Bit rate/sample rate question...

Hello, is anyone able to explain something to me regarding sample + bit rates.

I have recently "upgraded" to using a PC and audio interface. I plan to track digitally from the MPC to the computer.

I understand that the MPC2500 can only handle 16/44.1 samples. My audio interface can sample at 24/96...

So, if I track to the interface digitally from my MPC. And then, record, say a bassline from a bass guitar directly into the interface (sampling at 24/96)... I'm confused about what sample rate I am working at in the DAW.

If i start a 24/96 project on the PC for example, and track in from the MPC, is this still a 24/96 song? Can I mix these 16bit MPC samples and 24bit computer samples, with no problem? Would it just mean less dynamic range/clarity etc from the MPC part?

Would the finished track still be a 24/96 track even though I've made half of the beat on the MPC and brought it to the computer?

Thanks

Maybe you know this already, but here's a quick breakdown of sample rate and bit rate.

By way of analogy, consider your audio wave form like a movie on a digital camera. The sample rate is the measurement of frames per second. Bit rate is the resolution of each frame.

When it comes to recording one signal of a particular sample / bit rate onto a system with other settings, this is like taking a picture of a printed image. You can take a low rez picture of a hi-rez image, reducing it in the process. Alternatively you can take a hi-rez picture of lo-rez image and reproduce its lo-rez character with a great deal of accuracy. Taking a lo-rez pic of a low-rez image will have a compounding effect of reducing the accuracy of reproduction of the original scene.

As for your specific questions, your DAW project will be 24/96 if that's how you set it. That doesn't mean everything will sound pristine, but everything should sound closer to the original source material than if you recorded at lower rates.

In your example, your DI Bass will be recorded at 24/96 (a hi-rez image) whereas your MPC signal will be like a hi-rez picture of a lower rez image.

Thanks, that helps in clarifying how I should expect the 16/44 to sound within the 24/96 track.

I will be planning to do this digitally from the MPC into the Interface. So , I'm guessing I will have to set my interface to 16/44 as well in order to recieve it.. or were you saying I can record it in at 24/96? Although a lowres recording of a lowres would reduce sound quality, am I right in thinking this isnt the case in digital transfer and I just get an equal copy?

And so if thats the case, if I have recorded it in at 16/44, will it say within my DAW that some tracks are 16/44 and some are 24/96? How does this work when it comes to making it a 24/96 wav?

Hope that makes sense. I'm confused about the DAW having a mix of 16/44 and 24/96, and how this works when it comes to bouncing to a 24/96 or 16/44 WAV. Is there a conversion that takes place?

I know I've misunderstood something simple here...

Thanks

To use the 44100 mpc digital signal, both your pc and mpc need to be clocked at 44100.
If you don't lock the clocks together at 44100 you will hear random clicks/glitches in the audio coming from the mpc.

You can't send 96000 to the mpc because the mpc will play all weird at the wrong speed.
You can't send anything other than 44100 from the mpc.

Unless you daw has some fancy programming going on that means you can mix and match sample rates somehow I'm afraid you're stuck with keeping everything at 44100.

That is, unless you're not bothered about random clicks/glitches.

This is how I would do it:

Create a project on the PC 24/44
Record the digi out of the MPC to this project. I got no problem recording the 16/44 signal to the 24/44 project
Record the Bass in this 24/44 project

IMO a high bitdepth is important but a higher samplerate than 44kHz only take more space and in the end you'll need to render the mixdown to 44kHz.

peace

DJ Plan A wrote:Maybe you know this already, but here's a quick breakdown of sample rate and bit rate.

By way of analogy, consider your audio wave form like a movie on a digital camera. The sample rate is the measurement of frames per second. Bit rate is the resolution of each frame.

No. Bit rate is just that. The rate of transmission of data over a specific unit of time. For example, a stereo recording at 16-Bit 44.1kHz will have a bit rate of 1411.2kbps (kilo bits per second)

2 channels x 44100 samples per second per channel × 16 bits per sample = 1411200 bit/s (bits per second)

What you are referring too is bit DEPTH which is simply the number of binary digits recorded for each sample.

As for your specific questions, your DAW project will be 24/96 if that's how you set it. That doesn't mean everything will sound pristine, but everything should sound closer to the original source material than if you recorded at lower rates.

No, it won't. It doesn't need too. The reconstructed signal will match the original signal so long as the sampling rate exceeds twice the highest frequency of the OG signal.

In your example, your DI Bass will be recorded at 24/96 (a hi-rez image) whereas your MPC signal will be like a hi-rez picture of a lower rez image.

No. For reasons mentioned above.

peterpiper wrote:This is how I would do it:


IMO a high bitdepth is important but a higher samplerate than 44kHz only take more space and in the end you'll need to render the mixdown to 44kHz.

peace

definitely. not sure about the science behind it, but seems like to me anyways, too.