Taperssection.com

Gear / Technical Help => Ask The Tapers => Topic started by: ace5gt on June 23, 2024, 09:16:21 AM

Title: Distorted audio with PCM-M10
Post by: ace5gt on June 23, 2024, 09:16:21 AM
My Setup: CA CAF mics > SP SPSB-12 Battery Box > Sony PCM-M10
Settings: SPSB into Line In on the M10 with the gain set to 5.5.

When I import the WAV file into my Post editor, the volume is extremely low.  And even then, I'm still getting some distortion.  If you look at the attached screenshot you can see what I'm referring to.  What are optimal settings I can use to prevent this from happening?
Title: Re: Distorted audio with PCM-M10
Post by: unidentified on June 23, 2024, 06:47:23 PM
How fresh are the batteries in the battery box?
Title: Re: Distorted audio with PCM-M10
Post by: ace5gt on June 23, 2024, 08:19:23 PM
How fresh are the batteries in the battery box?

That's a good question.  Battery life is rated at "30-50 hours", and I'd estimate I have around 20 or so.  But I've had the battery box for years and was under the impression if the battery box was outta juice, the mics would stop working all together?

I'm going to change the battery anyway and see how things go at the next show.
Title: Re: Distorted audio with PCM-M10
Post by: joeldotc on June 23, 2024, 09:10:37 PM
A while ago, my battery box was not supplying a full 9 V to the mic capsules (thx chris church) and was only sending a couple volts instead - I got a super wacky recording which had a decent amount of distortion.

I’ve heard from others that low battery levels can cause similar looking waveforms/distortion.

My waveform looked somewhat similar to yours but more extreme. I ended up doing a +90 degree phase shift (I know audition and Izotope RX both have the ability to deal with this) and it made it sound so much less distorted - the tape actually ended up sounding pretty great IMO. It did have some lasting distortion from the mics not being able to handle such high SPLs at low voltage, but it definitely wasn’t clipping since the levels were set low like yours.

From the looks of your waveform, maybe it could use a -45 degree phase shift or so? I’d maybe try messing around with that. Again, you would probably also end up with some high SPL distortion assuming the band played loud and that wouldn’t be fixed by a phase shift.

For what it’s worth, I don’t think the waveform you posted is too crazy looking.
Title: Re: Distorted audio with PCM-M10
Post by: AbbyTaper on June 23, 2024, 09:42:16 PM

For what it’s worth, I don’t think the waveform you posted is too crazy looking.

My thought as well
Title: Re: Distorted audio with PCM-M10
Post by: robgronotte on June 23, 2024, 09:52:29 PM
Someone I know had a recording with low volume and significant hiss. Figured out it was because the battery had a loose connection so not giving full power.
Title: Re: Distorted audio with PCM-M10
Post by: ace5gt on June 24, 2024, 08:54:28 PM
A while ago, my battery box was not supplying a full 9 V to the mic capsules (thx chris church) and was only sending a couple volts instead - I got a super wacky recording which had a decent amount of distortion.

I’ve heard from others that low battery levels can cause similar looking waveforms/distortion.

My waveform looked somewhat similar to yours but more extreme. I ended up doing a +90 degree phase shift (I know audition and Izotope RX both have the ability to deal with this) and it made it sound so much less distorted - the tape actually ended up sounding pretty great IMO. It did have some lasting distortion from the mics not being able to handle such high SPLs at low voltage, but it definitely wasn’t clipping since the levels were set low like yours.

From the looks of your waveform, maybe it could use a -45 degree phase shift or so? I’d maybe try messing around with that. Again, you would probably also end up with some high SPL distortion assuming the band played loud and that wouldn’t be fixed by a phase shift.

For what it’s worth, I don’t think the waveform you posted is too crazy looking.

Please tell me more about this Phase Shift feature?  I'm far from a guru with Adobe Audition.
Title: Re: Distorted audio with PCM-M10
Post by: joeldotc on June 27, 2024, 10:44:06 AM
Please tell me more about this Phase Shift feature?  I'm far from a guru with Adobe Audition.

In audition, use the graphic phase shifter tool: Stereo Imagery > Graphic Phase Shifter effect

https://helpx.adobe.com/ca/audition/using/graphic-phase-shifter-effect.html

Just set the shifter so it is a flat -45 degree shift across all frequencies. The attached screenshot shows the editor - you can choose logarithmic or linear (doesn’t matter in this case), vertical axis = 180, channel = both, FFT size = default. You can start with the -90 degrees preset, then adjust each side so they’re both at -45 degrees rather than -90. You should be left with a perfectly straight line at -45 degrees across all frequencies.

See how that looks - it’ll make the waveform shift to be more “bottom heavy”. If it shifts too much, try going to ~-25 degrees across the entire freq range. Adjust it until the waveform looks pretty symmetrical across the horizontal (-infinity db) axis