Mystery BBC Loudspeaker stands revealed for the first time!

Published for the first time on the web, this photograph shows Maurice Whatton from BBC Design Department testing the corporation's top secret loudspeaker stands. For this test the LS5/9 was used mounted on top of the stand but it is known that this kind of good practice was used for measurement with all models of BBC monitors including the LS3/5a.

If you have any information about these stands please email me. If sufficient information is forthcoming we may be able to reverse engineer these stands and so publish a constructional article on how to build your own speaker stands just like the BBC used.

News. Since putting this photograph on the web site I have had an email from a former BBC employee who has asked to remain anonymous.

"Hi Paul

I saw the photograph of the speaker stands and thought I could help you get to the bottom of this mystery. I was working in Western House at the time of the development of the LS3/5a and LS5/9. I wasn't a member of the design team but I did have an interest in HiFi. Given my employment as a telephone sanitiser I was able to frequently chat for short periods to the other staff. They all wanted to use something that was the right height and stable. Crucially it couldn't be resonant, earlier tests had been done with metal and even ceramic. But ringing was a problem, they were not clean enough, they caused the sound to splash and there was unwanted colouration. As for the stands, the boffins debated and argued for weeks before settling on the model in the picture. I am afraid I can't remember what the wood used for the uprights and cross-bracing was but I remember that it was critical. A black vinyl layer was wrapped around the flat wood top plate and I remember them experimenting a lot with various thin foam material between the wood and vinyl for additional decoupling. You can't see the bottom of the uprights in your picture but each leg was further decoupled from the floor using round rubber pads about 1" thick. Like all BBC equipment these stands had a model number. They used the standard form of B = BBC, U = Universal, M = Mounting and S = Speaker. The Universal meaning that these were suitable for any of the range of BBC monitoring loudspeakers. Thus these were known as model BUM/s."