SpeakerTalk

[speakerguru]

I've posted this exchange, with Allen's permission, so that others can join in the general KM1 discussion. I'll be digging up more info on the KM1 and re-posting as soon as I can.

regards,

SG
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From: "Allen"
To: <speakerguru>
Subject: Re: KEF KM1
Date: Tue, 3 Jan 2006 10:18:56 -0500

Thanks for the email. Over the years I have become more and more convinced that an important and necessary factor in sound reproduction that appears 'real' is dynamic linearity, the ability to change levels at all frequencies and sound pressure levels without noticeable compression. And that the ear/brain is very sensitive to this. And since only large speakers have a chance to accomplish this, I became fascinatted by them. I saw the KM1 at a Chicago CES in the mid 80s and have a brochure on it. And then I saw nothing more on it. I expected more feedback. Very few people seem to even know of its existence.

And the design of speakers fascinates me. Thedesign of the KM1 seems awesomely well thought out as to the questions chosen to solve and the solutions. I do believe that a properly designed, conventional dynamic speaker with integrated amps and electronic crossover is the best solution so far. Besides that tweeter blows my mind just looking at the picture of it.

I just wanted to see if I could locate any more info on the speaker. I had tried before and gotten nothing.

By the way I had a pair of LS5/8 speakers on loan in the early 80s for a month and did a review for Stereophile magazine. At the time I was using a pair od B&W DM6 speakers and the LS5/8 ruined me for the DM6s. So if the the KM1 is an 'improved' LS5/8 then wow.

I suppose the KM1 was alittle before its time. It was too expensive for the mid 80s. Today it would be one of many costly speakers in the US. There must be at least 20 $50,000 and up speakers on the market now. It's too bad it didn't have more influence in audio and I wonder how it would fare today. Are any still in use that you know of. I'd love to find a pair near me in the US. that would be worth a trip to hear.

Allen

----- Original Message -----
From: <speakerguru>
To: <hahax>
Cc: <terry>
Sent: Tuesday, January 03, 2006 4:30 AM
Subject: KEF KM1


Allen,

The KM1 came into being because the BBC wanted something which sounded as clean and uncoloured as the BBC designed/Rogers built LS5/8 but played louder. They bought 3 pairs. Two pairs for Maida Vale studios 4 and 5 and one for the Golders Green Hippodrome theatre.

Altogether, around 50 systems were sold worldwide .

regards,

SG



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One of the speakers that most fascinated me was the KEF KM1 designed to be a high level (120 dB) monitor. I never really got to listen to it but I do have a blurb on it and it certainly is both technically and acoustically perhaps the most intersting KEF speaker. It never got a great rep but given its ability to play loudly with very minimal compression I suspect the main problem it had is it didn't sound like other audiophile speakers(then again it was obviously designed as a high level PROFESSIONAL design). I don't have the ability to read the brochure into my computer. But I could check with friends or copy it and mail the copy.

It certainly would be good to get more info on it from other enthusiasts, especially from those who may have heard it.

Allen Edelstein

[speakerguru]

Allen,

I’ve dug out some more pictures and information on the old beast here.

KM1 documents and photographs

Anything else you want to know, just ask. Thanks for the kind words about the design. Every aspect of speaker design was revisited, with nothing being taken for granted. I’m still a believer in active designs. Having line level crossover and eq filtering before the power amps gives a huge increase in headroom which cannot be economically achieved in any other way. The tweeter was a monster. If only there had been NeFeBo magnets and Uni-Q at that time.

Re getting to hear the KM1, I’m not sure that any were sold in North America, although I suspect that at least one pair made it to CES one year. Whether it stayed in the US or was returned to the UK, I don’t know.
I know that as well as the BBC, Angel Studios in London and also an Irish recording studio had a pair.

The KM1 may well have been “before its time” but you also have to have the combination of someone who likes a “BBC monitor” sound and is thinking of refitting a big studio before you stand a chance of making a sale, specially as most big studio speakers were “soffit” mounted.

SG

[proffski]

I couldn’t agree more.
There is no such thing as a prefect loudspeaker.

Low colouration Vs low efficiency.
Even two pairs of Quad 989s and Musical Fidelity KWs are not all there.

I still remember a pair of Tannoy Ardens driven by a cuddly Krell.
Coloured as hell, but the sheer breathtaking dynamics with little or no perceived compression left me speechless. That takes some doing…

[boyzo]

The KM1 was quite a beast loud active but with a wonderful symmetrical driver layout
would play very loud ...

A classic a KEF speaker with BEEB sound but with real grunt.

Heck 2 x B300 2X B110 + the T52 pretty awsome even today

[Parts]

, I am pleased to finaly find more info on the KM1, top stuff.

[qguy]

I think its 4 x B300 2X B110 + the T52

[darkmatter]

Now this is one speaker system I wish that I had the chance to experience!!

[Thierry]

Reviving an old thread...

[SaSi]

The KM1 design, in a different form factor with all drivers stacked up in a vertical row, is a bit close to what the Muon looks like. Granted, the Muon is a bit different and not active, but - to me - the product of the school of thought that plenty of drivers are needed to deliver uncompressed dynamic range.

There is some discussion about how the KM1 came to exist and a few stories about it and the BBC in the KEF 50 years anniversary book. Worthwhile reference for any KEF lover.