Distorted playback

[RHA]

I've been recording vinyl (50+ so far) at 24/96 and importing into iTunes. I had one problem where the files did not import into ITunes properly. The info window showed a XX MB file but no sound, even when playing back within iTunes. Problem solved... I reopened the audacity file > export multiple and added to the ITunes library again. This time they transfered fine. Any idea why the file showed data but no sound?

Second situation: I'm getting distorted/fuzzy sound on playback recently. Checked all settings within Audacity. Reinstalled firmware on audio interface. Repaired permissions. Reset pram on Mac. If I open a pre-recorded file it plays normally. Listening direct from the vinyl while recording is fine. I do not playback through Audacity during recording. Recent recordings are distorted with a buzzing sound behind the music but I can see nothing on the screen waveform. I downloaded a second copy of the software... does the same thing. (I did not uninstall the original software, only quit original and started the 2nd copy.) Any guidance will be appreciated. Thanks!

[kozikowski]

Audacity doesn't always get along so well with 24-bit sound. I think you'd be much further ahead with 16 bit. Even at 16 bit, the noise floor of a vinyl record is magnitudes worse that the digital channel you're putting it on.

16 bit should also resolve the problems with iTunes...

Koz

[waxcylinder]

I agree with Koz about avoiding 24-biy - I myyself record with Audacity at 44.1kHz 32-bit. I export to MP3 and also to 16-bit 44.1kHz PCM WAV.

The MP3s and the WAVs produced this way work fine on my iTunes(PC/Windows version) and my iPod. The WAVs also burn to good quality CDs.

WC

[kozikowski]

I recorded all the live voice performances for a theatrical short at 48000, 16 bit. Me, a mic, a mixer, a quiet room and my PowerBook.

Koz

[RHA]

After a day or so I again tried recording... again 24/96. Everything was working normal again. I continued recording for several more days with no problems. Today again the problem re-occurred. I updated my audio interface firmware (Focusrite Saffire). Still muddled recording. Redid permissions on my iMac. Still muddled. Reset PRAM. Still muddled. Changed my MIDI and Audacity setup to 16/44.1. Recorded fine. Reset MIDI and Audacity prefs to 24/96... again muddled playback.

I am trying to archive my vinyl collection in as high a quality as possible. Visiting various forums online I've tried to understand the advantages/disadvantages of each sampling/bit rate. I chose 24/96 for recording because on my system I think I can hear a difference. The 24/96 sounds a little fuller/richer textured/dynamic. The 16/44.2 sounds a little thin by comparison. Also there are several good sounding DACs that support native 24/96 playback via USB from my computer which can be a big convenience to listening to my vinyl collection without changing/flipping records, etc.

I know Audacity has worked very well for me in the past, and I enjoy Audacity's interface, ease of use and features. I have tried various 24/96 capable recording/editing programs but greatly prefer Audacity. So far I have recorded 74 albums and don't want to start with a new format and redo all that work, plus I'm looking for the highest possible playback via USB DAC. I'm hoping the new version will be able to work out this little quirk and be more 24/96 friendly.

I saved the data from a "muddled" recording and tried to attach to this post, but was unable. Perhaps I could send it via normal email if that would help find my problem and sort through this. Thanks for your responses and assistance. Best regards, Rod

[kozikowski]

<<<16/44.2 sounds a little thin>>>

It would. 16 bit, 44100 is a CD delivery format and is an intentional compromise between sound quality and pushing one entire Beethoven symphony out the door on one physical shiny disk. Many people screamed that they could hear the difference when that audio was accepted as the Music Compact Disk standard. It doesn't shock me that you can hear it, too.

When the digital video standards were formulated, they went straight to 16-48000 where most quality problems are not significant.

DAT machines run at the video standard. You can plug a DAT machine into a television broadcast facility and it interfaces perfectly.

Like some of the other digital audio problems, the 24-bit thing isn't broken. Worse, it's unstable. It stops working on Thursday afternoon when the humidity is over 75% and you're wearing blue pants. Change anything and the symptoms change.

USB. I do have one definite engineering thing you can try. Many USB audio processors run using power taken from the computer's USB connection. USB connections are designed to supply power, but traditionally, it's not very clean and pure. There are instances of people being able to hear the hard drives spin up over their microphone performances because of electrical interference.

Many turntables run from USB power because several people noticed they could digitize audio through the turntable even though the turntable was unplugged from the wall. There was one report of someone who slipped a USB hub between the turntable and the computer. The Hub is required to have a wall power adapter and not get its power from the computer. The report was that many if not all of the USB problems vanished when they did this.

Koz

[RHA]

Koz

Again thanks for your reply. Following your suggestions I decided to do some experimentation. My audio interface was powered by it's firewire feed (not USB). I dug out the power supply and connected that and moved the interface farther away from the computer just in case there might be some interference. No help. Next I tried recording at 16/44, 24/44, 16/96, 24/96, 16/48, and 24/48. The culprit is recording at 96kHz. 96 kHz caused distortion whether at 16 or 24 bit. Everything else recorded fine. Whether 16 bit or 24 bit.

It is my understanding that 24/96 is becoming the standard for mastering studios. It's difficult to believe that the industry would accept a standard that is unstable. There has to be a better way. I know Audacity has acknowledged the instability of version 1.3. I can only hope the new version will handle 96kHz. I definitely would prefer to use Audacity compared to any other program I have used but stability is a big issue when you get shutdown for hours/days or lose data.

By the way I stayed away from blue pants today and wore my lucky sweater and it still won't record at 96kHz. I would love to send you the file. It's only about a minute long... just enough to sample each combination. Anyway I'll keep trying. I'm not going to try the USB turntable because that's not a high fidelity option. If you can think of anything else to try I would love to hear it. Thanks again, Rod

[RHA]

It's working again. Didn't change any settings. Been recording like crazy until it gets pissed again. Cheers,

[waxcylinder]

It's sounding like you have a poor connection/dry joint/damaged wire somewhere in you recording chain,

WC

[RHA]

Hi WC
Not sure what the problem is... I've checked all connections, settings, etc. When I did the test in the previous post all the trials were done at the same time, within minutes, and all recording formats recorded perfectly except those at 96kHz. Duh! I don't know. Thanks! Rod