Strange scratchy noise when resampling

When I export my tracks recorded at 24bit/96khz to 16bit/44.1khz wav files, the beginning of the tracks have a noticible hissy/scratchy sound at the beginning of the files that slowly fades away. This doesn’t happen if I just export the files as 24bit/96khz. I’m using the Waves L2 limiter with 16bit dithering turned on on the master output channel. Does anyone know what could be causing this?

Does the problem go away if you turn off dithering?

No, I just tried exporting the file with nothing turned on in the master (no L2, dithering, or 16 bit quantizing) and it still makes the crackling noises whenever I export the wav with a 44.1khz sampling rate from the 96khz that it was recorded at in the project. Changing the bit rate doesn’t seem to have any effect though. Any clues?

I would try dropping the volume on the export. Drop it down to 3/4 of the output meter and export it. Does it still have this scratchiness?

My experience is that sometimes there are sample errors that show up when you max the volume. If what I suggest works, then reimport the mix, add some gain and export it again. Also, try this on your final output insert: http://www.stillwellaudio.com/plugins/specials/bitter/ . You can check your sample errors pretty quickly, click the oversample button and play your project. It will keep a running total and you might be surprised at what you see.

I’d be careful using this bitmeter without knowing how it works. There are some things in the ‘manual’ that sound at least quite trivial, like “A dither [plugin] will change the signal only as long as it remains unprocessed by the host program”. Not true. And a sample clip indicator is pretty useless in a floating point calculation system like a DAW.

Arjan, I always appreciate your input. It’s a simple download and install. Try it, be brave, and report back to me your findings. I will listen. For myself, it has been a great tool that helps explain some harshness in my mixes.

Quickly, it caused me to regroup and change my WLE7 plugin order and still get the mixdown volume where I needed it. And then running the bit sampler again, I could see that the oversampling errors were gone and, frankly, my mixes sounded much much better. ?? You may consider it trivial but I disagree. Try it. I realize it is a free plugin and therefore shouldn’t be worth much but it is to me.

Arjan, I taggged your email address to the soundbytes on the Cloud player. This is all a tune in progress but one has the sampling errors, the other with them removed. It’s the same mix from Cubase. I assume you can open these?

https://soundcloud.com/#retsoor-1/new-4-mix-buzz-andy-drums
https://soundcloud.com/#retsoor-1/new-5-march-22-mix-buzz-andy

Hi mr.roos. I wasn’t saying the plugin is useless - I’m sure it does show what it says it does. But the way the manual is written doesn’t give me much confidence in it. I’m very careful about which plugins to install, so I won’t try it. I learned the hard way - and even if a plugin is harmless, I probably forget about it’s existence and it remains as clutter. In Wavelab there already is a bitmeter that I always use and that serves me well.

BTW, your Soundcloud links didn’t work from here…

OK, it’s true, you have the bit meter in WL7, something that doesn’t come with WLE7. And certainly this is why I am happy to find such a tool. And I do understand your concerns about downloading unknown software. (It’s just a .dll file with a brief text file, for the record.) Also I did try the trial of WL7 now that I think about it, and I don’t recall the bit meter was storing oversample hits? Does it do this? I am thinking the bitter is not only different visually but also in it’s operation. Eh, I would dig your take on it, but not to be, no worries.

As to the links not working, I used the email address on your site, your studio contact email, and set it up for private access to my Soundcloud. Maybe I don’t understand your email system? PM me and I’ll Dropbox them to you if you like.

The difference I can achieve using the ‘bitter’ vs. not using it IMO is such that I will always use it. And here I can use it in Cubase, as well, something that you cannot do with the bit meter in WL7. …Ah, and I do recall your setup is such that you monitor straight into WL, so this, once again, is something you don’t perhaps need, Arjan. Understood.

So back to the OP. Did you try reducing the volume of your mixdown?

mr.roos, I’ll PM you about this, cause we’re kinda derailing the topic… :stuck_out_tongue:

A short sample would maybe help identify what’s going on.

Thanks for the replies, folks. Interesting discussion too…
Should the bit meter matter here, since I’m not changing the bit depth to cause the problem, just the sampling rate?

But anyway, I figured it out after much hair pulling. It had nothing to do with the Cubase export feature. My laptop internal card was set to play back out of the output at 96khz (for what reason, I don’t know)… I switched it to 44.1 and everything sounds fine now on listening tests… so it was apparently the poorly built drivers in the Mac resampling it back up… or it just couldn’t do it.

Here’s the solution: http://www.oaks.k12.or.us/macAudio.html

The mod, if they’d like, can remove this post since it’s not related to Cubase after all.

Mmh, strange that the noise slowly faded away then. But anyway, glad it’s resolved.