The dbx® 555 is a 500 series compliant 5-band parametric EQ. The 555 occupies 2 slots in a 500 series rack and is equally suited for studio and live sound use.
Each of the 555's bands offer the typical gain, frequency center, and bandwidth controls and operate as peaking (bell) type filters. Gain can be adjusted by up to +12 dB of boost or -15 dB of cut. Bandwidth is continuously variable between .03 and 2.0 octaves. Each band also has an on/off switch, making it easy to compare each band's affect against the original, unprocessed signal. And if you decide against using a band, simply leave the band off to easily remove it from the signal path - rather than having to "zero out" the controls.
Each band has a frequency multiplier switch, and this is where the fun begins! The frequency multiplier switches allow each band to cover the entire frequency spectrum. This means that bands can be adjusted to interact with each other any way you see fit. This allows for some very flexible and dramatic EQ curve possibilities!
The output section of the 555 houses a 5-segment signal level LED meter with peak indication, a circuit bypass switch, and master output level control.