Passeq

The original Passeq hardware is the first passive EQ which provides three separate frequency ranges for both boost and cut stages. One famous, if not the most famous, passive design was the Pulteq EQ from the decades of the 1950's and 60's. This EQ sported two frequency bands (low and high frequencies, or LF and HF), and had only a few switchable frequencies to offer. In contrast, the Passeq has 12 switchable frequencies per band, totaling 36 boost and 36 cut frequencies. Boost and cut frequencies are NOT identical, thus the resultant 72 frequencies per channel offer an enormous choice for the most elaborate EQ curves. The Passeq offers for the first time passive filter control possibilities extending throughout the relevant audio frequency range—and that with an unheard of abundance of filter choices.

* Reproduction of all interactions between the passive filters
* 72 filters on three bands per channel
* Emulation of input and output transformers
* Two graphical user interfaces: dual-channel and space-saving single-channel view
* Switchable M/S mode for independent processing of mid and side information