The Behringer Ultratone K450FX is the most compact and affordable keyboard combo amplifier made by Behringer. It features a 45-watt speaker combined with a three-channel mixing panel, feedback detection system, analog-to-digital converter, and effects processor. Despite its relatively modest functionality, the K450FX can serve as a professional amplifier when used in conjunction with additional devices, for which special interfaces are provided.
The Ultratone K450FX allows simultaneous connection of up to three musical instruments, or two instruments and one dynamic microphone. Each channel has a stereo pair of 1/4-inch TS jacks, which are duplicated by a microphone XLR socket in the first channel. Signal adjustment in each channel is done with a level control and a FX processor send control.
The effects processor supports one hundred processing presets, including reverb, modulation, and delay. For the performer's convenience, the effects processor control panel is equipped with a LED two-digit display showing the selected preset number, as well as signal presence and clipping indicators. In addition to channel sends to the effects processor, there is also the option to process the overall mix using the send control in the master section.
The final mix can be adjusted using a five-band equalizer with a dynamic range of -12 to +12 dB. The equalizer is combined with a feedback detection system that detects acoustic feedback occurring at peak amplifications of resonant frequencies. The FBQ detection system helps to identify critical frequencies with the press of a button.
The Ultratone K450FX can be connected to a large number of additional devices, from headphones (with a 1/4-inch TRS jack on the main panel) to an external audio system. The latter has a line output for connecting a mixer and a separate subwoofer output. There is also a stereo RCA input for connecting a CD player, the signal of which is overlaid on the output mix.
The Behringer Ultratone K450FX features a built-in full-range 10-inch BUGERA speaker. Signal conversion from analog to digital during effects processing is done at 24 bits with a sampling frequency of 40 kHz. The device weighs approximately 14.6 kg and can be mounted on a standard stand-mount if needed.
Package includes:
- Amplifier
- Power cable
- Manual

















































