Let me explain our admittedly biased point of view about differences between Dirac Live and DSpeaker...
DSspeaker is a standalone unit so it can be easily used with a number of different sources while Dirac Live is an application that consequently can be used with a PC or Mac only (Dirac Live may eventualy process one external source only, and only if an audio card is used instead of a DAC)
Needless to say no additional conversions are necessary with Dirac Live.
I understand that DSpeaker is a minimum-phase solution, so that its designers quite correctly concieved and limited it to low frequencies correction.
The reason is that minimum-phase filters can properly correct room behaviour in minimum-phase regions only, which tend to be at the lower frequencies (even at those frequencies that is not always true).
Let me cite an excerpt from the REW's measurement software developer site:
"Minimum phase systems can be inverted, which means that a filter can be designed that, if applied to the system, would produce a flat response and correct the phase response at the same time. That is clearly a nice property to find if we want to apply EQ. If we apply EQ to a system that is not minimum phase, or more particularly in a region where it is not minimum phase, the EQ will not produce the results we would like. It may still be possible to achieve a flat response, but correcting the phase response would elude us. It is simply not possible"
This quotation comes from this well informed document:
http://www.hometheatershack.com/roomeq/wizardhelpv5/help_en-GB/html/minimumphase.html
On the contrary Dirac Live is a mixed-phase solution that can successfully apply a full bandwidth correction to speakers/room behaviour which is mixed-phase.
We explain that as follows:
"Infinitely many different filters can be designed to have the exact same magnitude response. They differ only in their impulse response. Therefore, it is useful to classify filters according to how their impulse responses behave.
Two commonly used filter classes in audio applications are minimum-phase filters and linear-phase filters. They are two special cases that are relatively easy to design, but that come with tightly constrained impulse response characteristics. A minimum-phase filter, by definition, is constrained to apply only the smallest possible delay to the signal given a desired magnitude response. A linear-phase filter, by definition, applies a delay which is constant across the whole frequency range. Therefore, neither of these two filter designs can make a desired change to the phase or impulse response, unless the desired change is exactly the particular change they make by definition. Minimum-phase and linear-phase filters may even worsen both the impulse response and the magnitude response of a system, simply by applying their magnitude response corrections at the wrong time.
A more difficult design task is to make a mixed-phase filter that matches a desired magnitude response while also having a customized impulse response. A properly designed mixed-phase filter can make significant improvements to the impulse response of a sound system at the listening position"
In other words we are talking about two different products of different nature with different design goals
Ciao, Flavio
