will 44khz change the playback speed in a 48khz project?

[Dan Wake]

Hello to anyone, my DAW is Pro Tools 10 HD and I work as sound designer, I'm a sound designer student for cinema. My next buy could be a pair of radio mics brand model "Rode rodelink filmmaker kit", its are lavaliers.
The problem is this. The product specs say that those radio micrphones can reach only 44kHz but I need to work at 48kHz 24bit because it's the cinema standard. So if I must start a new audio movie project in Pro Tools I must set it at 48khz 24bit. So I must work in Pro Tools at 48khz 24bit for movie production and as far that I know if I import 44khz audio files into a 48khz session it will convert the file, so it will increase the playback speed (or slowdown I do not remember). But it will -change- the playback speed because of the conversion: is this true?
If yes is this change enough big to cause problems? Is it better to find other radio mic models? It's that those ones that I'm looking for are are relatively cheap and they are a new model.

Thanks a lot for help. :)

Dan

[GregV]

There is nothing in a microphone that determines what you can or cannot record it to. If you plug that mic into Pro Tools you can record it at any sampling rate you want. You can plug it into a DAT machine, minidisc, or cassette 4-track. The mic doesn't matter.

I think you might be confusing sampling rate with the mic's transmitter frequency. That is just a radio frequency that allows the mic signal attached to the actor to be received by the sound engineer. But what the engineer does with it is not determined by the mic's frequency.

Lastly, when you import audio into Pro Tools it automatically converts files to the session sample rate. So if you do field recordings on a portable unit you can import the files into Pro Tools and they will play back properly.

Hope that helps!...

[Benny_Cha_Cha]

If you import 44.1 files into a 48 session and just "add" them but not "copy" them (which you can do in 11 and IIRC 10,) then the files will play back at the wrong speed. This is probably what you are thinking of.

[joachim]

Originally Posted by GregV

I think you might be confusing sampling rate with the mic's transmitter frequency. That is just a radio frequency that allows the mic signal attached to the actor to be received by the sound engineer.

The sampling rate mentioned is the AD/DA sampling rate of the TX and RX, digital audio transmitted over analog FM. The radio frequency is 2,4 GHz.

[JFreak]

Originally Posted by joachim

The sampling rate mentioned is the AD/DA sampling rate of the TX and RX, digital audio transmitted over analog FM. The radio frequency is 2,4 GHz.

There are two very different Hz in this quote.

First of all, whatever you transmit and receive over radio is done on radio frequency (2.4GHz range) and this is regulated per country. It might very well be different frequency elsewhere, but it is still just transmitting audio signal no matter what the frequency.

Second, the audio sampling rate. Whenever you convert analog audio signal to digital audio signal you choose how you do it. If you take 44100 samples every second and use it in a session that assumes 48000 samples every second, your audio will not sound right.

So... take a moment to think about what it is what you want to ask :)

(post not intended for joachim but to the original poster. joachim made the point, I just clarified it...)

[joachim]

The RX will output analog audio. If that goes into PT by any 48kHz capable interface in a 48kHz session, it will be fine.
If the USB connector (not known to me) acts as an 44,1 kHz-interface, than recordings can be made in a 44,1kHz session and imported/converted to 48kHz in the "cinema standard" session.
"Apply SRC" is always automatically selected when I import non-48kHz-audio (does not matter if add/copy/convert).
Using audio of that Rode Kit will nevertheless be "reduced" (44,1kHz) in quality.

Question to the thread starter : a wireless setup with an omni mic for sound design ? For "stealth" recordings ?

[Dan Wake]

Originally Posted by GregV

There is nothing in a microphone that determines what you can or cannot record it to. If you plug that mic into Pro Tools you can record it at any sampling rate you want. You can plug it into a DAT machine, minidisc, or cassette 4-track. The mic doesn't matter.

I think you might be confusing sampling rate with the mic's transmitter frequency. That is just a radio frequency that allows the mic signal attached to the actor to be received by the sound engineer. But what the engineer does with it is not determined by the mic's frequency.

thanks a lot for help Greg! :) No I think my info are correct please can you take a look to this link? http://www.bhphotovideo.com/c/produc...maker_kit.html

Originally Posted by GregV

Lastly, when you import audio into Pro Tools it automatically converts files to the session sample rate. So if you do field recordings on a portable unit you can import the files into Pro Tools and they will play back properly.

Hope that helps!...

I did a test and the audio playback is very bad if I import 44khz into a 48khz project. I did a test with my voice and the sound of a clock. the time is accelerated, the voice is pitched (cartoon style) and the clock go faster.



I started with a blank session with standard settings for movies wich are 48kHz 24bit.





After this I import the 44khz 24bit file test into the 48khz 24bit session.

[GregV]

Hi Dan. I read the "specs" and it mentions "24/44.1 lossless transmission". I interpret this as the conversion rate made by the transmitter and receiver. It is sending that quality of audio from the actor's transmitter to the sound engineer's receiver.
But in the end, the transmitter will connect to a mixing board or audio interface using a standard audio cable. That means the sound engineer will be recording audio, not digital information. As such, he/she will record into Pro Tools at whatever sample rate you want.

As far as your importing experiment, there are options when importing. As joachim mentioned, you need to have "Apply SRC" checked. SRC = Sample Rate Conversion. I believe you can find that in Preferences. (Sorry, I can't remember right now)
I hope that helps.
Have fun with the mics!

[Dan Wake]

Originally Posted by GregV

Hi Dan. I read the "specs" and it mentions "24/44.1 lossless transmission". I interpret this as the conversion rate made by the transmitter and receiver. It is sending that quality of audio from the actor's transmitter to the sound engineer's receiver.
But in the end, the transmitter will connect to a mixing board or audio interface using a standard audio cable. That means the sound engineer will be recording audio, not digital information. As such, he/she will record into Pro Tools at whatever sample rate you want.

As far as your importing experiment, there are options when importing. As joachim mentioned, you need to have "Apply SRC" checked. SRC = Sample Rate Conversion. I believe you can find that in Preferences. (Sorry, I can't remember right now)
I hope that helps.
Have fun with the mics!

​Thanks for help again!

I'm speaking with Rode (of my country) I asked them: The product page refer lossless transmission 44.1kHz 24bit. does it refer to the sample-rate conversion or it refer to the transmission capacity?

product page http://www.bhphotovideo.com/c/produc...maker_kit.html



they replyed (sorry I used google translate plus my sense of bad english to translate this):

Loseless (covers the transmission) and is simply to indicate that the sending of data occurs in standard "withoud loss of data". In fact there are protocols that in practice, in transmission send a compressed version (for instance like MP3, AAC or ATRAC format, called LOSSY, as that what they take away is lost forever ...). In practice what is sent is what comes. is not subtracted anything from the passband, is not subtracted anything from the passband.



what do you think about it?:)

[GregV]

OK, so my interpretation was correct. It is the quality of the transmission.
There is a wireless signal being sent from the transmitter hardware to receiver hardware. The quality of that signal is equal to 24bit/44.1kHz audio files. (Approximately)
In other words, it is very high quality! The transmitter does not compress the audio signal down to mp3 size for transmission.

All that being said, you will still connect the receiver unit to Pro Tools with a standard audio cable. Which means you can record the signal at whatever sample rate you want.

No worries Dan. You can purchase it confidently! Enjoy!