Lowther Loudspeaker Systems Ltd.

Where Technology Becomes "Live" Music



'EX' Series Drive Units


Transform your existing loudspeakers.


EX4 drive unit

The latest EX series of drive units will completely transform all existing Lowther Loudspeaker Systems. Every Lowther Owner may now enjoy the greatly superior sound reproduction qualities which only the 'EX' drivers are capable of.


Each model in the 'EX' range incorporates an acoustic chamber precisely tuned for optimum performance. Cone assemblies are pressure balanced between the acoustic chamber at the rear and a phasing equalizer fitted to the front. No unwanted oscillations of the speech coil occur. Only bass frequencies will pass through the acoustic chamber, so avoiding bass/mid-range confusion, often a cause of coloration.


Using the latest method of construction, the inner cone is now isolated from the outer. This is not readily visible, but what is noticeable is that the rim of the inner cone is terminated with a reverse roll. Where once sound frequencies cancelled each other and information was lost, now all that information is retrieved and can be enjoyed. Where once sound frequencies were reinforced by the two cones working in unison at certain frequencies, now there is no over-forward sound reproduced. The frequency range is so smooth, and so much more detail from the recorded source is reproduced, that an entirely new level of listening experience will be enjoyed.


The latest 'state of the art' rare earth magnet technology is employed to enable complete control of the diaphragm throughout the entire audible range. This results in maximum information being extracted from the recorded source whilst delivering a very smooth response at all frequencies.


The 'EX' series Drive Units are the best full range drive units ever produced. They are designed to fit into every Lowther cabinet design, both past and present, without any modification being necessary. These revolutionary drive units are a must for all Lowther owners. Everyone can now enjoy an entirely new experience of listening pleasure.


There are 3 models within the 'EX' range, consisting of the EX2, EX3 and EX4. Each model is the best in its class.



Rear view of EX Drive Unit

EX4 Drive Unit


(1) Suitably housed, multi-unit assemblies do not necessarily require passive cross-over systems between bass, mid and high frequency units.

(2) All units are rated at 100 Watts.

(3) We will be happy to answer any questions, (especially those of a technical nature) - either directly from Lowther Loudspeaker Systems in the UK or additionally via your authorised Lowther Club or Distributor if overseas.

(4) We reserve the right to vary the specification and design without prior notification.

SPECIFICATIONS (for Thiele Small Parameters, please click on the appropriate link or picture below)


EX2 Drive Unit with latest cone assembly. EX3 Drive Unit with latest cone assembly. EX4 Drive Unit with latest cone assembly.
Overall diameter
22.5 cm 22.5 cm 22.5 cm
Overall Depth
8.5 cm 8.5 cm 8.5 cm
Depth from Rear of Mounting Frame
7.6 cm 7.6 cm 7.6 cm
PCD Mounting Centres
20.8 cm 20.8 cm 20.8 cm
Baffle hole cut-out
19 cm 19 cm 19 cm
Magnet Ring Diameter
7.6 cm 9.0 cm 9.0 cm
Voice coil diameter
3.9 cm 3.9 cm 3.9 cm
Voice coil impedance (nominal)
4, 8 or 15 ohm 4, 8 or 15 ohm 4, 8 or 15 ohm
Air gap width
1.0 mm 1.0 mm 1.0 mm
Air gap height
5 mm 5 mm 4.0 mm
Magnet type
'Hi-Ferric'™ Rare Earth Neodymium 'Hi-Ferric'™ Rare Earth Neodymium Hi-Ferric'™ Rare Earth Neodymium
Flux density (1 Tesla=10,000 gauss)
1.75 Tesla 2.1 Tesla 2.2 Tesla
Twin-paper Twin-paper Twin-paper
Frequency response
30 Hz - 20 kHz 30 Hz - 22 kHz 30 Hz - 22.5 kHz
Maximum voice coil travel
± 1 mm ± 1 mm ± 1 mm
Shipping weight
3.0 kg 3.0 kg 4.0 kg


Please email us if you require any further technical information.



Despatch of drive units, ex-works, worldwide, is within 10 working days of receipt of payment.



Specifications subject to amendment without prior notice where design developments permit advancement.


Designed, made in England and distributed world-wide by: