- <div class="title"><a href="http://people.skolelinux.org/pere/blog/First_rough_draft_Norwegian_and_Spanish_edition_of_the_book_Made_with_Creative_Commons.html">First rough draft Norwegian and Spanish edition of the book Made with Creative Commons</a></div>
- <div class="date">13th March 2018</div>
- <div class="body"><p>I am working on publishing yet another book related to Creative
-Commons. This time it is a book filled with interviews and histories
-from those around the globe making a living using Creative
-Commons.</p>
-
-<p>Yesterday, after many months of hard work by several volunteer
-translators, the first draft of a Norwegian Bokmål edition of the book
-<a href="https://madewith.cc">Made with Creative Commons from 2017</a>
-was complete. The Spanish translation is also complete, while the
-Dutch, Polish, German and Ukraine edition need a lot of work. Get in
-touch if you want to help make those happen, or would like to
-translate into your mother tongue.</p>
-
-<p>The whole book project started when
-<a href="http://gwolf.org/node/4102">Gunnar Wolf announced</a> that he
-was going to make a Spanish edition of the book. I noticed, and
-offered some input on how to make a book, based on my experience with
-translating the
-<a href="https://www.lulu.com/shop/lawrence-lessig/fri-kultur/paperback/product-22441576.html">Free
-Culture</a> and
-<a href="https://debian-handbook.info/get/#norwegian">The Debian
-Administrator's Handbook</a> books to Norwegian Bokmål. To make a
-long story short, we ended up working on a Bokmål edition, and now the
-first rough translation is complete, thanks to the hard work of
-Ole-Erik Yrvin, Ingrid Yrvin, Allan Nordhøy and myself. The first
-proof reading is almost done, and only the second and third proof
-reading remains. We will also need to translate the 14 figures and
-create a book cover. Once it is done we will publish the book on
-paper, as well as in PDF, ePub and possibly Mobi formats.</p>
-
-<p>The book itself originates as a manuscript on Google Docs, is
-downloaded as ODT from there and converted to Markdown using pandoc.
-The Markdown is modified by a script before is converted to DocBook
-using pandoc. The DocBook is modified again using a script before it
-is used to create a Gettext POT file for translators. The translated
-PO file is then combined with the earlier mentioned DocBook file to
-create a translated DocBook file, which finally is given to dblatex to
-create the final PDF. The end result is a set of editions of the
-manuscript, one English and one for each of the translations.</p>
-
-<p>The translation is conducted using
-<a href="https://hosted.weblate.org/projects/madewithcc/translation/">the
-Weblate web based translation system</a>. Please have a look there
-and get in touch if you would like to help out with proof
-reading. :)</p>
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/Measuring_the_speaker_frequency_response_using_the_AUDMES_free_software_GUI___nice_free_software.html">Measuring the speaker frequency response using the AUDMES free software GUI - nice free software</a></div>
+ <div class="date">22nd October 2018</div>
+ <div class="body"><p><img src="http://people.skolelinux.org/pere/blog/images/2018-10-22-audmes-measure-speakers.png" align="right" width="40%"/></p>
+
+<p>My current home stereo is a patchwork of various pieces I got on
+flee markeds over the years. It is amazing what kind of equipment
+show up there. I've been wondering for a while if it was possible to
+measure how well this equipment is working together, and decided to
+see how far I could get using free software. After trawling the web I
+came across an article from DIY Audio and Video on
+<a href="https://www.diyaudioandvideo.com/Tutorial/SpeakerResponseTesting/">Speaker
+Testing and Analysis</a> describing how to test speakers, and it listing
+several software options, among them
+<a href="https://sourceforge.net/projects/audmes/">AUDio MEasurement
+System (AUDMES)</a>. It is the only free software system I could find
+focusing on measuring speakers and audio frequency response. In the
+process I also found an interesting article from NOVO on
+<a href="http://novo.press/understanding-speaker-specifications-and-frequency-response/">Understanding
+Speaker Specifications and Frequency Response</a> and an article from
+ecoustics on
+<a href="https://www.ecoustics.com/articles/understanding-speaker-frequency-response/">Understanding
+Speaker Frequency Response</a>, with a lot of information on what to
+look for and how to interpret the graphs. Armed with this knowledge,
+I set out to measure the state of my speakers.</p>
+
+<p>The first hurdle was that AUDMES hadn't seen a commit for 10 years
+and did not build with current compilers and libraries. I got in
+touch with its author, who no longer was spending time on the program
+but gave me write access to the subversion repository on Sourceforge.
+The end result is that now the code build on Linux and is capable of
+saving and loading the collected frequency response data in CSV
+format. The application is quite nice and flexible, and I was able to
+select the input and output audio interfaces independently. This made
+it possible to use a USB mixer as the input source, while sending
+output via my laptop headphone connection. I lacked the hardware and
+cabling to figure out a different way to get independent cabling to
+speakers and microphone.</p>
+
+<p>Using this setup I could see how a large range of high frequencies
+apparently were not making it out of my speakers. The picture show
+the frequency response measurement of one of the speakers. Note the
+frequency lines seem to be slightly misaligned, compared to the CSV
+output from the program. I can not hear several of these are high
+frequencies, according to measurement from
+<a href="http://freehearingtestsoftware.com">Free Hearing Test
+Software</a>, an freeware system to measure your hearing (still
+looking for a free software alternative), so I do not know if they are
+coming out out the speakers. I thus do not quite know how to figure
+out if the missing frequencies is a problem with the microphone, the
+amplifier or the speakers, but I managed to rule out the audio card in my
+PC by measuring my Bose noise canceling headset using its own
+microphone. This setup was able to see the high frequency tones, so
+the problem with my stereo had to be in the amplifier or speakers.</p>
+
+<p>Anyway, to try to role out one factor I ended up picking up a new
+set of speakers at a flee marked, and these work a lot better than the
+old speakers, so I guess the microphone and amplifier is OK. If you
+need to measure your own speakers, check out AUDMES. If more people
+get involved, perhaps the project could become good enough to
+<a href="https://bugs.debian.org/910876">include in Debian</a>? And if
+you know of some other free software to measure speakers and amplifier
+performance, please let me know. I am aware of the freeware option
+<a href="https://www.roomeqwizard.com/">REW</a>, but I want something
+that can be developed also when the vendor looses interest.</p>
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