Audacity Forum

The problem can be clearly seen in the spectrum
Nearly all if the sound energy is below 800 Hz and there is very little sound above about 1000 Hz. It is the frequencies between about 1000 and 7000 Hz that makes voices bright and clear but they are almost completely missing. The recording is so bad that only a limited amount of improvement can be made by using extreme Equalization changes.

The attached XML file can be imported into the Equalization effect (as described here: http://manual.audacityteam.org/o/man/eq ... tml#manage) to provide a curve similar to that described by Trebor. The new curve is called "de-muffle".

Trebor wrote:

ngr wrote:... his voice is VERY bass'ed, or what ever you call it, and I cannot find out how to use the plugin to correct that............ Attachments test.wav (529.5 KiB)

That is an extreme case , the plugin may not be able to cope with such extreme cases.

Try this equalization ...

suggested equalization.gif

test, before-after suggested equalization.mp3

Thanks a lot. Now it's possible to hear what he's saying. Pitty that there is a scratch or what is is, every time he starts talking, but I guess I cannot have it all
It is an interview from 1990, and Holger, the old man, was 87 at the time, telling about his childhood in Aarhus about 1900, so I was very eager to have it work. But it's strange that this was part 2 of the interview, and part 1 was much better, I wonder why.

ngr wrote:... it's strange that this was part 2 of the interview, and part 1 was much better, I wonder why.

Possibly tape-head misalignment ...

If the azimuth is even marginally off, the head will be unable to read the magnetic pattern properly, leading to a loss of higher frequencies upon playback.

http://www.avpreserve.com/uncategorized ... ecordings/

or some error when digitising the tape.