The subwoofer is the large speaker in the center of the photo.
A subwoofer is a speaker that uses a large cone to accurately reproduce deep bass tones. Setting up a subwoofer is trickier than setting up normal speakers; adjust some settings on the subwoofer itself to get the sound just right. Unlike normal speakers, a subwoofer is not directional, but consider where in the room you want to place the subwoofer in order to optimize your sound system.
Instructions
1. Plug the subwoofer into the stereo amplifier using an RCA cable. If the amplifier is compatible with a subwoofer, it will have a phono jack labeled "sub" or "subwoofer." Don't use normal speaker wire for the subwoofer, because unlike normal loudspeakers, the subwoofer needs to do some processing to its input and requires a different input level than normal speakers. Use a long cable to have freedom to move the subwoofer around the room.
2. Set the crossover frequency using the dial on the back of the subwoofer. The crossover point is the frequency at which sound divides between the speakers. Set the crossover to 80 Hz, the subwoofer plays sounds below 80 Hz and the normal speakers play higher frequencies. If the subwoofer came as a set with the speakers, the crossover frequency may be preset for use with those speakers. Most subwoofers purchased separately have an adjustable crossover. Consult the manual for your speakers to find their usable frequency range. Set the crossover point to the lowest usable frequency for the normal speakers. This setting may not be perfect, but adjust it later.
3. Play a CD whose sound you are familiar with to test the level of the subwoofer. Use a CD that's cleanly recorded, has a lot of dynamic range and a wide range of frequencies. While listening to the CD, adjust the volume level of the subwoofer using the knob on the rear panel. Adjust the level to the point where the subwoofer blends cleanly with the rest of the speakers and isn't too dominant or underrepresented.
4. Move the subwoofer around the room, testing out how it sounds in different place. Factors to consider are the layout of the room, the look and feel of the space and the sound. Corners often produce good bass tones. If your other speakers are small, you may have to position the subwoofer near one of them to keep the illusion that all tones are coming from the same source.
5. Tweak the crossover frequency until it sounds best to you. The minimum frequency listed by speaker manufacturers is not always exactly accurate, so you may have to experiment to find the optimal setting. If you set the crossover lower than the lowest sound your speakers are reproducing, you will lose the range in between. However, if the subwoofer and loudspeaker frequencies overlap the sound will come out muddy and garbled. Some amplifiers allow you to adjust crossover settings for the loudspeakers, so consider tweaking these controls as well to get the best sound. If you change the crossover frequency in the amplifier, set the subwoofer crossover to the same frequency.
Tags: normal speakers, crossover frequency, around room, bass tones, crossover point