Chartwell LS3/5 BBC Licensed Monitor Loudspeaker
Graham Audio has purchased the CHARTWELL and SWISSTONE Companies. The famous Chartwell brand were historically regarded as the finest builders of the BBC LS3/5A speakers and their products are the most sort after of all the licensees who built the brilliant LS3/5A
Graham Audio is manufacturing the most famous of all the BBC speakers under one of its most cherished names with the attention to detail and sound that made Chartwell so famous. The bespoke drive units and crossover networks are by Derek Hughes working in conjunction with Volt loudspeakers to produce a fully licensed ‘Made in England’ speaker using the very finest materials available.
Graham Audio’s mission is to produce BBC monitors that harness advanced manufacturing techniques whilst keeping the heritage and design of the original speakers alive.
The Chartwell LS3/5 is hand made at Graham Audio’s South Devon facility in the United Kingdom.
Derek Hughes (father Spencer Hughes who founded Spendor) was part of the original team of engineers who worked on the development of the LS3/5, only 20 pairs were ever made and only very few images exist and difficult to source. Nobody else is better suited than Graham Audio working with Derek to bring the LS3/5 to the market for the very first time.
The LS3/5A was a commercially produced loudspeaker driven by the need of the BBC to monitor and assess broadcast program quality. It was derived from the LS3/5, which was conceived and developed by the BBC Engineering Department in the early 1970s. Having found no commercially produced small loudspeaker that met the requirement for naturalness and sonic neutrality, the BBC specifically set out to design a speaker to achieve natural overall sound quality and good dynamic range for monitoring broadcasts in tightly confined spaces. The LS3/5 was built using the KEF B110 (A6362) and the KEF T27 (A6340) drive units with an estimated development costs in the order of £100,000 or roughly £3M in today’s relative value. Only 20 units of the LS3/5 were produced in-house by the BBC.
As the BBC broadcasting unit was about to order another batch of the monitor, it was found that KEF had discontinued the B110 (A6362) and the T27 (A6340) in favor of the B110 (SP1003) and T27 (SP1032) specification, and was already using them in the Coda, one of their own-brand commercial loudspeakers. KEF claimed the original drivers were too difficult and costly to produce. The BBC’s Designs Department was called upon to adapt the product in light of the supply changes.
Significant modifications were made to adapt to the new drive units and deal with the altered resonance pattern, and the LS3/5 became the LS3/5A. The trouble was in three areas; the B110 had changed, exciting the cabinet in a different way, producing a coloration both from the LF unit and the cabinet; and the HF unit had developed a pronounced ‘lipsy’ quality. Several modification were made to the crossover, cabinet and tweeter (protection cover and felt as shown on the 3/5A but not on the 3/5) to help fix the discontinuities.
As a result the LS3/5 was never commercially available, and was only launched as the LS3/5A after Kef stopped making the driver they were using. The original LS3/5 driver was preferred and sonically superior, however using the substitute driver the team had to change the crossover and tweeter to suit the substitute driver resulting in the product model change to the LS3/5A.
Graham Audio are the first and only company to be granted a license for the LS3/5.
Chartwell LS3/5 Specifications
System: 2 Way Sealed Enclosure.
Cabinet: Thin wall construction, 9mm (critically-damped) Birch plywood, removable rear panel.
Finish: Real Wood Veneer.
Dimensions: 30cm (h) x 19cm x 17cm (d).
Frequency Response: 70Hz to 20kHz +/-3dB.
Nominal Impedance: 9 ohms.
Sensitivity: 83dB SPL (2.83V, 1m).
Maximum Output: 95dB, pair @ 2m.
Bass/Midrange: 110mm Bextrene cone.
Tweeter: 19mm Dome.
Recommended Amplifier Power: 25 to 50watts unclipped programme.
E. O. & E.