I imagine that even the youngest readers will have heard of the most famous BBC monitor speaker the LS3/5a, originally developed in 1975 for use in mobile recording vans to monitor speech. It was the successor to the LS3/5, and created because KEF no longer made the necessary drivers. The ‘a’ version made use of KEF drivers again, the B110 (SP1003) for bass and midrange and a T27 (SP1032) tweeter. The original LS3/5a had an impedance of 15Ω and a thin wall cabinet. This version is the most famous and most sought after. When KEF decided to bring out new drivers and a crossover again in 1987 the impedance dropped to 11Ω and it lost a transformer provided to overcome small efficiency differences in the tweeter. The LS3/5a was manufactured under license from the BBC by many UK companies including Rogers, Harbeth, KEF, Swisstone and Stirling Broadcast. Recently Falcon Acoustics obtained all the rights to bring out the closest approach to the original 15Ω version.
Stirling Broadcast commissioned KEF to produce T27 and B110 (SP1228) drivers for the 11Ω version of the monitor, but KEF ceased manufacturing them around the year 2000. Stirling then sourced drivers from SEAS and Scanspeak and asked Derek Hughes to develop a new crossover to match the original sound of the LS3/5a. The new mid-bass driver has a formed polypropylene co-polymer cone with a damping coat and a synthetic rubber roll surround. The tweeter uses a doped fabric dome. The crossover has 3-steps in the higher frequency range to match the drivers within 0.5dB of the original. Since this Stirling Broadcast monitor no longer uses the original drivers a V2 suffix was added, they claim that it is as close to the LS3/5a serial numbers 001/002 as possible. It uses 9mm birch plywood panels with bituminous damping pads, sticks to the same dimensions, has a cloth front panel that needs to stay in place, a lossy cabinet with screwed-on front and rear panels and of course has felt pads around the tweeter. The LS3/5a V2 was launched in 2005. Although the V2 is a true derivative of the original it is said to have improved and extended bass response and a greater handling of dynamics.
To experience the original LS3/5a sound, I set up a small system comprising of a Bluesound Node2 running directly into a overhauled but as original as possible 1980 QUAD 303. A cheap interlink is used with some Supra loudspeaker cables and Custom Design FS104 stands. The source should have been a record player and not a streamer but I don’t have any vintage turntables nor the space for one in this room. The Dutch distributor asked me to put a big amplifier behind this Stirling, which I did later by introducing a Metrum Acoustics Adagio DAC/preamp and swapping the QUAD for a Pass Labs XA30.5. Naturally I compared the Stirling Broadcast with my Harbeth P3ESR too.
I could have started with a Mahler composition for a full orchestra, but the LS3/5a was developed to monitor speech and not music. A better start therefore is Paul Stephenson with These days. His music is easy on the ear with a lot of acoustic instruments surrounding the voice and background vocals. A nice stereo image comes my way, wide enough but limited in height. Depth is a little strange, voices often stand further away from the listener while the instruments left and right are a little forward. This, however, changes from track to track, meaning it might be the recording that places the vocals at the back. The guitars sparkle with clarity and become real to my ears. The voice of Paul Stephenson is warm and clear, intimate and tender at times, never over the top or too exposed. It’s a system that I can listen to for hours. Even Melanie De Biasio singing songs from her album No deal seems to enjoy the system. Every LS3/5a has a small bump in its response around 160Hz to simulate extra bass and this creates the right atmosphere with Melanie. Midrange is open to the voice and percussion behind the singer. Electronic sounds are not a problem at all for this little monitor. The title track shows all the fine detail in the voice since it is more clearly recorded, it’s a nice way to enjoy this music. The ultra deep bass notes on the Nik Bärtsch album Continuum are missing but this is not a big issue. Only a few speakers are this good at holding my attention with this music. Percussion is reasonably fast and accurate; bass is well defined and piano has real attack in the high notes. Nevertheless the stereo image stays flat about a meter above the floor. Time to swap the QUAD for a better amp.
With the same track, ‘Modul 29 14’, the stereo image fills the room from floor to ceiling. Bass is much stronger and goes deeper with the Pass Labs XA30.5 in place. Music escapes further from the loudspeakers in much the same way that my Harbeths work in this room. The impact of the instruments is impressive given the size of the cabinets and main driver. Details appear with ease; new instruments have been added thanks to the upgraded electronics. Yes a QUAD 303 is nice, but it’s not capable of this degree of realism. Likewise, the internal DAC of the Node 2 is no match for a Metrum Adagio. The Stirling Broadcast fully lives up to the expectations and loves the Nik Bärtsch compositions. Jim Ferguson singing A Night We Called It A Day, is great on this system, again the voice is placed a little behind the left and right instruments, while closer to the middle the singer is in line with the band. A slight change in speaker positioning helps, I had the Stirlings toed-in, now they face straight forward. Stereo image becomes a little flatter but it’s still up to expectations. Higher notes, which often suffer from listening off-axis, stay alive and correct. Whoever said that the LS3/5a is not suitable for music was right for the low end, it is a small monitor that lacks deep bass, but they were very wrong for singer/songwriters with preferably acoustic instruments. Take for instance ‘Famous Blue Raincoat’ performed by Jennifer Warnes, her voice reaches deep into your soul, remaining natural and distinct from the band. The music has real impact and the absence of booming bass in my smaller listening room is a relief. The saxophone on this track is an audiophile dream with the Stirling in place. I love it!
A little Infected Mushroom shows that the LS3/5a V2 knows it way around electronic music too, but I would suggest some more robust speakers for those who love the genre at high volume levels, so I switch over to classical. Telemann’s Ouverture & Concerti recorded in 24/96 by the Holland Baroque Society adds to the already fine qualities of the Stirling Broadcast monitor. I admit I have never heard a 15Ω LS3/5a as far as I remember, but I dare say that this reincarnation does a marvellous job in reproducing music the way it was intended. My slightly larger P3ESR speaker goes deeper in the bass registers and produces a bigger stereo image and soundstage, but lacks a bit of the extremely refined and detailed midrange of the Stirling for which this BBC design has always been famous. The P3ESR is a different speaker and although the LS3/5a forms part of its DNA it is far from a clone. Part of why I prefer the Harbeth is the dedicated stand from Tonträger, I wonder if a Tonträger stand could improve the Stirling or any other LS3/5a, like it does the Harbeth P3ESR. It is a pity the Stirling is too small for on these stands, I suggest Tonträger add a dedicated model especially for the LS3/5a.
The Stirling continues playing baroque in an enjoyable way; lively and tender at times, strong and impressive at others. A very stable stereo image comes my way with all instruments equal in quality except for the deep bass notes. You need far bigger loudspeakers for deep low end, the rules of physics cannot be ignored. Even with today’s electronics small cones and compact internal volumes do not a big system make. Stirling Broadcast has a solution in the form of their Bass Extender AB-2 for the LS3/5a V2 that would do fine in larger rooms and doubles as a dedicated stand. It might be worth investigating if the LS3/5a sound is what you are looking for.
I stated before that I have never been able to listen to a 15Ω LS3/5a, so I cannot comment on how close the voicing of the Stirling is to the original and especially the serial numbers 001/002. I will judge the Stirling on its own merits and after reading the above you already know that I love this speaker for what it’s capable of. Even with an old QUAD 303 I enjoyed music for hours and hours, never being bored or getting tired. With a modern and powerful amplifier the little one livens up further and becomes a hero. The expectations were met for the midrange the BBC once had in mind, the higher notes are of the same quality, the bass is also impressive but limited. Just the way the BBC intended with this monitor. Admirers have tried to turn the reputation of the LS3/5a into one of a large, full range monitoring system, which it is not and never will be. The BBC had larger designs that are still being made if you want more bass output. For those who love singer/songwriters, light classical and easy listening pop and do not have a large listening room this Stirling Broadcast LS3/5a V2 should be on the shortlist. It may sound a little old fashioned at first compared to bright and detailed modern loudspeakers, but once you get used to these BBC designs you might fall in love with the classic voicing. It’s nice to see that recognition of sound quality hasn’t changed, at least not over the past 30 years and more.