Become a Site Supporter and Never see Ads again!

Author Topic: Audacity change tempo vs RX7 time & pitch  (Read 810 times)

0 Members and 1 Guest are viewing this topic.

Offline checht

  • Trade Count: (5)
  • Taperssection Member
  • ***
  • Posts: 333
  • Gender: Male
  • Old and in the Way
Audacity change tempo vs RX7 time & pitch
« on: November 24, 2019, 02:06:25 AM »
Anyone compared the sound of Audacity's stretch vs RX 7 dilate? Running both now to listen, but wondering if anyone else has checked this out.

~Chris
Schoeps MK41s > nbob KCY >
Naiant PFA 60v > Sound Devices MP-6  or  Naiant IPA > Roland R-07

Online morst

  • Trade Count: (2)
  • Needs to get out more...
  • *****
  • Posts: 3791
  • ISO ALL archival Cracker / CVB / Monks Of Doom etc
    • Soundscape Preservation Society
Re: Audacity change tempo vs RX7 time & pitch
« Reply #1 on: November 24, 2019, 01:41:24 PM »
Anyone compared the sound of Audacity's stretch vs RX 7 dilate? Running both now to listen, but wondering if anyone else has checked this out.
Not sure what you're trying to do, but I use CHANGE SPEED in Audacity to stretch or squash tracks in order to match recordings made on separately-clocked machines. There was a bug in some version where it didn't allow enough precision, so I've been using the old 2.1.0 for years. I think when I update to MacOS Catalina [DO NOT DO THIS YET!] I'll be forced to run a more recent version. Hope that works out.
Teams: Neumann, Bay Area Tapers, Multitrack,  Mac Geeks, Cassette Masters, Poster Collectors, Pro Audio
Alumni of teams St Louis, Upper Midwest & Milwaukee / Southern Wisco, Pioneertown Tapers

Offline checht

  • Trade Count: (5)
  • Taperssection Member
  • ***
  • Posts: 333
  • Gender: Male
  • Old and in the Way
Re: Audacity change tempo vs RX7 time & pitch
« Reply #2 on: November 24, 2019, 01:56:47 PM »
Hi Morst,

Hope you're well.

From the intertubes:
"Change Speed, affects both Tempo and Pitch." "Change Tempo" states "Change Tempo without Changing Pitch."

I use change tempo in Audacity so that I don't by accident change both tempo and pitch.

Just wondering if rx7, being modern and high quality as far as I've tested, might have a better sounding algorithm, though Audacity's change tempo is well regarded.

~Chris
Schoeps MK41s > nbob KCY >
Naiant PFA 60v > Sound Devices MP-6  or  Naiant IPA > Roland R-07

Online morst

  • Trade Count: (2)
  • Needs to get out more...
  • *****
  • Posts: 3791
  • ISO ALL archival Cracker / CVB / Monks Of Doom etc
    • Soundscape Preservation Society
Re: Audacity change tempo vs RX7 time & pitch
« Reply #3 on: November 24, 2019, 02:15:39 PM »
From the intertubes:
"Change Speed, affects both Tempo and Pitch." "Change Tempo" states "Change Tempo without Changing Pitch."
I use change tempo in Audacity so that I don't by accident change both tempo and pitch.
Just wondering if rx7, being modern and high quality as far as I've tested, might have a better sounding algorithm, though Audacity's change tempo is well regarded.
I think you're using the wrong one. You NEED pitch to change when you change the time. You probably won't hear it with your ears though.
The thing you're correcting is that one recorder and the other don't believe the same pitch is "middle C" or whatever. They have different references and so you'll need to compensate.
Teams: Neumann, Bay Area Tapers, Multitrack,  Mac Geeks, Cassette Masters, Poster Collectors, Pro Audio
Alumni of teams St Louis, Upper Midwest & Milwaukee / Southern Wisco, Pioneertown Tapers

Offline checht

  • Trade Count: (5)
  • Taperssection Member
  • ***
  • Posts: 333
  • Gender: Male
  • Old and in the Way
Re: Audacity change tempo vs RX7 time & pitch
« Reply #4 on: November 24, 2019, 03:07:36 PM »
Ah, different use cases.

I'm matrixing a sbd recording with an aud recording. Both have accurate middle C, but one is 5 milliseconds longer than the other, over a 93 minutes recording.

Cheers.
Schoeps MK41s > nbob KCY >
Naiant PFA 60v > Sound Devices MP-6  or  Naiant IPA > Roland R-07

Offline EmRR

  • Trade Count: (3)
  • Taperssection Member
  • ***
  • Posts: 472
    • ElectroMagnetic Radiation Recorders
Re: Audacity change tempo vs RX7 time & pitch
« Reply #5 on: November 24, 2019, 03:23:52 PM »
Ah, different use cases.

I'm matrixing a sbd recording with an aud recording. Both have accurate middle C, but one is 5 milliseconds longer than the other, over a 93 minutes recording.

Cheers.

Hmm, my math may be wrong, but isn't that only a 0.00009% difference in pitch?  Essentially undetectable, but still different.  Sure, someone hitting a guitar string hard bends it more out of tune than that, by far. 
Mics: DPA 4060 w/MPS 6030 PSU/DAD6001/DAD4099, Neumann KM 131, KMR 81i, Oktava MK 012, Sennheiser MKH 105, MKH 20, MKH 30, MKH 40, MKH 800 TWIN, lots of other studio appropriate choices
Recorders: Zoom F8n, Sony MZ-R50, portable MOTU based multitrack DAW for client work

Offline checht

  • Trade Count: (5)
  • Taperssection Member
  • ***
  • Posts: 333
  • Gender: Male
  • Old and in the Way
Re: Audacity change tempo vs RX7 time & pitch
« Reply #6 on: November 24, 2019, 04:33:16 PM »
My understanding is that change tempo compensates for the pitch shift and leaves it as it was, just (very slightly) longer duration.
Schoeps MK41s > nbob KCY >
Naiant PFA 60v > Sound Devices MP-6  or  Naiant IPA > Roland R-07

Online morst

  • Trade Count: (2)
  • Needs to get out more...
  • *****
  • Posts: 3791
  • ISO ALL archival Cracker / CVB / Monks Of Doom etc
    • Soundscape Preservation Society
Re: Audacity change tempo vs RX7 time & pitch
« Reply #7 on: November 24, 2019, 07:06:47 PM »
Ah, different use cases.
I'm matrixing a sbd recording with an aud recording. Both have accurate middle C, but one is 5 milliseconds longer than the other, over a 93 minutes recording.
Hmm, my math may be wrong, but isn't that only a 0.00009% difference in pitch?  Essentially undetectable, but still different.  Sure, someone hitting a guitar string hard bends it more out of tune than that, by far.
This is exactly the use case I was considering. And EmRR is on my wavelength here. I don't think that level of out-of-tuneness would register, thus you are safe to correct pitch along with time.
*note that if you play them back on their original clocks, they should both play at "true" pitch, but if you import them into a computer, or copy one file to another and listen with the same reference clock, then that would not be the case.
My understanding is that change tempo compensates for the pitch shift and leaves it as it was, just (very slightly) longer duration.

Right. You don't actually want that.
« Last Edit: November 24, 2019, 07:09:13 PM by morst »
Teams: Neumann, Bay Area Tapers, Multitrack,  Mac Geeks, Cassette Masters, Poster Collectors, Pro Audio
Alumni of teams St Louis, Upper Midwest & Milwaukee / Southern Wisco, Pioneertown Tapers

Online morst

  • Trade Count: (2)
  • Needs to get out more...
  • *****
  • Posts: 3791
  • ISO ALL archival Cracker / CVB / Monks Of Doom etc
    • Soundscape Preservation Society
Re: Audacity change tempo vs RX7 time & pitch
« Reply #8 on: November 24, 2019, 07:24:19 PM »
Hmm, my math may be wrong, but isn't that only a 0.00009% difference in pitch?  Essentially undetectable, but still different.  Sure, someone hitting a guitar string hard bends it more out of tune than that, by far.
My spreadsheet breakdown is as follows. I am assuming 48,000 samples per second.
https://docs.google.com/spreadsheets/d/1pQGfYwPgBFFzcY5m6aRj-Zbu9HsRumLy-tJB1d8Eufg

=(93*60*48000)+(0.093*48000)    length of longer source in samples
=(93*60*48000)   length of shorter source
4464 samples difference

I get
267844464/267840000 = 1.000016666666 which would be a percent change of +0.0016666% to speed up the longer source to make it have 4464 less samples and thus match the shorter one in time (length)
Teams: Neumann, Bay Area Tapers, Multitrack,  Mac Geeks, Cassette Masters, Poster Collectors, Pro Audio
Alumni of teams St Louis, Upper Midwest & Milwaukee / Southern Wisco, Pioneertown Tapers

Offline rumbleseat

  • Trade Count: (0)
  • Taperssection Regular
  • **
  • Posts: 91
  • Gender: Male
    • Sonicsational Audio
Re: Audacity change tempo vs RX7 time & pitch
« Reply #9 on: November 25, 2019, 02:06:56 PM »
Morst - You made my head spin.  Thanks!

After pondering and doodling, I agree that you're right - although that's not what I was thinking going into this thread.

Consider two decks, one running with a much faster clock.  When those files are loaded into Audacity, the file from the faster clock deck will have more samples and will appear longer in time length in Audacity.  If you play both of those files in Audacity, the longer file will sound at a lower pitch.  To match them, you have to adjust both tempo and pitch.
AKG C480B CK61 cards or AKG C568EB or Church CA-11 cards >  Canare L-4E6S with Neutrik EMC > Tascam DR-680 MKII or DR-44WL > memories

Offline checht

  • Trade Count: (5)
  • Taperssection Member
  • ***
  • Posts: 333
  • Gender: Male
  • Old and in the Way
Re: Audacity change tempo vs RX7 time & pitch
« Reply #10 on: November 25, 2019, 02:31:02 PM »
It is my understanding from the manual that adjust tempo shifts pitch to compensate for the tempo change, and doesn't need additional pitch adjustment.

That's where I get confused, as the info online all points that way.
 
Schoeps MK41s > nbob KCY >
Naiant PFA 60v > Sound Devices MP-6  or  Naiant IPA > Roland R-07

Online morst

  • Trade Count: (2)
  • Needs to get out more...
  • *****
  • Posts: 3791
  • ISO ALL archival Cracker / CVB / Monks Of Doom etc
    • Soundscape Preservation Society
Re: Audacity change tempo vs RX7 time & pitch
« Reply #11 on: November 25, 2019, 04:10:10 PM »
Does it help if I add the units of measure?
=(93 minutes * 60 seconds/minute * 48000 samples/second )+ (0.093 seconds * 48000 samples per second)    length of longer source in samples
=(93 minutes * 60 seconds/minute * 48000 samples/second )   length of shorter source
4464 samples difference

I get a ratio of:
267844464/267840000 = 1.000016666666, which would be a percent change of +0.0016666%, to speed up the longer source to make it have 4464 less samples, and thus match the shorter one in time (length)

Morst - You made my head spin.  Thanks!After pondering and doodling, I agree that you're right - although that's not what I was thinking going into this thread.Consider two decks, one running with a much faster clock.  When those files are loaded into Audacity, the file from the faster clock deck will have more samples and will appear longer in time length in Audacity.  If you play both of those files in Audacity, the longer file will sound at a lower pitch.  To match them, you have to adjust both tempo and pitch.

Your spinning head appears to have landed at the correct spot because you are correct.


It is my understanding from the manual that adjust tempo shifts pitch to compensate for the tempo change, and doesn't need additional pitch adjustment.
That's where I get confused, as the info online all points that way.

Most online info will be for people making music or processing audio, NOT synchronizing long tracks the way we are.
We... are a little different. Specialized use case around here. Adjust Tempo changes the length of the track but does NOT change the pitch at all. Imagine in the situation rumbleseat mentions, where there is a drastic difference in speed. You have to allow the pitch to change.

Musicians who just want to hear their song faster, or advertisers who don't want to sound like a chipmunk for their wordy disclaimer would use Adjust Tempo.
« Last Edit: November 25, 2019, 04:14:02 PM by morst »
Teams: Neumann, Bay Area Tapers, Multitrack,  Mac Geeks, Cassette Masters, Poster Collectors, Pro Audio
Alumni of teams St Louis, Upper Midwest & Milwaukee / Southern Wisco, Pioneertown Tapers

 

RSS | Mobile
Page created in 0.13 seconds with 54 queries.
© 2002-2020 Taperssection.com
Powered by SMF