Volt radial woofer


Anyone on Audiogon have hands on experience with either the 12" or 15" Volt radial woofer? Thinking about a custom build, and looking for useful commentary.
askye

Showing 1 response by audiotroy

Askye i will be getting a state of the art mj acoustics reference 800 in the beginning of november

https://mjacoustics.co.uk/reference-800mk2/

https://mjacoustics.co.uk/reference-800mk2-sr-ff/ this is the one we are getting


Mj acousticsWh s the Only company using rhe radial driver  in a consumer producf pmc uses the radial for studio use

The radial is not used in most commercial subwoofers due to the drivers  extreme cost which is two to three times more expensive then the woofers used in competing products

Mj acoustics has a custom radial built for them they use the radial because of tts lack of compression Unde rheating conditions the radial cools betterrwhich reduces distortion compared with conventional bass drivers 

Hete is a nice disscusion on how unique the radial is designed and built

you can observe that the Volt Radial Technology consists of a front-mounted eight-spoke proprietary cast aluminum frame that is mechanically coupled to both the back plate and to the top of the pole structure/phase plug, in contrast to a normal rear frame that is only coupled to the motor front plate. This not only has greater mechanical coupling to the major heat conducting elements of the motor structure, but much of the heat produced by the motor is being radiated to the air outside the enclosure rather than heating the air within the enclosure.

Additional cooling to the front plate is provided by a rather substantial 72 fin heatsink that also includes 36 vents (5 mm × 9 mm) beneath the primary spider mounting shelf. As can also be seen, the Volt RV3143 has a dual-spider suspension system, with a smaller diameter spider attached from the cone to the front located frame, and a larger primary spider that is attached from the cone to the front plate heatsink system. Note that air from the top side of the pole piece is vented to the outside of the enclosure rather than venting into the enclosure as with most venting below the spider mounting shelf systems. The Volt Radial Technology provides a powerful heatsink to the outside of the enclosure and a convection cooling system that is coupled to the outside of the enclosure.

Heating of the air inside an enclosure contributes to power compression, and it would be incorrect to think there is a lot of thermal communication through a port tube, as that is not the case. In fact, Patrick Turnmire who does the Klippel testing for Test Bench, and his partner Enrique Stiles (two of the best transducer engineers I know of in the industry) have a patent titled “Thermal Chimney Equipped Audio Speaker” (Patent US 7181039 still available for licensing), which uses a device to transmit heat away from a motor structure to the air outside the enclosure, again to decrease power compression at high thermal levels.

After reviewing countless driver cooling systems in Voice Coil, and not an inconsequential number of car audio subwoofers cooling structures in the now defunct Car Audio and Electronics magazine, this appears to me to be one of the best configured driver cooling systems I have examined to date. What this means is that a driver will stay cooler with less dynamic changes over time, an important aspect to recording studio monitors or to live sound PA speakers. For this reason, Volt Radial Technology is utilized in a number of highly respected UK studio monitors and high-end home speakers from companies such as PMC, Quested, and Robson Acoustics.

In terms of the rest of its features, the RV3143 has a stiff curvilinear paper cone suspended by an inverted NBR surround and a dual-spider system. The top spider is a 5” diameter flat cloth spider and on the bottom spider is a 6” diameter elevated cloth type. The assembled motor is driven by a 75 mm (3”) diameter four-layer voice coil wound with copper wire on a non-conduction Kapton former. The motor structure consists of a single 155 mm diameter × 25 mm high ferrite magnet sandwiched between milled and polished friont and back plates. The plates are bolted together to the frame through the shaped pole piece by a large central bolt. Tinsel lead wires connect to color-coded push terminals on one side of the driver.

you can observe that the Volt Radial Technology consists of a front-mounted eight-spoke proprietary cast aluminum frame that is mechanically coupled to both the back plate and to the top of the pole structure/phase plug, in contrast to a normal rear frame that is only coupled to the motor front plate. This not only has greater mechanical coupling to the major heat conducting elements of the motor structure, but much of the heat produced by the motor is being radiated to the air outside the enclosure rather than heating the air within the enclosure.

Additional cooling to the front plate is provided by a rather substantial 72 fin heatsink that also includes 36 vents (5 mm × 9 mm) beneath the primary spider mounting shelf. As can also be seen, the Volt RV3143 has a dual-spider suspension system, with a smaller diameter spider attached from the cone to the front located frame, and a larger primary spider that is attached from the cone to the front plate heatsink system. Note that air from the top side of the pole piece is vented to the outside of the enclosure rather than venting into the enclosure as with most venting below the spider mounting shelf systems. The Volt Radial Technology provides a powerful heatsink to the outside of the enclosure and a convection cooling system that is coupled to the outside of the enclosure.

Heating of the air inside an enclosure contributes to power compression, and it would be incorrect to think there is a lot of thermal communication through a port tube, as that is not the case. In fact, Patrick Turnmire who does the Klippel testing for Test Bench, and his partner Enrique Stiles (two of the best transducer engineers I know of in the industry) have a patent titled “Thermal Chimney Equipped Audio Speaker” (Patent US 7181039 still available for licensing), which uses a device to transmit heat away from a motor structure to the air outside the enclosure, again to decrease power compression at high thermal levels.

After reviewing countless driver cooling systems in Voice Coil, and not an inconsequential number of car audio subwoofers cooling structures in the now defunct Car Audio and Electronics magazine, this appears to me to be one of the best configured driver cooling systems I have examined to date. What this means is that a driver will stay cooler with less dynamic changes over time, an important aspect to recording studio monitors or to live sound PA speakers. For this reason, Volt Radial Technology is utilized in a number of highly respected UK studio monitors and high-end home speakers from companies such as PMC, Quested, and Robson Acoustics.

In terms of the rest of its features, the RV3143 has a stiff curvilinear paper cone suspended by an inverted NBR surround and a dual-spider system. The top spider is a 5” diameter flat cloth spider and on the bottom spider is a 6” diameter elevated cloth type. The assembled motor is driven by a 75 mm (3”) diameter four-layer voice coil wound with copper wire on a non-conduction Kapton former. The motor structure consists of a single 155 mm diameter × 25 mm high ferrite magnet sandwiched between milled and polished front and back plates. The plates are bolted together to the frame through the shaped pole piece by a large central bolt. Tinsel lead wires connect to color-coded push terminals on one side of the driver.
Long story sport wereplaced our jl udiofathom f113with the mj  reference 800 which will go down to 10 hz in a relatively Compact form factor 

We cant wait till wr get ours so we can tell you in november

Dave and Troy
Audio.intelleact Nj

Us importers Mj Acoustics subwoofers 


The ref 800 are supposed to be amazing