Focal Polyglass 33V1

image credit: hertz

French sub-builders recommend exclusively phase inverter design for this model, in three versions.

Car subwoofer Focal Polyglass 33V1

It just so happens that in our group tests only Focal subwoofers fall into the entry or intermediate level (as in this case). The diffuser of Polyglass heads is known to be made of cellulose with a coating of tiny glass beads applied to a synthetic adhesive layer. Diameter of the convex central cap is 111 mm. The diffuser holder is coated with durable powder paint. The width of the suspension is 25 mm, as is the height of the magnet, and exactly the same diameter at the axial hole of the magnetic system. The outer diameter of the magnet is 153 mm. A wide cooling belt located between the centering washer and the magnet system helps to organize the ventilation of the voice coil. There is no O-ring on the body rim. The concave centering washer is designed to limit the movement of the voice coil towards the lower washer of the magnetic system.

Let's see what the calculations showed. The value of the force factor of 14.9 T m practically coincides with the average value for 4-ohm coils. For such a magnet, this is even a lot, which means that the designers and technologists of Focal-JM Lab once again demonstrated their technological capabilities by choosing a narrow magnetic gap. The movable system (148 g) turned out to be noticeably lighter than the average for the group, from which it is clear why the reference sensitivity of this head came out almost the highest (second result). The indicators of nonlinear distortions are not so favorable, the average value of the c.i. here higher than the rest of the participants.

French sub-builders recommend exclusively phase inverter design for this model, in three versions. What everyone can give is on the chart. In terms of measurements, the subwoofer turned out to be noticeably tougher than the specialists from Saint-Etienne thought, we would not have undertaken to attribute this only to the "warm-up" process, before the measurements we drove the sub from the heart. The refinement of the parameters led to both the refinement and expansion of the set of recommendations. It makes sense to increase the FI by adjusting it higher in order to get a good acoustic gain and not waste air on the infrasound. However, people are not fed up with a "phasic" alone: ​​we did not find any contraindications to the work of "Polyglass" in a closed box: the range of recommended volumes is 20 - 25 liters.

SPECIFICATIONS

13" 4-ohm subwoofer

Polyglass cone with butyl rubber surround

zamak (zinc alloy) basket

power range: 100-400 watts RMS

peak power handling: 800 watts

frequency response: 30-500 Hz

sensitivity: 88 dB

top-mount depth: 6-3/16"

ported box volume: 1.06-1.77 cubic feet

warranty: 1 year