THE Room Mode Calculator
This is a room mode calculator with the possibility to save screenshots
for mailing, printing, discussing and analyzing.
There is a new version of amroc. It does not include all features of this old version yet, but does not need java anymore!
Roommodes or eigenmodes are areas in the frequency range, that love to
resonate. The resistance is much lower and therefore the energy that is
feeded into the room at this frequency range will last longer. You can
perceive this physical phenomenon in every room by simply playing music
in it. If your audio-source is able to induce energy low enough in
frequency, you will be able to recognize some places in the room where
the bass is louder and maybe some where you think it does not exist.
Even if you remain on one place the bass can turn up and down in
loudness depending on which note is played.
Why could one be interested in computing this room modes?
Even though those eigenmodes exist in every room, its possible to
reduce their negative effect on the musical enjoyment. Our intent is to
achieve a mode distribution that is as equal as possible. The locations
of modes are primarily depending on the dimensions of the room, and so
it's most effective if you are in the lucky position to plan a room as
a whole. It's not right, that you can eliminate the problem of droning
bass frequencies by splaying your walls. It will reduce the effect of
the axial modes by moving this resonant frequency range but it's not
sure, that the distribution of the modes will be better with one or
some walls splayed. However, it will be much more difficult to compute
them in advance.
Amroc is a room mode calculator with the possibility to save
screenshots of the distribution of the modes for mailing, printing and
I have used this title since the first day I started to develop it. I
thought I need a name and so I called it Andy Melcher Room Mode
Calculator because of the cool sounding acronym :)
What amroc is able to do:
It can greatly visualize the approximated modes of a rectangular
room. Please have in mind, that modes will change with every (larger)
piece of furniture. I have build in different possibilities to analyse
a room's mode distribution. You can also copy the values into an
Limitations of amroc
First of all it's just possible to compute rectangular rooms.
Fortunately most of our (intact) rooms belong to this group. I also
made some limitations concerning the rooms size, but I don't think/hope
that you will reach them with an existing room you want to know the
mode distribution from ;).
I've studied music science and I am now studying computer science. I
work as an audio engineer and (thanks to amroc and my affinity to audio
and acoustics) as java-programmer in a start-up combining all that
Why did you programm such a cool tool, excel-sheets are ok too...
When I started to read websites and scientific papers about
acoustics, I noticed that room modes are the most widely appeared
trouble maker in small rooms. A lot of people try to get help in
forums, asking 'where are the modes of my room?' and 'what can I do to
make things better?' They send around measures and get back values of
tables. I thought it would be better to type in those measures and get
screenshots, tables and all that stuff directly. Download a screenshot
and post it in a forum. Discuss your possibilities...that's what amroc
Development: It was in summer 2004. I decided to learn a programming
language, but didn't know which one. I wanted (want) to learn 3
things at all costs: programming microcontrollers (for building cool
tools like HUIs for mixing music (Assembler, C++), simply programming
in C++ (for example VST audio plugins) or simply programming in Java.
I decided to omit the hardware stuff for a start and thought about
cool projects that could keep my enthusiasm alive. I'm always a
friend of aiming high and so I had the idea to build a FEM (finite
element method)in C++ or make a cool graphical user interface (GUI)
for room mode calculations as my 'hello world'. I decided to go for
java and if I wasn't a java-programmer now, I think I would have a
HUI and a FEM too :D.
At that time it was an application (not an applet) but I thought
there could be more people out there who could want to have the
possibility to make those easy screenshots. So I made an applet
(small applications especially for browsers), translated it into
English and wrote some text for a page...and now I stop, because I
have to download the VST-Api and/or buy a microcontroller :)