From: Joerg Hansmann (info_at_jhansmann.de)
Date: 2002-01-02 18:27:12
Dear Jim,
----- Original Message -----
From: Jim Meissner <jpmeissner_at_mindspring.com>
To: <buildcheapeeg_at_yahoogroups.com>
Sent: Wednesday, January 02, 2002 4:07 AM
Subject: Re: [buildcheapeeg] Re: Meditation - UP mode
...
> > At 96kHz sample rate you get 10.4us resolution.
>
> Does that mean that at 44100 it would be 20.8 us?
Yes.
> That might be a bit jerky
> but maybe OK, I would have to hear it.
Hopefully I will have a SDL console application (with command line interpreter)
running the next days. Then it should be possible to play around with all
parameters without recompiling.
> > I have experimented with delays up to 1000us and could definitely
> > not tell the difference between 1000us and 500us. (So maybe I have
> > problems with my ears ;-) )
>
> I would not have believed that a biological system could respond to even
> millisecond delays. I was shocked when I discovered this. Try it again with
> two identical 3 msec. pulses. Shift
> the phase by 100 us and you will be surprised how sensitive the ear/brain
> system is to establishing the apparent direction.
Seemingly not my...
Without attenuating the delayed channel by at least 6dB,
delay alone only gives me a very vague direction impression.
> This sense has kept man alive for thousands of years. A large part of the
> brain is devoted to keeping track of his sonic environment.
Perhaps thousands of years ago I would have had no chance to survive ;-)
> > If you have a skeleton of the code that works I would be willing
> > to try to fine tune it.
> > The source is in the separate email too.
> > Alternatively you could tell me what could be improved and
> > I implement it.
>
> I was able to get your program to run. Nice job.
> Even though the frequencies went from 10 to 20 hz,
Should it have been another range for UP-Mode PROG 01 ?
> I found it
> very annoying to listen to.
I am confused: Is this good or bad ?
> Much of the programming of the sound sequence is art.
> I spent months fine tuning the
> frequencies. My joke is that Jimmy Hendrix and Andre Segovia
> both played the guitar, but what a difference.
Thanks, I needed that ;-)
Now I only have to guess, who I am...
> I looked at your code and will need a few hours to study it.
> If I am able to remember how to program in C, I would
> prefer to modify the code on my computer and do the fine
> tuning here.
Feel free to do that. However the code is under
construction and changes rapidly.
> Would you be willing to set me up with the
> programs needed to compile the C code and run it here?
I have used the MSVC6.0 compiler and can give you the
project files (*.dsw, *.dsp).
Everything else (SDL 1.2.3) can be downloaded at http://www.libsdl.org
If you do not have MSVC and want a freeware compiler instead, it should be
possible to use the GNU mingw32 compiler. However I do not have any
experience with mingw32.
> I have a Compaq Presario 1250,
CPU ? Mhz ? RAM ?
Soundcard ?
> with Win98.
Should be OK.
> Years ago I hired a programmer to write the core program and then
> I was able to push variables around until it
> sounded "right". There are about 12 variables that control all
> the programs in my Brain State Synchronizer. These
> are called up from the EPROM and loaded into the program and
> run.
The version currently under construction has 17 parameters:
/*
SweepDuration_sec;
PulseLength_sec;
// frequency sweep:
// ----------------
StartFreq_Hz;
StartFreqRnd_Hz; // +- random frequency modulation per pulse
EndFreq_Hz;
EndFreqRnd_Hz; // +- random frequency modulation per pulse
// stereo position sweep:
// ----------------------
StartPosition; // -1.0 max left, 0 middle, +1.0 max right
StartPositionRnd; // +- random per pulse
EndPosition; // -1.0 max left, 0 middle, +1.0 max right
EndPositionRnd; // +- random per pulse
MaxAttenuation_dB;
MaxDelay_sec;
// volume sweep:
// -------------
StartVolume_dB;
StartVolumeRnd_dB; // +- random amplitude modulation per pulse
EndVolume_dB;
EndVolumeRnd_dB; // +- random amplitude modulation per pulse
// misc:
// -----
next_to_do; // 0: repeat forever, -1: stop, n>0: load parameter set n
*/
So I guess, that I change things, that were fixed in your SW ?
> On the PC these could be in a BAT file that
> the program looks at and executes. During development it would
> be nice to have an on screen edit of the variables,
> and then to save that to a file for future use.
I am just working on that (using SDL_console package)
> What do you think?
Yes. Why not. It could be done that way.
Regards,
Joerg
This archive was generated by hypermail 2.1.4 : 2002-07-27 12:28:36 BST