The CEQ215 is a 19" rack mounted dual 15-band graphic equaliser, which allows the adjustment of labelled frequencies via the individual cut/boost faders. Up to 12dB of cut or boost for frequencies ranging from 25Hz to 16kHz for accurate audio spectrum control.

The Fostex FD4 is a hard disk multitracker without a hard disk. Pardon? You'll have to read on for the detail, but I'll say at the outset that the FD4 isn't weighed down with features (as some hard disk recorders are) and that Fostex seem to have struck a happy balance between features and usability in their new machine — they appear to have remembered that most potential purchasers will probably be complete novices in the recording arts.

• 2 Way Stereo, 3 Way Mono Crossover
• 19" Rack Mountable
• Butterworth Filters 18dB/Octave
• Continuously Adjustable Cut-Off Frequencies
• 40Hz Ultra Low Frequency Cut
• Phase Invert Function
• Inputs & Outputs via XLR

The Citronic CX34 is a 2-way or 3-way stereo or 4-way mono active crossover designed to split frequencies so that low frequencies are delivered to the amp driving the sub cabinets and mid/top frequencies are delivered to the amp driving the mid/top frequency cabs.

This type of system is more efficient and delivers more accurate sound quality, especially in larger PA systems.

Whilst primarily designed to deliver a more detailed sound, the Citronic CX34 also protects your equipment from overloading and avoids potentially blowing your mid/top speaker cabinets by sending the low frequencies just to the subs. 

The Citronic active crossover offers a user-friendly operation easily accessible when installed in a 19" rack cabinet. 

This is a great tool for anybody who wants to minimize feedback in a live situation. Can be used in Auto Mode to identify frequencies that cause the feedback and eliminate it. Or there is a Manual Mode which allows you to dial in up to 24 frequencies and tweak the bandwidth and gain yourself.