Home of cfuttrup

This is not a BLOG, where short pieces of information are published on a regular basis. Rather, it's a place for me to dump things onto the internet that didn't fit in other places. Call it "private digital landfill" if you like. It's organized with old stuff at the bottom and more recent stuff near the top.

A couple of months back, Jeff Candy and I launched a new web site, named Speakerbench (external link). This is a web application for assisting in speaker design, in particular measuring advanced parameters by using the dual-added-mass approach. More will come.

This DIY project describes how I've built a high-end replacement for my Squeezebox Touch streamer using a Raspberry Pi and a suitable DAC HAT-module.

Suitable as background image / wallpaper for your PC.

I looked several times for one of those time zone maps for my PC, like what came with the old IBM Thinkpads, but I only found bad ones (maybe upscaled from lower resolution images), and almost none that fitted to my 1920 x 1080 resolution. This summer I gave up and started to make my own. Here's the result, I hope you enjoy it and if not, that's just too bad: Think_Global_FHD.png - Made by Claus Futtrup © Copyright 2018. Here's some map facts.

At the ALMA International Symposium and Expo 2017 (AISE2017) Jeff Candy and I presented a paper titled "Physical Accuracy and Modeling Robustness of Motional Impedance Models."

The paper / presentation is available for download here: ALMA-2017.pdf. Enjoy!

It was either late 2011 or very early 2012. A German publisher approached me and asked if I would write a chapter for a book. Today, more than 4 years later, I've annually gone through the chapter and updated it, but the book will not materialize. So instead I received permission to publish the chapter here.

The concept behind the book itself was inspired by a garden book, if I remember correctly, where several authors wrote chapters. They may be controversial. Preferably something that catches a debate. Each author was free to choose whatever subject they wanted to write about.

The chapter is 24 pages of text: Book_05_Futtrup.pdf. Enjoy!

This chapter is somewhat like a "layman's" version of the AES paper I wrote in 2011, targeting a nontechnical audience, (almost) without the math. It adds historical background and some idea about how to ensure a nice impulse response by using Group Delay. I hope it's good for learning to understand what goes on in a loudspeaker. If you're engineering loudspeakers, using T/S parameters, I think you'll find this chapter interesting. I'd like to move forward with additional advancements in simulation, but I believe the presented FDD model is very good for explaining limitations within the classical Thiele/Small modelling.

This text on how to setup your hardware as well as your music library and using software to tag the files is from 2009 and may appear a bit old by now. Nonetheless, it is one of the most popular pages on my website so it must still be useful to a lot of people in the world.

Streaming Audio:

I have experimented with streaming audio, and eventually purchased a Logitech Squeezebox Duet. Here you can read about my experiments with streaming audio. Later, my setup has been changed for a Logitech Squeezebox Touch.

I was active in the Linux community from somewhere around 2005 and until 2008. Since the support for Microsoft Windows 7 has dropped (for example, I can't get an updated PowerShell) and only security updates are still rolling in, I just might bring my old laptop computer back to life with Linux again.

Linux:

I've been an active Linux user for a while, predominantly involved in the Zenwalk Linux project. For example, I wrote a welcome message for Windows users. With more than 100000 views it is safe to say that this text was very popular and maybe still is. It was posted on several other sites and translated into other languages. Unfortunately, as of October 2013 the Zenwalk Linux homepages are defunct and may not return.

I have recovered the page from archive.org. The page layout has been reworked to fit this web site. You can see the reworked page here: Welcome Windows Users (reworked).

This tutorial has existed on my web pages forever, yet it is so old it doesn't seem appropriate to put it on my front page anymore. Much of the material is from 1995. I'm proud to say people around the world have used the code inside. For example, one script was adopted by LaTeX (F_NAME.BAT - and it is still available on CTAN).

Batch programming tutorial:

At some point I decided to write a tutorial in batch programming (for DOS), and it became quite advanced. It is suitable for anybody who wants to write a little batch-file, or a large one. The tutorial contains examples that tend to look like magic in the control of the batch language, but even a newbie should be able to read it because it starts out really easy (no steep learning curve). Check out batching.zip. (P.S. Note that it is made for DOS 5.0 up to 6.2, not 100% compatible with all cmd terminals in MS Windows)