strobe, Oil-Damped Cueing, solid cabinet, and JVC height-adjustable, Dome isolating Suspension.

 


Specifications

Motor:  12-pole, 24-slot, DC type FG servomotor

Drive System:  Direct-drive

Speeds:  33-⅓ and 45 rpm

Wow and Flutter:  less than 0,025% WRMS

Rumble:  better than73 dB DIN-B (63 dB IEC-B)

Speed Detection:  Integrated FG

Starting Torque:  better than 0,8 kg-cm

Speed Deviation:  within 0,004%

Load Charcterisctics:  0% (with 100 g total tracking force)

Drift per Hour:  0,0001%/H

Power Characteristics:  0% (±10%)

Temperature Characteristics:  0,00005%/°

Platter:  312 mm diameter

Quick Stop Time:  within 1,6 sec.

Tonearm

Type:  Tracking-Hold system, static balanced, New Gimbal support

Effective Length:  245 mm

Tracking Error:  +1°48'  -1°31'

Overhang:  15 mm

Tracking Force Range:  0 -3 g (0,25 gram division, direct reading)

Weight Range (including headshell):  14,5 - 22 g (headshell 10 g)

Height Range:  39 - 51 mm (present to 43 mm)

Mechanisms Equipped:  Oil-damped arm elevator, Anti-skating system, headshell mountingangle fine adjustment possible

Cartridge

Type:  Moving Magnet (Cartridge body MD-1025)

Stylus:  0,3 x 0,7 mil. Diamond (DT-Z1TE)

Optimum Tracking Force:  2 grams

Output:  3 mV (1 kHz)

Frequency Response: 10 to 25,000 Hz

Separation:  better than 25 dB (1 kHz)

Load Resistance:  47 k Ω

Compliance: 

Dynamic ;  10 x 10¯⁶ cm/dyne

Static :  30 x 10¯⁶ cm/dyne

Power Requirements:  AC 110, 120, 220, 240 V 50/60 Hz

Power Consumption:12 watts

Dimensions (W x H x D) :  481 x 165 x 403 mm (18-15/16" x 6-1/2" x 15-7/8") with cover closed

Weight:  10,5 kg (23,1 lbs)

Magneplanar MG-IIc speakers

Magneplanars provide unique styling not available in box speakers. With optional trim and fabrics, Magneplanar Screens can blend or contrast with the surrounding decor, thus forming a backdrop in the same manner as curtains or drapes. With Magneplanars you have the ability to add a pair of speakers to your living area without adding the visual "weight" of box speakers. Magneplanars are easily moved for vacuuming or repositioning to other listening areas.

 

Magneplanar MG-IIc (and MG-Ic), these models are of similar design , both representing excellent value. The MG-IIC is one foot taller than the MG-Ic, providing better vertical dispersion and extension of the frequency extremes. Both models appeal to a wide range of listening tastes. For the classical music enthusiast, the critical midrange of the MG-IIc is often the speaker of choice. Having been introduced in their original versions many years ago, these speakers have benefited from years of gradual refinements.

They highlight Magnepan's belief that there should be no change for the sake of change. Improvements over earlier versions include a reduction in diaphragm mass, refinements in magnetic structure, improved crossover design, more rigid panel construction, inclusion of bi-amplification option, and improved diaphragm mass distortion.

Both models are worthy of the finest ancillary equipment and source material, and are remarkable in their respective price ranges.

 


Specifications

System :  Two-way full-range dipole radiator

Midrange/Bass Radiating Area:  500 sq/inch

Tweeter Radiating Area:  68 sq/inch

Frequency Response :  40 Hz - 18,000 Hz ±4 dB

Minimum Power Requirement:  50 watts RMS

Maximum Recommended Power :  can be safely used with amplifier up to 200 watts RMS per channel, when fused per instructions

Sensitivity:  84 dB (1 Watt/ 500 Hz / 1 m)

Impedance:  5 Ω  at any frequency (purely resistive)

Crossover System:  400 Hz to Low-pas); 1600 Hz to High-pass (6 dB/octave)

Finish:  Panels covered with off-white, black or brown fabric, with oak trim

Dimensions (W x H x D) :  22" x 71" x 2"

Weight:  45 lbs (each)

Onkyo Model 732 amplifier

Model 732 with newly discovered amplifier design

Amplify the input signal without any distortion. This is the most fundamental theme that runs through all efforts when designing an amplifier. But what is distortion and how is it produced? If these questions are not answered it is impossible to create a really excellent amplifier. Of course, every amplifier is designed to reduce distortion. In an ordinary amplifier the distortion is measured by feeding a sine wave into the amplifier. However, this wave form is very rare in real music. Usually live music has many loud and abrupt sounds. They are an integral part of good music but it is this very dynamic sound that causes much distortion due to the poor transient response of many amplifiers. Even if an amplifier has a Total Harmonic Distortion of, for example 0,01% at 1 kHz it does not mean that this amplifier can reproduce music with low distortion. If we consider the "live signal" we find it very complicated and man, without some help cannot analyse it very satisfactorily. That is the reason Onkyo resorted to electronic computer technology to analyse each signal. This computer technology was combined with extensive listening tests in an effort to discover just what distortion is and how it is caused. The result of this research enabled Onkyo to establish a new method for the design of an amplifier. Consequently, model 732 has precise equalization, big phono overload capacity, direct coupling, differential amplifier and pure complementary SEPP circuitry.

 

Equalizer Stage

Transient response is a problem left unsolved by many preamplifiers because their calculations depend on the input being a sine wave. However, this simple wave is quite different from the complex signal produced by live music. As is well known, live music contains many very abrupt and impulsive sounds and has an unbelievably wide dynamic range. The dynamic signal causes distortion in all circuits and must be taken into consideration when designing equipment.

This means that model 732's reproduction is faithful to the original music because it avoids the distortion caused by poor transient response. CAD (Computer Aided Design) is used in model 732 because it is impossible to analyse dynamic music signals with ordinary measuring instruments. By comparing extensive listening tests and the measurements of computers Onkyo was able to discover just what the distortion was and through this research established a new method of designing an amplifier.

In a preamplifier precise equalization is extremely important. To avoid distortion that is caused by saturation in this equalizer stage model 732 has a big phono overload capacity of 320 mV at 1 kHz and 1500 mV at 10 kHz.  The phono overload capacity gets larger with the rise in frequency so that it is the same as that of the RIAA equalization curve. RIAA deflection is ±0,5 dB from 30 to 15,000 Hz. The Signal-to-Noise Ratio is better than 75 dB

 


Power Amplifier Section

An unbelievable amount of effort has been expended in an endeavour to reduce distortion of any kind in the amplifier section of model 732. for this purpose model 732 has pure complementary SEPP, direct coupled and differential amplifier circuitry. The power amplifier circuitry was analysed by a computer but this analysis was not restricted to the audible range. It was extended beyond that range because live music contains many signals in this inaudible range. Onkyo found that the very low frequencies have a very important bearing on the music even though they cannot be heard. Ordinary amplifiers that do not take these very low frequencies into consideration cause a lot of distortion because this disturbance in the very low frequencies causes Intermodulation DIstortion throughout the whole range of the signal. The statistics for this amplifier are very impressive. It is capable of delivering a continuous power output of 56 watts per channel at 8 ohms. The distortion of model 732 is rated at less than 0,02% at 10 watts, 1 kHz. The same low rate of distortion is maintained regardless of whether model 732 is used at full power or played very softly.

The use of a differential amplifier means that this model is extremely stable. Instability in an amplifier will put DC voltage on the loudspeaker terminals and this will lead to distortion . Fluctuations in the power supply.

 


Specifications

Type:  All Silicon Transistor Integrated Stereo Pre-Main Amplifier

Circuit:  Direct-Coupling and Differential Amplifier, Pure-Complementary SEPP System

Semiconductors:  54 Transistors; 20 Diode; 2 Thermistor; 4 Posistor

Main Amplifier (8 Ω  load in case of no indication)

Dynamic Power: 

150 W at 8 Ω  IHF

200 W at 4 Ω  IHF

RMS Continuous Power (Both Channel Driven)

56 W + 56 W at 8 Ω  (1 kHz)

68 W+ 68 W at 4 Ω  (1 kHz)

Total Harmonic Distortion

Less than0,1% at rated output 1 kHz

Less than 0,03% at 0,5 W output 1khz

Less than 0,03% at 10 W output 1 kHz

Intermodulation DIstortion (SMPTE 70 Hz ; 7 kHz = 4 : 1)

Less than 0,05% at 34 W output

Frequency Characteristic :  10 Hz - 80 kHz (+0 -1 dB at normal output)

Power Bandwidth:  10 Hz - 100 kHz (IHF -3 dB, T.H.D. 0,2%)

Signal-to-Noise Ratio:  better than 110 dB (IHF A Network Shunt)

Damping Factor:  100 (DC - 20 kHz)

Load Impedance:  4 ihm - 16 Ω

Input Impedance:  100 k Ω  (10 Hz - 50 kHz)

Gain:  27 dB

Rated Input Voltage:  1 V

Input/Output Characteristics:  in-phase

Output Terminal:

Speaker:  A, B, C, A + B

Headphone

Pre-Amplifier

Input Sensitivity/Impedance

Phono 1 (1,03 kHz) :  2,0 mV / 50 k Ω , 30 k Ω

Phono 2  (MM) :  2,0 mV/ 50 k Ω

Phono 2 (MC) :  83 µV / 80 k Ω

Mic :  1,8 mV / 50 k Ω

Tuner, Aux 1, 2 Play :  100 mV / 100 k Ω

Total Harmonic Distortion :  less than 0,05% (at 1 V output, 1 kHz)

Intermodulation DIstortion : less than 0,05% (at 1 V output, 1 kHz)

Frequency Response

Phono 1, 2 :  30 Hz - 15,000 Hz (±0,5 dB)

Tuner, Aux 1, 2 Play :  10 Hz - 70,000 Hz (+0 -1 dB)

Max. Allowable Input Phono

MM :  320 mV (1 kHz), 1500 mV (10 kHz ) rms

MC :  13 mV (1 kHz), 60 mV (10 kHz) rms

Signal-to-Noise Ratio (IHF A Network Input Shunt)

Phono 1 :  better than 75 dB

Phono 2 (MM) :  better than 75 dB

Phono 2 (MC) :  better than 55 dB

Mic:  better than 69 dB

Tuner, Aux 1, 2 Play:  better than 90 dB

Output Voltage:

Pre-Out 1, 2 (100 k Ω  at load) :  1 V (Rated output); 4 V (Max. Output)

Output  Impedance:

Pre-Out 1, 2 :  2,2 k Ω

Tone Controls (2 dB/step Switch Type)

Treble :  ±10 dB at 100 kHz, 30 kHz

Bass :  ±10 dB at 100 Hz, 30 Hz

Turnover Frequency

Treble :  2,5 kHz, 8 kHz

Bass ;  400 Hz, 125 Hz

Filter

High Filte (-3 dB) :  7 kHz 12 dB/oct

Low Filter (-3 dB) :  70 Hz 12 dB/oct

Muting:  -20 dB

Loudness :  VR -30 dB , 6 dB (at 100 Hz)

Transient Killer Operation Time

When SW is turned On :  3 sec

When SW is turned Off :  0,5 sec

Power Requirements:  AC 100, 110, 120, 220, 240 V  50/60 Hz

Power Consumption:  80 W

Dimensions (W x H x D):  437 x 136  x 355 mm (17,5" x 5,4" x 14")

Weight:  12,5 kg (27,5 lbs)


 

Electro-Voice SP12 loudspeaker

 

Incorporating all the design advantages of the famous E-V Radax coaxial principle, the E-V Models SP12 (and SP12B) full-range coaxial reproducers include the latest developments in the electro-acoustic art.. Bass response is extended affording, for the first time, pleasing musical balance without the masking effects previously experienced from increased high-frequency reproduction. Tailored to optimum listening requirements, these new developments insure smooth, even coverage of the entire listening area.

 

Eclusive, E-V engineered features include true coaxial mounting of both reproducing elements insuring smooth room coverage, augmented balanced bass response in conjunction with smooth extended high-frequency reproduction. The carefully tailored midrange characteristic provides realism and "presence" at usual sound levels, off setting ear insensitivity at low volume. The exclusive Radax design features a true acoustical crossover in which the mass of the bass cone and its voice-coil coupling compliance is no proportioned as to decouple the woofer above crossover. The Radax unit is free from phasing dips and displays less than 1,4% Total Harmonic Distortion above crossover. The edgewise wound aluminum voice coil design affords 18% more efficiency and consequent damping of transient distortion. An unusually heavy magnet structure is used.

 


Specifications

Frequency Response:  30 - 13,000 Hz

RETMA Sensitivity Rating:  48 dB

Free-Space Cone Resonance:  35 - 45 Hz

Impedance:  16 Ω 

Power Handling Capacity

Program :  25 watts

Peak :  50 watts

Critical Damping Factor

In Aristocrat enclosure:  2,0

In an infinite baffle:  1,0

Voice Coil Diameter:  2,5 -inch

Magnet Weight:  3 lb

Mechanical Crossover:  3000 Hz

Dimensions

Diameter :  12-1/4" (7-3/4: d. overall)

Mounting:  11-1/2" diameter (four 1/4" holes equally spaced on circle)

Baffle Opening:  11"

Net Weight:  19 lbs

Electro-Voice SP12B loudspeaker

 The Model SPB12 (and SP12) may be used as low-frequency drivers in expanded separate 2 and 3-way systems. In this application, the operation of these units is comparable to the E-V Models 12 W and 12BW LF drivers. Compatible components for use with these drivers are shown on the 'Building-Block Method" Compatibility Chart.

 

Specifications

Frequency Response:  30 - 13,000 Hz

RETMA Sensitivity Rating:  46,5 dB

Free-Space Cone Resonance:  40 - 50 Hz

Impedance:  16 Ω 

Power Handling Capacity

Program :  20 watts

Peak :  40 watts

Criticasl Damping Factor

In Aristocrat enclosure:  4.0

In an infinite baffle:  2.5

Voice Coil Diameter:  2-inch

Magnet Weight:  1 lb

Mechanical Crossover:  3500 Hz

Dimensions

Diameter :  12-1/4" (6": d. overall)

Mounting:  11-1/2" diameter (four 1/4" holes equally spaced on circle)

Baffle Opening:  11"

Net Weight:  8-3/4 lbs

Electro-Voice SP15 loudspeaker

Electro-Voice Models SP-15 (and SP15B) are massive, 15-inch reproducers of deluxe construction. They offer outstanding performance as full-range loudspeakers or as low-frequency drivers in mutiway systems. The EV Radax coaxial principle employed in these speakers offers as extended high-frequency response beyond the normal capability of ordinary 15-inch loudspeakers; and the combination of outstanding magnetic structure, edgewise wound voice coil, and viscous-damped cloth cone suspension makes possible an unusually low cone  resonance and extended low-frequency response.

The Model SP15 incorporates an exclusive E-V circuit which dramatically improves high-frequency response through control of speaker impedance at high frequencies. Action of this unique circuit and adjustment of the speaker's high-frequency response is determinate by the setting of an auxiliary brilliance control.

 


SP15 Brilliance Control

Since the Model  SP15 was introduced several years ago, a number of improvements have been made in its design. Among the most effective is the additions of a brilliance control to allow adjustment of the speaker's high-frequency response to individual taste and room acoustics. The best guide to setting this control properly is, of course, a familiarity with the sound of live music. Acoustically "hard" or "live" rooms will require a retraed setting of the brilliance control to compensate for the greater amount of high-frequency reflection. In "soft" or "dead" rooms with soft furniture, carpeting, and draperies a more advanced setting of the high-frequency control will normally be required.

 


Specifications

Frequency Response:  25 - 15,000 Hz

Impedance:  8 Ω 

Power Handling Capacity

Program :  40 watts

Peak :  80 watts

Voice Coil Diameter:  2,5 -inch

Magnet Weight:  4 lb 10 oz

Magnet Material:  Ceramic

Nominal Cone Resonance:  25 Hz

Mechanical Crossover:  3500 Hz

EIA Sensitivity Rating:  53 dB

Dimensions

Diameter :  15-1/8" (8-1/4: d. overall)

Mounting:  14-7/16" diameter (four 1/4" holes equally spaced on circle)

Baffle Opening:  13-1/2"

Net Weight:  25 lbs


 

Electro-Voice SP15B loudspeaker

RADAX Coaxial Speaker

The Radax extends both bass response and high-frequency reproduction in pleasing musical balance-insures improved coverage of the entire listening area-minimizes distortion.

 

 

This exclusive E-V development achieves highest efficiency with economy. Two separate coaxially-mounted cones operating from a single voice coil, divide the audible spectrum. Each is specifically designed to reproduce its portion of the audible range. The large cone "woofer" provides maximum bass reproduction; the small cone gives effective high-frequency propagation. True mechanical crossover permits smooth transition and reproduction of lows and highs in proper phase and balance, without phasing dips at the crossover frequency. With the Radax, you have a coaxial two-way system that assures clean, sparkling, wide-range reproduction.

 


Specifications

Frequency Response:  3 - 15,000 Hz

Impedance:  8 Ω 

Power Handling Capacity

Program :  30 watts

Peak :  60 watts

Voice Coil Diameter:  2 -inch

Magnet Weight:  1 lb 6 oz

Magnet Material:  Ceramic

Nominal Cone Resonance:  30 Hz

Mechanical Crossover:  3500 Hz

EIA Sensitivity Rating:  51 dB

Dimensions

Diameter :  15-1/8" (7-5/8": d. overall)

Mounting:  14-9/16" diameter (four 1/4" holes equally spaced on circle)

Baffle Opening:  13-1/2"

Net Weight:  12 lbs