Fundamentals of Digital Audio Podcast

Direct link to the mp3: http://www.archive.org/download/darker-projects/FDA-13-Darker-Projects.mp3

An interview with Eric Busby, creator of Darker Projects, superb science fiction audio theatre.

Boss1200CD

Boss BR-1200 CD Review

• Direct link to the mp3:http://www.archive.org/download/Boss_BR1200_CD_Review/FDA12Boss1200CD.mp3


• Samson announces 2 new usb mics: CO3U condenser mic ($129 retail) and the Q1U dynamic mic ($49 retail) http://www.samsontech.com/
• Pros
• Complete studio, 2 XLR inputs, preamps, guitar and midi inputs, insert effects, CD burner, usb import and export, RCA component in and out.
• Solid manual. I was able to use the BR 1200 CD right out of the box following the manual step by step even though
• Evertything worked as expected
• With built-in 40 gb
• Cons
• Has a bit of a learning curve
• If you're used to editing and recording on a computer, it feels like you're trying to write left handed at first
• $999 is a bit steep
• Boss BR 900CD is a similar model for $699 with simlar features except it records onto compact flash cards http://www.bosscorp.co.jp/products/en/BR-900CD/index.html
• Boss BR - 864 is a similar model that is very small and portable for around $400 http://www.bosscorp.co.jp/products/en/BR-864/details.html
• Next time an interview with Darker Projects. http://www.darkerprojects.com/

News and Notes

Direct link to the mp3: http://www.archive.org/download/Levels_Redux/FDA-11.mp3 If you want to include a short promo send an mp3 to digiaudio.podcast@gmail.com

Sony Announces new Minidisc recorders

Full Mac Support Record to mp3 - great for conferences, classrooms. Record and post right to the web. Good levels with the automatic gain control feature http://forums.minidisc.org/index.php?showtopic=14814

Other podcasts with a focus on Digital Audio The Point http://www.pfiggianimsc.com/blog/ Inside Home Recording http://feeds.feedburner.com/insidehomerecording The Podcast Academy from IT Conversations : http://www.itconversations.com/series/podcastacademy.html Take control of Podcasting on the Mac - new podcast: http://www.takecontrolbooks.com/mac-podcasting/

Look for a review soon of the Boss 1200CD: http://www.bosscorp.co.jp/products/en/BR-1200CD/

Audio Hijack Pro: check it out - very useful. Inexpensive $32 or $16 -10 minute limit in Demo. Classic podcast use is to record Skype interviews: http://www.rogueamoeba.com/audiohijackpro/

Levels Redux

Peak Levels vs. RMS levels - what's the difference? We need to keep track of both

I became infatuated with the idea of getting the RMS levels spot on (-17.5 db) right from the recording. The problem with this is it requires recording at very high or hot levels. This means I would at times shoot past a peak of 0db which causes terrible distortion called clipping. I thought I could use a software peak limiter to control this, but I have learned that once it is clipped it stays clipped (or distorted) in the digital domain. So you need to keep track of both

What to do about this?

Invest in a hardware limiter that limits the signal before it is convered from analog to digital. This probably mans investing in a compressor/limiter, xlr mic and mixer with inserts.

Or, record at lower levels and boost in post - best way is to use the RMS Normalization feature of apps like Peak Pro, Audition or SoundForge, but those are expensive

Step by step in Garage Band Set input levels Check levels with RMS buddy on the Master track. I get about -25db average or RMS level and a peak of about -4 to -6db. Garageband lets you boost a track by a max. of 6db. So i've boosted by 6db and added a peak limiter on the vocal track. In this case the peak limiter is set to -5db. I'm finding that the limiter can't react fast enough to limit at a level of -1db - I still get clipping so I had to lower it to -5db. After boosting I get RMS levels of about -21 db or so with peaking still under 0db. We are shooting for about -17.5 so we are a little short. Still this gets us at an RMS level about the same as public radio uses - all in all not bad.

If you are really bent on getting to -17.5 db you can export the vocal track out of Garage band, import it back in and boost it by 4 to 5 db, and apply a peak limiter again. May not be worth the trouble.

It's a lot easier to use a tool that has RMS normalization like Peak Pro or Audition, Sound Forge, Wave Editor, etc...

Wrap up

digiaudio.blogspot.com for show notes and links

digiaudio.podcast@gmail.com for comments, feedback or audio promos

Next time Boss BR 1200CD

Still working on into to DSP as promised