Advanced driver systems
Whereas most affordable speaker systems are based on drive units that are built down to a price, Wharfedale started with the premise that Diamond drivers should be aimed at performance. That is why the Diamond 11 Series sports advanced driver systems incorporating elements that normally only find their way into high-end loudspeakers.
For example, the bass and midrange drivers use a basket with a network of ribs that maintain the rigidity of the basket while leaving a large open area behind the cone. The rigidity improves transient impact while the big open area reduces early reflections to cone and allows the generous, specially chosen internal cabinet absorbent to do its work.
The Diamond 11 Series speakers also feature massive magnet designs to both raise sensitivity and ensure absolute control of cone movement over lower bass frequencies. In addition, the use of a specially shaped single-forged pole piece with copper cap controls the magnetic flux and ensures low distortion through the critical midrange area.
Then there is the progressive suspension which features a lightweight foamed surround for an extended midrange response, in conjunction with a super-long-throw voice coil motor system, to achieve unparalleled linearity and accuracy in this sector of the market. Naturally the woven Kevlar cone, a long-time favourite for Diamond designs, has been treated to provide a precise match to the new suspension elements.
High-frequency performance has been similarly enhanced with a newly evolved tweeter design. Again, an over-sized ceramic magnet system is used, with a copper cap for flux control. And, here, the pole piece is vented through to a specially shaped rear chamber. This provides a low resonant frequency, ensuring excellent linearity throughout the operating system and allowing the textile dome to contribute to a lucid midrange performance in addition to precise high-frequency detailing.
While the drive units are the heart of a loudspeaker system, they would be nothing without the integration of a precisely derived crossover. Wharfedale’s engineers use a highly evolved virtual crossover software system to help create a series of circuit options for combining the bass/midrange and treble units seamlessly. These circuit options are then evaluated using stringent listening tests over a period of months, involving a wide range of music.
Once the final circuit strategy has been chosen, the design team fine tunes the crossover component values, the type of components and the circuit board layout to yield the most accurate, detailed and, above all, enjoyable musical performance using only listening tests as an arbiter of quality.
Special attention is paid to the lifelike qualities of vocals and natural instruments, as these are always the focus of listeners’ subjective appraisal of a loudspeaker’s performance. It is this attention to fine tuning, allied to excellent technical design, that gives Wharfedale Diamond speakers their enduring appeal in the affordable sector of the hi-fi market, from one generation to the next.
While the cabinet, to the owner, is often just a piece of furniture, Wharfedale has long realised that it is the final piece of the design process that marks a speaker out of the ordinary. Since the early days of Wharfedale, when the founder, Gilbert Briggs, was experimenting with such rarities as sand-filled baffles, cabinet construction has always been part and parcel of the ‘sound’ of Wharfedale speakers.
For the Diamond 11 Series, Wharfedale’s engineers have refined the multi-layer sandwich of woods of differing density to subdue the identifiable characteristics of the cabinet ‘sound’ and so let the drive units speak for themselves. Critical bracing of the cabinet panels, together with the curving of the cabinet walls to provide a non-boxy shape, have reduced resonances more than 25dB below the driver outputs. In addition, the cabinet walls are lined with a specially developed internal fibre which has been chosen because of its outstanding absorbent qualities across a wide bandwidth.
The result is that the listener hears the drive unit output unsullied by unwanted colorations caused by panel vibration or internal resonances, revealing more of the detail of the musical performance.
Slot-loaded distributed port
The slot-loaded distributed port is a recent Diamond innovation, first introduced in the Diamond 100 Series in 2012, where the internal port tube opens into a slot formed between the cabinet and the plinth. This reduces the turbulence and audible ‘chuffing’ suffered by conventional ported systems, which is caused by the sudden outrush of high pressure air into the low pressure in the room. A further benefit is to increase the efficiency of energy transfer from the bass reflex tuning to the room.
Wharfedale has taken this one stage further for the Diamond 11 Series, profiling both ends of the port with a semi-parabolic entry and exit curve that linearises airflow through the port tube. This has allowed us to increase the volume of air in the slot-loaded system and further improve the performance of the low frequency output.
|Enclosure type||Bass reflex (slot- loaded)|
|Bass/mid driver||130mm woven Kevlar|
|Tweeter||25mm textile dome|
|Recommended amp power||25-100W|
|Nominal impedance||8 Ohms compatible|