This system is a culmination of many years of realizing what I value most in music. With audio, the only way to move forward is to know what you want and then work your way to achieve your goal. With that in mind, every component in this system was chosen to deliver what I value most in music. I strongly believe that the first step in any system is to choose the speaker that delivers what you want, and then choose all upstream electronics to make the speaker work.

The Acapella Violon delivers what I want. The plasma tweeter is simply without equal. It works by ionizing air from a high voltage electrode so that the air is sufficiently energized to erupt into a ball of glowing plasma. The size of the plasma flame is modulated to produce sound. No moving mass, no inertia, no coloration from cone material. This tweeter sounds like nothing. There is no metallic ring like you would get from a metal dome tweeter, and no softness associated with textile tweeters. Sound simply emerges fully formed, the speed and dynamics is unmatched. It just sounds real. This is without doubt the best tweeter technology in the world.

The midrange horn very nearly keeps up with the tweeter. It covers a large range from 500Hz-5kHz with shallow (-6dB/oct) slopes either end. The dynamics from the horn match the tweeter, and it excels in delivering instrumental timbre and loads of inner detail.

The weakness in the system is obviously the woofer. The overall quoted sensitivity is 91dB/W/m, and I am certain that the horn and tweeter were padded back to match the woofer. The drivers are 10", and arranged in a pseudo-isobaric configuration. Strangely, the external woofer is run from the crossover (500Hz, -6dB/oct), but the internal woofer is run directly from the speaker binding posts - i.e. full range. The bass is muddy, sluggish, and there isn't much of it. It obviously sounds disconnected from the horn and tweeter.

Furthermore, the speaker exhibits a wicked impedance curve with 600 Ohms for the tweeter, 8 Ohms for the midrange, and down to 2 Ohms for the woofers. This further exacerbates bass problems when run with valve amps.

I was obviously aware of these problems when I bought the speaker, so why did I choose such an obviously compromised speaker? The answer is - I strongly believe that midrange and treble should be gotten right first. If your midrange and treble are not right, you will spend endless sleepless nights trying to fix a problem which may not be fixable. Bass, in contrast, is relatively easy to fix.

I am about to embark on an adventure to fix the bass on my speaker. The first step is to purchase a solid state amplifier to bi-amp. The next step is to purchase a DEQX to control the phase response and group delay of the individual drivers. After this, I will remove the crossover in the bass unit (converting the speaker to active), and change the woofer to a more suitable driver. Finally, I will build a custom crossover to go before the midrange/tweeter, which will prevent the ADC/DAC stage of the DEQX from contaminating the all-important midrange and treble.

Last but not least, I will return to an analogue source, but such a purchase is still very much on the horizon.

Watch this space.

Previous entry ---

Thanks to AudioGon, I became aware of this speaker. After salivating at some of the nicer Acapella setups here I had to go have a listen. Boy, was I captivated. The most revealing speaker I have ever heard. The plasma tweeter is something else!

I am currently also upgrading from the Cary CAD-805AE to the Cary CAD-211AE, which should allow me to control the Violons a little bit better.

I named this system "Southern Lights" after Eliotswede's Acapella Violon system ("Northern Lights"). After all, i'm in Australia!

-- Old description below --

Years ago I became aware of the sweet combination of Cary amplification and ProAc speakers. It has been my intention for a long time to replicate this system and I finally got the opportunity to build my dream system from scratch.