This review page is supported in part by the sponsors whose ad banners are displayed below
About setup: "One hint on placement. The Graphica's reflex tuning was designed so that it can be placed quite close to the front wall without getting boomy. In some rooms the Graphica tends to lack a bit of midbass punch. This
can be compensated for by placing the speakers closer to the wall. In my room for example I have the Graphicas 80cm from the front wall as measured from the baffle. They work brilliantly like that. Obviously all this
depends on the properties of the listening room and user preference."
Baffles at 110cm from the front walls
About the switches: "In the lower position of the midbass control there's a 2dB cut at the center frequency of
120Hz starting at 70Hz and ending a bit above 200Hz. In the
crossover this is accomplished by switching one big capacitor and resistor in parallel
to the coil.
The presence switch tilts the treble so that in the higher position there is a 1dB
boost at 10kHz. At 5kHz the boost is down to 0.5dB and at 2kHz just 0.2dB.
This is a subtle fine-tuning provision for the tonal balance. In the crossover it is accomplished by switching a capacitor in parallel to the tweeter filter."
The Graphica arrives without its round plinth installed. Six screws with short plastic spacers take care of that. Though narrow and tall this scheme proved surprisingly stable on my flat Tatami-style floor mats. Plush carpet should likely want spikes. For those there presently are no provisions. Quality binding posts are for single wiring so the questionable expense for double runs of speaker cable doesn't apply.
The short-flare ports seem to be 75mm in diameter. Their twin array centers on the tweeter wave-guide module and is just a tad taller.
The mid/woofers lack the usual hole for dust caps and voice coils. They are solid smooth cones instead. I've always harboured suspicions about the mechanical integrity of common cone profiles. While I'm clearly no engineer the type of geometry Aurelia runs makes more intuitive sense for stability. Joseph Szall of ATD whose Titanium Hypergraph driver became famous in the original Magico Mini and today shows up in Volent and Capriccio Continuum speakers as well as Armonia in a carbon-fiber variant champions something similar. His drivers exhibit a small central dimple. As he explains it, "the first patent for such a solution dates back to 1930 with Nagelvoort in the USA. 30 years later Rouy in France used the same geometry with some clever improvements and nodal drive. It showed up again in the late 80s in Görlich's Zellaton cones." I don't know why this type of profile—or flat cones like TangBand's 3-inch and 4-inch mid/tweeters which Sven Boenicke uses in his SLS and newer models—aren't more common in the 21st century.
Antti again:
"Funny coincidence you should mention Joseph Szall's designs of cones
and bass units in general. I began to collaborate with him many years ago while still at
Amphion. Joseph recommended specific driver
manufacturers in China and India and advised me on many issues.
Without his efforts the whole Aurelia venture wouldn't have been possible.
In the future we will use a 6.5" driver of his design which incorporates a similarly shaped 'eagle-wing' cone as was used in the Magico*. However the
cone material will be similar to what's in the Graphica and Cerica drivers today - an Isotact matrix
nano composite. I will use these drivers in our new Physica flagship model next year as an array of eight 6½
inch units with a quad tweeter module to deliver dynamics
and low-end grunt that should inhabit a totally different league from the Graphica now.
But I won't hurry this. I want to be sure the Physica is fully
polished in every conceivable way before I launch her."
________________________
"Our Isomatrix cones use TPX glass fiber layers similar to carbon fiber. Joseph also sent me samples of his Magico-style cones and they are even
better but we had to draw an essential line between acoustical design over extreme parts
technology to keep costs at a moderate level."
I'd also left word with Anthony Gallo about the ubiquity of the dust-cover driver. "I believe that traditionally the voice coil was 'shimmed' for centering whilst the moving-mass assembly—cone/surround/VC/spider—was attached to the basket. Once all adhesives set, the fish-paper (?) shims were slid out from between the VC and magnet pole pieces. All that was left was attaching the dust cover and you were done. Without that access location it is very difficult to insure perfect positioning of both spider and surround. Some of Dynaudio's drivers have a single-piece cone with integral dust cap to answer your rigidity question. Those have tiny holes at the cone/dust-cap apex. I believe they use thin wires to center the VC, then slip the wires out through those holes and just put a dab of sealer over them when done. There is no doubt that back in the day the logical choice for large pistons were cone shapes for optimized strength-to-weight ratios. The materials available for transducer engineering today just didn't exist back then. To get for example a flat diaphragm to behave purely pistonic even at 3 inches in diameter is extremely difficult even today, let alone keeping it light enough to overcome the inertial forces prevalent at 20kHz or even 3kHz for that matter."
