Not recording frequencies above 6Khz.

[Molkar]

Hi all,

I'm having a problem that I can't seem to find a solution for.

Two days ago I recorded a lecture, total length of 4 hours (breaks included).
I recorded the lecture in four parts, each part around 1 hour of length.
The audio was recorded in Audacity 1.3.12 (beta) on an Acer laptop using the
mic-in port. Track settings were set to: 16 bit, 48 Khz.

Yesterday I went through my material and noticed something quite strange.
The first clip sounds fantastic, the following three clips sounds quite tinny
and not at all as clean and rich as the first clip. Therefore I did a Plot
Spectrum analysis on each clip in Audacity. The first clip has a frequency span
from "0 Hz" to 20 Khz. The other clips only had a span from "0 Hz" to 6 Khz,
after that it's completely flat!?
Today I tried to do another recording and every time I got the same result;
tinny sound, almost nothing above 6 Khz (a spike or two around 15 Khz)...?

What might be the problem? Any help would be greatly appreciated!

Thanks, Molkar

[kozikowski]

That's a good one.

The two ends of your question don't match. Analyze Spectrum that doesn't go further up than 6KHz should sound muddy, dull, flat and restricted like an AM radio. Not tinny, harsh, and insubstantial.

You also missed an important step: "I exported a wav file for later use." -or- "I Saved an Audacity Project for later editing."

Koz

[kozikowski]

<<<The audio was recorded in Audacity 1.3.12 (beta) on an Acer laptop using the
mic-in port. >>>

Oh, wait. First clue. What was plugged into the Mic-In?

Koz

[Molkar]

Thanks for your reply,

I apologize, your description is better. It sounds muddy and dull. I just couldn't find
the right words for it.

I have four saved project files and I also exported each project as a wav file and aiff file,
just in case.

The two lecturers each had a wireless headset mic sending signals to a mixer and I got a
mono signal from the mixer. The sound guy on set plugged it in for me.

However the strange thing is that the first audio project, and both wav and aiff files sounds
great. I didn't change a single setting from the first project file to the next. And yet, the
other audio files sounds muddy and dull.?

And now when I try to reproduce that first recording with great audio I can't. This time
using a Røde videomic though.

Molkar

[Molkar]

Why can't I record frequencies over 6000 Hz with Røde Videomic?
Am I overlooking something in Audacity?

Thanks,
Molkar.

[steve]

"Edit menu > Preferences > Quality tab"
What is the default Sample rate set at?

How is the Røde Videomic connected to your computer?
I presume you are using a laptop PC?