A subwoofer helps open up your stereo loudspeakers and make them sound fuller, richer and larger while taking a little bit of strain off your amplifiers! Compared to a regular loudspeaker though, a subwoofer doesn't look much different and technically it isn't since a subwoofer is basically a loudspeaker tuned to automatically play low frequencies.
The Edifier T5 uses a 8 inch subwoofer driver enclosed inside an MDF (Medium Density Fiberboard) housing with a wood veneer finish. MDF is a composite of real wood fibers and dense resin and, it's particularly popular for making speaker cabinet enclosures because MDF is strong and dampens vibrations much better than wood could.
MDF doesn't shrink or enlarge either like wood does when it's warm or cold, which would compromise the air tight seal of the enclosure. The Edifier T5 enclosure seams are snug, buffed and perfectly aligned without any gaps or crevices. Metal fasteners have not been used for joining the enclosure panels; hence the Edifier T5 enclosure is sealed with some type of wood adhesive. The Edifier T5 subwoofer is supported by rubber feet, which are reinforced with solid metal rings. On the side, there is a large vent port to let air escape.
The Edifier T5 is a beefy and weighty subwoofer, weighing 14kg and measuring 25cm deep, 28cm wide and 30cm high. The Edifier T5 dial knobs are made of metal alloy and are driver by potentiometers with stop points that provide gradual adjustments with good resistance as you turn the knobs. Both knobs protrude 2cm out.
The Edifier T5 cone driver has a metal cap in the centre and, it is made of polypropylene, which feels like rubbery plastic so, it is strong and stiff, unlike the paper cone drivers in the Edifier R1010BT, which can tear easily. Because the Edifier T5 cone driver is very sturdy, you can leave it exposed by detaching the grill fabric cloth cover, which easily pulls apart via four speaker grill (ball and joint) pegs.
Being a powered subwoofer, the Edifier T5 connects just like a regular loudspeaker and, it's powered using mains electricity via the included figure 8 power cord, which measures 1.7 meters long. The Edifier T5 also comes with two sets of cables - a 1.4 meter long RCA to 3.5cm male cable and a 1.6 meter long RCA to RCA audio cable. While the Edifier T5 is plug and play, it needs setting up just like all subwoofers and that means finding the right placement, phase timing and crossover. You may also need an external amplifier if your loudspeakers are passive (non-powered). If you have an active-passive desktop speaker setup like the Edifier G2000, the T5 will be compatible.
Phase timing is, basically, having the subwoofer driver firing in time (in phase) and in the same direction as the loudspeakers. If the subwoofer is not in phase with the other speakers, it will be firing opposite directions, siphoning out the bass (watch video above), which defies the whole purpose of having a subwoofer in the first place and that is to pump in more bass! The Edifier T5 subwoofer has a basic two setting phase switch (0 degree and 180 degree). More capable sub-woofers come equipped with a variable phase dial knob, which lets you better adjust the balance between your loudspeakers and the subwoofer.
The crossover is the point in which the bass is directed from the loudspeakers and sent to the Edifier T5 subwoofer. The crossover depends mostly on the size of your loudspeakers and, it's important to set correctly to get the most bass out of your loudspeakers. The crossover typically ranges from 60Hz (floor standing loudspeakers), 80Hz (large bookshelf speakers) and 120Hz (small desktop loudspeakers) and, it can be easily adjusted via the low pass filter crossover dial, which in the Edifier T5 is the right dial (LPF) located next to the volume bass dial.

Like with most subwoofers, the connectivity ports and user controls are hidden on the rear and include the RCA pass-through, which makes setup easier when connecting the subwoofer to a signal source and loudspeakers. The signal source can be a computer or dac. If it's a computer, you simply connect the line out from a pc to the RCA input in the T5. Then, RCA output from the T5 to the speakers (that way you can control the volume with the pc). If you want to use a dac with volume control, you RCA out from the dac to RCA input in the T5. Then, RCA output to speakers. Some subwoofers only have left and right inputs - no RCA passthrough - which means, you would need two use two 3.5mm male to 2 female RCA cables in order to add the subwoofer directly to a signal source and loudspeakers.

The low pass filter determines how much frequency comes into the subwoofer. Sub-woofers tend to have a frequency response, ranging from 20Hz to 150Hz and the Edifier T5 is within that ballpark with a frequency response of 38 Hz to 200 Hz. The human voice frequency response can range from 88Hz (bass voice) to 1,170Hz (soprano voice), which is capable of breaking glass as it is reported Ella Fitzgerald was able to do, shattering glass with her voice! There are three other types of voices, namely baritone voice, tenor voice and contralto voice.
Not all subwoofers have a low pass filter (LPF) crossover and the ones that do have a low pass filter crossover may not be properly implemented to stop vocals coming through the subwoofer. The Edifier T5 has a properly implemented low pass filter crossover built-in, which you can set to 38 Hz (lowest setting) to stop almost entirely vocal output from coming through the subwoofer. You can tell when a subwoofer LPF crossover works well when vocals come through the subwoofer muffled as if the singer is singing with a pillow in their mouth! You can buy the Edifier T5 subwoofer on amazon. Check out the review of the Edifier R1850DB bookshelf speakers, the Edifier M201BT and the Edifier P12 passive bookshelf speakers