Steve Slyuter - SpectraFlora
Our first GM for the year with feature Steve Sluyter from SpectraFlora, presenting his 2- way Celata 88 Standmount Speakers. These are made in Winchelsea, 110 km south-west of Melbourne. The speakers are 4 ohm, ~86 dB/2.8 V, and are rated at 300W. I haven't yet heard a class D amp that sounded good through the waveguides.
When Steve was at the recent StereoNet HiFi show he had the speakers running with a laptop playing tracks connected by USB to an RME ADI-2 DAC, then through an Audio Research Ref 1 preamp into a Parasound A21 power amp. He will be bringing the same outfit to the presentation.
The following information has been lifted from the SpectraFlora website www.spectraflora.com and will give you an excellent insight into what to expect.
The Celata 88 by SpectraFlora is crafted in Australia using sustainably sourced Australian timber. The cabinets are made from hoop pine plywood, a native Australian species sustainably grown in Queensland plantations.
The horns are available in either hoop pine plywood or solid timber, which is either plantation-grown or salvaged. For instance, we offer horns made from plantation-grown Northern Silky Oak, Southern Silky Oak salvaged from Melbourne's eastern suburbs, and red ironbark salvaged from a former RAAF base in Dubbo.
The sound quality is exceptional, thanks to its innovative technology-intimate and engaging. We refer to the waveguide as a Dynamic Waveguide because its horizontal geometry is a waveguide, providing an open and transparent sound with constant directivity. It is a hybrid design because, in the vertical dimension, it features a traditional horn profile, which acoustically loads the compression driver to deliver a dynamic and captivating sound. In short, it combines the best of both worlds: the powerful dynamics of a horn and the transparent, even horizontal dispersion of a waveguide.
Our crossover design is the result of 11 months of measurements, modeling, and listening tests to optimise transparency, vocal clarity, dynamics, and instrument timbre. As the brains of the Celata 88, it delivers stunning sound across the Dynamic Waveguide, magnesium mid-bass, and Celata subwoofers. DC-biased by two 9V batteries, it features custom copper and aluminium foil capacitors and thick film resistors chosen for gorgeous, emotionally gripping sound.
The Celata 88 base model speakers retail at $35,000.
Dave Polanske
Programme Coordinator
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2024 MAC D.I.Y. Night
The December GM is where the club showcases its members expertise and talent, and we have three examples for this year. Phil Norman, who brough his speakers along to the August meeting, will be bringing his speakers along and have them powered by Alan's battery-powered amp and Richard's Silicon Chip Mk3 Class AB kit amp. Electronics is part of the story; case construction is an important part of the project and we will hear about how the cases were made for each amplifier and reprise the huge amount of work that Phil put in to make the cabinetry.
Phil's speakers, Oval MK1 are constructed from Rimu (Dacrydium cupressinum), a wood native to New Zealand which is also used for high-quality furniture. The cabinet is constructed from 36 layers of 18mm ply Remu, laser cut and laminated.
Phil's speakers are configured as a 3-Way bass reflex with a frequency response of 40-18000hz (+/-3db), a sensitivity of 90dB (SPL/m/2.83V), nominal impedance 4ohm. They have a power rating of approximately 40W RMS. The crossovers are second and fourth order and have frequencies of 330hz/1850hz. The Fb of the cabinet is 40hz.
Alan's amp is a battery powered integrated amplifier. More specifically it employs the latest type of lithium batteries that supply nearly 1kW of DC power to drive solid state amplifier modules that use low power consumption Lateral MOSFETs, which operate with a very low biasing current - the idea being that by not having a conventional power supply there is no 50 or 100hz hum and therefore it has a lower noise floor. It produces 175W per channel, can comfortably run all day without charging, has 4 inputs and remote control volume.
Components that are in the amp include Onsemi brand NJL3281D and NJL1302D Complementary Thermal Trak Transistors bipolar power output transistors which feature:
The amplifier is a Silicon chip Mk3 built to magazine instruction. It is class AB and has 500VA transformer with 61V DC rails at no load and standard SC speaker protection circuits. It has been tested by Stephen Miles and Damian Ware and has had continuous home use the last 10 months, performing well. Case and module layout is Richard's own design and includes 3mm aluminium panels that are hand/self/bandsaw cut and assembled with some use of epoxy glue joints and then professional paint job in black automotive 2 pack.
We will also have a few static displays at the meeting:
And Finally...
I wish you and your families a safe and joyous Christmas and a wonderful 2025. Thank you for supporting our General Meetings as they do take a fair bit of organisation and effort from quite a few people. I look forward to 2025 as we have some great nights lined up and I still have a few ideas that I'm sure you will love!! All the very best.
Dave Polanske
Programme Coordinator