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Reviewer:
Srajan Ebaen
Financial Interests: click here
Source: 1TB iMac (AIFF) via FireWire into Weiss DAC2, iPod Classic 160GB (AIFF) via Peachtree Audio iDecco as DAC
Preamplifier: Esoteric C-03
Amplifier: FirstWatt F5 and J2, Trafomatic Audio Kaivalya monos
Loudspeakers:
Zu Essence
Cables: ASI Liveline
Stands: 2 x ASI HeartSong 3-tier, 2 x ASI HeartSong amp stand
Powerline conditioning: 1 x Walker Audio Velocitor S, 1 x Furutech RTP6
Sundry accessories:
Furutech RD-2 CD demagnetizer; Nanotech Nespa Pro; extensive use of Acoustic System Resonators, noise filters and phase inverters, Advanced Acoustics Orbis Wall & Corner units
Room size: The sound platform is 3 x 4.5m with a 2-story slanted ceiling above; four steps below continue into an 8m long combined open kitchen, dining room and office, an area which widens to 5.2m with a 2.8m ceiling; the sound platform space is open to a 2nd story landing and, via spiral stair case, to a 3rd-floor studio; concrete floor, concrete and brick walls from a converted barn with no parallel walls nor perfect right angles; short-wall setup with speaker backs facing the 8-meter expanse and 2nd-story landing.
Review Component Retail: €3.500/pr with stand


Think trademark cylindrical pressure wave which propagates to the listener with less acoustic distance loss than a point source. How many paralleled drivers does it take to make a line source? Aurelia's €7.000/pr Graphica flagship clearly makes the cut. But, does the €3.500/pr Cerica? It takes the Graphica's 5-driver center section, then cuts out four of the six middlemen aka mid/woofers above and below. Is what remains an unusual d'Appolito point source with three tweeters? Or is it a mini line source? While compiling obvious questions for ex-Amphion designer Antti Louhivaara—his Aurelia company launched in 2006, today counts 30 dealerships in Finland alone but now looks to go global—what about that rippled waveguide assembly that's made from recyclable natural fiber composite? Why three tweeters? What does the marketing jargon of DDC dynamic damping control woofers really mean?


Let's start with how famous speaker designer Siegfried Linkwitz defines a line source, namely "...as a speaker with a very narrow and long radiating surface used at frequencies above  f = c/2L, where its length L is greater than 1/2 wavelengths. Often such line sources consist of a vertical array of a large number of identical drivers on a narrow baffle. In other cases it might be a ribbon-like narrow and long conductor in a magnetic field or a narrow and tall electrostatic source. Specifically I am referring to lines that are at least 1.5m/5ft long.


"Under free-field conditions such lines will have a wide and fairly uniform  horizontal radiation pattern The vertical polar response will be very irregular and highly distance dependent due to the finite length of the source. In a room though, the images of the source in floor and ceiling will make it appear as infinitely long, the more so the shorter the gaps are between the ends of the source and the reflecting floor and ceiling surfaces. Consequently, the line launches a cylindrical wave and illuminates the room very uniformly. The acoustics of the room therefore are of similar importance as for an omni-directional point source. At sufficient distance the direct SPL falls off with the square root of distance, which improves the direct-to-reverberant sound ratio over that of a point source.  


"It surprises me that in a reverberant environment such as a typical living room, these radiators give little indication of poor vertical polar behavior even when the line does not fully extend to floor and ceiling. Clearly the reverberant field in the room fills in any perceptual notches in the polar response. Standing close to the line and moving with one's ears up and down, the acoustic image does not change and follows the ear over the active length of the line almost to its ends. Imaging is very precise when standing or seated in the near-field of the line, which is closer than the typical listening distance given by the apex of an equilateral triangle. At greater distances the images grow in height. This can be impressive on big orchestral pieces as if looking through a large window onto the soundstage. Small acoustic sources like a vocalist or a cello become overblown in size though. Line-source speakers are at their best when listened to close up like giant headphones. This preserves proper size imaging and gives the illusion of a large soundstage. Vertical height of the soundstage adds to its realism. I find small two-way speakers very unsatisfactory in this respect even when they are correctly positioned at ear level height.


"Line sources provide this height as do single-tweeter symmetric driver layouts like W-M-T-M-W. In the latter case separate frequency ranges are assigned to each symmetrical set of drivers such that any free-space vertical lobing is minimized. This type of source suffers considerably less from the image size distortion of a uniform line.


"An added advantage of tall sources is their relatively large radiating surface area, which means small excursions and therefore progressively lower non-linear distortion for a given maximum sound level. The low-distortion aspect is even more important than soundstage height, wide-angle horizontal dispersion and uniform power response. Low distortion means increased dynamics and clarity and the ability to play back at near live levels without listener strain. It brings the naturally occurring distortion mechanisms of the ear into play, which are necessary elements for creating an illusion of reality."


Available in gloss white, black or Walnut, stand integral, the single-ported Cerica's 5.25" mid/woofers maintain the narrow profile which the above definition demands of a line source. The 545mm height certainly doesn't meet the typical mark. How would Antti Louhivaara categorize this model's mode of operation? Basic specs include 1-inch Titanium domes, 87dB sensitivity, 1.500Hz crossover point, F3 of 40Hz and weight of 15kg. The tops and bottoms are aluminum shells clamping MDF construction.


Given this intro, for the Aurelia Cerica one would expect controlled directivity for less room involvement; increased top-end dynamics and power response from the thrice-paralleled 'zero' excursion tweeters; superb soundstaging; and superior integration of the tweeter-to-mid/woofer transitions. The waveguide guarantees the latter. It enlarges the tweeters-meet-air diameter to that of the bigger drivers. That equalizes directivity mismatches in the crossover region and presents the ear with less seam detection. On the minus ledger, three stacked tweeters raise lobing fears. Wasn't Siegfried Linkwitz very specific about symmetrical arrays around a single tweeter? Paralleled HF drivers have precedents in pro applications and McIntosh home speakers of course but otherwise seem verboten. If—as one would expect Antti Louhivaara to claim—this was such a brilliant idea, why wasn't it more widely used? Time for some answers from the Finnish engineer. His previous designs have met with fine commercial and critical success. It's reasonable to assume that his Aurelia efforts advance over where he left off with Amphion. The Cerica is his second-best current model. After having been very favorably impressed with Amphion's entry-level Helium 510, I thought all this background promising enough to commit to today's assignment in person.
 

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