Saturday, November 18, 2006

Software upgrade

After all the hard work and the system is working flawlessly for a few months, it is time for an upgrade. As I menetioned before, the convolution filter was generated by Uli for me before. Now, Uli has come up with a complete solution for convolution with measurement sweep and digital crossover. This program is called Acourate and can be donloaded from here.

Now, what does it do? You can use it to generate room correction files pretty much the same way as Tact but much more accurate. More importantly, you can generate crossover files to allow digital active crossover. Now this is the area this programm is supposed to outshine the others. First, it can generate the crossover, this is simple and most program can do well. But then you can use this program to compensate for the difference in tweeter/mid/woofer placement and their relative arrival time to your sitting position. At the same time, it also does speaker driver linearisation. What is that?

Uli explains it as "as you know I try to describe in my white paper how crossovers have to look like to match perfectly. The paper is based on the assumption that a driver is itself perfect. But of course this is not the case in reality. So the measurement of the driver shows that it follows the given crossover but there are deviations. Now you could assume that the room correction will help here. Yes. But it is even more better first to optimize the components themselves. So the difference from the real driver behaviour to the desired behaviour (the target is here the crossover curve) is taken to correct = linearize the driver."

In other words, the program predicts the deviation of the driver behaviour from the perfect crossover and compensate for that first. It is only after that will room correction filter applies. In theory, this will give a perfect crossover and many have reported excellent results. I will also report my findings soon!