I couldn’t figure out how to search the forum, so I will just ask my question. If you can inform me on how to search existing threads, I am happy to do so.
We have an urgent problem. We need to deliver a master as soon as possible and try to work professionally with Linux.
We use Ubuntu studio and Ardour. This problem didn’t occur in the past. We converted from analog digital tape with a Tascam DA3000 to a high quality WAVE file. When importing, we need to reduce the quality, to make it fit into ardour. We realised, that the result is unacceptable. A huuuge noise floor, like someone is showering while recording. The high quality WAV file does not have that problem, it only occurs after importing.
Does anyone has an idea, what we could change in the import settings, to avoid that problem? Or any other hints?
Can you go a bit more into what you mean by…
When importing, we need to reduce the quality, to make it fit into ardour.
What about it doesn’t fit in Ardour? Is it just a hard drive space issue? How are you reducing quality precisely?
sorry, I meant that we tried to import 192/24 files, that are working perfectly on another system. We tried to import these in a system that is working in a 96/24 and ardour of course automatically converted the sample rate when importing. The conversion quality was set to “best”. When the process was finished, we found, that there was a tremendous amount of hiss added to the files.
If you are reducing sample rate, typically you’d need to have some low pass filtering involved, at the appropriate frequencies, otherwise you’d get artifacts. I’m not sure if this is built-in to Ardour’s coversion process (I’d assume it is but that’s just a guess on my part. And 96kHz is still quite high of a sample rate though, so it’d be surprising to me, based on your description of the amount of noise, if that was the whole of the issue anyway.
How exactly are you doing the conversion? If it’s on a DAT/Hi8 you’re getting it from one machine to the other somehow…what are your connections? Or is it already on your Ardour machine’s HDD? Maybe you’ve got a clock issue, one or both interfaces have the driver issues…hard to say without more details.
If you are reducing sample rate, typically you'd need to have some low pass filtering involved, at the appropriate frequencies, otherwise you'd get artifacts. I'm not sure if this is built-in to Ardour's coversion process (I'd assume it is but that's just a guess on my part. And 96kHz is still quite high of a sample rate though, so it'd be surprising to me, based on your description of the amount of noise, if that was the whole of the issue anyway....
Ardour uses libsamplerate.
(and you might consider that using 192kHz sample rate doesn’t gain you any extra audible quality, no matter what anyone might tell you. You can completely reproduce a bandlimited audio signal provided it is sampled at more than twice the highest frequency, in which case, even 44.1kHz is just fine unless you have superhuman hearing)
I have never heard of someone having this problem before that I can recall, can you try a nightly build of Ardour and see if it happens there?
You could/should also try using the standalone command line program
sndfile-resample on the files, since this uses the same library (Secret Rabbit Code, or libsrc) as Ardour uses. Note that the SRC comparison web site http://src.infinitewave.ca/ gives Secret Rabbit Code extremely positive results. I suspect that the noise you are hearing has nothing to do with the conversion at all.
I have heard noise I wasn’t expecting while playing back files through Ardour, and then found the reason was that Ardour’s mixer had several channels with the faders up, connected to mic preamps with the gain turned up and nothing plugged in. They can make a lot of noise like that!
I might have had the ‘input’ override button selected on some channels too, or some other routing oddity which made this possible.
As Paul says, it’s unlikely to be the conversion process itself.
Du kannst die wavs auf dem “another system” umwandeln und dann im Ardour weiter arbeiten, oder?
Ich habe schlechte Erfahrungen mit Speicherkarten gehabt.