The smaller the car, the harder it is to find a
suitable subwoofer. That is, if you don’t want to lose a lot of cargo space and
add a lot of weight. In small sedans you can use a free-air sub, where the
driver is mounted through the rear shelf, but in hatchbacks that’s much harder
to do. In those cases most people elect for a small sealed box with an 8 or 10
inch driver in it, but the finished design still often ends up an awkward
package to fit in the back. If you want to transport a suitcase or anything
large and square, the box will have to come out.
And it’s just this sort of car that suits Jaycar’s
new subwoofer – cat no CS2275. It runs an 8-inch driver, 75 watt amplifier and
all comes in a package just 110mm thick! The design appears to use a wave-guide
style folded port, which allows the box to be tuned to a much lower resonance
than a straight, shorter port. A single driver is mounted in the enclosure (although the
cardboard box the unit comes in claims that “dual woofers” are fitted!) and
directly behind the driver, built into the enclosure, is a modest amplifier. The
heatsink for the amp is the rear panel, which is aluminium but doesn’t use any
cooling fins. Amplifier power is claimed as 75W RMS, or 150W music power, or
380W - depending on whether you read the instructions, the box or the amp
control panel!
On the control panel you’ll find level, phase and
crossover controls. There are also LEDs for power, ‘fail’ and gain (volume). A
wiring harness is supplied that includes a thick, fused positive supply, short
ground wire, remote switch-on wire and two RCA inputs. A separate speaker level
adaptor is also supplied.
MDF is used for the box walls and the dimensions
are 600(L) x 380 (W) x 110 (H) mm. We measured the mass at 10.2kg – very light
for an amp plus sub – and cost is just AUD$200.
The Unit
On the bench using a frequency generator and with
both crossover controls turned up to their highest frequencies (more on these
controls in a moment), the amplified sub had decent response down to 40Hz.
That’s not very low for a sub but is fine for an enclosure with such a small
volume.
The internals of the amplifier look pretty cheap –
the way the thermal overload thermistor is connected to the unimpressive
heatsink is nothing wonderful and care in construction doesn’t look
overwhelming.
Installation
We mounted the unit in a Honda Insight, where it
could sit in the small cavity directly above the spare wheel. The storage space
above the sub was therefore made shallower by 110mm, but the major load space
was left unchanged.
Installation was straightforward – we shoved the
sub enclosure into the space (it’s actually a nice tight push-fit!) and then
earthed the two ground wires nearby. Run forward towards the front of the car
were the 12V supply, the remote switch-on wire and a double RCA/RCA extension
cable that we purchased.
Rather than taking the 12V lead right to the
battery, we found a very heavy gauge, permanently-on cable at the under-dash
fuse box and used that supply. The remote switch-on lead (blue/white) connected
to the same colour output wire of the aftermarket JVC head-unit and the RCA
cable connected to the subwoofer OUT cable on the head unit.
And that was the first problem – there was only
one RCA sub OUT on the head unit, and two RCA INs on the sub. But the sub seemed
to work fine with just one RCA input connected so we ran it like that.
Next were the settings of the crossover controls.
Frankly, these don’t make any sense – even the Jaycar store personnel had no
idea. Two pots are provided, one marked 40 – 280Hz and the other 40 – 600Hz.
We’re not sure if the controls are meant to be used in series, in parallel or
only one is to be used. But since in our case the crossover of the sub output
can be set at the head unit, we just turned up both crossover controls and set
the crossover frequency with the head unit.
Note: the supplied instructions are terrible -
some aspects make no sense at all and others are misleading.
Results
Even when covered in carpet, the output in the
small cabin of the Insight was damned impressive. Go mad with levels and/or
volume and the sub could be overloaded but set it up with sense and the increase
in bottom-end was excellent. We played around with the phase switch and amp gain
level and so tweaked the outcome a little, but from the moment of switch-on
there was never any doubt that the bass was phenomenally improved. However, we
don’t recommend this unit to someone who really likes to shake the inside of the
car to pieces at high SPLs.
But if you’re pushed for space and don’t want to
add much weight while still requiring a better bass response than you’ll get
from normal sized speakers, this innovative product deserves a long look.
We’re happy with it.
The
subwoofer was purchased for this review.
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