Volt Introduces 10" Radial Triple Suspension Midbass Driver

British OEM speaker manufacturer Volt Loudspeakers launched the new RV2501 Radial Midbass driver, its first 10" Radial model, designed to deliver into applications that need consistent performance with its larger counterparts. With 91dB/W/m sensitivity, a frequency response between 30Hz to 800Hz at 8 Ohms - which enables its use well into the midbass range - and rated for 250 watts AES power, the new RV2501 not only expands the Volt range for monitoring solutions in smaller studios, it could also find its way into home hi-fi designs.
 
A fundamental component in the sound of iconic British loudspeaker brands, from PMC Speakers and Martin Audio to Quested, Graham Audio, ProAC or Funktion-One, speaker drivers from Volt Loudspeakers have been making history since David Lyth founded the company in 1978. The focus for its founder was originally to design and produce exceptionally linear bass loudspeakers and its efforts resulted precisely in the development of the Volt Radial Technology. This consists of a front-mounted eight-spoke cast aluminum frame that is mechanically coupled to both the back plate and to the top of the pole structure/phase plug. The mechanics not only deliver greater coupling to the major heat conducting elements of the motor structure, but much of the heat produced by the motor is radiated to the air outside the enclosure, rather than heating the air within the enclosure.

In Radial designs, there is no frame on the back side of the driver, and cooling to the front plate is also provided by heatsink fins and vents beneath the primary spider mounting shelf. Volt Radial designs use dual spiders and triple suspension systems creating, as Vance Dickason described, "one of the best configured driver cooling systems I have examined to date."

Initially, Volt produced its loudspeakers in Hayes, London, but during the 80's transferred its premises to Dorset, where it expanded drive production and also started to manufacture inductors, focusing on air and E core then later ferrite core types. Volt patented the Radial chassis in 1990, to offer a unique solution to the industry’s ever increasing requirement for greater power handling and reliability.

"My drive to design exceptional and enduring bass units was born from the need to minimize the various types of distortion that plague them: harmonic, latching, zero drift, and power compression. The research that I have carried out at Volt has been firmly underpinned by the results of the analysis carried out by the BBC, AES, Phillips, and other respected technical sources. Volt bass drivers have a symmetrical field magnet system and a long coil that ensure consistent linear performance, while double rear suspensions guarantee transient stability at high drive levels. The result is a smoother, clearer sound that is further augmented in the Radial range," says David Lyth.
  Recently, Volt has seen growing demand for its products, and in 2021 the company doubled its production facilities by moving to the building of a former BBC transmission site, now transformed into a business park. Rampisham Down was the location of one of the main short-wave transmitters of the BBC World Service until it was shut in 2011. The new facilities have also allowed Volt to expand its R&D facilities, allowing its engineering team to respond to increasing demand for new transducer designs from OEM manufacturers.

The launch of the RV2501 midbass driver reflects this increasing level of activity, revealing the first catalog item from the company in a while, and also the launch of the smallest Radial driver yet. The new RV2501 is a 10" Radial that Volt says resulted from nearly six years of R&D efforts, evaluating new cone materials, and investing in die-cast tooling for a higher quality chassis finish. Key features of the RV2501 Radial include a new high-pressure die-cast chassis, redesigned for extended bass movement, gravity die-cast magnet intercooler allowing more airflow to the voice coil, combined with the introduction of a new FEA designed magnet system that includes an extended and fully copper-plated center pole. Another distinct set of features are the use of the triple suspension system, including the low loss mirrored spiders now standard in all Radial designs, combined with a carbon-fiber infused paper pulp curvilinear cone and low damping NBR rubber surround, attached to a 2", 4-layer copper voice coil wound on an aluminum former to maximize BL. The result of this uniquely designed Radial technology driver endues the RV2501 of exceptional power handling and reliability. In effect, the RV2501 features three very effective cooling systems, combining the mentioned vented magnet with the Radial chassis, which acts as a giant heatsink, plus the unique multi-finned magnet intercooler. This, Volt confirms, keeps voice coil and magnet temperatures exceptionally low, resulting in 3dB less power compression and tight, clean bass even after prolonged operation at maximum power. The RV2501's symmetrical field magnet with extended center pole contributes to the driver's absolute linearity and transient control on high power peak inputs. 

No doubt, the Volt RV2501 Radial Midbass driver will easily find its way into new outstanding examples of creativity from speaker builders and designers, extending the options in multiway designs and more compact constructions that require stability and precision.
www.voltloudspeakers.co.uk