harsh distortion introduced by impulse filter

[simonhui]

Hi,

I use DCArt for restoring and transferring my old LP's onto CDR's. What I do is pass a whole side through the impulse filter with the LP Declick Start Point preset once, and then listen through it and fix any leftover clicks with paste interpolate. I had been working on my older LP's dating from the late 60's and early 70's and noticed some harsh distortion on loud, high pitched passages like saxophones and female voices. I thought it was just because the record is old and had been played with bad stylii and had damaged grooves. Until I did a brand new LP last night, one of the last vinyl LP's I ever purchased and never even unsealed. Michael Bracker sounded like sawing steel after the impulse noise filter. On comparing the processed file with the original file I discovered that the distortion was introduced by the filtering process. In the original file the same passage sounded silky smooth.

So maybe I've been doing something wrong all along. But as I said, I was only using the LP Declick Start Point preset. I thought that would be safe.

What can/should I do?

Thanks,
Simon

[Rick]

Re: harsh distortion introduced by impulse filter

The sound you are hearing is the impulse filter doing too much on the high passages. You should adjust the Tracking control higher so that the filter will not trash the transients. Loud high frequency passages like sax or certian cymbal sounds will be tougher to track than others. If you are generally satisfied with the side, but only have a couple of sections of distortion, it may be easier to selectivly re-process only the sections that are distorted.

Rick Carlson

[simonhui]

Re: harsh distortion introduced by impulse filter

Hi Rick,

Thanks for your reply. I tried that, and notched 'tracking' up 10 at a time, but didn't get a satisfactory result until I got it up to 80. Is this normal? Am I maybe introducing other artifacts by using such a setting?

Thanks,
Simon

[Rick]

Re: harsh distortion introduced by impulse filter

Moving the tracking higher will cause DC-art to do LESS to the file, so higher numbers will generate less artifacts, if anything.

Rick Carlson