Rogers LS5/9

The Broadcast Monitor Heritage

We are particularly pround of our long and close association with the B.B.C. under whose Approved Accerditation we manufacture the world renowed LS3/5a and LS5/9 Broadcast Monitors. Rogers is one of only a select handful of Approved Licensees who have proved they can maintain the impeccable manufacturing standards required for their production. It is those very same standards which form the benchmark for our total production and Quality Control Procedures.

LS5/9

The LS5/9 marks 20 years of close association between the design and development departments of the B.B.C. and Rogers. It is compact system designed for studio monitoring purposes, and capable of outstanding resolution and authority in a matching audio system.

At the heart of every conventional loudspeaker ies the voice coil - crucial to its power handling and resistance to overload. At Rogers we design and produce our own very high temperature voice coils as well as all the tooling required to wind and handle them.

Polypropylene has been recognised for some time as an excellent cone material combining rigidity, low mass and self-damping. Againg we make our own tooling and vacuum-form all our cones giving us complete control over virtually every aspect of the bass unit performance.

Surrounds and spiders are specially selected or manufactured to our specific requirements.

The latest generation of metal dome tweeters has allowed us to make significant advances in the high frequency response of our new models. Clean, transparent, detailed sound with extended response is the hallmark of this exciting unit. Power handling, sensitivity and damping are enhanced by the use of ferro-fluid in the magnet gap.

Matching Stand S-59 - The S Series Stands, designed specifically to match the LS3/5a and the LS5/9, are constructed from heavy duty steel tube and sheet to achieve rigidity, low resonance characteristics and high mass. They are fitted with adjustable carpet piercing spikes to give maximum stability.

Specifications

LS5/9

System Type:  2-way with bass reflex

Driver Unit:

Bass/Mid :  Rogers 200 mm Polypropylene unit to BBC LS2/14 spec

Tweeter:  Son Audax HD13D34H selected and modified to BBC LS2/14 spec by Rogers

Crossover:  Rogers/BBC FL6/36 24 precision elements

Bass Loading:  well damped quasi 3rd order high pass acoustic transfer function at 50 Hz

Frequency Response:  50 Hz - 16 kHz ±3 dB

Distortion (2nd & 3rd harmonic): no

Nominal Impedance:  8 ohms

Sensitivity (2,83 V/1m):  87 dB SPL

Maximum Output (at 2 m per pair):  105 dBA SPL

Recommended Amplifier Power:  15 - 100 watts/channel

Cabinet:  critically damped Birch multiply construction

Connectors:  high quality gold plated  binding posts

Finish: selected Black Ash, Teak or Walnut wood veneer

Grille:  Black woven cloth

Dimensions (H x W x D):  460 x 280 x 275 mm (18 x 11 x 10,8 inch)

Weight:  13 kg (28,6 lb) each

Recommended Placement:  Stands S-59

Rogers LS2

 Designed to suit the smaller room where space is at a premium the LS2 needs no excuses made for its modest proportions. Presenting music in a bold and explicit way, the LS2's natural balance and ease of drive will compliment any system.

 Cone materials

The type of material used to form the cone of a loudspeaker has a marked effect on the overall sound and consistency of the loudspeaker. Over the years,a variety of materials has been used.

The original material was paper, which was pulped, compressed, and formed. This offered only the minimum of control over the resultant sound quality, especially in the critical midrange area, and effort was made to find an alternative.

In the mid-sixties, partially as a result of development work at Kingswood Warren, Bextrems - a kind of polystyrene - started to be used. …Bextrene with a damping compound to remove colourations in the region of 1,5 to 2 kHz. …polypropylene - developed considerably during the 1970s, again with pioneering work at research department, Polypropylene offered similar improvements over paper as did bextrene.  … as the material was inherently self-damping. Because of its lower density, polypropylene yields greater efficiency than Bextrene and hence greater sound levels are possible for the same power input.

Specifications:

System:  2-way reflex system

Frequency Response:  60 Hz - 20 kHz ±2 dB

Impedance:  8 Ω nominal

Sensitivity (2,83V):  87 dB at 1 m

Suitable for amplifiers:  15 - 100 watts per channel into 8 Ω

Maximum Output:  103 dB at 2 meters

Recommended Placement:  shelves wall brackets or Rogers S55 stands

Finish:  walnut

Dimensions (W x H x D):  230 x 360 x 210 mm

Weight:  6 kg

Rogers Export Monitor

 The Rogers Export Monitor meets the demands of thousands of enthusiasts that have pleaded for an LS3/6 loudspeaker with increased power handling. Based on design expertise acquired from five years of manufacture of the Rogers BBC LS3/6 Studio Monitor, this three unit system offers a standard of performance which makes it a class leader and power handling more than adequate for domestic use. The BBC LS3/6 has enjoyed an enviable reputation both home and abroad and has come to be regarded as a standard by which others are judged. The need for higher power handling, especially for the export markets has been researched exhaustively with a refusal to accept deterioration in sound quality. The Export Monitor has been received with enthusiasm worldwide and shows a remarkable lack of colouration, with very low harmonic and intermodulation distortion.

The Rogers Monitor pioneer units in Bextrene Cone Technology, are the result of many years research by the British broadcasting Corporation into loudspeaker cone behaviour.

Available in Teak or walnut veneer finish as standard with black grillecloth. De-luxe castor trolleys are available which provide correct positioning relative to the floor, whilst allowing easily manoevorability for cleaning or listener position change.

 Application

Originally intended for monitoring purposes in the smaller studio, this loudspeaker will give superlative reproduction in domestic high fidelity installations, where the associated equipment is of a sufficiently high standard.

The superb bass response is not dependent on corner location and the speaker is best set away from wall and corners, so avoiding too much excitation of room resonances. Due to the efficient and exxtended treble response of the speaker a slight amount of filtering may prove beneficial an all but the very best programme material. For this reason an amplifier with a good low pass filter should be used.

The nominal power handling capacity of the loudspeker is 35 watts speech and music. This power level is entirely adequate for all normal domestic applications and is also satisfactory for the small studio.

 Construction

The main drive unit used in the system is specially constructed and the performance carefully evaluated for each loudspeaker. The special plastic cone and surround material employed ensures a uniform response, any slight residual colouration being minimised by individual doping of the cone, a process carried out by hand by a skilled craftsman.

The tweeter units are specially selected and all must meet a rigid pass specification. Matching of bass unit and tweeter unit efficiencies is controlled by a low loss autotransformer with 1 dB tappings.

A sophisticated crossover uses close-tolerance inductors and stable low-loss capacitors for lifelong stability of operation. The enclosure is made from selected woods, which in conjunction with special internal damping materials,  avoids resonance and colouration.

The standard finish is teak or walnut veneer.

Testing

All Rogers Export Monitor Loudspekaers are individually measured on Bruel and Kiser automatic curve tracking equipment, installed in our own anechoic building at Catford. Each speaker is carefully adjusted to meet a rigid specification and an individual response curve graph taken.

After frequency response tests have been carried out the final performance of each individual speaker is  compared to a Reference Standard BBC LS3/6 Loudspeaker on pink noise and master tapes of the highest quality.

Specifications;

Enclosure Type:  3-way, bass reflex

Overall Frequency Response:  40 - 25,000 Hz;  40 - 14,000 Hz ±3 dB

Power handling capacity:  35 watts, speech and music

Impedance:  suitable for 8 - 16 Ω matching amplifiers

Drive Units:  3

Dimensions (W x D x H):  305 x 305 x 635 mm (12" x 12" x 25")

Weight:  15,5 kg (34 lbs) net

Finish:  Teak or Walnut veneer with black grillecloth

Rogers LS4a

 Over the years, our products have earned a worldwide reputation for fine sound quality and high standards of construction. The primary design aims have always been tonal neutrality, low colouration, transparency and wide bandwidth. Another major consideration is consistent and trouble free performance from a system over many years of operation. To ensure this, only high quality components are used in the construction of our loudspeakers.

 From time to time we introduce a new model, when we do, the new design must possess the strengths of its predecessor, plus other substantial advances, in order to justify the change. Our new designs tend therefore to be few and far between.

 Constant background research does, however, yeild improvements in our understanding of loudspeaker systems and advances in the performance of drive units. The use of Polypropylene as a cone material, and the recent introduction of high performance metal dome tweeters has meant that advances are possible.

 The friuts of this research and increased understanding of system behaviour has yielded new systems of advanced design and high quality performance.

Specifications

Frequency Response:  55 Hz - 20 kHz  ±2 dB

Impedance:  8 Ω Nominal

Sensitivity:  88 dB at 1m for 2,83 volts input

Power Handling:  150 watts (unclipped programme)

Recommended Amplifier Power:  15 - 100 watts per channel

Maximum Sound Pressure Level:  105 dBA (pair at 2 m)

Drive Units:

Tweeter :  19 mm Aluminium dome

Bass/Mid-range:  Rogers 205 mm Polypropylene coned of advanced acoustic design , with high flux magnet and Kapton voice coil former.

Crossover:  8 precision elements crossing over at 3 kHz at 18 dB per octave

Bass Loading:  Acoustic suspension to form a well damped Butterworth 2nd oreder maximally flat alignment with a -3 dB point at 55 Hz.

Distortion:  Less than 1% 2nd and 3rd harmonic 50 Hz -20 kHz at 90 dB S.P.L.

Connectors:  4 mm binding posts, spaced at 19 mm

Recommended Placement:  Stands - minimum 500 mm high with loudspeakers angled inwards so that their axes cross just in front of the listener.

Cabinet:  Critically damped partical board with medite baffle.

Finish:  High quality synthetic veneer, and black grille cloth

Dimensions (H x W x D):  430 x 255 x 245 mm (17" x 10" x 9,7")

Weight:  7,8 kg 917 lb)