Spendor Se Series Range
18cm Drive Unit Components
22cm Bass Drive Unit
22cm Bass Drive Unit Section
18cm Bass/Midrange Drive Unit
18cm Bass/Midrange Drive Unit Section
SR5 Bracket Detail
As Technical Director for Spendor Audio from 2002 to 2007, I developed the Se Series range of loudspeakers comprising SR5, S3e, S5e, S6e, S8e, S9e, C5e, C9e.
Spendor Audio is one of England’s best-loved and most respected loudspeaker manufacturers. Founded in the 1960’s by Spencer and Dorothy Hughes, Spendor has gained an enviable international reputation for class-leading R&D innovative design and no-compromise engineering. Outstanding musical performance and exceptional value for money are also a big part of the Spendor ethos.
Spendor is first and foremost an engineering led company focused on performance. All Spendor loudspeakers and drive units are designed and hand-built in-house to ensure control over all aspects of design and production. Many other loudspeaker manufacturers source ‘off-the-shelf’ drive units but they are the foundation of the performance of the finished product and should be designed and built for purpose and without compromise.
The drive units were designed using innovative technologies and materials. All of the magnetic motor circuits were FEA optimised for efficiency and linearity. Bass/midrange diaphragms were manufactured from a bespoke ep38 polymer to provide an optimal balance of stiffness and damping. Phase plugs were introduced to reduce moving mass and midrange distortion. Woofer diaphragms used a composite of Kevlar and Kapok to provide structural rigidity and a dual, balanced suspension system was designed to ensure linearity.
Spendor Audio has a reputation for intrinsic quality, so the fit and finish of the product is paramount. All the cabinet enclosures were manufactured from real wood, balance veneered MDF. Extensive internal bracing was designed to increase the rigidity of the structures and minimise panel vibration. To prevent the drive units from imparting vibration into the cabinet panels, damping elements were placed between the rear of each drive unit and an internal brace to mechanically earth the system.
A linear flow reflex port was developed to prevent airflow turbulence and minimise low frequency distortion to allow the loudspeakers to be placed close to walls in customer’s homes. This porting profile was CNC machined into the base plinth which aligned with the under-side of the cabinet to complete the waveguide.
The filter networks used high voltage, polypropylene capacitors and iron powder/air core inductors were selected for their superior sound quality. Gain matching of drive units is usually achieved using series resistors but this method introduces distortion due to the thermal non linearity. To overcome this deficiency, auto transformers were chosen with the added benefit of tighter control of the filter slope.