Lowther Loudspeakers

All units are rated at 100 Watts.

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

We reserve the right to vary the specifications and designs without prior notification.

Despatch of drive units, ex-works, worldwide, is normally within 28 working days of receipt of payment.


Silver voice coils are available for all Drive Units for an extra cost of £45.00


DX Series Drive Units

DX4

The DX series of drive units employ state of the art rare earth magnet technology. The magnet assemblies are extremely light and compact, yet much more powerful than any conventional magnets. The acceleration and damping factors are increased well beyond anything achieved in the past, even with the extremely large and powerful magnet assemblies for which Lowther has always been renowned. These all-powerful magnet assemblies allow the diaphragms to reach acceleration rates well beyond the capabilities of any conventional magnet system.

The effect of such powerful magnet assemblies coupled to the coil control system, increases the speed of the cones and yet has a truly remarkable degree of damping. This results in an exceptional transient response, but with the oscillating factor reduced to an absolute minimum.

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.

DX2 DX3 DX4 DX45 DX55 DX65
Datasheet PDF PDF PDF PDF PDF PDF
Overall diameter 22.5 cm 22.5 cm 22.5 cm 17.4 cm 17.4 cm 17.4 cm
Overall depth 7.0 cm 7.2 cm 8.6 cm 7.0 cm 7.2 cm 8.6 cm
Depth from rear of Mounting Frame 6.2 cm 6.6 cm 7.7 cm 6.2 cm 6.6 cm 7.7 cm
PCD mounting centres 20.8 cm 20.8 cm 20.8 cm 15.6 cm 15.6 cm 15.6 cm
Baffle hole cut-out 19.0 cm 19.0 cm 19.0 cm 13.7 cm 13.7 cm 13.7 cm
Magnet Ring diameter 7.6 cm 9.0 cm 9.0 cm 7.6 cm 9.0 cm 9.0 cm
Voice coil diameter 3.9 cm 3.9 cm 3.9 cm 3.9 cm 3.9 cm 3.9 cm
Voice coil impedance (nominal) 8 or 15 Ω 8 or 15 Ω 8 or 15 Ω 8 or 15 Ω 8 or 15 Ω 8 or 15 Ω
Air gap width 1.0 mm 1.0 mm 1.0 mm 1.0 mm 1.0 mm 1.0 mm
Air gap height 5.0 mm 5.0 mm 4.0 mm 5.0 mm 5.0 mm 4.0 mm
Magnet type Neodymium Neodymium Neodymium Neodymium Neodymium Neodymium
Flux density (1 Tesla=10,000 gauss) 1.7 Tesla 2.1 Tesla 2.2 Tesla 1.7 Tesla 2.0 Tesla 2.2 Tesla
Diaphragm Twin paper Twin paper Twin paper Twin paper Twin paper Twin paper
Frequency response 30 Hz-20 kHz 30 Hz-22 kHz 30 Hz-22 kHz 80 Hz-20 kHz 30 Hz-22 kHz 30 Hz-22 kHz
Maximum voice coil travel ∓ 1 mm ∓ 1 mm ∓ 1 mm ∓ 1 mm ∓ 1 mm ∓ 1 mm
Shipping weight 2.0 kg 2.5 kg 3.0 kg 2.0 kg 2.5 kg 3.0 kg

EX Series Drive Units

EX Front EX Rear

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 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.

EX2 EX3 EX4
Datasheet PDF PDF PDF
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 19.0 cm 19.0 cm 19.0 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) 8 or 15 Ω 8 or 15 Ω 8 or 15 Ω
Air gap width 1.0 mm 1.0 mm 1.0 mm
Air gap height 5.0 mm 5.0 mm 4.0 mm
Magnet type Neodymium Neodymium Neodymium
Flux density (1 Tesla=10,000 gauss) 1.7 Tesla 2.1 Tesla 2.2 Tesla
Diaphragm Twin paper Twin paper Twin paper
Frequency response 30 Hz-20 kHz 30 Hz-22 kHz 30 Hz-22 kHz
Maximum voice coil travel ∓ 1 mm ∓ 1 mm ∓ 1 mm
Shipping weight 3.0 kg 3.0 kg 3.0 kg

A Series Drive Units

PM2A

Lowther Loudspeaker Drive units are for use where only the finest standards of sound reproduction will satisfy. Their unique design and performance are world famous. Only the finest proven materials and micro-precision techniques are used in their production.

The A Series range maximises design potential enabling Lowther quality to be enjoyed in systems using single drive units to multi-unit assemblies such as Lowther's incomparable horn-loaded designs.

The A Series range utilises the extremely large and powerful magnet assemblies for which Lowther has always been renowned.

The model shown to the left is the well known PM2A

PM2A PM6A PM7A A45 A55
Datasheet PDF PDF PDF PDF PDF
Overall diameter 22.5 cm 22.5 cm 22.5 cm 17.4 cm 17.4 cm
Overall depth 13.0 cm 10.5 cm 11.0 cm 10.5 cm 11.0 cm
Depth from rear of Mounting Frame 11.0 cm 9.6 cm 10.1 cm 9.6 cm 10.1 cm
PCD mounting centres 20.8 cm 20.8 cm 20.8 cm 15.6 cm 15.6 cm
Baffle hole cut-out 19.0 cm 19.0 cm 19.0 cm 13.7 cm 13.7 cm
Magnet Ring diameter 11.5 cm 9.1 cm 9.7 cm 9.1 cm 9.7 cm
Voice coil diameter 3.9 cm 3.9 cm 3.9 cm 3.9 cm 3.9 cm
Voice coil impedance (nominal) 8 or 15 Ω 8 or 15 Ω 8 or 15 Ω 8 or 15 Ω 8 or 15 Ω
Air gap width 1.0 mm 1.0 mm 1.0 mm 1.0 mm 1.0 mm
Air gap height 5.0 mm 5.0 mm 5.0 mm 5.0 mm 5.0 mm
Magnet type Alcomax 3 Alcomax 3 Alcomax 3 Alcomax 3 Alcomax 3
Flux density (1 Tesla=10,000 gauss) 2.1 Tesla 1.8 Tesla 1.9 Tesla 1.8 Tesla 1.9 Tesla
Diaphragm Twin paper Twin paper Twin paper Twin paper Twin paper
Frequency response 30 Hz-22 kHz 30 Hz-20 kHz 30 Hz-20 kHz 80 Hz-20 kHz 80 Hz-20 kHz
Maximum voice coil travel ∓ 1 mm ∓ 1 mm ∓ 1 mm ∓ 1 mm ∓ 1 mm
Shipping weight 6.0 kg 4.0 kg 4.0 kg 4.0 kg 4.0 kg

C Series Drive Units

PM6C C45
Datasheet PDF PDF
Overall diameter 22.5 cm 17.4 cm
Overall depth 7.6 cm 7.6 cm
Depth from rear of Mounting Frame 6.7 cm 6.7 cm
PCD mounting centres 20.8 cm 15.6 cm
Baffle hole cut-out 19.0 cm 13.7 cm
Magnet Ring diameter 11.5 cm 11.5 cm
Voice coil diameter 3.9 cm 3.9 cm
Voice coil impedance (nominal) 8 or 15 Ω 8 or 15 Ω
Air gap width 1.0 mm 1.0 mm
Air gap height 4.0 mm 4.0 mm
Magnet type Feroba 2 Feroba 2
Flux density (1 Tesla=10,000 gauss) 1.7 Tesla 1.7 Tesla
Diaphragm Twin paper Twin paper
Frequency response 30 Hz-20 kHz 80 Hz-20 kHz
Maximum voice coil travel ∓ 1 mm ∓ 1 mm
Shipping weight 3.0 kg 2.8 kg

Phase Equalizer

Phase Equalizer

The Phase Equalizer is yet another amazing innovation to come from Lowther.

As everyone who is aware of Lowther Loudspeakers knows, for more than half a century every drive unit we have manufactured has incorporated a Phasing Stabilizer. The main function of the standard stabilizer is to reduce interference caused by opposite sides of the inner cone cancelling out sound waves at certain frequencies. The function of the full stabilizer, in addition to reducing sound wave cancellations, is to act as a diffuser to guide the sound waves to the walls of a horn fitted to the front of a drive unit.

The Phase Equalizer not only better achieves all that the originals can, it accomplishes so very much more.

The Phase Equalizer forms a horn contour between itself and the wall of the inner cone. This allows the high frequency response to be much improved. For the same reason the higher mid-range response is also greatly improved. The reproduced sound is cleaner and clearer with much better separation of musical instruments.

The series of tubes are of a precise size, number and depth in order to maintain equal pressure either side of the cone assembly throughout the complete audible frequency range. Without some stabilizing device, pressures either side of the diaphragm assembly become increasingly unequal the lower the sound frequency to be reproduced. By fitting the new Phase Equalizer the pressure both sides of the cone is equalized throughout the complete audible frequency range. The control applied to the diaphragm eliminates the possibility of over extended oscillations when the cones are moving forward. The effect is similar to fitting a forward radiating horn but without the possible distortion and coloration that such horns may develop.

Originally the Phase Equalizer was designed to balance the pressure from either side of the diaphragm assembly of the Lowther DX4 Module. (The DX4M is now superceded by the EX series drive units.) The acoustic chamber fitted to the rear of these drive units requires that a compensating device be fitted to equalize the pressure. The Phase Equalizer is fitted as standard to the EX series of drive units and to the DX4 and DX65, and is now available as an optional extra for all new Lowther drive units. In addition we are making it available to all existing Lowther users. The Phase Equalizer may be fitted to all types of Lowther drivers irrespective of age. No modifications are necessary. It is a simple task to unscrew the original stabilizer and refit the new one. Then an entirely new level of listening pleasure will be experienced.

Lowther Designs

The Lowther designs show a single drawing from the complete set to give a potential constructor an impression of the enclosure's complexity. Full sets of plans are available from Lowther Loudspeaker Systems Ltd. on CD in .pdf format. There is a charge for plans, but they are free if requested when drive units are ordered.

Academy

Academy

Accolade 2

Accolade 2

Accolade 4

Accolade 4

Accolade 2011

Accolade 2011

Acousta 90

Acousta 90

Acousta 109

Acousta 109

Acousta 116

Acousta 116

Acousta 124

Acousta 124

Bicor 20

Bicor 20

Bicor 200

Bicor 200

Bicor 2000

Bicor 2000

Fidelio

Fidelio

Fidelio MkII

Fidelio MkII

Tp1-Isis

Tp1-Isis