Systems ListJTR SpeakersCaptivator 118HT

ManufactureJTR Speakers
System typeVented
Driver Size18 "
Number of drivers1
Internal volume5.5 ft3
External volume7.81 ft3
Dimentions (Width Height Depth)30 " 20 " 22.5 "
Weight129 lbs
Native Tuning Frequency17 Hz
Power700 W
Aprox. Price$1599 USD


The JTR Speakers Captivator 118HT is a relative newcomer to the JTR subwoofer lineup. As might be expected from the 118HT model designation it is subwoofer built around a single 18” driver and is intended for home theater applications. The cabinet is a vented design with a front firing driver and a pair of slot vents. The cabinet measurements are 30x20x22.5 inches with 18mm Baltic birch ply construction. The cabinet is stiffened by a couple of large cross braces internally and is also lined to keep unwanted out of band energy from bouncing around. The cabinet is finished in a durable, low gloss, black finish. JTR can provide other automotive grade and veneer finishes on request with an upcharge.

The plate amplifier is mounted on the back of the cabinet and is a 700w class D unit based on an ICE module sourced from Speakerpower. The amplifier has controls for the usual stuff: Phase/delay, input sensitivity, low pass filter, auto on/off, both unbalanced and balanced XLR inputs and a detachable power cord. The amplifier also has a low frequency adjustment control for balancing the amount of low bass to the space the subwoofer is being used in.

The driver at the heart of the 118HT is a proprietary design sourced by Eminence and the result of a number of discussions, design iterations and even extensive packaging testing according to Jeff the founder of JTR Speakers. The driver utilizes a pro audio style accordion surround and a spider selected to achieve the linearity and suspension compliance targets. The cone is a lightweight treated paper with paper dust cap. The motor is said to be the largest used on one of their drivers to date, with double stacked 120oz magnets and a half inch thick top plate. The voice coil is a 3” diameter and the motor employs an aluminum shorting ring to lower distortion. The frame is a fairly common cast aluminum design. The goals for the driver were high efficiency with a generous xmax and low distortion. To that end the drivers resulting parameters show a light moving mass of 253g, a normalized motor force of 166 and a very soft suspension which will lower the Fs and the final Qts of the driver. By all rights it should be quite an efficient driver. All of that efficiency is no good in a subwoofer without a healthy amount of cone excursion to back it up. The xmax rating on the driver is 19mm one way with a xmech rating of 30mm one way. This is plenty of stroke to make a generous amount of bass especially in a vented cab.

The total system weighs in at 129lbs and is manufactured in the US like the rest of the JTR line. The price direct from JTR is 1599 plus shipping. The 118HT is not a huge sub, in fact it is quite compact for a vented 18 inch system. The physics simply dictate that a system such as this is going to have some heft to it and a bit of size. While it is no micro sub, it is a quite reasonable size and girth when considering the performance it can provide. If the 118HT seems similar to the Captivator 1400 that is because it is the same cabinet design but tweaked for the different driver and amplifier. The driver and 700w amplifier seem to be a good match, with the driver efficiently making the most of the available power and the amplifier running out of output at the point that the driver has provided most of what it is capable of doing cleanly. The performance measurements bear this out. In summary the Captivator 118HT is yet another compelling offering from JTR Speakers. It slots into their powered subwoofer lineup as a more cost effective option that still retains the dynamic output, sound signature and durability that JTR is known for.