I am having random tempo change issues in Cubase LE4. The most recent problem is occurring during mixdown. My tracks play just fine, but when I go to export a mix, the result comes back sped up with a pitch change of about 1/2 step.
Earlier in the day my actual tracks where playing slowed down with a lowered pitch. I gave up and just re-recorded. I recall having similar problems in the past. Is it possibly related to cutting the front and end of the tracks then moving them? I have read the documentation and searched this forum, but haven’t really found an answer.
My recordings are really simple, just a one take stereo recording with two mics through Lexicon Omega. I am not purposely manipulating the time at any point. The only editing I am doing is cutting the front and end of the track, then moving it to zero.
Thanks for the reply Thinkingcap. I am recording at 48k 24 bit, exporting to 44.1k 16 bit (typical CD setting), which is what I have always done and (usually) works. I opened the properties (windows) of the mix file and it is saying it is at 1411 kpbs. I don’t know why it is at that sample rate, it’s not what I had exported it at. What I can do to change what I am doing during mix down to solve the problem. Any clues.
1411 kps = 141120 b/s = 44100 (samples) x 16 (bits) x 2 (channels)
The thing is, that when you take a 44,1 kHz file and play it at 48 kHz samplerate, witout converting, it will play faster and pitched by roughly a semi tone…
For example, when “truncating bits”, as a result of moving
from 24 to 16 bit resolution, quantization errors are added
to an otherwise immaculate recording. By adding a special
kind of noise at an extremely low level, the effect of
these errors is minimized. The added noise could be perceived
as a very low-level hiss under exacting listening
conditions. However, this is hardly noticeable and much
preferred to the distortion that otherwise occurs.
Ok. I read the title too quick and jumped in to reply. For converting the sample rate you could use a plugin such as the crystal resampler. I don’t think it is included in Cubase LE, but I’m sure there are free alternatives.
Dithering properly is still a good idea. (It just depends on how fast these tempo changes are. )
I solved the problem, sort of. I just went to the project settings and changed to 44.1k 16 bit. I didn’t have to re-record. The mixdown went fine after that.
I went into an older project and did the same setting change and it slowed down the tracks. I hope I didn’t ruin the recording files.
So I guess the procedure should be to record with settings at 48k 24 bit, then change to 44.1k 16 bit for mixdown? I had read you should always record at the best rate our system can handle regardless of what your output is going to be. Should I ignore this and just record at 44.1k 16 bit and be done with it?
No you didn´t. They do play slower, because they are 48 kHz and are now played with a 44,1 kHz sampleclock.
The procedure is, to record at any samplerate you like, but adjust the playback device´s samplerate to the actually played file´s samplerate.
You can´t have two samplerates at the same time. So close your 48 kHz project set the soundcard to 44,4 kHz and play the 44,1 kHz file. Or use a player, that converts on ther fly. If you play back within Cubase, it will play with the project setup´s samplerate. In that case, the file has to be (temporarily) converted to have correct playback parameters
The problem is that I don’t use my computer’s soundcard for recording/mixing, it’s not really powerful enough. The Lexicon Omega is the “processor” for my recording projects. Obviously I want to play back the files using my computer’s sound card, but not while in Cubase. I generally use windows media player for playback.