"Chiptune" distortion when recording system audio (Camtasia for Mac and external sound card)

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  • Updated 11 months ago
Hi,

Firstly, it comes from a large thread with Joseph Beaubien who recommended me to post this issue here.

I have an external USB 2.0 sound card Native Instruments Komplete Audio 6 (KA6) which has been released in 2011 and is a very popular and valuable device in it ́s price range. I ́m using a Macbook Pro Retina 15", OS X 10.5 Yosemite and Camtasia 2.10.4 for Mac.



I sent to Joseph several recordings demonstrating I can record with this setup within Photo Booth, Audio Hijack 3, also Quicktime, Logic, etc. with no issues at all.

The problem comes when trying to record system audio within Camtasia and the KA6 selected as the main input/audio in Audio & MIDI Prefs (44.100Hz I/O): the system audio is recorded with a constant digital distortion all the time. But the sound recorded from the condenser mic is good. It only happens with system audio. 

I think it ́s something related with the system audio component, as this issue only happens with Camtasia.

Joseph told me that I should record directly from the internal sound card to avoid this issue, but I need the most quality in audio as my video tutorials are related with audio, mixing, etc. so recording with the internal mic is not possible.

I ́ve tried removing com.techsmith.camtasia2.plist from Library, reinstalling Camtasia, reinstalling the KA6 driver, with no results. I ́ve also tried it in a second Macbook Pro and the same distortion issue has occurred.

I ́ve found this page at Native Instruments where they share a driver, I think for developers.


With this information, could you please check in deep your system audio component and tell me how I could fix it up?


Best regards,

Pablo
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Pablo

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Posted 4 years ago

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Jack Fruh, Champion

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Hi Pablo, 

  Sounds like a frustrating experience!

  You might be best opening a support ticket with Techsmith - this is the public forum and I suspect many of the public helpers such as myself will not be able to fix it, whereas support would at least be able to look at the source code.

That said, here are a few thoughts I had as I read your post:

#1) Use a tool like Audio Hijack Pro to create a recording of all your system sound, or at the very least to confirm that that recording can be made without distortion.

#2) Play with settings in the KA6 driver - maybe you'll see the issue at 16bit 44.1 but not 16/48. 

#3) you mentioned digital distortion, what I imagine when I hear this is straight up noise,  but if it's just that its 'too loud' which is causing digital clipping, maybe there's a volume slider you can adjust in the audio/midi prefs.

#4) You didn't mention but are you using an aggregate device? If so, try it without the aggregate to see if the problem goes away, and then when you go back to the aggregate try changing the Clock source and drift correction to see if changing these settings has any impact.

- Jack
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Pablo

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Hello Jack,

It ́s pretty confusing because as I said, I come from a large thread on a support ticket with Joseph Beaubien (TechSmith Support). Finally, after he couldn ́t give me a solution, and I asked him about asking Tech Smith developers to check the system audio component, he told me:

"While I can certainly pass on this suggestion, it is best to use the following link - it is page that all our product teams are using to track feature requests and feedback. http://feedback.techsmith.com

That ́s the main reason I ́m here posting this issue, so I ́ve already tried the Tech Smith support.

Regarding your suggestions:

#1)  I ́ve already tried Audio High Jack Pro and I could record my condenser mic mixed with system audio with no distortion at all. (I gave Joseph the audio file). After several recording tests, the issue only happens within Camtasia.

#2) I ́ve tried from 44.1K to 96K. Regarding the bit depth, the KA6 cannot manage 16/24bit within the Audio& MIDI setup, which is the main control panel for that sound card. I think it runs by default at 24bit. Could it be the main reason of the issue?

#3) It sounds like downsampling distortion, like "chiptune" sound. It ́s not digital distortion in terms of exceeding above 0dB in a mixer. Here you have an audio example.

#4) I ́m not using the KA6 as an aggregate device. The current Clock Source is the only one I can select: Internal.


Thank you very much for your help,

Pablo
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Jack Fruh, Champion

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I listened to the audio - some of it is making it through - I don't have enough experience with digital distortion to know if that's what would happen if you went from 16 bits to 24 and put the 16 bits in the wrong place or not - so it's just a guess at this point.  Might be something a pro audio engineer would know?

I think at this point my best suggestion would be to use Camtasia to record your Mic, but no system audio.

Use Audio Hijack to record two files: one with system audio and your mic, and one with just the system audio.

Then sync the audio files in camtasia by visually looking at the waveforms.
The two from Audio Hijack should both be in sync to start with.
You'd use the combined one from audio hijack to sync your voice with your voice in camtasia, then mute that track. Whats left should be the camtasia voice only recording, and a synced recording from Audio hijack of your system audio.
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Pablo

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Hi Jack,

It could be a solution, I ́ll try it recording with Camtasia and Audio Hijack Pro simultaneously. Anyway, I ́ve founded some posts dated 4 years ago regarding the 16/24bit issue with Camtasia, they look the same that this one, but it seems it ́s not solved yet.

Thank you again,

Pablo
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Max Wheeler

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Having the exact same problem with a mac pro & universal audio apollo soundcard. Total nightmare. Anyone any closer to a fix?
(Edited)
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Bora Uslusoy

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Same here! No solution yet?
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javierlorenzo1986

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2017 and no solution yet? frustrating =(
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Jack Fruh, Champion

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Has anyone tried loopback from Rogue Amoeba, I wonder if it would work better in this scenario?
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Pablo

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Since 2015, I ́ve tried Camtasia, then Screenium 3 and finally Screenflow. Guess what ́s the only app that works like a charm with audio on Mac OS X.
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globalspex

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It's 2018.. I started having problems. Every time, the audio was disrupted and distorted. Camtasia's response to was to remove the preference files and delete the application and reinstall. First, there were no preference files which was odd. Second, deleting the application didn't seem to fix that issue.

I recently switched to Screenflow. Worked right out of the box.
(Edited)
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weisylomo

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i like camtasia   but  i don't know how to fix this problem either