New Stratton Acoustics Elypsis1512 Speakers.

“In my early years of working in hi-fi retail, I decided on the ideal scenario: if I ever became wealthy, I would employ an Audio Butler™. The thinking was that, on some days, I fancied listening to the visceral dynamic full-on delivery of a large JBL-based system, but there were other days when the cerebral performance of a pair of Quads would feel right. My thinking? I’d just say, “James, let’s go with the JBL system today,” and James would set up the system accordingly. A sort of ‘best of both worlds’ situation but, of course, at a vast expense and requiring extra storage space.”

 

Elypsis1512 on white background 

 
However, there is a solution, even though it’s simple but amazingly rare. It requires a loudspeaker system with high efficiency and wide bandwidth, very low colouration and distortion, and the ability to paint solid aural images. The Stratton Acoustics Elypsis1512 is such a speaker.
Stratton Acoustics sometimes feel that the rarefied world of high-end audio has tended to focus on the cerebral aspect of music playback and lost sight of the absolute emotional joy of recorded music. Examples, perhaps, would be Hotel California played on a 1970s large JBL – west coast rock played on a west coast loudspeaker or The Four Seasons played on an old pair of Quads – European music played on a European loudspeaker. Try both on an Elypsis1512 and experience the combination of accuracy and fun with music. This will not be notes on pitch and in the correct order. This will be heart-tugging music.

Background

Stratton Acoustics, the new UK-based high-end loudspeaker manufacturer, takes inspiration for its products from the iconic, large-scale studio monitors that shaped recording in the 1970s and 1980s. Products such as the legendary JBL 4350 and the extraordinary Tannoy Buckingham provided the effortless dynamics and massive soundstage that only large-diameter bass and midrange drivers housed in a substantial cabinet can provide.
While the inspiration is that of vintage giants, Stratton Acoustics’ goal is to produce thoroughly contemporary high-end loudspeakers, so it employs only the best materials, processes and construction techniques. Vintage studio monitors were tools built to do a job; exposed fasteners, chipboard cabinets, hook-and-loop grill fixing pads, blanked-off driver apertures and industrial finishes were all acceptable. Stratton Acoustics’ loudspeakers, however, are intended as fine objects of furniture as much as they are high-performance music transducers, so elegance, style, finesse and refinement replace the old functional palette of materials and finishes.
Amy Richards, one of Stratton’s founding partners, defined the company philosophy: “While our products always have to create an exhilarating musical performance, they also have to provide excitement through all aspects of their ownership. When not making music, they must be stunning pieces of fine furniture capable of complementing and defining any interior design. After years of development, we can fulfil this goal with various materials and finishes limited by the customer’s tastes and daring. I can’t wait to see how our customers will challenge us and what wonderfully unique, bespoke pieces we will be lucky enough to produce.”
Stratton Acoustics also takes a no-compromise approach to cabinet design through engineering complex, comprehensively braced birch plywood enclosures finished to the finest bespoke furniture standards.
The team works with suppliers to conceive unique finishes, which they can manufacture to the highest standards, with all aspects designed and engineered in-house using advanced technologies and materials.
Stratton Acoustics’ manufacturing processes are equally fastidious, exclusively employing a combination of high-accuracy computer-controlled production techniques allied to the finest artisanal, hand-finished, low-volume manufacture.
Stratton Acoustics designs our loudspeaker models driven by the philosophy that combines the innocent joy of recorded music with artisanal design and craft in manufacturing. And we won’t shy away from stepping well off the beaten track with detail and finish.
Bespoke design and custom manufacture mean Stratton can indulge almost any aesthetic desire.

Audio Engineering

Stratton Acoustics’ audio engineering is grounded in robust and thoughtful electro-acoustic design principles expressed with the latest driver and crossover technology. 


If you are familiar with the history of high-performance speaker design, you’ll perhaps see in the Elypsis1512 the influence of a particular style of 1970s studio monitor. That’s no accident. Part of the inspiration for the Elypsis1512 is products such as the JBL 4350, the Tannoy Buckingham and the Urei 815a. These are speakers that, above all else, play loud, with, for their time, absolutely minimal distortion and compression, and do so with an intense sense of musical involvement and communication – something that some audio folk talk of as being somehow lost in the rarefied contemporary world of high-end speakers. The Elypsis1512 partly constitutes an effort to push back against that feeling. But along with glancing reverently back at vintage speakers and their qualities, the Elypsis1512 is also an entirely contemporary design that employs the best of modern driver technology and electro-acoustics and the most up-to-date design and manufacturing techniques.

System Concept

The Elypsis1512 is a three-way passive speaker built around a driver complement of twin 380mm bass drivers, a single 300mm midrange driver and a mechanically decoupled, 29mm soft dome tweeter with a precision waveguide. The drivers on the enclosure front panel are in an asymmetric array, which results in similarly asymmetric horizontal dispersion. Pairs of Elypsis1512 speakers are built in mirror image format in front panel component arrangement. The phase relationship through the crossover region between the midrange driver and tweeter ensures that the off-axis frequency response on the midrange side of the speaker remains linear. In most installations, position a pair of Elypsis1512 so that the tweeters are positioned outermost.

Bass Driver

The Elypsis1512 incorporates twin 350mm (15 inch) reinforced paper diaphragm drivers, each rated at 800 Watts power handling. The driver features a 113mm (4.5 inch) voice coil, an aluminium demodulation ring and a twin spider suspension system. It is capable of ±14mm linear excursion.
The Elypsis1512 enclosure provides a 230-litre internal volume for the bass drivers. Reflex loading utilises four large-diameter laminar flow internally and externally flared ports tuned to 34Hz. Elypsis1512 low-frequency bandwidth extends to -6dB at 28Hz.
System group delay remains under 12mS above 40Hz.

Midrange Driver

The Elypsis1512 midrange driver incorporates a 300mm (12 inch) reinforced paper diaphragm with a 75.6 mm (3 inch) voice-coil, a neodymium-iron-boron magnet system and a copper sleeved pole-piece. The drive unit is carefully hand-doped to fine-tune its response characteristics when torqued into a sealed enclosure filled with an optimal selection of damping materials.

Tweeter with Patented decoupling system

The Elypsis1512 tweeter is a 29mm diameter soft dome device fitted with a CNC machined aluminium waveguide that defines its dispersion characteristic and provides some increased efficiency through acoustic impedance matching. The tweeter mounts within the Elypsis1512 enclosure via a Stratton Acoustics patented (GB2606586) decoupling arrangement that ensures its isolation from mechanical vibration. The tweeter features a neodymium-iron-boron magnet system with a double copper capped, T–shaped pole piece and a flow-optimised rear enclosure. 
 

Crossover and System Characteristics

The Elypsis1512 passive crossover integrates the drivers at 350Hz and 2.5kHz via asymmetric 2nd and 3rd-order filter slopes. Targeted impedance compensation is employed to linearise the system impedance and to enable close control of filter slopes. Crossover components are all audiophile grade and comprise predominantly plastic film capacitors and air-cored inductors. EQ controls on the front baffle offer ±2dB adjustment on the midrange and tweeter drivers.
The system impedance that results from the combination of drivers and crossover remains above 8Ω between 100Hz and 10kHz. The electrical phase remains within ±20° over the same frequency range. System sensitivity for 2.83V at 1m is between approximately 94dB and 98dB, depending on the midrange and tweeter EQ settings. The Elypsis1512 can be partnered successfully with almost any amplifier – from the least to the most powerful. Levels of odd-order harmonic distortion above 100Hz are generally below 0.3% for 90dB at 1m. 
 
Despite its large diameter and traditional paper diaphragm bass and midrange drivers, the Elypsis1512 has a remarkably flat axial amplitude frequency response. The response curve above was measured using a ground plane technique at 1.5m on an axis midway between the midrange and tweeter drivers. Notice also the very low 2nd and 3rd harmonic distortion.
 

Enclosure

Manufactured from a combination of 24mm and 18mm precision CNC routed birch ply panels, the Elypsis1512 enclosure also includes a 46mm Front Baffle capped with a solid CNC machined acrylic outer baffle. Complex and comprehensive internal bracing ensures that the construction is effectively inert, and the internally divided midrange enclosure volume incorporates non-parallel panels to help suppress internal resonance.

Audio Engineering Conclusion

The Elypsis1512 demonstrates what is possible when, in parallel with a philosophy of maximising musical impact and communication, design restrictions of cost, size and weight are almost entirely disregarded. The result is an electro-acoustic performance unlike almost any other contemporary hi-fi speaker: half-power (-6dB) bandwidth from 28Hz to over 20kHz, sensitivity of 96dB for 2.83V at 1m, and impedance that doesn’t drop below 8Ω between 100Hz and 10kHz.
The Elypsis1512 also displays group delay of less than 12ms down to 40Hz and, at normal listening volume, has distortion levels closer to amplifier values than typical speakers. It is also pretty much immune to thermal compression and, thanks to its hugely rigid and inert braced birch ply cabinet, displays effectively no panel resonance.
Its high sensitivity (more than 8dB above a typical hi-fi speaker) and easy load means it can be driven by almost any amplifier – from a 5-Watt valve amp to a 1kW high-end monster. In the latter case, you might want to stand back.