Opera Callas

This very compact and exquisitely presented stand-mount has a thoroughly unconventional multi-tweeter

Opera and its associated electronics brand Unison Research both share premises near Treviso in north east Italy. And in the best Italian tradition, this standmount looks absolutely gorgeous and is very substantially built too, though it’s not exactly cheap at £2,875 per pair.

A solitary and rather small 135mm driver with a 100mm diameter magnesium alloy cone covers the bass and midrange. It has a large (38mm) fixed solid copper ‘bullet’ phase plug and is assisted by reflex loading from twin rear ports. Instead of just the usual single tweeter, there are no fewer than five in each speaker – two on the front and three on the rear (each a 25mm soft fabric dome). It’s an arrangement that has implications for the way that high frequencies are distributed into the listening room.

The enclosure sides are crafted in subtle curves from substantial MDF panels and finished in high- gloss veneer. Presentation is exceptional, with a chamfered solid wood top and a front panel that’s shaped to assist lateral dispersion and elegantly trimmed in hide.

The SEAS-sourced bass/mid driver has an advanced Excel-type motor, incorporating copper rings above a T-shaped polepiece. The tweeters (also from SEAS) have compact neodymium motors so they can be mounted close to the main driver and each other.

Distributing the treble signal across five tweeters increases the treble power- handling dramatically, though part of this extra headroom is used up by crossing over to the front tweeters at a relatively low 1.5kHz. In actuality the front two tweeters operate in parallel at the bottom end of their working range; the upper tweeter is slowly rolled off as the frequency rises, so that the overlap ‘lobe’ is progressively directed upwards. The rear tweeters are active above 2kHz and will tend to behave as a line source concentrating output in the horizontal plane, adding to the room-reflected sound and helping to flatten the overall far-field power response.


The Callas was pretty well received by the listening panel, achieving a solid though not quite unanimous third place in the overall ranking. The impressive dynamic range is particularly noticeable and a testament to the solidity of the high-quality enclosure engineering. The bass has ample weight and while it might pack a bit too much midbass thump, the bottom end is, in anything, a little too well damped.

Stereo imaging is probably its strongest point. It attracted consistent praise for an impressive spaciousness that seemed to be achieved without significantly diluting the precision or focus, which would seem to go a long way towards validating the unusual multi-tweeter arrangement.

One listener felt that the overall sound might have been smoother and sweeter, but others praised its fine sense of rhythm, good dynamic expression and fine musical communication skills.

LIKE: Notably spacious imaging with good dynamic range
Dislike: Could be smoother with less damping
We Say: A costly but exceedingly attractive little speaker with wide dynamic range

Origin: Italy
Weight: 12.5 kg
(WxHxD)    230x375x340mm
• Beautiful real wood and leather finish
• Multiple tweeters add spaciousness
• High gloss over veneer on four faces
• Solid copper
phase plug
Distributor: UKD
Telephone: 01236 420199
Website: operaloudspeakers.com