Rutcho's Audio Page dedicated to Hi-End Audio Systems Fullrange Speakers Tube Amplifiers

Ruitcho's page dedicated to hi-end audio Blackswift Audio Logo

Audio Nirvana Super8 Cast Frame

Audio Nirvana Super8 Cast Frame 8 inch Fullrange Drivers

With its build quality, sensitivity and performance, Super8 Cast Frame is a typical sample of the Audio Nirvana line. The phase plug is copper anodized, machined solid aluminum. The cone is made of rigid yet very light paper. The surround is accordion style and made of cloth, treated with a substance, that after more than six years of operation is still soft and a bit sticky in touch.

This is the manufacturer's datasheet for Audio Nirvana Super8 Cast Frame Link To GUI Sound FR222B8-11F Manufacturer's Datasheet

My Measurements

Driver Properties Thiele - Small Parameters
Chassis material Vacuum-molded aluminum alloy   Parameter Measured Datasheet
Membrane material Paper   Fs 48.3 Hz 42.8 Hz
Magnet System Neodymium Re 7.2 Ω 7.2 Ω
Surround Impregnated Cloth Qms 2.55 3.38
Voice Coil Diameter 32 mm Qes 0.18 0.184
Nominal Impedance 8 Ω Qts 0.17 0.175
Sensitivity 95.8 dB/W/m   Vas 74  ltr 73.3  ltr
Rated Power 30W   Le 0.15 mH N/A

                                       

This driver is suitable for back-loaded horn applications.
That's why I included a measurements in so-called "Universal" Horn.
More details about this project can be found here.

Audio Nirvana Super8 Cast Frame responce at 1m on axis and 15 and 30 degrees of axis in 18 ltr sealed box Audio Nirvana Super8 Cast Frame responce at 1m on axis and 15 and 30 degrees of axis in the Universal Horn

Frequency response at 1m with 2.83 V input RED - on axis, BLUE - 15 º off axis, GREEN - 30 º off axis


Second, Third and Fourth Harmonic of Audio Nirvana Super8 Cast Frame in 18 ltr sealed box Second, Third and Fourth Harmonic of Audio Nirvana Super8 Cast Frame in the Universal Horn

The second, third and fourth harmonic curves measured at 2.83V input RMS.



Burst decay Responce of Audio Nirvana Super8 Cast Frame at 1m in 19 ltr sealed box Burst decay Responce of Audio Nirvana Super8 Cast Frame at 1m in the Universal Horn

Burst decay response, measured at 1m on axis


The impedance of Audio Nirvana Super8 Cast Frame in free air and in 18 ltr seled box The impedance of Audio Nirvana Super8 Cast Frame in Universal Horn

The impedance curves


Conclusion

As a typical Audio Nirvana driver, Super8 Cast has excellent sensitivity,  pronounced trebles and excellent power capability. It can perform a loud music with ease and sureness. The aggression in the upper middle is perceptible, which should be corrected by a proper crossover network according to the listener's liking. Before start with corrections, the long break-in time (3 mints or more) should be taken into account. The only reasonable application for a driver with such a is backloaded horn. The best matching amplifiers are single-ended triode designs based on low internal resistance valves like 6П19П or 6C41C

Arrow up icon To The Top Arrow up icon