DEQX - Digital Audio Technology for Active Crossovers

                  DEQX
                    Active Linear Phase Digital Crossovers
                

In addition
                    to detailed correction of loudspeaker frequency response,
                    phase and group delay timing errors, DEQX’s ‘active’ implementation
                    also provides extremely steep linear-phase crossovers
                    to 300 dB/octave.
                   
                  This compares with today’s ‘passive’ speaker
                    crossovers that are typically 6 to 12dB/octave, with no phase
                    correlation, no ability to correct frequency response errors
                    and usually unable to correct even gross timing errors between
                    drivers.
                   
                  While "going active" offers some improvement over a passive
                    setup, the listener will still miss the full benefits of
                    a digital linear phase crossover, as the following diagrams
                explain. 

Figure 1:  Loudspeakers
                    with passive crossovers use a single amplifier to drive them.
                    Its high power is only roughly separated into high and low
                    frequencies for tweeter and woofer using up to 12dB/octave
                    filter slopes. Note that high frequencies (blue) sent to
                    the tweeter also contain significant levels of low frequencies
                    (red) that cause tweeter distortion. Yet the woofer also
                    receives significant ‘highs’ that it’s
                    large diameter must ‘beam’ narrowly towards the
                    sweet spot while unable to produce high frequencies as cleanly
                    as the tweeter. This results in ‘crossover distortion’ and
                    unnatural dispersion over several octaves. Additional
                    distortion is caused by passive components that present complex
                loads to the amplifier. 

Figure 2:
                    In a normal active loudspeaker design, such as those oftern
                    used by audio professionals, each driver has its own amplifier.
                  This allows the crossover to run at ‘Preamp’ (rather
                  than amplified) signal levels. This enables steeper crossover
                  slopes, being typically up to 24dB/octave, which provide better
                  separation of highs and lows going to the drivers. However,
                  these loudspeakers are still NOT able to maintain ‘linear
                phase’ due to each drivers inherent errors. 

DEQX active loudpseaker crossover - digital crossover

Figure 3:
                    DEQX ‘active’ crossovers correct phase and
                    frequency response for each driver. Note the far steeper
                    crossover slopes than ‘normal’ active (Figure
                    2 above). Steep crossovers, up to 300dB/octave, quarantine
                    energy to the ‘comfort zone’ of each driver.
                    The results include:
                  
                      Increased power handing
                    

                      Improved dynamics 
                    

                      Better dispersion and a wider sweet spot 
                    

                      Elimination of interaction between drivers while maintaining
                        phase coherence. 
                    

                  The resulting frequency response and group delay behaviour
                    is corrected to a level that is impossible to achieve with
                normal passive crossovers, or even with normal active crossovers. 

DEQX active digital crossover with subwoofer

Figure 4: DEQX
                  allows various configuration options. Popular 2-way configurations
                  for Stereo and Home Theatre are accurately integrated and time-aligned
                with sub-woofers. 

DEQX Active Linear Phase Digital Crossovers

In addition to detailed correction of loudspeaker frequency response, phase and group delay timing errors, DEQX’s ‘active’ implementation also provides extremely steep linear-phase crossovers to 300 dB/octave.

This compares with today’s ‘passive’ speaker crossovers that are typically 6 to 12dB/octave, with no phase correlation, no ability to correct frequency response errors and usually unable to correct even gross timing errors between drivers.

While "going active" offers some improvement over a passive setup, the listener will still miss the full benefits of a digital linear phase crossover, as the following diagrams explain.

Figure 3: DEQX ‘active’ crossovers correct phase and frequency response for each driver. Note the far steeper crossover slopes than ‘normal’ active (Figure 2 above). Steep crossovers, up to 300dB/octave, quarantine energy to the ‘comfort zone’ of each driver. The results include:

Increased power handing

Improved dynamics

Better dispersion and a wider sweet spot

Elimination of interaction between drivers while maintaining phase coherence.

The resulting frequency response and group delay behaviour is corrected to a level that is impossible to achieve with normal passive crossovers, or even with normal active crossovers.

Figure 4: DEQX allows various configuration options. Popular 2-way configurations for Stereo and Home Theatre are accurately integrated and time-aligned with sub-woofers.