This area of the site is being produced primarily to create an online record of speaker systems which were not produced by KEF but which used KEF drive units. Anyone who can add information to this table should email enquiries with details including pictures if possible.

Technical details of Speaker Systems

Speaker Systems which used KEF Drive Units

LS3/5 (1970) Drive Units B110 A6362,T27 A6340 - only a few made

LS3/5a Drive units B110 SP1003 and T27 SP1032,  All drive units were specially selected.

LS3/5a Still available from Stirling Broadcast - but perhaps with different drive units. Drive units B110 SP1228 and T27 SP1032,  All drive units were specially selected.

Linn Isobarik - KEF Drive Units B139, B110

* IMF Monitor TLS80 A four unit system incorporating KEF B139; modified KEF B110; Rola Celestion HF1300 44mm diaphragm unit for HF; Coles 19mm chemical dome super tweeter for EHF. Dimensions 978 X 467 X 406. Weight 34kg

**old version : B139, B110A, Celestion HF1300, Celestion HF 2000
**new version : IMF 128/20, IMF 5/36, IMF TW 1350 F, IMF TW 2100 F

++ IMF TLS50mk1 used B200 SP1014 drivers initially but changed to the B200 SP1063 later in the production run

* Audiomaster Image 2 A two unit system incorporating KEF B200 and Peerless HF type K010 25mm soft dome. Dimensions 463 X 287 X 231. Weight 8.1kg

* and ++ Celef Mini Professional A two unit system incorporating KEF B200 SP1039 and Audax HF unit 20mm doped fabric dome. Dimensions 584 X 305 X 279. Weight 15kg

*Celef Studio Professional A three unit system incorporating KEF B139; Audax 203mm Bextrene unit to cover upper bass and mid range; Audax 25mm soft doped fabric dome tweeter. Dimensions 762 X 343 X 381. Weight 30kg

* JR 149 (Jim Rogers) Round vertically with aluminium cage. KEF B110 and KEF T27. Dimensions 370 h by 230 diam. Weight 5.5kg

* LNB Para-Lab Super A two unit system incorporating KEF T27 and Elac 165mm long throw bass unit. Dimensions 597 X 228 X 260. Weight 8kg

* and ++ Monitor Audio MA 4 A two unit system incorporating 220mm Bextrene cone unit, KEF B200 SP1039 and a special modified Isophon unit. Dimensions 694 X 316 X 280. Weight 16kg

* Tangent RS 6 A three unit system incorporating KEF B200 connected out-of-phase with KEF B110 and KEF T27 tweeter. Dimensions 810 X 315 X 05. Weight 15kg

Tangent TM1 - Dimensions 24 X 12 X 12 inches. B200A SP1014; T27 SP1032 and the Chorale DN13 SP1015 crossover. It sounds fuller than the Chorale because it is a slightly bigger but more rigid box. Picture on right supplied by Colin Royle on Tuesday 24 February 2004. Information supplied by Colin Royle on Monday 15 March 2004.

+ Nightingale NM3. A three unit system incorporating HF SIARE TWM; MF SEAS 11F-GX; LF KEF B139 SP1044. Dimensions h800mm X w355 X d485mm. Weight 30.35kg. Nominal Crossover Frequencies 500Hz and 3kHz

++Meridian M1 (~2.5 active Concertos)

Meridian M2 (active, 2 B110B, T52 SP1072). Picture on right and information supplied by Colin Royle on Friday 20 February 2004.

Meridian M20 - ( 2* B110B, T33 mk2 as used in its contemporary the 104-2). Information supplied by Colin Royle on Friday 20 February 2004.

++Griffin (active B139A, Celestion MF & HF - as used in Ditton 66)

++Toccata (home constructor 2 B110B, T52)

++JR 150 (2 B110B, Audax )

Cambridge R40 (Bailey design Wireless World) used B139A, B110A and both types of T27 plastic case Alnico magnet and steel plate ceramic magnet. Very late versions used the B139B. Information supplied by Colin Royle Tues 10 February 2004

Cambridge R50 - The early R50 (Bert Webb Audio Amateur) used B139A B110A,T27 (plastic), STC/Coles 4001G. Those made around April 1975 used the metal T27A. Those after June 1975 also used the B139B bass unit. Information supplied by Colin Royle Tues 10 February 2004

The Daline System (a Decoupled Anti-resonant LINE loudspeaker by Robert Fris) - various models which is not limited to be used with any particular size of drive units does however offer best results with as small a bass unit as possible. Designs include one with B110 and T27; another with B110, T15 and Coles 4001G super-tweeter; and a third with B110, Peerless KO 10DT tweeter and Coles 4001G super-tweeter.

Articles referenced above were first printed in HiFi News & Record Review November 1974 and May 1975 by Robert Fris.. Articles include crossover designs and constructional details. Details above were extracted from these articles.

Photographs provided by Bob Thompson

David Hughson has provided details of a simple modification for a pair of Dalines he built back in the 1970s. He claims that it transforms the sound.

Heathkit produced two KEF based kits (up to 1975?) one was B139A, B110A & T27 in a 80 litre cabinet, another used Two B139's, three (?) B110A's & four T27's in a 120-150 litre cabinet, it cost £200 plus tax for the kit in 1973 - KEF lost money on every driver that they supplied to Heath btw.
The mid Heath design btw used the JBL L100 Century drivers.
(Information from Colin Royle 10 Feb 2004). Has anyone any further details?

When Wilmslow Audio were in Altringham (~1988) they had plans for a hexagonal cabinet (three long, three short sides) and a pseudo time delayed design with a sloping front baffle for the KEF B139B, B110A & T27 with a non-time delayed 18/24 dB/octave crossover. (Information from Colin Royle 10 Feb 2004). Has anyone any further details?

Mordaunt Short produced a design (~1970) using a B139A, T15 & Coles/ STC 4001. (Information from Colin Royle 10 Feb 2004).

MS 400 1970~1974 Frequency response 35Hz - 25 KHz. Power handling 35 watts
into 8 ohms. Dimensions: 27" high, 15" wide, 9" deep, standing on a 1.75"
plinth. Weight - 17.7 Kg each. (Information from Colin Royle 21 May 2004).

Dalesford produced a design which used B200A SP1014, metal T27 and a Chorale SP1015 crossover. The only difference between it and the KK1 (Chorale!) crossover SP1106 is that L2 is a ferrite-cored inductor as opposed to an air (wooden dowel) cored component. A contemporary of this Dalesford design was the 24"*12"*12" B200A, metal T27 Tangent TM1 square ported reflex design. (Information from Colin Royle 11 Feb 2004). Has anyone any further details?

Tangent TM1 (square ported reflex design) - 24"*12"*12" B200A, metal T27 (Information from Colin Royle 11 Feb 2004).

Tangent TM3; 8 ohm, weight 8kg each; 37cm H x 25.5cm W x 28.5cm D. Drive units are KEF, T27/SP1032 the 8ins bass driver is B200 SP1014. (Information from Colin Royle 23 Feb 2004)

Celef PE1. The last Celef design (running from top to bottom) consisting of a 75mm Piezo unit, 20mm Audax dome and a KEF B200 SP1039 and the port full of straws. Cabinets 32-36" tall. (Spotted at the Audiojumble, Angel Centre, Tonbridge, UK, 15 February 2004. Information supplied by Colin Royle 16 Feb and 23 May2004).

Proac 3 - consisting of a mirror pair with the KEF B200 centrally located at the top and then the handed Audax and Piezo units again with the straw port in line with the bass unit at the bottom. Cabinets 32-36" tall. (Spotted at the Audiojumble, Angel Centre, Tonbridge, UK, 15 February 2004. Information supplied by Colin Royle 16 Feb and 23 may 2004).

Goodmans Mezzo 3 'High Fidelity Multi-Unit Loudspeaker System'. 30 Watts. 4-8 ohms. 9" main drive units, KEF T27 tweeter 6535, KEF SP1017 crossover. Size 310mm X 503mm X 235mm approx. Owned by hifiloudspeakers.info.

Ferrograph S1 monitors (B139B in transmission line plus Audax mid and treble). Ferrograph known for tape recorders was owned by the Willmot Breeden Group and based in South Shields. The Ferrograph S1 is an eighth wave transmission line like the B&W DM2a and was probably the longest production run of any speaker! Information supplied by Colin Royle 24 Feb 2004

*Additional information. Bass reflex cabinet constructed of walnut finish polyester-faced high density chipboard, Dimensions 603 X 350 X 440mm. Weight 25kg. midrange is 102mm and HF unit 25mm. RRP in 1976 was 228GBP. Review available in 'HiFi Choice Loudspeakers' by Angus McKenzie 1976; Aquarius Books Ltd

Allen Edelstein (3 Oct 2005) comments as follows about the S1: - I don't believe the Ferrograph S1 was a transmission line. It was more like a more complex version of the Dynaco A25 or Dynaudio variovent which is a highly damped port that gives little or no port output. It gives the same resonance as the driver in a closed box but with lower Q and thus tighter bass. The Ferrograph had a complex triangular port that was made by triangulating one corner in the back with a panel at 45degrees to the back and the side. It started on the bottom of the speaker and turned a corner at the top, finally venting at the top of the front panel. The port was filled with long hair wool. I can see why it might be thought a transmission line as it is long and fairly large in cross section but it's not. It's also related to the IMF line tunnel that was first used in the IMF Super Compact. I believe that Bud Fried once told me the Ferrograph was part of the inspiration for the Super Compact bass loading.  

There are a number of ESS-AMT designs with Heil tweeters. Almost all used KEF bass units. Historically they are important for two reasons, firstly if you couldn't afford them you bought IMF TLS8s or Reference Monitors and secondly the design which intergrated the big four sided Heil and B139's inspired the Gradient sub used with Quad ELS-63's. Information supplied by Colin Royle 24 Feb 2004).

* source: 'HiFi Choice Loudspeakers' by Angus McKenzie 1976; Aquarius Books Ltd
+ source Falcon Acoustics in pdf format
** source Stéphane Tsacas || www.frenchimages.com || site - section dealing with IMF Electronics Speakers
++source Colin Royle Mon 9 February 2004