The PEQ4 parallel parametric EQ algorithm -- or "para para" EQ -- is the latest from BTE Audio. In the most primitive parametric EQ units, filter bands were connected in parallel instead of series-cascade, the preferred method for the more modern conventional parametric EQ.

Parallel architecture has its own unique flavor which BTE describes as having a "distinctive musicality." Hold it up to the light and examine its color. Swish it around your ears. The phase behavior is different and adjacent bands smoothly interlace. To achieve symmetrical curves for boost and attenuation, the filter bands are put in feedback paths during attenuation.

In analog gear, placement of the filter bands is a fairly simple process, but try doing that in the digital realm, and you'll be met with a challenge -- delay-free feedback loops, which cannot be computed in classical DSP theory. With PEQ4, BTE simulates the challenging digital parallel parametric EQs that emulate these delay-free feedback loops.

• Extremely High Processing Efficiency
• Supports sampling frequencies up to 384 kHz
• Clickless parameter update
• Proprietary topology which is optimized for low latency, low noise and high dynamic range
• Supports both 32 bit (single precision) and 64 bit (double precision) floating-point processing
• Built-in reference-quality upsampling algorithm which is automatically enabled at sampling frequencies below 88.2 kHz
• Clearly and concisely implemented in pure C++: portable to any platform that is supported by a C++ compiler