I use the Levelator software to enhance the WAV file before editing the audio (this software is free from the Conversations Network). I pull the files off the Sansa Clip Plus using the USB cable provided and copy the files to my computer (it just looks like another drive).Ģ. Here are the post processing steps I go through to get the best possible audio from this device.ġ. Recording devices that record directly to MP3 do not easily allow for this option without further loss of audio quality. I really like this particular file format because it allows for post-processing/editing. The Sansa Clip Plus records audio in WAV format (tech details are: 24kHz, 16bit, Mono = 384kbps, good enough for speech, not really good for music). Recorded audio consumes almost 3MB per 1 minute of audio, this means an hour of recording would take up about 180MB of space on the device, so even the 2GB model has plenty of space to do hours of recordings. Record mode would be a bit less since the device is actively writing to storage, I have easily recorded up to 3 hours of audio at one time (I’m really curious to know how long it would record). The AGC function is also helpful in capturing distant questions in the room.Īll the audio is recorded to solid state storage inside the device (there are 2GB, 4GB, and 8GB models), the battery is self-contained (not removable) and can run up to 15 hours in playback mode. This device does employ a Automatic Gain Control (AGC) function, so it’s helpful if the presenter simply says something like 1 … 2 … 3 before really starting into their content. The microphone is on the clip side of the device at the top, and since there are no wires the person is free to move around while talking. This is the same microphone placement that makes professional wireless lapel microphones sound so good. By doing this I get the built in (omnidirectional) microphone very close to the audio source (person’s mouth) which greatly improves audio quality. I use the voice recording function of this MP3 player to capture presentation audio by placing (actually cliping) the device on the shirt of the person doing the presenting. I’m just the concept guy on this one.The SanDisk Sansa Clip Plus MP3 player has been very useful to me for capturing mobile audio and I’ve decided to write about it so others know about this useful little device. I would have posted this earlier, but I wanted to first run it by Bruce Sharpe, our resident math professor and designer of The Levelator’s algorithms. If you share my passion on the topic, or if you want to know more about how The Levelator deals with RMS levels, you may enjoy a page I just posted entitled The Levelator™ Loudness Algorithms. It’s a problem I’ve worked on personally for some time, and I continue to geek out on it. But I’m sure it’s not as interesting to many other people. Personally, I love the discussion of RMS levels, particularly because it’s so full of prejudices and misinformation. The level your application reports as the RMS level is *your* answer to what we’ve found to be the sweetspot for podcast RMS levels. If you are looking for an answer relative to your audio-processor of choice, the best way is to run a real-world program through The Levelator then measure the resulting RMS level using your software. So the answer to Gregg’s question is that The Levelator adjusts speech to -18.0dB RMS, but that isn’t a value you can plug into any other program. (Is one recording half as loud as another because the speaker in the first one pauses twice as long between words?) In fact some of the most-expensive utilities don’t exclude silence at all, rendering them virtually useless for this aspect of spoken-word processing. Each application has a different way of excluding segments of silence from the RMS calculation. wav file and said, “this is standard,” and then you measured the RMS level of that track in various apps such as Pro Tools, Sound Forge, Soundtrack Pro, etc., each app would give you a different value. There isn’t a single value that works for even two different audio-editor applications let alone all of them. I’m not trying to be elusive or secretive. Unfortunately, it’s a very complex answer. Two days ago Gregg McVicar asked: “So what was the RMS value that you found to be the sweet spot for podcasts?” Over on the discussion mailinglist from AIR (The Association of Independents in Radio), we’re revisiting the recurring discussion about RMS levels in spoken-word audio files.
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