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Silver or Aluminium?
If the chosen drive units are to be used in a 'live' environment: i.e. wood flooring, minimalist furnishing and colour washed walls etc. silver coils may be the best choice; they will slightly attenuate the top response. Silver coils are also recommended if the speakers are not used regularly, i.e. in a holiday residence or if needed to be stored for periods longer than three months.
For rooms that are carpeted, have soft furnishings, papered walls and curtains (drapes), then aluminium coils will provide the 'attack' that such rooms can absorb.
For aluminium coils, it is recommended that prior to playing music through your speakers, a minute or so warming-up period is given. This is acheived by switching on the amplifier without volume gain, thus permitting the aluminium coil to warm through, allowing the wire to become more malleable. This is particularly important when using your Hi-Fi equipment for the first time after a lengthy period of non-use.
8 Ohm or 15 Ohm?
8 ohm speech coils are favoured by transistorised amplification owners.
15 ohm speech coils are favoured by valve (tube) amplification owners.
15 ohm speech coils should be used where two units are required in one enclosure.
Lowther developed their unique 'HI-FERRIC' Coil Control System in order to overcome the problem of keeping colloidal ferromagnetic fluids within the magnet's air gap throughout the frequency range of our full-range drive units.
We realised ferromagnetic fluids offered advantages, but except for the higher frequencies we were unable to keep the fluids in place. This was disappointing as we, like many other loudspeaker manufacturers, realised magnetic fluids could offer improved performance. Determined not to lose the advantages ferromagnetic fluids provided we developed our own coil control system.
The Lowther 'HI-FERRIC' Coil control System incorporates all the benefits of ferromagnetic fluids with some additional advantages. Lowther's latest 'HI-FERRIC' Coil Control System is based on a compound of ferrous oxides securely encased in a high temperature resistant plastic cocoon which is attached to the voice coil. It remains securely in position throughout the entire frequency range of our full-range drive units.
The 'HI-FERRIC' Coil Control System, as with ferromagnetic fluids, can assist in maintaining better temperature control. Sensitivity can fall approaching 1.0 percent for every 2 degrees C increase in temperature of the coil. In addition unwanted voice coil oscillations are greatly reduced. The improved damping factor allows for a faster transient response.
The 'HI-FERRIC' Coil Control System has another advantage. It is actually an energised magnet system in it's own right. As current passes through the voice coil, the ferrous material of the 'Hi-ferric' system is magnetically energised. As like poles repel and unlike poles attract, the 'Hi-ferric' system attached to the voice coil is either attracted to or repelled from the host magnet's air-gap, depending on the polarity of the applied signal. As the velocity of the voice coil is substantially increased the transient response time is reduced. Between signals the 'Hi-ferric' system is immediately attracted to the central position within the air-gap, thus increasing the rate of damping. Unwanted Coil oscillations are therefore reduced to a minimum.
Lowther's design engineers have again achieved another first in loudspeaker design. Following hard on the heels of the invention of the 'Hi-Ferric'™ coil control system, our engineers have now designed a system that allows each loudspeaker to be individually tuned exactly to the room environment within which it is to operate. In fact, each speaker may be tuned to the exact part of the room in which it is situated.
The system has enormous advantages over conventional systems, each speaker has it's own characteristics of performance even before it is placed in the position where it is to be used. Further to this, other imbalances may occur within the audio system itself. Often the two channels do not have precisely the same matching. Apart from these problems there is the certainty that, with time, the Drive Units within the cabinets will develop variations in compliance that will be a further source of imbalance affecting performance. Finally, there is the room itself. It is virtually impossible to find a room that has precisely identical positions for each speaker to operate perfectly in balance with its partner and so give optimum performance. These problems are completely eradicated with the Lowther Ambience Matching System.
In order to overcome the inherent problems of these imbalances, our design engineers invented the Lowther Ambience Matching System. This system allows each speaker to be exactly tuned to its room environment, irrespective of any shortcomings caused by cabinet and audio system variations.
Lowther's Bel Canto and Delphic models are fitted with the Ambience Matching System. These models are conventional horn designs incorporating our unique Bicor compensating system. The speaker enclosures are then mounted onto stands that are designed to be raised or lowered onto specially manufactured flared discs that then become the horn mouths. By adjusting the mechanism the air pressure within the cabinet may be infinitely varied. This allows each cabinet to be tuned exactly and precisely to the room environment as well as the partner of each pair. The adjustments are simply performed with only finger tip pressure required. This precise tuning gives an entirely new world of listening realism and pleasure.
An additional benefit of this system is that, by fine tuning, each speaker may be adjusted to give a totally smooth sound reproduction response. The Bass, Mid-Range and Highs may be tuned to give exactly the performance result required.
Incorporated within this system is the ability to rotate each speaker to allow perfect stereo imaging. Again by simple finger tip control.
No other loudspeaker system has these enormous advantages of self-tuning that all committed audiophiles will surely insist upon from now on. Rigid systems will never again give sufficient listening satisfaction to true music lovers.