RTX128

The MTX Thunder RTX128 is a 12" mid-bass speaker from the Road Thunder Extreme series, which borrows PA system technology to bring high-output sound to a vehicle. It is built for one job: reproducing the mid-bass and midrange frequencies that a subwoofer cannot handle, at volume levels most car speakers give up on.

Power handling is 300 W RMS and 600 W peak through a single 8-ohm voice coil. Sensitivity is 96.0 dB, which is the number that matters most here: high efficiency means high output from whatever amplifier you already have, so you get real SPL without a large power budget. Frequency response runs 66Hz - 5.2kHz.

The cone is treated paper, chosen for a high stiffness-to-weight ratio that keeps output high and cone flex low. A large magnet on a stamped steel basket supplies the motor force. Mounting depth is 4.61" (11.71 cm).

A single 8-ohm voice coil lets you run multiple speakers per amplifier channel, which is how SPL builds get to high speaker counts without odd impedance loads. In a system with one or more subwoofers, mid-bass speakers like this fill the range between the subs and the tweeters, so vocals and midrange detail stay clear instead of being buried under low frequency output. Pair them with Road Thunder Extreme bullet tweeters and MTX subwoofers for a full high-output build, in a door, a kick panel, a rear deck, or a custom baffle.