Impulse Noise Filter Suggestions

[weskola]

Does anyone out there have any inputs as to how to get optimal results using the Diamond Cut Impulse Filter on vinyl LPs? What methods did you use to obtain what you felt are optimum settings?

[quartet87]

Re: Impulse Noise Filter Suggestions

Having used DC Mill for only a few months, so far I've seen best results from impulse filter by selecting the first pass vinyl HQ setting, then moving the tracking slider down to 40 or 45, which is just above the level that causes the file preview play to hang. On lp's that are in good condition this setting produces very good results in automated declicking. In fact, I'm now finding that after this first pass I can hear no need for further de-clicking, save stubburn clicks which I remove by hand. By way of info, I copy the vinyl flat to minidisc, then to the hard drive via optical connection. I find this method very handy. I monitor with a Yamaha RX777 receiver connected to Paradigm Studio 40 v2 speakers and a Infinity subwoofer. Hope this helps.

[weskola]

Re: Impulse Noise Filter Suggestions

Thanks for the suggestion. Do you get any distortion at all on the high passages with the tracking set down that low? I've tried countless combinations of settings and my experience has been that, in general, going below 60 or 70 increases the chances of distortion. However, I sometimes get the impression that the larger the size that is selected the lower the tracking can go. I have tried this in the past and I still had some problems with distortion on high passages. But, this may have been caused by my running the filter several times with the same settings through the multi-filter. I have experienced distortion when doing this. I'll give your suggestion a try and see if I get better results.

[weskola]

Re: Impulse Noise Filter Suggestions

I've given this a try but I haven't had much luck. I have had to set the tracking to about 85 in order to avoid distortion on a saxophone solo. But at this level there aren't too many clicks removed. Even if I run it a half dozen times.

[DougMac]

Re: Impulse Noise Filter Suggestions

Another trick you might try is to reverse the file, then declick. I've also found some instruments make it hard to declick, the algorithm can't distinguish between the characteristics of the instrument and noise on the record. For some reason, Joni Mitchell's voice is especially difficult. I have to back off to keep her from distorting.

Doug

[weskola]

Re: Impulse Noise Filter Suggestions

Doug, once the album is reversed how are you going to be able to tell if your settings are too aggressive unless you un-reverse it and then listen? Are you able to effectively use tracking levels as low as 40-50? I simply cannot go that low. As a point of reference, the material I am working with is early to mid 70's pop (Fleetwood Mac, 3 Dog Night, BTO, etc.). My equipment consists of a Yamaha stereo receiver, Bang & Olufsen turntable, Behringer mixer, Gadget Labs audio card, 500Mhz Pentium with 256MB RAM. My WAV files are clear and strong and not even close to clipping.

[Dan McDonald]

Re: Impulse Noise Filter Suggestions

When I reverse the file, I simply use the last setting I used in the forward file. That seems to work pretty well.

Dan

[Jason Begley]

Re: Impulse Noise Filter Suggestions

HI Weskola,

I have noticed, whilst browsing through the user groups, that you have been hit by the common problem of "clipping/distortion" when
using the Impulse filter in DC.

A few suggestions from my own experience are as follows;
1. Use the Multifilter with TWO Impulse filters, One set as follows; Threshold of 1, Size of 30, Tracking start at 50 and move it down (until you reach the point of distortion and then back up). The Second set as follows; Threshold of 1, Size between 7 to 14, Tracking start at 70 and move it up until distortion stops.

2. Another thing to try is record your audio in at a lower level, effectively giving the filter a "bit more room" to play with

One thing to note is that continual use of the same filter setting over and over again WILL produce these distortions no matter what, that's why I use TWO completely different settings, one for LARGE/LONG clicks and one for SMALL/SHORT clicks or tics. The thing to remember here is that the SIZE setting is relevant to the amount of samples that are examined in order to define a click. Also consider using a MEDIAN filter at the end of the suggested chain of filters and then finally a Continuos Noise Filter to finish it off. Regarding the CNF, play with the Attack and Release settings, setting them HIGHER, say 100 of Attack and 200 for Release, also give the Threshold ONE Click up and set your attenuation to about 30 - 40.

In worst case scenarios, I have used the Adaptive Voice Filter (as suggested by HopHead some time back) to filter residual crackle on REALLY BAD recordings and then "tacked" on a Virtual Valve Amp set up as an exciter to restore the highs that go missing after using the Adaptive Voice Filter.

I hope that these tips help you to achieve what you are trying to. Please post your results/findings.


Regards,

Jason Begley - Multimedia'n'Music - AUSTRALIA http://www.multimedia-music.com.au

[weskola]

Re: Impulse Noise Filter Suggestions

Mr. Begley. This must be my lucky day. I had finally figured out my optimal EQ settings and then I saw your posting. I tried your suggestions and they worked very well. With the size set at 30 I had to settle on a tracking of 70-71 and with the size set at 14 I had to set tracking to 80-81. I have played around with a lot of settings but I never thought of going to a size of 30. The largest I ever tried was probably around 22-24. With the documentation I have read and some of the postings, I had a tendency to follow those recommendations closely.

Even though my WAV files are nowhere near being over-recorded, I decided to take your advice and record a bit lower. In combination with my EQ settings it seems to make for a much clearer sound which lends itself to more efficient cleanup. I use the VVA preset "Triode Tube PreAmp 3" after all of the other processing and it seems to work very well for me.

Thanks again.

[Jason Begley]

Re: Impulse Noise Filter Suggestions

Hi Weskola,

That's great to hear, I am glad I could be of assistance.

Regards,

Jason Begley - Multimedia'n'Music - AUSTRALIA http://www.multimedia-music.com.au

[Craig Maier]

Re: Impulse Noise Filter Suggestions

Jason, thanks for the useful hints. Obviously, you have a lot of experience with the software. Just one question. What mode did you use for the Impulse filter? Did you use Vinyl LP or HQ, (or even 78, although I doubt it). Or did you use a combination of the various modes in conjunction with the multifilter?

[weskola]

Re: Impulse Noise Filter Suggestions

Another thing that I recently tried was to run the channel blender preset "FM Stereo Multiplex Noise Filter" prior to running the impulse filter. For me, it made a tremendous difference. I was able to set the tracking control down anywhere from 10 to 20 points depending on the size selected. For the size 30 I was able to move tracking from 70 to 50. I was able to remove a lot more clicks this way.

The reason I ran the channel blender was because I noticed one brief instance of a high vocal that had a barely audible break up or distortion. Normally, the INF would magnify this unless you set the tracking fairly high. This would also mean that fewer clicks would be removed.

I don't know that running the channel blender prior to running the INF is recommended but I noticed quite a difference on 2 albums. I ran the INF in HQ mode and, in this instance, it removed more clicks than vinyl mode.

To compensate for some loss of high frequencies I use the graphic EQ to boost 8Khz and 16Khz about 3dB each prior to running the VVA.

[Jason Begley]

Re: Impulse Noise Filter Suggestions

Hi Craig,

In answer to your questions;

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Craig Maier:
Just one question. What mode did you use for the Impulse filter? Did you use Vinyl LP or HQ, (or even 78, although I doubt it). Or did you use a combination of the various modes in conjunction with the multifilter? <HR></BLOCKQUOTE>

I used the INF's set to HQ mode, and used them in the Multifilter along with a few other filters such as Median and CNF.


Regards,

Jason Begley - Multimedia'n'Music - AUSTRALIA http://www.multimedia-music.com.au