<h3>Entries from October 2018.</h3>
+ <div class="entry">
+ <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>
+
+<p>As usual, if you use Bitcoin and want to show your support of my
+activities, please send Bitcoin donations to my address
+<b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
+
+ </div>
+ <div class="tags">
+
+
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software</a>.
+
+
+ </div>
+ </div>
+ <div class="padding"></div>
+
<div class="entry">
<div class="title">
<a href="http://people.skolelinux.org/pere/blog/Web_browser_integration_of_VLC_with_Bittorrent_support.html">Web browser integration of VLC with Bittorrent support</a>
are used for. By adding x-scheme-handler/magnet to the MimeType entry
in the desktop file, at least the browsers Firefox and Chromium will
suggest to start VLC when selecting a magnet URI on a web page. The
-end result is that now, with the plugin installed in Buster og Sid,
+end result is that now, with the plugin installed in Buster and Sid,
one can visit any
<a href="https://archive.org/details/CopyingIsNotTheft1080p">Internet
Archive page with movies</a> using a web browser and click on the
<div class="tags">
- Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug</a>, <a href="http://people.skolelinux.org/pere/blog/tags/offentlig innsyn">offentlig innsyn</a>, <a href="http://people.skolelinux.org/pere/blog/tags/standard">standard</a>.
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/n
oark5">noark5</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug</a>, <a href="http://people.skolelinux.org/pere/blog/tags/offentlig innsyn">offentlig innsyn</a>, <a href="http://people.skolelinux.org/pere/blog/tags/standard">standard</a>.
</div>
<div class="tags">
- Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet</a>.
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/noark5">noark5</a>, <a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet</a>.
</div>
<h2>Archive</h2>
<ul>
+<li>2020
+<ul>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2020/02/">February (2)</a></li>
+
+</ul></li>
+
+<li>2019
+<ul>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2019/01/">January (4)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2019/02/">February (3)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2019/03/">March (3)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2019/05/">May (2)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2019/06/">June (5)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2019/07/">July (2)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2019/08/">August (1)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2019/09/">September (1)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2019/11/">November (1)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2019/12/">December (4)</a></li>
+
+</ul></li>
+
<li>2018
<ul>
<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/09/">September (3)</a></li>
-<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/10/">October (4)</a></li>
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/10/">October (5)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/11/">November (2)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/12/">December (4)</a></li>
</ul></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/bankid">bankid (4)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/bitcoin">bitcoin (10)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/betalkontant">betalkontant (8)</a></li>
+
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/bitcoin">bitcoin (11)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/bootsystem">bootsystem (17)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/chrpath">chrpath (2)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/debian">debian (163)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/debian">debian (168)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu (158)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/debian-handbook">debian-handbook (4)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/digistan">digistan (10)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/digistan">digistan (11)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/dld">dld (17)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/docbook">docbook (25)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/docbook">docbook (26)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/drivstoffpriser">drivstoffpriser (4)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/english">english (389)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/english">english (412)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/fiksgatami">fiksgatami (23)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/fildeling">fildeling (13)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/fildeling">fildeling (14)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/freeculture">freeculture (32)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/freeculture">freeculture (34)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/freedombox">freedombox (9)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/frikanalen">frikanalen (18)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/frikanalen">frikanalen (20)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/h264">h264 (20)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/isenkram">isenkram (16)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/kart">kart (20)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/kart">kart (22)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/kodi">kodi (3)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/kodi">kodi (4)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/ldap">ldap (9)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/mesh network">mesh network (8)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/multimedia">multimedia (41)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/multimedia">multimedia (42)</a></li>
+
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software (12)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software (10)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/noark5">noark5 (21)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/norsk">norsk (299)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/norsk">norsk (311)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug (191)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug (196)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/offentlig innsyn">offentlig innsyn (34)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/offentlig innsyn">offentlig innsyn (37)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/open311">open311 (2)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett (72)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett (75)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern (107)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern (111)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/raid">raid (2)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/rfid">rfid (3)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/robot">robot (10)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/robot">robot (12)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/rss">rss (1)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/ruter">ruter (6)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/ruter">ruter (7)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/scraperwiki">scraperwiki (2)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet (55)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet (56)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/sitesummary">sitesummary (4)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/skepsis">skepsis (5)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/standard">standard (56)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/standard">standard (69)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/stavekontroll">stavekontroll (6)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/stortinget">stortinget (12)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/surveillance">surveillance (55)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/surveillance">surveillance (57)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/sysadmin">sysadmin (4)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/valg">valg (9)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/verkidetfri">verkidetfri (13)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/verkidetfri">verkidetfri (17)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/video">video (69)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/video">video (73)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/vitenskap">vitenskap (4)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/web">web (41)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/web">web (42)</a></li>
</ul>
projects / homepage.git / blobdiff