These are sub-roof long, the HP used is a 46cm (18 ") Double spider die cast basket thick to withstand the enormous mass of working within the ferrite magnet. The coil of 125mm and HP is one of excurtion xmax + /-8mm.
The set is very well assembled, and is also very heavy ... two are designed to handle the fund, which avoids the use of metal handle.
Four rubber feet support the box when it is placed standing on floor care, however, concrete or gravel, drag the sub can damage the pads or scratch the paint underneath as they are quite thin.
The sound of the subwoofer is extremely physical performance far exceeds many good sub not flats, an amplifier capable of delivering very high currents at low impedance is absolutely necessary, proline 3000 of thomann works very well, even at 2 HPs 118 per channel.
They must be filtered from 90Hz or slightly below, the results are not very good at it.
Although well filtered and amplified, the bass is absolutely devastating, a set of 4 HPs 118 is able to deliver over 120dB at 10m, the pressure is really impressive, the scope too.
the sub, however, are fairly straightforward, once the axis past, one senses a clear drop in SPL and lobes in the frequency response, good coupling and the delay is necessary to "open" directivity. It can also separate a little open to sub at the expense of a little pressure on the axis.
Nevertheless, his boxes are for use with a broadcast system medium acute high efficiency and high power, the coupling with fullrange speakers distort the classical spectrum in the grave, with a lack of pressure in the lower medium.
All in all a great sub for large config has not to any hand, (a Smaart measurement system or equivalent is strongly recommended)