Classic Rogers LS3/5a 15 Ohm – BBC Licence.

Rogers over seventy years of excellence.

For over seventy years the name of Rogers has earned the high regard of music lovers worldwide with the high standard of musical integrity it’s products have consistently achieved.

Founded in 1947 in North London, by Jim Rogers, a highly successful range of thermionic vale equipment was produced, including several exquisitely built amplifiers.

Later in the 1960’s and early seventies, Rogers was one of the first British companies to lead the way with good sounding transistor amplifiers and tuners.

During this period many loudspeaker designs from a new factory in Catford, London, culminating in 1970 with the introduction of the LS3/6 studio monitor. This was the first BBC licensed design and heralded a significant advance in moving coil loudspeaker performance.

This was followed four years later by another BBC licensed design, the legendary LS3/5a. Undoubtedly one of the all-time greats in loudspeaker design it has inspired more interest and critical acclaim than almost any other product. Now*  entering its forty fourth year of production it continues to astonish and impress listeners the world over with its fine musical performance.

*2019

Technical Specifications.

Classic LS3/5a 15 Ohm Monitor Speaker
System Type: Two way infinite baffle ( closed box)
Frequency Response: 70Hz – 20KHz +/- 3dB
Bass/Midrange Driver: 138mm polymer cone
Tweeter: 19mm mylar dome
Crossover Frequency: 3KHz
Sensitivity: 83dB for 2.83V at 1M
Nominal Impedance: 15 Ohms
Recommended Amplifier Range: 30-80 Watts ( Warning do not connect to any amplifier exceeding range as damage may result )
Cabinet: Cabinet 12mm Birch ply critically damped
Grille: Black Tygan
Finish: Selected real wood veneers
Recommended placement: On rigid mass loaded stands. 200mm from rear wall, clear of side walls, angled in so axis cross just in front of the listener.
Dimensions: 188 x 304 x 164 ( W x H x D )
Weight: 5.12Kg each speaker.

If the cabinet isn’t right, the music won’t be either

· Critically damped 12mm Russian birch ply enclosure
· Hardwood beech fillets
· Balanced real wood veneers
· 12mm birch ply baffle
· Tygan grille
· Walnut or Rosewood as standard
· Special finishes to order

AN AUDIOPHILE LEGEND IN ITS OWN RIGHT

Listed as one of the 12 most significant speakers of all time (the absolute sound September 18th 2010) states that the Rogers LS3/5a offers a: “startling realistic vocal reproduction and a remarkably expansive and box-less sound picture”. The LS3/5a has stood the test of time as few other speakers have. Ultimately the Rogers LS3/5a has transcended it’s BBC monitor status to become an audiophile legend in its own right.

The smallest of details make all the difference

· Single wire, 4mm Multi-Contact sockets, Silver plated for the best connection
· Choice of beautiful real-wood veneers finished by master-craftsman, rosewood, walnut and olive as standard
· Custom finishes* and RAL colour options* available at extra cost and to special order*.
*Please speak to your nearest Rogers specialist or contact Rogers to discuss your requirements.

Measurements only take you part of the way, because you cannot measure emotion

· Single layer one ounce copper track fiberglass PCB
· M6 laminated transformer cored crossover inductors
· M6 laminated transformer cored auto transformer for tweeter level matching
· High voltage Metalised capacitors
· All components hand soldered with silver solder

Sometimes what you cannot see,
is more important than what you can

· Tweeter Mylar dome tweeter with kraft nomex voice coil former. Hand finished and pair matched in UK
· Doped Bextrene cone bass unit hand finished and pair matched in UK

Artykuł Classic Rogers LS3/5a 15 Ohm pochodzi z serwisu Rogers HiFi.

Rogers LS3/5a XLR BBC Monitor Speaker

XLR Connector

The speaker cable will have some form of colour coding or ribbing on the insulating material as to which conductor is „+“ positive. For the left speaker solder the + conductor to the XLR connector pin number 2 and solder the other connector negative to the XLR connector pin number 3. Then connect the other end of the lead to the amplifier output for left hand channel, take care to ensure that the „+“ conductor is connected to the „+“ or red connector of the amplifier and that the other conductor is connected to the or black connector of the amplifier.

Repeat the procedure for the right-hand speaker.

If on audition the sound lacks bass and the image is vague, then one of the speakers

has been wired up out of phase, check both speaker and amplifier connections to ensure that the red „+“ from the amplifier is connected to the speaker XLR pin 2. Connecting the speakers out of phase will not damage you amplifier or speakers in any way.

The speakers can be supplied in a specially adapted aluminum case – Cat.No. LS3/5a XLR Alu BOX)

Introduction

Thank you for choosing to purchase Rogers loudspeakers. We are confident that these loudspeakers will provide you with high quality sound and music reproduction for many years.

Please read the short section of this manual headed ‚Quick Installation’. It contains essential information to enable you to get your speakers up and running safely.

To obtain the maximum performance and benefit your new speakers can bring, please take time to read the remainder of this manual and to familiar yourself with the speakers. You will find the rest of this manual contains helpful advice on connecting-up, matching equipment, room placement and maintenance.

Rogers – over half century of excellence

In 1947, an armed forces communications engineer turned his expertise to audio amplifiers. Jim Rogers took up a license to produce the Williams mono valve amplifier thus founding the company.

In the early years Rogers was best known for its amplification products but by 1954 could boast a complete ‚Junior‘ system comprising amplifier, AM tuner and compact loudspeakers. The 1960s were dominated by the launch of stereo and the Rogers stereo ‚Cadet‘ integrated amplifier become a world best seller.

Loudspeaker development at Rogers included unique horn-loaded designs, and even a wall hanging system called the ’Wafer¹ that was well ahead of the times. The transistor revolutionized the entire communications / entertainment world and Rogers was on of the first manufacturers to offer transistor products including the famous Ravensboume and Ravensbrook stereo amplifiers and tuners.

Transistor amplifiers offered ever more power and the focus of development passed to loudspeaker materials prompting the BBC to begin extensive research into monitor speakers for studio use. Fundamental acoustic research and scaling techniques produced the compact LS3/5a that become a benchmark product used throughout the broadcast industry in a wide variety of monitoring situations. Rogers took up a license to produce the LS3/5a and began to produce speakers of its own using the latest polymer materials derived from BBC research. Still innovating, Rogers now uses the world’s first carbon fibre dome tweeter.

In 21st century, Rogers has been continuing its spirit in developing the high-end audio product to reproduce the most natural sound reflecting every details of the original recordings. To celebrate the sixties history, Rogers specially works with BBC again to launch the new LS3/5a limited edition to satisfy the needs of the global audiophiles.

Quick Installation

Unpack your loudspeakers carefully and retain the packing for possible future use.

Position you speakers approximately where you want them and select cable runs of appropriate length.

Switch off the amplifier. Check the Bi-wire links are in place between the terminal on the rear of each speaker. Deal with each channel separately. Identify the left speaker of the pair as the speaker on the left when viewed from the listening positions.

Connect the black terminal on the amplifier left channel (possible marked ‚ negative‘ or with a symbol) to the black terminal on the left loudspeaker. Connect the red terminal on the amplifier left channel (possibly marked positive or with a ‚+‘ symbol) to the red terminal on the left loudspeaker. Make the connections to the upper pair of terminals marked HF.

Repeat these connections for the right channel. Check the integrity of the connections and that there are no shorted wires. Turn down the volume and switch on the amplifier. Select a known source and turn up the volume cautiously.

Details of how to check for phase and polarity, channel identification and the benefits of bi-wiring and bi-amping can be found later in this booklet.

Unpacking

Always unpack speakers with care so as not to damage the finish. It is always advisable to open the packaging at one end, invert the carton with the open flaps folded back so the loudspeaker is standing on the floor. Then remove the packaging from the loudspeaker. Care should be taken with larger or heavier models to avoid back or muscle strain. Get someone to help you if you are in any doubt. Retain all the packaging materials in case you need to transport the speakers later.

Connecting up your system

Cables

Connecting cables have an important effect on final sound quality. Similar lengths of good quality speaker cable should be used. Your dealer can advise you of suitable cables for your installation. Longer cable runs will generally require heavier gauge cables.

All system connections should be clean and tight. Cleaning of all signal path connections in your system is recommended annually. Simply breaking and remaking each connection ensuring a positive contact is all that is needed.

Conventional wiring

Switch off the amplifier. Never make or break any connection with the amplifier powered or with the volume turned up.

Leave the Bi-wire links fitted between the input terminals in place. Take each channel separately to avoid confusion. First, identify the amplifier left channel. You will be connecting these terminals to the left loudspeaker, this is the speaker on the left as seen from the chosen listening position.

HF: High Frequency LF: Low Frequency

Connect the black terminal on the amplifier left channel (possibly marked ’negative‘ or with a ‚-‚ symbol) to the black terminal on the left loudspeaker. Make the connections to the upper pair of terminals marked HF. Your speaker cable maybe ribbed or overprinted along on conductor to help with wiring up. Now connect the red terminal on the amplifier left channel (possibly marked ‚positive‘ or with a ‚+‘ symbol) to the red terminal on the left loudspeaker. Repeat this process for the right channel with the second length of cable. Refer to the diagrams.

Bi-wiring

Rogers loudspeakers feature split crossovers to allow for bi-wiring. This can improve the overall sound quality for the cost of a second set of cables. Bi-wiring keeps the low frequency ground currents from modulating the higher frequency signals int he trebles ‚leg‘ of the crossover network. The split crossover design permits the mid/treble and bass sections to be fed separately.

Two lengths of four-core bi-wire cable or additional lengths of your existing cable are required.

HF: High Frequency LF : Low Frequency

Switch off the amplifier. You may find it helpful to label the cables before starting to wire up the system. Label one pair of cables HF and one pair LF. Remove the Bi-wire links from between the speaker terminals and store them in case you wish to revert to conventional wiring at any point in the future.

Take each channel separately. Connect the black terminal on the amplifier left channel (possibly market ’negative‘ or with a ‚-‚ symbol) to the black HF terminal on the left loudspeaker. Make certain your connection is to the upper pair of terminals market HF. Your speaker cable maybe ribbed or over-printed along one conductor to help with wiring up. Now connect the red terminal on the amplifier left channel (possibly marked ‚positive‘ or with a ‚+‘ symbol) to the red HF terminal on the left loudspeaker.

Repeat this process for the cable pair you have marked LF connecting the same amplifier terminals but making the connections on the left speaker to the lower pair of terminals also market LF. Refer to the diagrams.

Repeat for the HF and LF right channel connections.

Bi-amping

Bi-amping uses separate full bandwidth power amplifier to drive the separate HF (high frequency) and LF (low frequency) legs of the crossover network and appropriate drivers.

Two lengths of four-core bi-wire cable or additional lengths of your existing cable are required.

HF: High Frequency

Switch off the amplifier. You may find it helpful to label the cables and power amplifiers before starting to wire up the system. Label one pair of cables HF and one pair LF. Remove the shorting links from between the speaker terminals and store them in case you wish to revert to conventional wiring at any point in the future. Designate one amplifier High (HF) and one Low (LF).

Take each channel separately. Connect the black terminal on the HF amplifier left channel (possibly marked ’negative‘ or with a ‚-‚ symbol) to the black HF terminal on the left loudspeaker. Make certain your connection is to the upper pair of terminals marked HF. Your speaker cable may be ribbed or over-printed along one conductor to help with wiring up. Now connect the red terminal on the HF amplifier left channel (possible marked ‚positive‘ or with a ‚+‘ symbol) to the red HF terminal on the left loudspeaker.

It is easier at this stage to wire up the right channel for the HF amplifier connecting the black terminal on the HF amplifier right channel (possibly marked ’negative‘ or with a symbol) to the black HF terminal on the right loudspeaker. Then connect the red terminal on the HF amplifier right channel (possibly marked ‚positive‘ or with a ‚+‘ symbol) to the red HF terminal on the right loudspeaker.

Repeat these four connections using the cable pair you have marked LF connecting the left and right LF amplifier terminals to the lower pair of terminals, also marked LF, on the left and right speakers. Refer to the diagrams.

Power ratings

Rogers speakers are designed to present an easy load to the amplifier and, to make the most of the power available, they are efficient enough to produce reasonable sound pressure levels even with lower powered amplifiers.

Because our drive units and crossover networks are conservatively rated and constructed using the latest high technology materials the finished speaker has very high technology materials the finished speaker has very high-power handling capabilities. The recommended amplifier range reflects this lower efficiency and upper power handling limits in offering a range of powers that will suit each model. Room size will influence choice. Installations in larger rooms will require amplifiers from the upper end of the range to produce wholly satisfactory sound levels, while in small rooms an amplifier near the minimum recommended power rating will be able to produce adequate volumes.

Loudspeakers are rarely damaged by being overdriven by large amplifiers, a low powered amplifier used at a high volume setting is much more likely to damage your loudspeakers due to the amplifier ‚clipping‘ the music signal and creating a ’spray‘ of high level, high frequency distortion that can rapidly bum out a tweeter or midrange driver voice coil. It is preferable to use a 200 watt amplifier cautiously at half power into 100 watt rated loudspeakers than it is to run a 50 watt amplifier at full volume into the same speakers.

Phasing

It is important to observe the correct polarity when you wire up your system. There are two areas of concern – channel identification and phase.

Correct channel connections should ensure that the left amplifier channel is connected to the left speaker (the speaker on the left as seen from the listening position). A test CD, record or tape can be used to identify the correct channels.

It is recommended that you connect positive terminals on the amplifier to positive terminals on the speaker, ie. red to red and black to black. Reversing the connections on both channels achieves a reversal in absolute phase. This may mean that the speaker bass cone moves backwards rather than forwards on the transient or beginning of a bass note. Come listeners are sensitive to this effect. You should note that absolute phase will differ from recording to recording and sometimes between amplifiers. You may wish to experiment.

Positioning

The correct frequency response (tonal balance) is achieved from your loudspeakers with their grilles in place. Removal of the grilles will compromise high and mid frequency performance.

Loudspeakers should never be placed tightly in the comers of rooms. Though this dramatically increases the bass in one frequency band, it produces a cancellation ’suck-ouf in the next. Though certain types of music may be artificially enhanced, the effect is very unnatural as can be heard in reproduced speech as a ‚boomy‘ or congested quality.

Placing stand mounted speakers on the floor will create a similar effect.

If speakers have to be placed close to the comers of a room they should be place asymmetrically with respect to the two walls, that is at a different distance from the side and rear wall. Careful listening and experimentation with positions can minimize the effects of room reflections on bass reinforcement and cancellation.

Reflections at higher frequencies from any large flat sound-reflecting surface (wall, mirror, furniture) can adversely affect stereo imaging. Soft furnishings and fabrics can be used to change reflections if the speakers can conveniently be repositioned

Caring for your loudspeaker

The real wood veneers used on certain models can be maintained by regular dusting and gentle cleaning with furniture polish and a soft cloth. Over use of waxy polishes may change the colour of the veneers.

The high-quality synthetic veneers chosen for some Rogers loudspeaker systems will retain their appearance for many years if dusted regularly and cleaned periodically with furniture polish. Spray polish onto the cloth. Do not spray polish onto the loudspeaker as this may damage the drive units.

Grille cloth is best kept clean with a length of sticky tape wrapped around the hand adhesive side out or with a clean soft brush. Do not use undue pressure as you may damage the drive units beneath the grille.

Warning

Rogers loudspeakers should not be connected to any amplifier which exceeds the recommended amplifier requirements, as stated within the individual model specifications.

Artykuł Rogers LS3/5a XLR <br />BBC Monitor Speaker pochodzi z serwisu Rogers HiFi.