[R_burke]

great - nice shot.  With your management ability and their DSP and coding ability, I expect to see your version out in what - about a year from now?

My comment was meant not as a shot.  The s/w engineers that I work with are currently working to SEI Level 3, and perhaps the DEQX people are working to much higher levels that take much more time.

The underlying point to my original comment was that the price should come down in a couple of years and that although I doubted it, I could hope because I was intrigued by the technology but too cheap to spend the $3000 right now.

[Occam]

Sorry, but I think you have it exactly backwards. The benefit of FIR over IIR filters in the mid/treble range is mostly just lobing control and stop-band steepness. There *may* be slight audibility directly related to phase in some cases on some material, etc, but it's not a huge impact.

However, room correction is inherently and unavoidably a non-minimum-phase problem, and any minimimum-phase (ie IIR) correction is at best a partial approach. The types of things that can be done in terms of correction using long FIR filters are so far advanced compared to a simple parametric notch/peak as to make them different things altogether....

dwk,

Thanks for the comments. My own post was specific to the differences between the DEQX and The Behringer DCX2996, not a generalization as to the 'ultimate' methodology. I'm sure you realize that an FIR does not have to be linrear phase, and that specifically, DEQX uses a FIR linear phase for its speaker correction, and FIR minimum phase for room correction. One man's slight audibility may be anothers huge impact.

The room correction comments were again, specifically adressing the differeces between the Behringer and Deqx, which are both parametric equalization(s). Your preference for digitally 'removing the walls' is far more sophisticated, and is not attempted by either vendor or Rives.

[Davey]

Now Mac.    Please include the rest of story also.  Mac, (as I did also) was able to identify a difference between between the processed and unprocessed tracks, but he did not correctly identify which was which.  We both actually thought the all-pass filtered tracks were the unaltered tracks.

The way I set the disk up was to create three "chunks" of music.  Two of these were the same and one different.  The listeners job is to identify which piece of music was the oddball and also to identify which was the "original."  We both passed the first part of the test but failed the second.
Interesting result.

Cheers,

Davey.

Davey was kind enough to provide me with a test CD and I took the challenge. What surprised me was how easily I differentiate between the altered and unaltered music. If you're interested in taking the challenge yourself I'd be happy to send you the CD.

Cheers,
mac.

 ...