De-essing filters

[JCook]

I'm cleaning up some LPs I recorded in Audacity and some of them have some severe sibilance in the vocals, whenever there is an s, sh, t, or ch in a word. I've tried various de-essing filters, but the one that seems to work the best is the Spitfish de-esser (it's a free one). I'm nothing close to being an audio engineer, so my question is should I apply this filter to the entire file (or song) or do I have to isolate each instance of sibilance and apply it only to them? I did try some large samples where there was some sibilance as well as a lot of non-sibilant sound, and it seem to work fine without affecting the rest of the music. I'm just wondering what the best procedure might be, according to some of you who have a lot of knowledge in this area. I'm using Audacity 1.2.6 on Mac OS 10.4.11.

thanks,
Jack

[kozikowski]

In thousands of years of buying and playing vinyl, I've only had one record that had bad peaking. The "Liza with a "Z" (not Lisa with an "S") album was recorded with killer high peaking. Dogs can't listen to this thing. Still with all that, it wasn't distorted, just very harsh and peaky.

That's it. One in a row.

Which means your original captures are damaged. You can go really far by cleaning up the distortion at the capture stage than trying to suppress it later. Once you hose a recording, you can never patch it up good as new.

How did you get the captures?

Koz

[JCook]

I played the LPs on a Sony PS-LX350H turntable with a Shure M97xE cartridge. The turntable ran through a preamp, which went directly into the computer via a Griffin iMic. I could hear the sibilance while recording. I have a few records that sound this way, and they are old ones, but I dont' ever remember hearing them sound this way. There is no clipping in the recording, and everything else in the music sounds fine. I agree, cleaning them at the capture stage would be best, but how do you do that? Other records I've recorded the same way sound fine, so I think these particular ones may be damaged, so my only option may be to do the cleanup afterwards.

Jack

[JCook]

But meanwhile, back to my original question - should I use the de-essing filter on the whole file or song, or only on the selected sibilant bits (which is a lot more work, and a pain in the neck to do)?

thanks,
Jack

[steve]

But meanwhile, back to my original question - should I use the de-essing filter on the whole file or song, or only on the selected sibilant bits (which is a lot more work, and a pain in the neck to do)?

It depends on the type of material as to how badly affected the recording will be by applying the de-essing filter on the whole song. And it depends on how you think it sounds as to whether it is worth spending much time on.

De-essing filters usually work by compressing the dynamics on high frequencies. This means that if there is a loud burst of high frequencies, then it will be made less loud, but high frequencies at low volume are unaffected. This means that most of the music will pass through the filter unaffected, but if the vocalist makes a loud "sss" type sound, then the high pitched noise will be attenuated, making the "ss" less "zingy". However the same will also be true of any other bursts of high frequencies. For example, any cymbal hits will be made to sound a bit dull.

However, I read that you suspect record wear (damage) to be the cause of the sibilance, in which case it is likely that the exaggerated high frequencies apply in all cases ("ss's" and cymbals etc.), in which case it would be correct to apply it to the whole song.

Another thing you could try, is simply using Equalization.

Whatever your solution, it is just a matter of what sounds right to you.

[kozikowski]

<<<went directly into the computer via a Griffin iMic.>>>

Directly to the computer by way of one of the worst pieces of audio equipment in the world? And connected via USB which Audacity sometimes has trouble managing.

If there is an analog Line-In on your computer, even if it's a PC and not a Mac, you may find the audio enormously improved by going that route. I put my iMic out in the garage.

If you have a PC laptop which tend to only have Mic-In, then you're stuck cleaning it up in post. If you're on a Mac or a deskside PC, then you're in a perfect position to record excellent quality via the analog route.

Koz

[JCook]

Thank you stevethefiddle for your explanation. I'll play with it, saving a song with the filter applied to the whole song and without, and compare to see if there's much difference. In the couple of records that are having this problem I don't think there are too many cymbal sounds, but there is acoustic guitar. I'll listen closely to the guitar to see if it's affected.

Koz, thanks. So, the iMic is not particularly a good piece of equipment? Didn't know that. It makes sense, though. I'll give a try to connecting to my Mac through line in. I might have to find some cables. I'll give it a try this weekend.

thanks,
Jack

[steve]

Let us know how you get on

[JCook]

Here's an update. I tried running the de-essing filter on a whole song, and it seemed to help the problem a lot. I didn't notice much difference in the accompaniment music at all, so I ran the filter on the whole file (one side of an LP), and also on the other side of the LP. Then I burned a CD. It sounded pretty good, the sss sounds that were so annoying were brought down to a tolerable level in most cases. Some of these sounds were just excessively loud, and they were improved quite a bit. But some of these sounds were not only loud but distorted also. These sounds are still distorted, but not as loud as they were, so it's better than it was. I don't think it can really be improved upon much more. So, at least the record is more listenable than before. It'll probably always bug me, because I know exactly where all the bad sounds are, having worked with them so much, but it's better.

I tried plugging in directly to the line-in port on the back of my Mac, and was able to record, but there was a fairly loud low hum that I couldn't get rid of, so I'm back to using the iMic until I can figure it out. It's probably some sort of ground problem I would think, but as far as I can tell everything is grounded. I don't know what to do about the hum.

Jack

[kozikowski]

<<<as far as I can tell everything is grounded.>>>

Stop doing that. If you're recording on a portable computer, see if the hum doesn't go away if you run batteries and disconnect the wall power. Another possibility is the flip the Mac power supply over in the wall. It will plug in either direction.

Take the 1/8" plug out of the Mac and clean it with a cloth moistened with rubbing alcohol and then a dry cloth.

See if the turntable will plug in to the wall upside down.

Make sure everything is plugged into the same wall socket even if you have to borrow a power strip to do it.

Even more exotic, if you are working with a entertainment wall, unplug the roof antenna or cable TV connection. Go ahead. Ask me how I know that one.

Koz