15 posts categorized "Audio"

Marantz video demonstrating their new PMD620 portable recorder

As listeners to FIR may know (or longtime readers of this blog), I'm a big fan of the Marantz PMD660 and have been using it now for recording interviews in the field for most of 2 years, if not longer. It's a great unit and I've been very happy with it.

However, it's rather on the large side (looks like an old tape recorder!) and I've always been looking at the smaller units like the Edirol R9, Zoom H4, m-Audio MicroTrack, etc. Out at the New Media Expo last fall, I saw the preview of Marantz's new PMD620 and was quite intrigued. Not enough yet to buy one, but after my last trip where the PMD660 took up so much room in my travel bag, I am starting to think about it again.

Anyway, the folks at Marantz have now put up a YouTube video talking about the product:

FYI, I found it on their Education Blog after receiving an email from them announcing the video being on their blog. The comments are amusing because predictably someone was asking if the video was an example of the audio quality (or lack thereof) of the PMD620 (it wasn't).

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Trying to kill a buzz in a podcast with Audacity

Frustrating night tonight... I was doing the post-production on a Blue Box Special Edition podcast of the 90-minute workshop that I did along with podcast co-host Jonathan Zar and security researcher Shawn Merdinger out at O'Reilly's Emerging Telephony conference last month.  Unfortunately, even though I'd jacked into the mixer provided at ETel (or perhaps because I was connected into the mixer), I wound up with an annoying buzz throughout the recording.   I can only guess that it was something with one of the audio components in the setup for the room out there at ETel.  I've seen a buzz be created by something as simple as a bad wire or a connector not fully inserted into a jack.  In any event, I wound up with a buzz.

Since I had solved (and blogged about) a similar issue before using Audacity, I spent literally a couple of hours trying to kill off the buzz.  I used hi-pass filters.... notch filters... equalizer effects... all sorts of things.  Searched the web, the Audacity wiki and more.  Unfortunately, this particular buzz seemed to be located right down on the end of the frequency spectrum where our voices are also located!  So when I used a high-pass filter to allow through only frequencies over, say, 300 Hertz, you could hear the effect on our voices.  If I moved the high-pass filter down to say 100 Hz, there was no impact on our voices, but the buzz was still at full strength.  Move it up to 500 or 600 Hz and the buzz was reduced... but so was the quality of our voices.

Wanting to get this episode posted today, I finally gave up and ran it as it was recorded, which was not overly appealing to me.  I always strive to have the highest audio quality possible, which is why I spend the time I do on post-production.  But in the end, there was just no way I could figure it out.  Perhaps with better tools... or more time... perhaps not.  Fun, fun, fun...


Any suggestions for a travel-size audio mixer? (That can also do a mix-minus?)

Last week as I packed for the trip to our corporate office in Ottawa, I naturally grabbed my bag of audio gear in case I was inclined to do any recording while I was up there.  Unfortunately, the one piece of gear I am still missing is a small audio mixer that I can carry with me.  What I want to do is fairly simple.  It's one of the following:

  1. Connect two condenser mics (or lapel mics) to a mixer and have the audio output go into a recording device (either my PC or my Marantz PMD-660).
  2. Connect one mic to the mixer and a laptop (running a softphone) to the mixer with the output going to a recording device - and with a mix-minus bringing the microphone audio back to the laptop PC.  (so that the person on the softphone can hear me through my microphone)

It's #2 that is a killer so far.  The usual route to do this is to have a mixer with an AUX or FX port.  You take the headphone output of your laptop and connect it to one of the channels.  You then connect the AUX (or FX) port back to the microphone jack on your laptop.  On the channel coming from the laptop you turn the AUX send (or FX send) to 0 so that the person on the laptop softphone doesn't hear themself (and get any kind of echo or other feedback loops).  It works great and this is how I record pretty much all my podcasts (both Blue Box and others).

But I can't seem to find this in a small mixer.  I can get my #1 fairly easily- the picture here is of the Tapco Mix 50 and, let me tell you, it's wonderfully small!  About 5 x 7 inches.  Perfect to stick in a travel bag... but it doesn't do a mix-minus.  For that you have to go to a Mix 60, which is just a bit bigger.  The Behringer UB502 is similar in size... but it, too, doesn't do a mix-minus.  I've looked at some of the USB or Firewire audio interfaces... but I want the simplicity of an analog mixer - and when I'm doing a mix-minus I'm very often recording to my Marantz PMD-660 so an audio interface doesn't help much there.

Anyone have a suggestion for a nice small mixer that also has an AUX or FX port?


The Levelator saves the day...

There's a very twisted irony in the fact that I don't use the Levelator very often at all... but after I wrote the post early this morning about the Levelator, it would wind up being a key tool for me to use this day.  I had an interview scheduled in the early afternoon for an prototype of an internal podcast we're working on.  Just minutes before I was to do the interview, I determined that something was wacky on my laptop and my normal route of using a softphone on the laptop with a mix-minus from my condenser mic was not going to work.   Not having the time to diagnose the problem and not wanting to lose the interview window, I went to Plan B (well, it should be Plan Z, as in "just don't do it", but it was B) and grabbed my JK Audio QuickTap from the closet, inserted it inline between the handset and one of my teleworker phones, and ran a cable over to an input on my mixer. As I did this, I was dearly hoping the Levelator could help out... or I was going to be re-recording another day.

You see, the problem with the QuickTap is this - you get both sides of the conversation on a single track, and I'm right there talking into the handset microphone, and the other person is on the other end of a phone connection.  The result is almost always: I'm loud and the other person is soft.  Maybe others have different results, but that's almost always how it is for me.

However, the Levelator did save the day.  Dumped the recording to a WAV file, dropped it on the Levelator and opened up the levelated file.  Ta da... the levels were at least much nearer to each other.  Not the quality that I'd get out of my regular audio rig (because of the handset microphones and QuickTap), but certainly acceptable and a decent way to recover.

Just very ironic given my post this morning...


The Levelator gets coverage in Make magazine... All Hail The Levelator!

Nice to see The Levelator getting coverage in the Make magazine website.  Knowing of my interest in podcasting audio quality, a Blue Box listener sent me the note about this posting in Make, which was great to see.  I've actually been a huge fan of the The Levelator ever since Doug Kaye, Michael Geoghegan and Paul Figgiani released it through their Gigavox company.  It's done wonders with some interviews I have recorded. 

If you aren't aware of it, the Levelator is basically a tool to do most all of the audio post-production you need to do on a podcast or other audio file.  The Gigavox team wrote it for their own usage so that they could level out the different audio levels in podcasts they were producing.  They were then kind enough to release it to the broader community - and we have all benefited from that.

For me, where the tool is most useful is with field-recorded interviews or podcasts that are recorded via a conference call.  When I'm doing my own podcasts, my audio setup is such that I can control the audio levels of myself and a partner.  But field interviews often have varying levels of audio, sometimes purely by mic placement.  And conference calls?  Either on a traditional audio bridge or by using a tool like Skype?  Audio levels can be way off between the speakers.  And from a production point-of-view on my end, all of those people are one track coming into my recording rig (with my microphone being the other).  So, yes, I could do all the audio post-production to make it sound great.... or I could simply export it to a WAV file, drag and drop it on the Levelator window... and listen to the generally outstanding result.

If you are doing podcasts, or any other kind of audio production, the Levelator is definitely worth checking out.