making of giya - suncoast audio · so how were we going to incorporate this acoustic design into...

Making of Giya

Vivid Design Ethos

Freedom from Resonance and Reflection

Why is this so important?It may be a matter of Life and Death!

How has this philosophy been manifested in the current range?

Catenary Dome Profile with Carbon Fibre Ring to push first break-up frequency up by over 50%

Tapered Tube Loading to absorb rear output without reflections

Vivid Audio Dome Drivers

Highly Ventilated Former to relieve pressure behind central dome without reflections or cavity resonance

Enhanced Radial Magnet to increase flux for high efficiency

Vivid Audio Cone Drivers

Reaction Cancelling Drivers Reaction Cancelling Ports

Both features prevent transmission of vibration to enclosure

Enclosure Isolation and Reaction cancelling

Chassis designed with slim but deep radial support struts to allow free passage of rear wave while still presenting large area of metal for good heatsinking.

90% Open Area Chassis design

All these features found in first Vivid products; B1 and K1.

Drivers used in C1 and V series

May 2006 - First vision of GIYA

• G1 to be top of our existing range

• Target volume 180litre, -twice the volume of K1

• 4-way design

• New 225mm cone bass driver front & back

• A Wooden prototype was built but low crossover causes difficulty with Front & Back driver

• Improvement observed with side facing drivers in prototype

• Design clearly not suited to established Vivid shape

August 2006 - a setback

A new beginning

• The K1 shape wasn’t suitable so we decided to start from a blank sheet

• G1 was to be the flagship with no design link to the existing range

• We even considered a fully active design with sub-resonance Low Frequency enclosure (right) but decided to stay with a more generally acceptable reflex loading and passive crossover

G1 gave us an opportunity to reconsider all aspects. Were there any improvements we could

make on our already established drive units?

• C125; Established as high excursion bass in full range systems was re-optimised for upper bass only which requires smaller linear travel. New magnet designed with shorter gap and higher flux and new exponential tube enclosure

• D50; high efficiency and very smooth response through mid-range – no change required

• D26; smooth extended high frequency response, and high efficiency – no change required

Vivid 8Ω Aluminium tweeter (green) vs. 4Ωdiamond showing extra 9dB power efficiency

New C225 bass unit featuring 225mm aluminium cone. Radial magnet system with 75mm coil and highly perforated former. Open chassis structure

with high efficiency thermal design

• Could anything be done to improve acoustics of a plain box?

• Was it possible to combine the benefits of the highly effective exponential tube absorber with reflex loading without compromising either?

• Perhaps if horn cut-off was higher than port tuning we would get the best of both worlds.

• Experiment performed with old parts from archives (right) showed promise.

• Set up computer model to see what’s happening.

Just one part had escaped close scrutiny:the bass enclosure

Square box shows strong longitudinal eigentones but good port output. Added damping reduces strength of resonances but also stifles port

output. Example is for 15” driver in 200litre enclosure.

Long horn ( cut-off frequency below port tuning) annihilates box resonances but severely compromises port performance. Still 200litre

total volume.

Increasing horn cutoff frequency helps. Here it is twice that of port tuning and total volume of enclosure is still 200litres.

Increasing horn cutoff to four times port tuning frequency gives full port output but still without longitudinal resonances. First section of horn can

be replaced by parallel sides without affecting performance.

Test setup showing horn added to original wooden prototype

Measured results of prototype test setup.

• Without horn there is a strong 180Hz resonance corresponding to height of cabinet.

• With horn added to top of enclosure this is virtually eliminated. Remaining modes are lateral and out of band for 200Hz cross-over

So how were we going to incorporate this acoustic design into the final product? It deserved to be a visible feature and at first opted to make it

fully symmetrical. This is a typical AutoCad work sheet showing attempts to marry aesthetic spiral with acoustic requirements.

• Result then modelled in 3D using SolidWorks (right)

• Dual spiral quickly rejected on aesthetic grounds

• Design consultant, George Elphick, suggests asymmetric enclosure with bass near ground

• First sketches in collaboration with Chris Stevens showing tightly coiled absorber

• Rapidly tapered horn proved difficult to marry visually with large enclosure

• Hole was added to increase the visual weight of spiral. First signs of double spiral ridge make their appearance

Sprial ridge causes 3D modelling headache so the essence of form distilled into sketch below and sent out as challenge CAD suppliers. The result prompted a switch to Rhinoceros for all future modelling.

First proof of concept in CAD, Feb 2007

New modelling technique devised to accurately guide shaping

• Difficulty experienced keeping CAD visual model acoustically accurate

• Tapered form made in modelling material

• Basic form can then be moulded while retaining taper dimensions

Examples of early Plasticine models

Final choice of Plasticine model to work from

Curves extracted from model

Importing curves into CAD to start modelling

Evolution of 3D CAD model

Choice for first GIYA prototype, June 2007

Prototype made in GRP and tested at the VIVID factory in 4π and 2π space

Work continues through late 2007 to improve surface quality and to enlarge mid/high driver baffle.

Prototype re-machined to test new baffle design

• Prototype taken right through to highly finished stage

• Crossover optimised through simulation and listening

• By November 2007 the decision was made to show the prototype at CES 2008 in Las Vegas

Giya unveiled at Mirage Hotel CES Las Vegas Jan. 2008

Final production design January 2008

• Tooling models extracted from CAD model

• Inserts for drivers, ports and removable base modelled

Design moved forward to production

Master Pattern Production

Block machined with CNC process Surface finish applied

GRP mould tool taken from master and prepared for vacuum infusion

Finished Giya in Lamborghini

Orange for our Korean distributor