Microcassette Recorder User Manual

Audacity
©2008 Audacity Audio
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pick the audio type that satisfies your taste. There are many more including the basic hardware and
software. Palm provides the hardware. They generally do a good job, but there are major differences. In
the paragraphs that follow, I will go into greater detail regarding differences in the Treo 650, 680, 700P,
and the 755P. Audacity is excellent and flexible software. You're in good hands.
Other things that affect audio quality are the speaker's voice. For instance, I tend to emphasize sibilants
(sounds like s's and z's). That hurts the audio quality on a Treo 650. The Treo 700P filters out the high
frequency sounds so it isn't so noticeable and the 680 does an even better job. It causes problems for
me on the Treo 650 at PCM 8, but PCM 16 and some of the compressed formats sound quite good.
The author can control many items like how close to his mouth the mic is and also mic and speaker
volumes. We try to set the Audacity default values to accommodate most people without any changes,
but that is really hard to do. Hardware is very different, and people are very different. Don't be afraid to
experiment with different settings. You will probably find a setting mix you like.
Here is a good example of the challenges we face. I like to use a headset called the Boom O by
UmeVoice. It is a high quality headset designed for a high noise environment and it also works well with
speech recognition applications. We set the mic gain on a Treo 650 very high because the Treo 650 has
an internal mic volume problem. If I use my UmeVoice, I completely overdrive the circuit. Not only is the
audio too loud, but it also has lots of static and crackles. It just sounds bad. I am overdriving the circuit.
If I set the mic gain very low, it sounds absolutely great.
The bottom line is: If you experience a problem, most of the time, it can be fixed with an adjustment. It
may be something as simple as holding the hardware closer of further away from your mouth or setting
the mic gain higher or lower or perhaps using a different audio type. I will explain some of the
differences in the popular Treo models.
Treo 650--The Treo 650 has a couple of hardware deficiencies that you must adjust to. The first is the
internal mic doesn't have enough amplification for normal useage. We set our default mic gain to 7
which works pretty well if you hold the hardware about 4 inches from the mouth. I personally like to set it
down to 5 and then hold the hardware about 1 or 2 inches from the mouth. It is difficult to overdrive the
internal mic circuit. The same can't be said when using the headset jack. My UmeVoice has a long
boom mic that can reach my mouth. It is a high quality mic with excellent noise cancellation. I set the
mic gain all the way down to 1 and then make sure the mic is at least 2 fingers away from the corner of
my mouth. Be careful not to overdrive the mic circuit when using a mic like that.
The second problem with the Treo 650 is it doesn't filter out high frequency sounds with a low grade
audio type like PCM 8 or our compressed 6. Conversely, it works very well with the higher quality audio
types, like PCM 16 or our compressed 12 and 24.
Treo 700P--The audio circuit is superior to that of the Treo 650. Our default mic setting is 2. There is no
problem with volume on the Treo 700P. If anything, it is too sensitive. I recommend holding the Treo
700P four inches from your mouth, but it is easy to overdrive the mic circuit. If you experience crackles
and static, hold the mic further from your mouth. You could also lower the mic gain to 1. With my
UmeVoice headset, I use a mic gain setting of 1.
The 700P picks up high frequency sounds much better that the Treo 650. PCM 8 is almost as good as
PCM 16. Even our compressed 6 setting sounds good. A compressed 6 one minute file is less than 50k
compared to almost 1 MB for PCM 8 and 2 MB for PCM 16.
Treo 680--The 680 audio circuit is very sensitive. I overdrive the mic circuit unless I hold the 680 12 to
14 inches away from my mouth. The default mic gain setting is 2, but it could be lowered to 1. It is a little
too sensitive in my opinion.
One of the things I notice about the 680 is how good the audio sounds at the lower quality settings.
PCM 8 is very good. It is the first device that has very good audio at compressed 6. I just recorded a
one minute file (49K, amazingly small) and it is perfectly clear. I is certainly not speech recognition
quality, but very clear.
I pointed our some major differences in three consecutive Palm models. Both, different hardware and
people, have very different needs. Don't be afraid to experiment with different settings.