[Tech1] BBC LS3/1

[Alasdair Lawrance]

I’ve recently discovered that my hearing drops off a cliff (almost) after  2khz, and is almost useless above 8khz. Fortunately, both ears are about the same.

I said to the consultant, “so what I need, I suppose, is the inverse of that curve?”, and she said, yes, more or less.

The aids I’m getting can apparently be controlled by an iPhone app, and I will be interested to see how that works.  

I’m sure Mr Walker could agree that’s a good idea to have a response the opposite of his life’s work!

Alasdair Lawrance

Don’t blame me, I voted Remain.



> On 28 Dec 2019, at 17:15, Nick Ware via Tech1 <tech1 at tech-ops.co.uk> wrote:
> 
> I thought it curious at the time, that while the rest of the World was Hell-bent on designing loudspeakers and amplifiers with as flat a frequency response as possible, BBC designers seemingly thought it OK to make a speaker cabinet with anything but a flat response, and put a fixed mirror image of that response in the amplifier. Not a bad approach as it turned out, as that has become the basis of every active loudspeaker you see around you today. Bi-amped drivers are a further progression on that concept, removing the need for passive crossovers.
> Good old Kingswood Warren you might think, but what a shame they gave away so many pioneering ideas rather than capitalising on them.
> Our dear and tragically lost friend John Staple, was a good friend of Peter J Walker (Quad), and I jumped at the opportunity of going to Huntingdon with John to visit Peter at the Quad factory on several occasions. I remember a conversation with Peter on just this subject. Peter was, as we all know, totally focussed on flat frequency response at every point in the signal path, not the least being the Quad Electrostatic loudspeakers. I liked his assertion that his Quad products were for music-aware purists listening to top quality recordings, “the closest approach to the original sound”, whereas BBC monitor speakers were only for showing up faults! I felt comfortable with both sides of that argument.
> Interesting times!
> Best,
> Nick W.
> Sent from my iPad mini 5
> 
>> On 28 Dec 2019, at 14:02, David Newbitt <dnewbitt at fireflyuk.net> wrote:
>> 
>> Further thought re Nick's mention of a tailored frequency response. In the case of the LS5/1 (though not I believe in the LS3/1) the crossover circuitry employed only fed both of the tweeters up to a certain frequency, above which only one was fed. In order not to lose overall output level at the frequencies where only one tweeter was in use, the feed amplifier had a 'tailored' response built in to compensate.
>> 
>> I just wondered if this might be what Nick had remembered?
>> 
>> Dave Newbitt.
>> 
>> --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>> 
>> Nick's recollection of the Leak amplifier was not entirely without
>> foundation. The LSU/10 loudspeaker was driven by an amp coded by the BBC as
>> LSM/8 but which was commercially sourced from H J Leak, it being basically
>> that company's TL/12 amp with modified programme input circuitry.
>> 
>> The LS3/1 used an amp coded by the BBC as AM8/1 which doubtless would also
>> have been commercially sourced though I personally wouldn't have remembered
>> from where. Step forward the ever reliable Hibou!
>> 
>> Best to both,
>> 
>> Dave Newbitt.
>> 
>> -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>> 
>> -----Original Message----- From: John howell via Tech1
>> Sent: Saturday, December 28, 2019 8:23 AM
>> To: Nick Ware
>> Cc: tech1 at tech-ops.co.uk
>> Subject: Re: [Tech1] BBC LS3/1
>> 
>> Sound Sales I think Nick, not Leak or Quad
>> 
>> John.
>> 
>> John.
>> 
>> (Sent from the ifone)
>> 
>>> On 27 Dec 2019, at 18:25, Nick Ware via Tech1 <tech1 at tech-ops.co.uk>
>>> wrote:
>>> 
>>> https://images.app.goo.gl/DqzR7iTjjNFytK8j9
>>> 
>>> Google and ye shall find. The ones we had in the studios were mounted on a
>>> base containing (I think) a Leak TL10 power amp with a tailored frequency
>>> response . The whole thing on casters.
>>> Nick.
>>> Sent from my iPad mini 5
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>> 
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