Jaycar 10 inch precision

10 inch Precision Response Carbon Fibre

Jaycar Part no: 2278 - Cost $179.95aus (5th May 2005)

Estimated values area highlighted in red

	Single coil driven	2 series coils	2 parallel coils
Znom Nominal Impedance	4ohms	8ohms	2 ohms
Pmax Power Handling	125 watts	250 watts	250 watts
SPL Sensitivity	84.105	87.105	87.105
Re Voice coil resistance	3.4 ohm	6.8 ohm	1.7 ohms
Fs Resonant frequency	38.258 hz	38.258 hz	38.258 hz
Qms Mechanical Q	3.788	3.788	3.788
Qes Electrical Q	0.904	0.452	0.452
Qts Total Q	0.730	0.404	0.404
Vas Equivalent volume	26.950 litre	26.950 litre	26.950 litre
Xmax Maximum excursion	9 mm	9 mm	9 mm
Sd Cone Area	346 sq cm	346 sq cm	346 sq cm
EBP Efficiency Bandwidth Product	42.3 - sealed	84.6 - all rounder	84.6 - all rounder

Here are the driver files for WinISD Pro ver 0.50a7

Here is my parameter file for this driver ( single coil driven )

Here is my parameter file for this driver ( two series coils driven )

Here is my parameter file for this driver ( single coil driven, second coil shorted)

The Xmax figure is not stated in the catalog, but Jaycar provide a link on their website, where the details for this driver eventually lead to a screenshot of an analysis using "BassBox" software. On that page Xmax is shown as 9.0mm, which is the value I used above. The screen shows designs using the 1.7ohm parallel arrangement, which is not suitable for use with the HT plate amps. It also shows Sd = 615 sq cm as opposed to 346 in the catalog

Suggested designs

There are more designs here than usual, for several reasons.

Firstly, there are three ways to wire this driver - single coil of 4 ohms, utilsing the 240w amp, or both coils in series, giving 8ohms, which requires the larger 350w amp, or one coil driven with the second coil shorted using the 240w amp.
Secondly, I wanted to show an extra design which exceeds my target box size of 130 litres, but gives better response for Home Theatre.
Since the graphs are already crowded, I have omited any sealed designs - they are poor performers in the 25hz area anyway.

Jaycar shows no designs in their catalog, so these are all mine

Ported - single coil	180 litre - 130w-4ohm - 240w amp	27hz	Four 86mm ports @ 467mm
Ported - single coil	130 litre - 130w-4ohm - 240w amp	25hz	Two 102mm ports @ 527mm
Ported - series coils	130 litre - 240w-8ohm - 350w amp	25hz	Two 86mm ports @ 365mm
Ported - one coil driven with second coil shorted	100 litre - 125w-4ohm - 240w amp	27hz	Two 86mm ports @ 414mm

SPL

If you can live with a 180 litre box, the light blue design gives about 108dB

The orange graph of single-shorted arrangement gets box size down to 100 litres

Cone excursion

No problem here

Port air velocity

Port flares would be required - see the note at the bottom of this page

This driver likes a large box - most designs are 130 litre. The single coil arrangement gives better results than the series arrangement, and requires the smaller amplifier.

Here are the project files for WinISD Pro ver 0.50a7

180 litre ported 27 hz tune (single coil)

130 litre ported 25 hz tune (single coil)

130 litre ported 25 hz tune (series coils)

100 litre ported 27 hz tune (one coil driven, one coil shorted)

Port Flares - calculated with Flare-it

I would recommend 19mm routed flares. for the 103mm ports. Alternatively, you could move to heat molded flares in 20mm or 25mm radius.

For the 86mm ports, 25mm heat molded flares would be required. For the blue design only, the flare radius could be reduced to 20mm.

In all designs, the intakes should be flange mounted with a 13mm routed flare or you could fit a donut ring . If you are using a heat molded flare, you could do a one-piece design with a 20mm flare on the inlet

Depending on the flaring options, you'll need to adjust the physical length so that the effective length is as shown above. The port flares page has a section on calculating effective length as well as some information on availability of commercial flares.

Last update to this page 10th December 2006

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