About the D8B UFX Card
The Mackie UFX card provides robust processing power for computation-heavy plug-ins. The UFX card is a 4-in/4-out architecture, which means that it supports four mono plug-ins or two mono and one stereo, or two stereo plug-ins simultaneously. Up to four UFX cards can be installed in the D8B, allowing up to sixteen simultaneous single-channel effects, eight stereo plug- ins, or combinations there of.
Note: Earlier D8Bs were fitted with 16 MB of memory. It is recommended that 
you increase this to 32 MB (as fitted in newer D8Bs) if you install more than one 
UFX card. Memory upgrade instructions are supplied with each UFX card.
About the DSR-1 (De-esser)
The DSR-1 employs mid- or high-frequency compression. The frequency and bandwidth controls are used to isolate the problematic frequency range. No external keying device is required. The ess band Key Listen feature allows you to solo (or listen) to the isolated frequency range. The DSR-1 can also help to compress shrill, high-pitched sounds that may accompany acoustic instruments. The DSR-1 includes a high-pass filter that helps you to clean up other artifacts such as microphone pops. The DSR-1 includes a series of great male and female vocal, instrument, and spoken word presets that can make the toughest job easy to correct. As with all D8B plug-ins, all of DSR-1’s parameters are automatable, and can be saved as user presets.