IMF TLS80 II loudspeakers

Based upon the world acclaimed Reference Standard Professional Loudspeakers, the Monitor TLS80 fulfills the need of the dedicated audiophile for a speaker of comparable quality, but tailored for home use.

Full transmission line loading incorporates new damping materials. Acoustic foam, as used in anechoic chambers, is "sculptured" to produce a wedge effect where the maximum surface area is exposed to damp the line, yet presenting the minimum of restriction. A separate midrange line is similarly terminated whilst standing waves are progressively absorbed by long hair wool. Both a tweeter and a super-tweeter are employed to ensure power handling conducive with wide dispersion and extended response beyond the limits of human hearing. Only a transmission line can provide the dynamic impact experienced in the concert hall. Bass is reproduced within the listening room rather than in a box. If there were a better method of loading, we would have employed it.

The whole system is integrated by a complex crossover, developed as the result of research in depth into the problems of phase correction, impulse response and amplifier matching. A three position "Tilt" control enables the energy response to be modified from nominally flat to "Rise" or "Fall", compensating for the location, the characteristics of ancillary equipment, or even personal preference.

 

 Like the Reference Standard, the speakers are designed to be used on the stands provided. These ensure that the loudspeakers are supported off the floor, reducing room colouration components. Importantly they slightly tilt the speakers back, maintaining a substantially flat response both axially and hemispherically.

 

 There is very little that need be said about the Monitor, which is both neutral yet exciting. Supplied in matched "mirror image" pairs the stereo presentation is stable, portraying great detail with the uncanny ability to reproduce the acoustic environment of the original performance. We suggest that you audition these speakers with the finest ancillary equipment. In the tradition of our monitoring approach to loudspeaker design the TLS 80 is capable of providing greater satisfaction over a wider range of programme material.

 

Specifications

Drive Units

Bass :  300 x 210 mm (11,75" x 8,25") flat polystyrene bass unit loaded by transmission line

Mid :  150 mm (6") plastic cone midrange in separate line

High :  45 mm (1,75") diaphragm high gauss tweeter; 20 mm (0,75") chemical dome super-tweeter

Crossover:  Electrical four way at 350 Hz, 3 kHz and 13 kHz

Frequency Range:  20 Hz to beyond audibility

Control:  Tilt

Matching Impedance:  4 - 8 Ω

Efficiency (Measured via Pink Noise at 1 m for 40 W):  98 dB (dependent on Control setting)

Driving Power Requirement:  40 - 100 watts

Dimensions (W x H x D):  460 x 980 x 410 mm(18" x 38,5" x 16")

Overall height on stand: allow 1070 mm (42")

Weight (Net/ Gross):  37 kg / 45 kg

Stands Weight (Net/Gross):  7 kg (each)/ 20 kg (pair)

 

Castle Isis loudspeakers

In this digital, computer age loudspeakers are often seen as poor relations of the electronics in a hi-fi or home cinema system. As electro-acoustic devices they are often, incorrectly thought of, as "old" technology - one design indistinguishable from another. You couldn't be more wrong.

 

The Castle Isis sets new performance standards for a speaker of its compact dimensions thanks to the use of castle designed and developed advanced technology drive units. Smooth high frequency detail is delivered by our 25 mm polyamide dome tweeter. Its shallow horn loading ensures good treble dispersion on and off-axis for a wide listening area.

The 130 mm mid/bass driver is built into a strudy die-cast chassis with a lightweight injection moulded plastic cone. A high temperature Kapton voice coil former is used to allow the driver to produce high levels of clean, undistorted sound. A simple crossover, employing audiophile quality components, integrates these exceptional drivers without sacrificing transparency or "slam"

The Castle Isis cabinet is pleasingly proportionated with a front-facing reflex port that suits it equally to bookshelf or stand use.

 

Specifications

Frequency Response:  60 Hz - 20,000 Hz

Nominal Impedance: 8 Ω

Sensitivity:  87 dB for 1W at 1m

Amplifier requirements:  20 - 80 watts

System type:  Reflex

Drivr Unit

Bass :  130 mm in a cast chassis with injection moulded cone

Treble :  25 mm composite soft dome

Dimensions (W x H x D):  170 x 350 x 195 mm

Weight (Packed):  11,6 kg

 

Acoustic Research AR-28B loudspeakers

This group of speakers - the AR -28b, -18b, and 8b - exemplify a fundamental belief we have held through nearly three decades of acoustic research. Listeners whose system options are highly restricted by budgetary considerations need not be deprived of true quality sound. These B-series acoustic suspension speakers use long throw woofers with energy absorbent diaphragms damped to an extremely low Q. the bass stays tight and clean, even at 100 watts of power on the 28b and 18 b, and 75 watts on the 8b. For added protection during peak power surges, the 1-1/4-inch high range drivers are cooled with magnetic fluid and fitted with S-Shaped lead outs.

A special feature of the 28b is a new 8-inch woofer that produces remarkably smooth frequency response in the mid-range, the critical aera for vocal reproduction.

Acoustic Research proudly presents three types of loudspeaker systems and one great sound.

 

AR-28B Specifications

System Type:  Bookshelf acoustic suspension, 2-way system with drive units in vertical array

Drive Units:

LF :  200 mm (8") long-throw acoustic suspension woofer

HF :  32 mm (1-1/4") liquid cooled cone high range driver

Voltage Sensitivity:  2,83 watts produces 88 dB SPL at 1 meter on axis

Efficiency:  1 watt produces 88 dB SPL a 1 meter on axis

Power Requirement:  10 watts per channel minimum

Power Handling Ability:  maybe used with amplifiers rated at up to 100 watts per channel

System Frequency Response:  -3 dB (half power) points at 52 Hz and at 22,000 Hz

System Low Frequency Performance:  -3 dB at 52 Hz with an effective Q at resonance of 10

Impedance:  8 Ω  nominal

Crossover Network:  Woofer has a 12 dB/octave mechanical crossover. High range has a first order electrical network plus mechanical slope to give a total of 18 dB/octave

Crossover Frequency:  2,000 Hz

Cabinet Internal Volume:  14,75 litres (52 cu.ft)

Cabinet Dimensions (W x H x D):  279 x 508 x 184 mm (11" x 20" x 7-1/4")

Cabinet Finish:  Walnut or oak grain vinyl veneer

Weight:  8,6 kg (19 lbs) 1 speaker; 19,2 kg (42,3 lbs) 2 speakers packed in carton (shipping)

 

Acoustic Research AR-18B loudspeakers

This speakers - the AR-18b - exemplify a fundamental belief we have held through nearly three decades of acoustic research. Listeners whose system options are highly restricted by budgetary considerations need not be deprived of true quality sound. These B-series acoustic suspension speakers use long throw woofers with energy absorbent diaphragms damped to an extremely low Q. the bass stays tight and clean, even at 100 watts of power on the 18b,  For added protection during peak power surges, the 1-1/4-inch high range drivers are cooled with magnetic fluid and fitted with S-Shaped lead outs.

Acoustic Research proudly presents three types of loudspeaker systems and one great sound.

 

AR-18B Specifications

System Type:  Bookshelf acoustic suspension, 2-way system with drive units in vertical array

Drive Units:

LF :  200 mm (8") acoustic suspension woofer

HF :  32 mm (1-1/4") liquid cooled cone high range driver

Voltage Sensitivity:  2,83 watts produces 88 dB SPL at 1 meter on axis

Efficiency:  1 watt produces 88 dB SPL a 1 meter on axis

Power Requirement:  10 watts per channel minimum

Power Handling Ability:  maybe used with amplifiers rated at up to 100 watts per channel

System Frequency Response:  -3 dB (half power) points at 62 Hz and at 22,000 Hz

System Low Frequency Performance:  -3 dB at 62 Hz with an effective Q at resonance of 10

Impedance:  8 Ω  nominal

Crossover Network:  Woofer has a 12 dB/octave machanical crossover. High range has a first order electrical network plus mechanical slope to give a total of 18 dB/octave

Crossover Frequency:  2,000 Hz

Cabinet Internal Volume:  9,86 litres (35 cu.ft)

Cabinet Dimensions (W x H x D):  267 x 432 x 168 mm (10-1/2" x 17" x 6-5/8")

Cabinet Finish:  Walnut or oak grain vinyl veneer

Weight:  6,8 kg (15 lbs) 1 speaker

 

Acoustic Research AR-8B loudspeakers

Acoustic Research proudly presents three types of loudspeaker systems and one great sound.

This model of speakers - the AR-8b - exemplify a fundamental belief we have held through nearly three decades of acoustic research. Listeners whose system options are highly restricted by budgetary considerations need not be deprived of true quality sound. These B-series acoustic suspension speakers use long throw woofers with energy absorbent diaphragms damped to an extremely low Q. the bass stays tight and clean, even at 75 watts of power on the model 8b. For added protection during peak power surges, the 1-1/4-inch high range drivers are cooled with magnetic fluid and fitted with S-Shaped lead outs.

 

AR-8B Specifications

System Type:  Bookshelf acoustic suspension, 2-way system with drive units in vertical array

Drive Units:

LF :  150 mm (6") long-throw acoustic suspension woofer

HF :  32 mm (1-1/4") liquid cooled cone high range driver

Voltage Sensitivity:  2,83 watts produces 88 dB SPL at 1 meter on axis

Efficiency:  1 watt produces 88 dB SPL a 1 meter on axis

Power Requirement:  10 watts per channel minimum

Power Handling Ability:  maybe used with amplifiers rated at up to 75 watts per channel

System Frequency Response:  -3 dB (half power) points at 74 Hz and at 22,000 Hz

System Low Frequency Performance:  -3 dB at 74 Hz with an effective Q at resonance of 85

Impedance:  8 Ω  nominal

Crossover Network:  Woofer has a 12 dB/octave machanical crossover. High range has a first order electrical network plus mechanical slope to give a total of 18 dB/octave

Crossover Frequency:  2,000 Hz

Cabinet Internal Volume:  7,17 litres (25 cu.ft)

Cabinet Dimensions (W x H x D):  241 x 375 x 159 mm (9-1/2" x 14-3/4" x 6-1/4")

Cabinet Finish:  Walnut or oak grain vinyl veneer

Weight:  4,8 kg (10,5 lbs) 1 speaker; 10,9 kg (24 lbs) 2 speakers packed in carton (shipping)

 

Sony APM-66ES speakers

Reference quality speakers with Sony's unique APM flat driver technology for sonic performance that fully meets the demands of digital audio.

Extremely uniform, extended frequency response for superb tonal accuracy and smooth, untiring sound.

Low distortion and coloration not possible with conventional cone drivers.

Near-perfect linearity over a wide dynamic range

Advanced crossover design for smooth response and stable stereo imaging over entire frequency range

Heavy-duty cabinet construction with rounded edges for reduced diffraction effects.

 

Features

The APM-66ES's flat diaphragm is a very lightweight but very rigid honeycomb sandwich structure whose pistonic motion moves air very efficiently.

The 424 cm² woofer reproduces a powerful bass

The acoustically rounded enclosure improves directivity characteristics by minimizing the diffraction effect.

 

Specifications

Speaker System:  3-way speaker system

Nominal Impedance:  6 Ω

Power Handling Capacity (DIN 45500):  100 W (Nominal); 200 W (Maximum)

Sensitivity:  89 dB (1 W, 1 m) [DIN 45500 5 W (96 dB, 1 m)]

Frequency Range:  30 Hz - 30,000 Hz

Crossover Frequency:  600 Hz and 4,500 Hz

Speaker Units;

Woofer :  424 cm² (66 in²), APM type

Midrange :  48 cm² (7,4 in²), APM type

Tweeter :  9 cm² (1,4 in²), APM type 

Enclosure Type:  Bass reflex type, Removable front grille

Finish:  Grained vinyl of Walnut

Volume:  56 litres

Dimensions (W x H x D):  380 x 660 x 365 mm (14" x 26" x 14-3/8") including front grille

Weight:  26 kg (57 lb 6 oz)  including front grille, ( net per speaker)

 

Toshiba SS-100 speakers

Concave Speaker System

Features:

Crystal, full-bodied bass reproduction from big 30 cm (12") concave woofer

Unusual mid-range tonal response from 22 cm x 11 cm (8" x 4") exponential horn type squawker

Clear, lifelike high tone rendition from 6 cm (2,5") horn tweeter with acoustic lens,

Switch and input terminals for electronic crossover multi-amplifier system

 

Specifications

Enclosure:  Pressure balance type

Mounted Speakers:

Woofer :  300 mm (12") concave

Mid-range :  220 x 110 mm (8" x 4") horn

Tweeter :   60 mm (2-1/2") horn with acoustic lens

Frequency Range:  30 - 20,000 Hz

Crossover Frequency: 

Low-Mid-range :  700 Hz,

Mid-range _ High :  5,000 Hz

Power Handling Capacity:  60 W (max)

Impedance:  8 Ω

Sensitivity:  92 dB /IEC

Fundamental Resonance Frequency:  40 Hz

Timber Control:  Mid & high each 4-step 6 dB

Multi-amp Connection:  2 & 3 way

Front Panel:  Removable

Dimensions (W x H x D):  490 x 790 x 441 mm (19-1/4" x 31-1/8" x 17-3/8")

Weight:  43 kg (95 lbs)

 

Coral CX-7 speakers

Model CX-7A

 

Model CX-7 MkII

 

3-Way, 3-Speaker System

Specifications

Type:  Air Tight

Speakers

300 mm (12") woofer

One soft dome squawker

One hard dome super tweeter

Impedance:  8 Ω

Program Source Input:  80 W

Frequency Response:  35 - 40,000 Hz

Output Sound Pressure Level:  93 dB

Crossover Frequency:  1,500 Hz ; 8,000 Hz

Dimensions (W x H x D):  350 x 580 x 314 mm (13-13/16" x 22-13/16" x 12-6/16")

Weight:  17 kg (37,4 lbs)

Finish

CX-7A :  rose wood

CX-& MkII :  walnut or black

 

Coral CX-77 loudspeakers

12-inch 3-way 3-speaker system

Symmetric Paired Cabinet Systems - Enclosure

The higher the performance of the speakers, the more important the quality of their enclosure becomes. The CX-77 system uses a bass-reflex enclosure, which features a highly condensed multi-layer particle board, eliminating unwanted vibration. The side, baffle and back boards are strongly reinforced. Ester wool, Tetoron wool and soft felt, all with excellent sound properties, are used as acoustic material. The speakers are symmetrically mounted to achieve optimum directivity. Beautifully finished with UVD coating, the CX-77 system enclosure symbolizes the perfection of the system.

 

Woofer

The light, tough cone paper ensures optimal linearity.

Proper balance among tweeter, squawker, and woofer is crucial when assembling a good speaker system. Cone paper, the heart of the woofer, must possess high Young's modulus and be fully flexible. The woofer in the CX-77 speaker system features Coral's own specially developed micro-crystal cone paper, the surface of which is coated with fine hollow crystal grains 0,1 mm in diameter and with a specific gravity of 0,3. thus partial vibration has been greatly enhanced, refining the transient characteristics of the lower and bass ranges. The rest of it, too - the free edge with full linearity, diecasting frame absolutely without resonance, powerful magnetic circuit help - all contribute to some of the richest, most listenable low frequency sounds available.

 

Squawker

Titanium dome ideally shaped to overcome molding difficulties.

Coral, having developed its own exclusive method for loading highly rigid titanium speaker domes, is now able to provide the audiophile with the most superb mid-range speakers ever. The voice coil in these speakers features CCAW winding and flawlessly maintains optimum balance of mass, extending the high range limit ans largely improving transient characteristics. The aluminum bobbin boasts large input resistivity, and a spacious back cavity easily expands the Frequency Response of the lower range to efficiently cover everything from 700 Hz to 7,000 Hz. Clear, faithful sound.

 

Tweeter

A super-tweeter with a super-high limit - 40,000 Hz

The ultimate limit of high-frequency sound reproduction, plus the elimination of distortion and the optimum in transient characteristics. The attainment of these goals is what audio engineers are continually stribing toward - to build a tweeter which will flawlessly reproduce the delicate high-range sound properties of every musical instrument. Coral's is a hard dome-type super-tweeter that uses a diaphragm of 18-micron-thick ultra-thin Super Duralmin having a crossover frequency of 7,000 Hz. The expanded high-range frequency response of 40,000 Hz easily reproduces everything within the normal audible frequency of 20,000 Hz with outstanding directivity. The sound quality is amazing.

 

Level Controller

An attenuator that enables continuous variation of the mid- and high-frequency ranges independently. The levels may be easily regulated simply by removing the front Saran cloth net.

 

Dividing Network

Low-loss design employing a Mylar film capacitor and a coil featuring a high permeability reluctance ferrite core, which refuses to cause linear distortion even under large input. The design brings out the maximum transient characteristics of each speaker, the result being thoroughly well-balanced sounds.

 

Specifications

Enclosure:  Bass-reflex type

Speakers

1 x 300 mm Woofer

1 x 50 mm titanium dome squawker

1 x 20 mm hard dome tweeter

Frequency Response:  30 - 40,000 Hz

Crossover Frequency:  700 Hz ; 7,000 Hz

Output Sound Pressure Level:  94 dB

Program Source Input:  80 W

Impedance:  8 Ω

Dimensions (W x H x D):  390 x 650 x 320 mm

Weight:  22 kg

 

Jensen G-610B Triaxial loudspeaker

Triaxial - 15-inch 3-way Unitary Loudspeakers

 

The famous Jensen G-610B (and G-600) are genuine 3-way unitary loudspeakers, the only 15" speakers made with three electrically and acoustically independent L-F , M-F and H-F radiating and driving systems. These superb 15" speakers represents the ultimate in balance, efficiency, smoothness and tonal purity. They have no equal.

 

G-610B

Unquestionably the world's finest unitary loudspeaker. A precision combination of a 15" woofer with powerful 6-1/2 lb. Damping Factor-Alnico 5-magnet for bass notes to below 25 cycles; low 600 cycle crossover to a thru-bore compression mid-channel horn (whose final section is the entire woofer cone); and compression-driver super-tweeter for response from 4,000 to beyond 20,000 cps.

Heavy cast frame. Separate dual crossover network provided with individual M-F and H-F controls.

Impedance 16 ohms.

Power Rating 40 watts program, 80 watts peak.

Woofer Resonance 50 cps.

Weight: 46 lbs

 

 

Jensen G-600 Triax loudspeaker

 Triax - 15-inch 3-way Unitary Loudspeakers

 

The famous Jensen G-600 (and G-610B) are genuine 3-way unitary loudspeakers, the only 15" speakers made with three electrically and acoustically independent L-F , M-F and H-F radiating and driving systems. These superb 15" speakers represents the ultimate in balance, efficiency, smoothness and tonal purity. They have no equal.

 

G-600

True 3-way performance at moderate cost is yours with the G-600 Triax. Lows from below 30 cycles to 900 cycles are handled by the 15" edge-damped woofer with heavy duty 3-1/2 lb. Damping Factor-Alnico-5 magnet; compression-driver horn-loaded thru-bore midchannel for 900 - 4,000 cycle range, and compression horn phase-balanced super-tweeter for frequency extension beyond 20,000 cps.

Separate dual crossover network, M-F and H-F balance controls.

Impedance: 16 ohms

Power Rating: 35 watts program; 70 watts peak

Woofer Resonance:  35 cps

Weight:  33 lbs

 

Jensen 1200-XL loudspeakers

Contemporary Jensen 1200-XCL 7-speaker, 4-way decor-styled loudspeaker system

Jensen's new 1200-XL four-way loudspeaker systems blend the ultimate in high-fidelity sound reproduction with finest furniture styling.

Seven, speakers, uniquely arranged in a solid acoustic enclosure, provide sound magnificence for the most discriminating ear. Crisp, clear high notes. Pure, bold midrange. Full, rich bass notes. The entire sound spectrum - from 15 to 25,000 cycles - comes to life as never before. Controls for both mid-range and high-frequency permit exact musical balance for room conditions. This Contemporary model with pleated, textured grille fabric, is of open-grain oiled walnut. Mediterranean and Early American cabinets on following page are of select distressed pecan.

The 1200 XL series represents the finest loudspeaker systems Jensen has ever built.

 

Specifications

Components:

Four 15" FLEXAIR® woofers with a combined magnet weight ot 14,4 lbs; a compression-driver horn-loaded midrange; a compression-driver horn super-tweeter and a direct radiating Sono-Dome® ultra-tweeter

Frequency Range:  15 - 25,000 cps.

Crossover Frequencies:  500, 4000 and 10,000 cpe

Power Rating:  100 watts

Total Magnet Weight:  17-1/2 lbs

Impedance:  8 Ω

Controls:  Mid-frequency and high-frequency balance controls on rear of cabinet

Dimensions (W x H x D):  40" x 30-1/2" x 22-3/4"

Shipping Weight:  243 lbs

 

1200-XLM Mediterranean

The cabinet - select pecan with textured grille fabric high-lighted by screened patterns. Reflects the warmth of Mediterranean styling.

Cabinet dimensions: 31-1/4" Height; 40" Width and 22-3/4 Depth

Shipping Weight:  245 lbs

 

1200-XLE Early American

The cabinet - distressed pecan with textured grille fabric. Solid pecan spindles recreate the Traditional look.

Cabinet dimensions: 31-1/4" Height; 40" Width and 22-3/4 Depth

Shipping Weight:  240 lbs

 

Magneplanar MG-II loudspeakers

We'd like to have a word with you. It's about Magneplanar loudspeakers. The word is "revolutionary". Revolutionary design concept; revolutionary sound reproduction, revolutionary beauty. In fact the Magneplanar system is patented because of the unique principles on which it operates. The Speaker are designed to be seen and not heard. So if you're listening to music, all you hear is music, not annoying vibrations from speaker cabinets and cavities. The first time you see Magneplanars you'll know something new is going on. They look like beautiful decorator screens. Or handsome room dividers. We know you've heard the word "revolutionary" before. But you've never heard anything like Magneplanars before.

 

What is Magneplanar?

The Magneplanar loudspeakers is a totally new type of loudspeaker. It is neither a cone type speaker, nor is it an electrostatic. The actual speaker itself is only about 1/8th inch thick. Its construction consist of a large area (planar) permanent magnetic field with a very thin film diaphragm stretched over it. The audio current is carried by conductors which are attached to the diaphragm in a zig-zag fashion.

As the audio current passes through the conductors, the interaction between the magnetic field around the conductors and the permanent planar magnetic field under them causes the entire diaphragm to pulsate. This creates sound waves in the air which is the sound your hear.

 

A few of the important characteristics of Magneplanars

Purely resistive impedance for ideal amplifier loading

Puts out same sound front and back (bi-polar radiator)

No cavity or cabinet wall resonance to colour sound.

Superior transient response throughout entire audio range due to low mass of diaphragm

Distortion level far below other loudspeakers because of complete control of diaphragm

Can be placed to look more like part of furnishings than a loudspeaker

56" long, 1-1/2" wide tweeter section provides horizontal sound dispersion previously unattainable

Fantastic power handling capability

Large radiating area provides width and height and depth of sound only equalled by live performances

The bi-polar radiation of Magneplanas provides a means of optimizing stereophonic and quadraphonic sound imaging.

 

Specifications

System:  Two-way full-range Magneplanar

Midrange/Bass Radiating Area:  500 sq. In

Tweeter Radiating Area:  85 sq. In

Frequency Response:  60 Hz to 18,000 Hz ±4 dB

Power Handling:  up to 200 watts RMS per channel (without equalization)

Minimum Power Required:  Depends of type of listening. If you are a background music listening, 15 - 25 watts might be sufficient. In most cases 40-50 watts is recommended

Efficiency:  85 dB SPL

Impedance:  6 Ω

Crossover System:  2400 Hz

Finish:  Walnut hard wood and light colored fabric

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

Weight:  41 pounds each

 

Vandersteen Model 3 loudspeaker

The Aligned Dynamic Design

The Model Three uses the proven Vandersteen Aligned Dynamic Design to optimize the dispersion and transient accuracy of the drivers while maintaining the input signal's time and phase integrity. The drivers, their positioning and their associated minimum baffles were developed with the aid of FFT computer analysis to minimise diffraction, cone break-up, multi-driver interference and out-of-band phase irregularities. The construction, alignment and positioning of the driven allow a point-source wave front and maximize the phase coherence of the loudspeaker at the listening position.

The Aligned Dynamic Design is used for the Model Three due to its many potential advantages:

Precise, more dimensional imaging and a wider listening area

A greater flexibility of placement options within the listening room and better "real word" transient response due to the lack of out-of-phase rear-wave cancellations.

A high level of genuine transparency and detail typical of planar speakers without the dege-clamping distortion that exist in all rectangular electrostatic and planar panels

Increased efficiency and improved dynamic range.

 

The components used in the Model Three combine durability and strength with innovative design and construction. The metal-alloy dome-tweeter is a dual-chamber design to improve range and linearity. It is critically damped to extend the high frequencies past audibility without the excessive ringing associated with open or underdamped metal dome tweeters. The alloy used for the dome was chosen for its superior strength and resistance to break-up compared to common dome materials.

With the application of years of experience in FFT computer analysis and research into the negative effects of diffraction, a unique, proprietary midrange driver has been developed that outperforms previous designs in several significant parameters. In conventional cone midrange, the acoustic energy from the back of the cone immediately strikes the front of the driver's magnet assembly and is reflected back through the cone and into the listening room.

This distorted secondary signal created by the internal diffraction smears the sound of the driver and inhibits true transparency. The frontal area of the magnet assembly on the Model Three midrange has been minimized through the use of advanced materials and construction techniques to reduce internal diffraction and the resultant distortion to inaudible levels. With the elimination of this distortion, the sound of the Model Three is cohesive and smooth with a level of inner resolution unequalled by other dynamic loudspeakers.

The active acoustic coupler and woofer use costly cast-metal baskets rather than more common stamped baskets. The cast-metal baskets inherent rigidity and superior vibration control increase cone movement accuracy and reduce sympathetic resonances for cleaner and more natural sound. Filled polycones are used on the woofer and midrange to insure higher internal stiffened and greater neutrality than woven plastic or treated paper cones. The stiff, low weight polycones resist flexing under all drive conditions for lower distortion and increased detail.

The dual-spider active acoustic coupler accurately complements the woofer to reduce box loss, thermodynamic loss and active/passive transfer nonlinearities. This novel Electro-Mechanically Optimized Woofer System provides powerful, detailed and extended bass response as the Model Three operates much more closely to the ideal than any conventional ported or passive design.

 

The crossover in the Model Three is comprised of transient-perfect, first-order networks designed to preserve the phase integrity of the music. It is compensated to allow the drivers to operate in absolute phase with each other for more precise and stable imaging than conventional multi-way speakers using out-of-phase drivers. The crossover's computer grade components, including low impedance air-core inductors and high-quality film capacitors in the signal path, are hand soldered on a double-sided, plated-through PC board tested to insure less than 0,1 dB deviation from a reference circuit. Custom 6N wire with polypropylene dielectric is used for internal wiring to maximize signal transfer.

The crossover is engineered for bi0wiring with a stereo amplifier or two monoblock amplifiers or passive vertical bi-amplification with two identical stereo amplifiers or four identical monoblock amplifiers. Inputs are heavy-duty screw terminals.

 

The baffles holding the drivers of the Model Three are as small as possible to eliminate virtually all of the early reflections that affect dynamic speakers with conventional flat or low diffraction baffles. Reducing both early reflections and edge diffraction improves the imaging and enhances the openness and transparency of the speaker.

The enclosure of the Model Three is constructed of MDF, a wood product far more dense and acoustically inhert than conventional particle-board. Broad-spectrum, low -Q resonances are controlled so as to cancel rather than become additive.

 

Specifications

Impedance:  6 Ω  nominal; 4 Ω  minimum

Efficiency:  89 dB with 1 watt of pink noise input at 1 meter on axis

Recommended Amplification:  100 to 200 watts per channel into 8 Ω .
The amplifier must be stable into a 4 Ω  load.

Frequency Response:

26 Hz to 30,000 Hz ±3 dB

30 Hz to 22,000 Hz ±1,5 dB by FFT step function

Dispersion:  26 Hz to 17 kHz ±3 dB 30degrees off axis

Crossover Frequencies:  600 Hz and 5 kHz First-order, 6 dB per octave

Input Connections:  2 pair of heavy duty screw terminals

Recommended Placement:  12-inches or more from the rear wall,

Cabinet Finish:  Hand-matched and finished natural oiled wood veneers

Dimensions (H x W x D):  48" x 16" x 10,25"

Weight:  88 lbs net

 

JBL 4430 monitor loudspeakers

Developed to meet the challenge of digital and advanced analog recording technology, the JBL Model 4430 {and Model 4435} represent a significant new approach to two-way studio monitor design. The incorporation of the unique JBL Bi-Radial ™ horn in a monitor loudspeaker provides constant vertical and horizontal polar coverage, control of the reverberant field, flat power response, image stability, and coherent sound. The two models also feature improvements in compression driver, low frequency transducer, and dividing network technology. Both systems exhibit the traditional )BL attributes of wide bandwidth, smooth frequency response, high efficiency, wide dynamic range, and exceptional reliability.

The practical benefits of the Bi-Radial monitors include stable stereo imaging that remains fixed over a wide range of horizontal positions, the result of unusually smooth off-axis response. The design allows considerable latitude in physical placement. The wide vertical response, identical to the horizontal, includes both standing and seated listeners within the coverage angle, even in proximity to the monitors.

 

THE JBL BI-RADIAL ™ HORN

The Models 4430 offer performance levels normally achieved by three- and four-way systems. The key to this performance is the JBL Bi-Radial ™ horn 1 and its integration in a monitor design.

Most horn designs compensate for the failing power response of the compression driver with directivity that increases with frequency. This provides flat axial response, but power response that typically falls by 6 dB per octave from as low as 3 kHz. The resulting decrease in coverage angle (as the frequency increases) gives generally poor control of the reverberant field and (in two-way designs) is not well matched to the coverage angle of the low frequency driver at the crossover frequency. By contrast, the JBL Bi-Radial ™ horn provides constant coverage over its operating bandwidth. Both on-axis and off-axis pressure response are flat, and the vertical coverage angle is identical to the horizontal. This angle is wide, 100° x 100°, but very tightly controlled, and it matches the coverage angle of the low frequency driver at the crossover frequency. Additionally, the horn's rapid flare rate reduces second harmonic distortion, and its reduced depth puts its driver in the same acoustic plane as the low frequency driver. The Bi-Radial ™ monitors present a coherent sound source, with extremely stable stereo imaging over a wide variety of listening positions. The monitors offer a high degree of placement flexibility, and the listening position can be quite close with no loss of stereo imaging.

Equalization of the 4430  will typically be needed only to correct for inherent room anomalies rather than for monitor response. This is the result of uniform frequency response within the coverage angle. The controlled power and polar response of the JBL Bi-Radial ™ monitors effectively removes them from the variables with which a recording engineer must contend.

 

HIGH FREQUENCY COMPRESSION DRIVER

The Bi-Radial ™ horn is coupled to a compression driver which is crossed over at I 000 Hz. The driver features a titanium diaphragm with a three-dimensional diamond-pattern suspension . Developed by JBL, this diamond surround offers an extended frequency response normally associated with exotic materials while retaining ruggedness and high power capacity. The diaphragm is pneumatically drawn to shape to eliminate stresses that cause fatigue, and a phasing plug of concentric exponential horns eliminates phase cancellation.

 

LOW FREQUENCY

The low frequency loudspeakers used in the Bi-Radial ™l monitors incorporate the latest technology to deliver smooth response, extended bandwidth, and extremely low distortion. The magnetic structures feature JBL's Symmetrical Field Geometry (SFGI design to reduce second harmonic distortion to inconsequential levels. New adhesives technology and coil former construction improve power handling. The coil itself, 100 mm (4 in) in diameter, is fabricated from edge-wound copper ribbon, and operates in a magnetic field having a flux density of 1.2 T (12,000 gauss). The 19 mm(% in) length of the voice coil allows increased linear excursion, and a careful choice of suspension elements helps to completely eliminate dynamic instabilities.

The 4430 differ chiefly in their low frequency capabilities. The 4430 uses a single 380 mm ( 15 in) low frequency driver and is 3 dB down at 32 Hz; it can handle full power input to 27 Hz.  The system is down 3 dB at 27 Hz and will handle full power down to 22 Hz. The systems use similar low frequency drivers, but the cone assemblies.

 

FREQUENCY DIVIDING NETWORK

The frequency dividing network of the Bi-Radial ™ monitors has a crossover frequency of I kHz and a nominal slope of 12 dB per octave. The cut-off slope and shape were chosen to provide the smoothest possible response over the widest bandwidth, restricting any off-axis anomalies to a very narrow portion. JBL has paid considerable attention to both the off-axis response and the total power response, and the network optimizes these parameters. While

the response is smooth at all angles, the flattest response is, by design, on-axis and above. This offers a greater number of listening positions when the system is mounted at or below ear level; for mounting above ear level, the system can be inverted to offer the same advantages. The network also provides equalization of the compression driver. Because the power response of the driver and the Bi-Radial ™ horn is greater in the midrange than at high frequencies, this equalization attenuates the lower end of the compression driver's response, lowering distortion and giving greater dynamic headroom. The equalization is provided in two stages, allowing separate adjustments (via front panel level controls) for the midrange and high frequencies.

A switch located adjacent to the connection terminals allows the monitor to be bi-amplified. A special crossover card is available for the IBL Model 5234A electronic frequency dividing network to provide the appropriate crossover characteristics.

 

Specifications

Frequency Response:  35 Hz - 16,000 kHz ±3 dB

Sensitivity:  93 dB SPL

Efficiency:  1,3%

Dispersion Angle

Horizontal :  100° (+10°; -30°)

Vertical :  100° (+0°, -30°)

Impedance:  8 Ω  nominal

Max. Power Input:  300 W

Continuous Sound Pressure Level:  119 dB

Crossover Frequency:  1,000 Hz

Driver Complement:

Low Frequency :  2235H

Compression Driver :  2425H

Horn :  2344

Enclosure Volume:  0,14m³ (5 cu. Ft)

Resonance Frequency:  34 Hz

Dimensions:  908 x 556 x 400 mm (480 mm deep w/horn)

Weight Net:  26 kg (57 lbs)