Sunday, February 26, 2006 

How do I get the right volume levels?

  • Direct link to the mp3

    • Special thanks to Doug Kaye of IT Conversations and Paul Figgiani of The Point Podcast and IT Conversations. Although I don’t know them personally, I would not understand audio levels at all without the guidance they have provided to the podcast community.
    • Ironically, the levels in this podcast are just a touch too loud as I peak in some spots. It’s not too bad though and I don’t have time to re-record.
  • Notice how some podcasts are too quiet while others have a nice big sound while others still sound too loud and distorted in spots (especially poppig ps)?
  • Getting the levels right is tricky because on one hand you want to have a nice big loud sound but if you get too loud it distorts or peaks above 0 db.
  • You need a tool for measuring the average levels or RMS levels - root mean square.
  • Higher end editors have RMS Normalize - Peak Pro, Wave Editor (mac, on the PC - Soundforge, Audition
    • Punch in -17.5 db and your done
    • The application boosts levels that are too soft and quites those that are too loud
    • These apps are expensive star at $299 up to $599 (Peak Pro) - get academic discount
  • I don’t have $300 for software - what do I do? 2 free Mac prgrams - one can also work on Windows
  • RMS buddy is one free tool available as a AU plugin on OSX and a VST plugin in Windows - works in Garage Band, Soundtrack Pro
    • Using RMS Buddy
    • Gives a running measurement of RMS levels
  • AudioLeak (Mac) is standalone app that can measure RMS levels of a whole audio file in a few secondes - even of it’s a 60 minute audio
  • How to control this?
    • 1. Manually with mic technique - I turn input levels up 80% of the way, move in close (approx. 8 inches from the mic of to the left side a bit) and speak in a steady voice. If you speak loudly in some spots move your head in the other direction a bit.
    • Limiter - software or hardware. A limiter cuts the volume levels of at a set point like -1db or -0.5db. It doesn’t allow a recording to get louder than this. I use this in recording with garaqge band. Works well.
    • Compressor similar to a Limiter but more gradual. Starts limiting lelvels as they get to a certain threshold - say -12db. This alloes you to boost the average levels without getting too loud. Can be tricky in pratice.
    • Record at lower levels and boost in post using a limiter to assure you don’t get too loud (clip).
  • Even if you take these measures - you may find it’s not right in fact how do you know the levels are right or if you just have your headphone volume too loud or roo soft.
  • You want to shoot for RMS levles of about -15 to -17 db
  • How to boost
    • Otherwise measure, boost and apply limiter
      • Measure say RMS buddy give -24db

Friday, February 17, 2006 

GarageBand 3 Review

GarageBand 3 for podcasting - a lot to like and a few drawbacks

Direct link to the mp3 (18.5 mb 22:58 min)

  • App is much faster, reponsive previous versions a dog
  • Open garageband chocie for a podcast episode you see: a podcast, male voice, female voice, Jingles and radio sounds tracks
    • Podcast track for chapter markers and photos for making enhanced podcasts
      • mixed feelings
        • Positive for long tracks, podcasts and audiobooks lets you jump around easily
        • Positive - easy drag and drop photos, put in titles and links. Formerly done via the command line app.
        • Negatives -Set up AAC (Mpeg 4) compatibility won't play on iRiver, Creative Zen or even a stock pc without iTunes, quicktime or Real Player installled. Mp3 plays everywhere. I never look at the enhanced podcast pictures on my iPod Video - so in the end I'm not sure of the value on shorter tracks. Stay tuned for a tip on how to get an mp3 from your Garageband recording
    • Sound Effects and Jingles
      • Brilliant. High quality, royalty free, sound effects and music that sound fantastic. I've been using them in my last few podcasts. In fact I'm half-tempted to get one or two of the jam packs Apple sells to get more of these (but they cost more than iLife itself). This really adds something to your podcast. I find a short musical interlude really helps break up a monologue.
    • Podcast Radio Engineer
      • Another great feature set
        • Ducking. Lowers music track automatically if you start talking. Automatic ducking can be a little abrupt, but can be adjusted on the master track
        • Male and female voice tracks are tweaked with eq, compression, noise gate to really improve on the sound. These really are "templates" - a feature Apple has been putting in many of their consumer applications - you could do better if you're an expert
        • I do like the way my podcasts are sounding coming out of Garage Band
      • iChat interview recording and iMovie scoring. Great sounding features haven't tried them yet. If you'd like to plug your podcast with mme over iChat - let me know.
    • One click iWeb publishing - mixed feelings here -
      • Great if you want to fork over $99 for dot mac web hosting -which you may want to do. It has some nice features and simplifies amost all aspects of online sharing plus adds features like email, backup, etc.... I don't plan to purchase this. I find I can find plenty of places to host things for free or cheap (Flickr,, Gmail, etc..)
      • A bit of a minus if you don't want to use iWeb/dotmac. Everything set up for this by default. There are workarounds though such as export to folder.
    • Other thoughts
      • Some have reported long export times from GarageBand 3. I think is due to the need to mixdown all the tracks into one stereo or mono track and then compress the file into aac format.
      • How to make an mp3 file and avoid this problem alltogether? Delete the podcast (photo) track and then choose Share -> send to iTunes. This will mixdown an uncompressed aiff file and send it to iTunes. From there you can convert the aiff file to mp3 with itunes or another tool of your choice (LameBrain).

Friday, February 10, 2006 

Microphones and Mic Technique

Direct link to the show (18.2 mb mp3 23 minutes).
  • Welcome and welcome back - thanks for taking a few minutes of your day to listen to the Fundamental of Digital Audio
  • A few follow up points from last week's podcast
  • Another company to check out for usb and firewire audio interfaces is MAudio prices start at about $100.
  • Edirol UA1 EX is really for giving mixers a usb interface. It doesn't have some of the features the other usb/firewire interfaces have like phantom power, xlr inputs for higher quality mics. Not even sure it has a preamp

  • Microphones
  • Use this as a starting point for research not your entire research. I've only used 1 mic in the group I wil mention in the next finutes
  • Dynamic vs. Condenser
    • Dynamic
      • more durable
      • don't need phantom power
    • Condenser
      • more fragile
      • need phantom power (external power) most mixer and usb/firewire interfaces provide this - but don't take my word for it - check with your delaer or RTFM

  • Directional or Cardiod vs Omnidirectional
    • Directional or Cardiod - pics up the sound directly in front of the mic. Denser, more bassy sound
    • Omnidirectional - picks up sound from all around the mic. Multiple people. Sound is more spread out and more treble emphasis

  • Go to They have 18 mic samples with a bassy male voice, a female voice and another male voice. These include mics under $100 to $500-600 to over $2000. See if you can tell a big difference. If not, go for one of the less expensive ones. At the bottom of the samples you can view the key with the mics listed.
  • A few safe choices for the budget conscious
    • Shure SM-57, Shure SM-58 $90 and $100. Durale dynmaic mics that are tried and true
    • Studio Projects B1 $79 Condenser - heavy on bass
    • Kel HM-1 $100
    • Heil PR-30, PR-40 $289 and $325 being used by Leo Laprte, Paul Fiagiani and others
    • Wireless Sennheiser EW122-G about $500. Great quality. Defualt settings too hot check out tutorial at:

  • Mic technique
    • Check your input level. Try to get your peaks (loudest to between -6 to -3db) below 0 db for sure
    • Spend some time and find the sweet spot. Play around. The sweet spot on mine seems to be about 8incehes from the mic pointing my mouth slightly to the left
    • Avoid plosive "popping Ps"
    • Closer - more bass
    • Control peaks/louds parts in one of three ways:
      • Hardware limiter/compressor - requires external unti more complex but probably most efective. Limiter cuts off louder sound before or at 0 db to avoide clipping/distortion. Compression pushes down on louder parts and can optionally boost the average levels.
      • Software limiter/compressor - no extra equipment many software apps even audacity have some ability to limit and compress. Garage band can do this. require a lot of cpu power so you need a realtively fast machine and lots of ram
      • Low tech move farther away during lounder parts. Email exchange with singer