The BBC monitor sound Loudspeakers from Spendor Rogers, Harbeth....

[GrimJosef]

We have to remember that in the 1960s, which is when most of these speakers were developed, broadcast material was some of the highest quality audio that there was. FM stereo was in place and it was capable of broadcasting live music, so didn't have to use tape (although it often did). In the home it was competing with vinyl records and tape, both of which had significant background noise and had to jump through hoops (RIAA correction, Dolby) to achieve a decent frequency range. Hi-fi was much more of a domestic pursuit than it is now and there was a good deal of critical listening going on, despite a few teenagers having transistor radios.

Whether the speakers warrant the cult following or not depends on what you want your speakers to do. If you want them to sing along with music, making it more 'warm' or 'lively' or giving it more 'presence' then these aren't the boxes for you. If you want the speakers to be as neutral as possible however, to 'disappear' if you like, then you'll be in agreement with the people who were working for the Beeb. These speakers won't make your music sound good if it doesn't start out sounding good. They will make it sound the way it sounds.

Looking at recent eBay completed listings a pair of BC1s sells for anything between £300 and £500 (typically closer to the £500 end). They do benefit from stands but those don't need to be anything special. I've heard much worse modern speakers which cost a good deal more than that.

Cheers,

GJ

[Radio Wrangler]

There is a strong element of something I once jokongly called the 'Pokemon Syndrome'.... Gotta gettem all!

BBC speaker designs were for in-house use, so numbers on the open market have always been limited. Allied with a cult following, this makes them very expensive. Next add in the contractors who built the BBC designs flogging a variety of derivatives on the open market, some to the licensed design, some cheapened a bit by skipping selection processes, some offering various improvements, all offering quite high prices when new. Consequently the numbers our there were never large. The number now available is low, there is a small number of people interested in pursuing these speakers, but their desire is strong. This means that there is active competition for them pushing prices up. If you miss this pair, you may never see another, and for some people that means they must buy them at any cost.

Dark Matter has a very expensive addiction! Not as bad as an audiophile getting into Wilson Audio or top end B&W speakers.

What made the BBC speakers special was the careful engineering which went into their development followed by careful quality control of the manufacturing process.

The 'trust you ears only' approach is the opposite of what the BBC research department did. They used their own ears and they used panels of ordinary consumers and broadcast professionals and musicians. They had excellent measuring equipment and source material and knew how to use it. They had neutral test rooms as well as rooms set up to represent the intended use of a speaker. Their thoroughness was matched by honesty. They weren't trying to sell things, they didn't have to have some sort of design quirk for marketing to point to. No flim-flam.

Their speakers were designed for specific applications... a mixing suite, a TV control room, an OB van, a hospitality room. But not a domestic front-room.

Why did they (BBC) do it?

Their listeners would have a wide variety of circumstances and equipment. It would be unreasonable to bias the transmitted material to favour one circumstance to the detriment of others. Best send a good neutral signal and let people live with their own choices. Imagine sound equalised for a crappy tranny fed to some decent amplifiers and speakers.

Record manufacturers knew their market and knew it was segmented, but they knew the relative sizes of the segments and knew each segment paid the same price for a record. So they tried out their mixes on a tranny because that's where their target market first heard new music. They needed theirs to be impressive enough to sell. Then they needed to try it on something like a cheapy Dansette. Commerce pushed for powerful processing on broadcasts, CD loudness wars to match. The great unwashed masses may not have audiophile 'perceptions' but their numbers make a mockery of the money to be made from the audiophile market. - Also their hearing may be just as good, and sometimes better, but they just might not care.

Darkmatter is searching for something, I don't really know what it is, and I suspect he isn't sure himself. He's on a journey and he seems to be enjoying it. He may not have an objective destination. He may have already heard or got the best that he'll ever come across, but there is no way of knowing this and the search goes on. It's just a hobby and needs no more justification than that. He's in a much more expensive area than if woody valve radios floated his boat, but so long as it's not causing financial or spatial hardship to his family, there's no downside.

I did what the BBC did. I engineered a pair of speakers to my environment. I tried them out on other people and shamelessly used measuring equipment . Then I stopped developing them and I've been listening to them ever since. Yes there might be some things a bit better, but most seem to have disadvantages, and don't fit my environment as well. so not really better, but different. I have sound I like and enjoy. It's fun seeing visitors react. It sounds bass-light without the usual bumped response, then they notice that there is bass and that it goes a long way down. It's fun watching the rare audio hobbyist which meets them. There are no badges names or model numbers to tell them what to think they hear, yet it looks very professional. Sometimes I can be a complete rotter!

Different people have different interests and views. Life would be awfully boring otherwise.

David

[Diabolical Artificer]

Wasn't for a second denigrating Dark Matter's hobby David, just curious as to why these speakers have such a following and the Beeb went to such length's to design them; fair play to them both.

Andy.

[D_S_J_R]

For myself today, I'm moving away from this kind of sound as used domestically. Smaller UK living spaces do the full-on bass no favours at all although many owners in the UK love the mellower tones exhibited by Harbeths and so on, underdamped bass and deliberate shallow crossover dips included. I'm beginning to want a bit of life and energy in my reproduced music, more as you hear it live (yes I know recorded music goes through mixing and various types of compression, but you can still get this 'live sound' in miniature. Recent exposure to the updated version of the large ATC active monitors I used to own () and their current smaller siblings has shown me I wasn't wrong in the 90's and funds permitting, this is where I want to return to in future, with maybe a modern JBL Synthesis passive monitor or two on the way

[darkmatter]

Very interesting posts folks. Good.

Will look through later and respond

Thanks

DM

[darkmatter]

Originally Posted by Diabolical Artificer

Wasn't for a second denigrating Dark Matter's hobby David, just curious as to why these speakers have such a following and the Beeb went to such length's to design them; fair play to them both.

Andy.

That is an interesting question, for me personally hands up!! There is a small element of collecting but have since sold the Spendor BCIs and BCIIIs at inflated prices to fund other things.

My affliction is far from some however, The BBC speakers are very popular in the Far East and now fetch daft prices.

I like some aspects of their sound balance, but one must caution as aging effects that afflict older speakers as components age (More later)

I design and build my own speakers not really commercially for myself and a few others. In the past I used the Spendor BCIs and other speakers as a balance reference, the bass of the BCI was not suitable for this but they have a glorious midband which was a great help.

My own designs have a BBC influence in terms of overall balance but with a bit more drama and dynamics as D_S_J_R alludes to in his post above.

Derek Hughes has designed the newer BBC licenced LS5/8 for Graham Audio and I want to get to hear them at some point. His VOTU system is influenced by BBC engineering and balance but with a more dynamic and punchier sound somewhat similar to my own views / tastes. – Derek is a first class engineer.

The biggest design I have built to date was influenced by the Wilson Audio X1 but looked again at the overall design and dare I say made improvements to suit my own views / needs!!

They were featured in HiFi News / RR April 2002 issue, in search of SLAMM!!
The SA3s I bought in the late 90s and have kept them as mine are the last pair ever made!! They were used with the BCIs to compare to and help me tune and align the above 'SLAM' system, together with several other designs and indeed live music too!!

The KEF made BBC LS5/1s I have are a piece of history, mine are a late 60s pair in use in a second system.

I never got too excited by the LS3/5a as I like a wider bandwidth speaker sound; though I appreciated their vocal reproduction, which was excellent, they happen to ‘image’ (stereo presentation and soundstage) very well too.

However I recently heard the 'new' Falcon LS3/5a and to my ears they have the balance of the old well preserved, they should have as Falcon make the drivers as well; re-engineered by the ex KEF engineer Malcom Jones to exacting original approved standards.

Do they exceed the original? I cannot really say as the older LS3/5a speakers would be difficult to compare as many are 30+ years old and have like many speakers do, have likely suffered aging effects, safe to say I like the new Falcon speaker a lot!!

[darkmatter]

Originally Posted by Radio Wrangler

There is a strong element of something I once jokongly called the 'Pokemon Syndrome'.... Gotta gettem all!

BBC speaker designs were for in-house use, so numbers on the open market have always been limited. Allied with a cult following, this makes them very expensive. Next add in the contractors who built the BBC designs flogging a variety of derivatives on the open market, some to the licensed design, some cheapened a bit by skipping selection processes, some offering various improvements, all offering quite high prices when new. Consequently the numbers our there were never large. The number now available is low, there is a small number of people interested in pursuing these speakers, but their desire is strong. This means that there is active competition for them pushing prices up. If you miss this pair, you may never see another, and for some people that means they must buy them at any cost.

Dark Matter has a very expensive addiction! Not as bad as an audiophile getting into Wilson Audio or top end B&W speakers.

What made the BBC speakers special was the careful engineering which went into their development followed by careful quality control of the manufacturing process.

The 'trust you ears only' approach is the opposite of what the BBC research department did. They used their own ears and they used panels of ordinary consumers and broadcast professionals and musicians. They had excellent measuring equipment and source material and knew how to use it. They had neutral test rooms as well as rooms set up to represent the intended use of a speaker. Their thoroughness was matched by honesty. They weren't trying to sell things, they didn't have to have some sort of design quirk for marketing to point to. No flim-flam.

Their speakers were designed for specific applications... a mixing suite, a TV control room, an OB van, a hospitality room. But not a domestic front-room.

Why did they (BBC) do it?

Their listeners would have a wide variety of circumstances and equipment. It would be unreasonable to bias the transmitted material to favour one circumstance to the detriment of others. Best send a good neutral signal and let people live with their own choices. Imagine sound equalised for a crappy tranny fed to some decent amplifiers and speakers.

Record manufacturers knew their market and knew it was segmented, but they knew the relative sizes of the segments and knew each segment paid the same price for a record. So they tried out their mixes on a tranny because that's where their target market first heard new music. They needed theirs to be impressive enough to sell. Then they needed to try it on something like a cheapy Dansette. Commerce pushed for powerful processing on broadcasts, CD loudness wars to match. The great unwashed masses may not have audiophile 'perceptions' but their numbers make a mockery of the money to be made from the audiophile market. - Also their hearing may be just as good, and sometimes better, but they just might not care.

Darkmatter is searching for something, I don't really know what it is, and I suspect he isn't sure himself. He's on a journey and he seems to be enjoying it. He may not have an objective destination. He may have already heard or got the best that he'll ever come across, but there is no way of knowing this and the search goes on. It's just a hobby and needs no more justification than that. He's in a much more expensive area than if woody valve radios floated his boat, but so long as it's not causing financial or spatial hardship to his family, there's no downside.

I did what the BBC did. I engineered a pair of speakers to my environment. I tried them out on other people and shamelessly used measuring equipment . Then I stopped developing them and I've been listening to them ever since. Yes there might be some things a bit better, but most seem to have disadvantages, and don't fit my environment as well. so not really better, but different. I have sound I like and enjoy. It's fun seeing visitors react. It sounds bass-light without the usual bumped response, then they notice that there is bass and that it goes a long way down. It's fun watching the rare audio hobbyist which meets them. There are no badges names or model numbers to tell them what to think they hear, yet it looks very professional. Sometimes I can be a complete rotter!

Different people have different interests and views. Life would be awfully boring otherwise.

David

Interesting post David,

Yes an interesting journey, indeed, has always but may have been more? fun in my naive early days until I discovered that I could design and build excellent systems for myself. Astronomy and Engineering degree permitting

As an aside to my main Audio design activities, the BBC loudspeaker designs have interested me since early teenage, I am lucky enough to have clear objectives only gently hinted at in the post above.

I have had much exposure to some serious kit via HiFi reviewer friends and some really expensive kit can be found wanting even to my ears!!

Loudspeaker design is an area of the greatest variance in my view and even at the top end there is real difference of opinion between designers resulting in designs like and between £200K + loudspeakers, just compare the Wilson XLF to the Magico M6 let alone the Living Voice Vox Olympian. At this level personal preference comes into play.

My own design compares favourably to the above with <20Hz bass response, an easy load and ~ 95 db/w 2.81v sensitivity and can really hell raise with my big Krell power amp!! And quite delicate stuff with some other amps I use for development work. Similary they were carefully engineered, measured and developed to work in a specific environment and again produce bass when the programme feed demands it, then editor of HiFi News / RR Steve Harris was shocked at how they could reveal mastering faults in different recordings and the poor quality of many modern LOUD re-masters, since 2002 this has got far worse!!

Interested David in what you built?

Simon

------------------------

Brief bio note I posted elsewhere for interest

Had I been born a number of years earlier, I would have likely pursued loudspeaker engineering rather than civil engineering! I studied the latter in the late 80s.

My interest in Loudspeakers started when I met Malcolm Jones ex KEF (he was involved in the LS5/1s) in the early 80s whilst at an Astronomy conference in Cambridge, and have learned much from him!!

Martin Colloms as well when I met him at an audio show again a little later in 1987, so I kept audio as a hobby rather than a career.
I have been interested in loudspeaker design since early teenage and whilst listening with Martin learnt about his listening from both a reviewer's and engineer's point of view.

From this, I developed an interest in BBC loudspeakers / design and hankered after a pair of LS5/8s in the early 80s!! Well out of my financial reach, I designed and built several smaller systems to hone my design skills.
In 1996 aged 30 I designed and built from scratch, buying in all the drivers, a large 4 way modular system with nominal 18Hz – 30 Khs bandwidth of 95 db/m 2.8 volts input partly balanced against a Spendor BCI , S100 and SA3 monitors, this featured in HiFi News April 2002 issue. I can send you a copy of this if of interest?

From this I designed and built several systems for friends and others, consulted on other designs for one or two small firms semi pro status at last!!
The last few posts in my BBC loudspeaker thread Here https://www.vintage-radio.net/forum/...d.php?t=103746
are of some interest.

Prompting me to consider these random thoughts?
Loudspeaker performance decline due to aging, of driver’s surrounds and crossovers. I am considering Passive systems here.
One thing that struck me some years ago having heard a pair of Spendor S100s again, after 15 years in 2011 is the possible aging effects on loudspeaker systems, their crossover components and drivers. I don’t think many people have considered this when assessing old speaker systems.

I bet my LS5/1s do not sound as good as they would have done back in the 60s. The bass driver surrounds like the LS5/8 are pvc so are subject to aging, thus changing the electro mechanical properties. I think the LS 3/5 bass drivers with their rubber surrounds are less prone to this?
Crossover components do age I have heard this; within passive crossovers capacitors are the most vulnerable to this. This I feel many overlook particularly reviewers who keep components as comparative references.
Again recent exposure to the Falcon LS3/5A engineered by Malcolm Jones convinced me of this as they sounded very fresh, open and transparent against an older original spec pair Malcolm Jones whilst at KEF up to 1974(Falcon Acoustics after that) designed the B1814 in the Carlton and its M65 midrange dome unit and a host of other drivers like the B139, T27 and the B110 used in the LS3/5a

I can go on!!

[darkmatter]

Originally Posted by darkmatter

Alternatively I am going to have a listen to the newer Graham LS5/8 system sometime in the future, there is a dealer not so far from me

I am soon going to audition the Graham Audio LS5/8 Loudspeakers locally. I am eventually going to try and compare them to the Harbeth M40.2 to get more recent experience of the latest design thinking and approach to the larger BBC monitor systems out there.

Has anyone here heard either of them? I would be most interested in your experiences.

[darkmatter]

As an aside, I wonder how in sound quality terms, the KEF BBC 5/1AC active studio monitors compared to the active Rogers LS5/8?

[Hartley118]

Originally Posted by darkmatter

As an aside, I wonder how in sound quality terms, the KEF BBC 5/1AC active studio monitors compared to the active Rogers LS5/8?

I've listened to both the KEF 5/1 and the LS5/8 , though under very different circumstances and at very different times.

I recall Raymond Cooke (founder of KEF) bringing along a KEF 5/1 to a meeting of the Society of Acoustic Technology which we were hosting in the late 1960s at UMIST in Manchester. Whether it was a 5/1AC I don't know. My recollection is of a very transparent sound, though that may have had as much to do with the excellent BBC master tape recording as with the speaker itself. I also recall that my then young ears were a little bothered by the restricted HF bandwidth of the Celestion HF1300 tweeters, though that may have been just a psychological reaction to knowing too much about their measured response.

I've mentioned elsewhere on this forum my experiences with a couple of early prototype LS5/8s around 1980. This was at Neve when we were working closely with BBC Research at Kingswood Warren on digital studio systems. I actually managed to break the LS5/8s with disco music! That surprised me (and the BBC!) at the time because, being active speakers, it should have been impossible to overload them with their integral amplifier. I think that the manufacturers were still at the time working on a suitable adhesive to join the voice coil to the polypropylene LF cone and I'd managed to separate the joint. As far as subjective quality was concerned, I recall them sounding transparent in typical control room acoustics. However, when I took them home to try in domestic acoustics, I found them very bass-heavy. That I now gather is a common criticism of the LS5/8.

I confess that my view of BBC monitors may be influenced by an early discussion with the BBC's rather reputable D.E.L. Shorter in the 1960s. When I asked him why the BBC didn't select a high quality commercial speaker for monitoring, such as those used by top recording studios, I found him disparaging of commercial speakers in general, which came over as a rather strong 'Not Invented Here' impression. What I do recognise is the need in the BBC for repeatable performance and interchangeability of monitors. However, with modern production quality standards, it may be that volume production can result in better repeatability than the smaller quantity manufacture of BBC custom designs.

How well or badly speakers 'age' is of course another matter, Gilbert Briggs of Wharfedale suggested that they usually improve: I guess that a good layer of dust on a paper cone may well improve its damping. However, any owner of a speaker with an elderly foam surround knows that decay can set in catastrophically!

Martin

[darkmatter]

Does anyone here have experience of the BBC LS5/5?

[darkmatter]

Currently listening to a very nice pair of Spendor BCI Loudspeakers in my system, a recent purchase to replace a pair I sold.

[Radio Wrangler]

Originally Posted by darkmatter

Interested David in what you built?

Simon

Speakers... Constant cross sectional area folded transmission lines with B139 drivers. Peerless K040 mid-range and Seas H107 tweeters.

I went through several iterations of cabinet ans the stuffing pattern in the line. The K040 and H107 are complete with their own rear works. I'd heard these drivers in a number of speakers and rather liked them.

Balancing and setting up was a mixture of my ears, friend's ears and a B&K 1/2 inch capacitor mike with homebrew bias/preamp into an HP3580 spectrum analyser. The analyser made it possible to look at harmonic content and to play with line damping to minimise harmonic output while keeping the bass flat in my room.

The amplifier was much more amusing.

A colleague and good friend was designing hifi amplifiers for fun. His ethos was to use as few stages as possible and to minimise component count. I'd been playing with audio amplifier design for some time and for a bit of a laugh I decided to do one using as *many* transistors as possible. I did give myself one limitation. Every transistor had to do something useful. The result was, um, excessive, however you look at it. About 150-200W per channel. It has a 6Hz RC lowpass and a 56kHz RC highpass on the front end. Without them, it's very flat from DC to 2MHz. As a laugh, it has driven a 1.8MHz radio signal across the Atlantic. I tried it running 1dB below clipping point and al harmonics for signals in the 20Hz-20kHz band are more than one hundred dB below the wanted signal. With pairs of signals of equal amplitude set so the PEP is 1dB below the clipping point, all intermodulation products are more than 100dB down as well. The preamp has + and - 15v rails. Even if it switches instantly from one extreme to the other, the dv/dt through that 56kHz lowpass does not drive the amplifier into slew-rate limiting. With signals at lower levels, the harmonic and intermod product levels fall at rates appropriate to their order number, fall into the noise and never reappear. I had to design some special test gear to be able to measure the thing! Built to HP standards... in fact a number of copies were made. I wonder where they all are now? The other audio amp done at HP was Barney Oliver's design.
The other amp, the minimalist approach, evolved into a Linn product after Bill left HP and became their development manager.

Shortly after I got the set-up going to my liking, the whole hifi world went silly. Weird beliefs were thundered out of various magazines. At one point I went into Russ Andrew's shop to buy a new turntable drive belt, and he tried to sell me an LP12/Isobarik/Naim triamp setup. I was told that I couldn't buy anything more natural sounding for the price. My reply was "A wheelbarrowful of concert tickets?" So I lost interest in hifi machinery. I was happy with what I'd got, and I just got on with listening to more music. I built some rally cars and I got back into amateur radio and spent more time horsing around.

David

[dave walsh]

How would you do something similar now David ? Can I buy one ?

Dave W

[Radio Wrangler]

Well, Falcon seem to have put the B139 back into production, though there may now be better choices. I'd stick with the transmission line loading. There are superb tweeters nowadays, but nothing which seems to replace the Peerless midrange.

I would certainly tri-amp them and have the crossover at low level.

On the amplifier front, the power transistors I used have long been unavailable but a bipolar version was done for comparison (As was a valved 100W direct-coupled wideband amp)

The fully symmetrical complementary, differential, cascoded input and VAS stages I'd keep.

It's stupidly far beyond what could be heard, but I did it just for the hell of it. Only a design engineer could love it

It's now 38 years old. I have never intended to produce it, entering the expensive end of the hifi market seems to me like entering a piranha-filled tank. There is so much complete crap being bandied around there is a huge risk that even something good will get pooh-poo'd by some pundit and that will be that. A sensible market where things are judged on real performance, I can handle. A market steered by the perception of imaginary characteristics is dangerous. I suppose bribery of some form might be involved. I couldn't do the charismatic figurehead job, I'd just laugh too much.

David

[Ted Kendall]

Re the piranha-filled tank, I had a brief but rather shocking glimpse the other day of how perceptions of good sound have changed since I were a lad...

I was on site, fixing some machines in an archive transfer facility, using the Beyer DT100s I've had for donkey's years. I use other 'phones for other purposes, but these are a tough and truthful tool, within their limits. At one point I wanted to confirm that a signal was reaching the convertors, so I reached for the 'phones already connected. These are made, or marketed, by a well known British speaker manufacturer. Granted, I could establish the presence of signal, but any qualitative judgement was impossible, owing to the enormous lump in the bass end. The contrast with the Beyers was grotesque, and not in a good way - it put me in mind of the undamped bass so beloved of radigrams of a certain age, but hefted up several decibels.

The worst of this is that these 'phones carry a reputable label and are not by any means cheap.

The BBC sound has its critcs, but the fact remains that it is rooted in the need for an accurate balancing tool and has been developed at least partly by direct comparison with live sound. That which came out of these headphones must have been from an alternative reality...

[Radio Wrangler]

There are enough people living in that alternative reality, and they are people prepared to exert themselves financially. Their universe may be imaginary, but their cash is real. All sorts of firms will do whatever it takes to collect some of that cash.

The BBC speaker development operation was wonderfully free of commercial pressure. They were just after speakers which fitted in with their standard environments and produced a sound as close as they could get to live performers as they could get. They were in a position to get performers and even an orchestra to make true comparison possible and also spread the judging job across many people... musicians, consumers engineers.

I can't think of anywhere that speaker development was pursued so comprehensively.

Good speakers vanish. You can suspend reality and imagine yourself in the place where the music came from. This is the exact opposite of what many hifi aficionados want. They want dramatic results. They want to shock visitors with something in their face, something which makes their wealth conspicuous. They won't say they want these things. It's not the sort of thing people ever admit, but if you look at what they buy, you can see the influence. They really go for looks too. Things milled out of blocks of solid unobtainium go down well. Exotic materials that can be pointed at... solid diamond tweeter domes... wow! Midrange cone surround bellows made from unicorn leather! Rare mystic thermionic glassware made generations ago and whose secrets of construction have long been lost. Expense and exclusivity are the prime parameters. The BBC never covered these things.

But now that we're in the era decades after the BBC was active in engineering, the speakers they designed have acquired exclusivity, and with that comes expense.

My old faithfuls are a pair of Sennheiser 555s. Not perfect, but I'm used to their characteristics and I can tell if anything is unexpected.

David

[Bobsound]

I have a limited experience with the LS5/5s. The first I heard was in the film dubbing theatre at BBC Manchester, I cannot say I noticed anything about the sound; it was just a monitor speaker. Later I bought a pair, they came with the dedicated Quad 50D power amps and the custom pre-amps built into black painted diecast boxes. These provided for balanced input, level control and EQ tappings accessible behind a perspex cover. They also came with the stands! The speaker was a three way system with a massive passive crossover containing a large amount of iron and large non- electrolytic capacitors. There were tappings on the cross over. The purpose of the various tappings on the preamp and crossover was to adjust the performance to the specific acoustic. They sounded fine to my ears (as a professional 'jobbing' sound engineer rather than an audiophile) but I could never get the soundof the pair to match. Possibly age had pushed them ouside their specs. These were after all BBC cast offs. I eventually gave them to a colleague who was into 'Drum and Bass'. I later acquired a pair of LS5/8s which I still have and love listening to. As previously said, they aer rather bass heavy in a domestic situation. I believe that the LS5/5s were designed as single monitor speakers but the 5/8s were the first to be designed intended to be used in stereo pairs.

[julie_m]

You'd expect the BBC to specify a "standard" loudspeaker with tightly-defined characteristics, precisely so that any two examples fed with the same input signal would produce the same sound; that then being the "original" that every receiver was trying to recreate. And such speakers probably would tend to sound "ordinary" and "boring", if not "a bit lifeless", for that reason. You'd also expect them to sound a bit "boomy" in a small room without anti-reflective wall surfaces -- that's probably because the room is a bit boomy, and the BBC speakers are exciting resonances that other speakers could not.

[JerryLeeFan]

Google found your discussion about BBC monitors.

I have have been enjoying the sound from my two BBC LSU /10 for 45 years. They truly are vintage speakers.

There are two pages of photographs, one minute videos, BBC technical circuits, Lockwood cabinet design, and photographs of my audio set up that is still in daily use - all detailed as this link.

http://www.knightsaberdeen.com/bbc1.htm

keep rockin'

Graham