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Frequences from 110 to 190hz with 10hz pass

PostPosted: Thu Mar 06, 2008 8:15 pm
by Telstar
Hi to everyone,

I found this forum googling for a test cd. I have some nasty resonances in my listening room, which are "AROUND" 100hz.

I downloaded the sample files that may be useful but i was wondering if somebody has more waves with higher frequencies with low pass.
Ideally also up to 300hz.

Cheers
T.

PostPosted: Fri Mar 07, 2008 3:25 pm
by Glenn
Audacity has a tone generator. Also impluse generator. Only way to deal with standing waves is careful placement of the speakers and chairs. Speakers designed to work in corners or against walls are the most predictable. Lots of damping on the walls and corners helps to keep things under control.

PostPosted: Fri Mar 07, 2008 4:08 pm
by Telstar
Glenn wrote:Audacity has a tone generator. Also impluse generator. Only way to deal with standing waves is careful placement of the speakers and chairs. Speakers designed to work in corners or against walls are the most predictable. Lots of damping on the walls and corners helps to keep things under control.


I'm going to build an helmholtz resonator. I did an empirical test last night and the range seems to be between 70 and 90hz.

I need to check the "smaller" frequencies out of this range.

PostPosted: Fri Mar 07, 2008 6:13 pm
by Glenn
My fav is the 1/4 wavelength transmission line. I you want to make sure room resonances are the least of your probs check this out:

http://www.passdiy.com/projects/el-pipe-o-1.htm

Seriously, if you want a better wave generator download diamond cut dc 7. I think the demo is full with time limit. Plenty enough to burn a cd. Pink noise can be made by band-pass filtering the white noise.

PostPosted: Sat Mar 08, 2008 5:03 pm
by Ray Bell
If you want a simple and free tone generator check out SigJenny

http://www.natch.co.uk/downloads/SigJenny/SigJenny.html

It will do simple tones, sweeps (between any two frequencies at any rate), tonebursts or white noise; and you can save a WAV file for writing to your own test CD if you don't have a pc connected up to your audio system.

If you do you can even hook up a microphone and measure the overall system response including room resonances.

Ray

PostPosted: Sat Mar 08, 2008 7:21 pm
by citguy
Hi Ray. I thought the "Natch sig generator" looked good so I downloaded it. Warning: It uses many "shared files", did not work properly on my pc and would not uninstall even using a third party uninstaller. May work fine on other computers but it was a failure on mine.
Stan

PostPosted: Sun Mar 09, 2008 11:10 am
by Ray Bell
Hi Stan

Sorry about that, I downloaded it a while ago and it worked fine on my son's laptop as far as I remember. I don't think I tried to uninstall it though.

Ray

PostPosted: Sun Mar 09, 2008 1:32 pm
by Telstar
let's see if works under vista.
I dont care about uninstalling it. i have a computer where i do test audio stuff.

well it does not work: it cannot find a wave device.

PostPosted: Sun Mar 09, 2008 1:33 pm
by Telstar
btw i'm concentrating in having all frequencies between 51 and 99hz, with 1hz pass to define exactly the spectrum of the resonances to be countered.

PostPosted: Mon Mar 10, 2008 2:21 am
by Glenn
Hi fellas;

I checked out sigjenny too. Was it just me or was the default wave-out set to 0dbVU? Scary stuff, either way. Here http://marchandelec.com/programs.html is a simple function generator that doesn't use an installer. I've had the old version a while and wondered if the program was still around. Surprisingly it still is, and it's been updated with white and pink noise. There's also a real time spectrum analyzer that looks promising, but I haven't tried it. Don't know if they work with xp, vista, etc.

Cheers,
Glenn

PostPosted: Mon Mar 10, 2008 7:33 pm
by citguy
Thanks Glenn.
http://marchandelec.com/programs.html
is a great little frequency generator. I especially like that it doesn't install but just runs. I did manage to get the 'left overs' from sigjenny removed after a reboot. I suspect it has more bells and whistles but if it doesn't run on my computer it doesn't matter.
Stan

PostPosted: Mon Mar 10, 2008 8:12 pm
by Telstar
citguy wrote:Thanks Glenn.
http://marchandelec.com/programs.html
is a great little frequency generator. I especially like that it doesn't install but just runs. I did manage to get the 'left overs' from sigjenny removed after a reboot. I suspect it has more bells and whistles but if it doesn't run on my computer it doesn't matter.
Stan


It works but needs a computer to be put in the listening room possibly connected to the audio chain, which is not the simplest thing.

I wanted a software that would allow me to save the file to be burned later as audio cd.

keeping looking

PostPosted: Tue Mar 11, 2008 2:40 pm
by Glenn
Yes, it's a simple tone generator - a little too simple. I notice the pink noise center frequency is not adjustable - so what's the point? For the price though, can't complain.
I wanted a software that would allow me to save the file to be burned later as audio cd.

The sound card could be rigged up to record the output. Easier would be the programs I already suggested. Better still would be a hardware function generator with a frequency counter and scope. Can't design enclosures without them.

PostPosted: Tue Mar 11, 2008 10:36 pm
by Ray Bell
Hi Telstar

I've found another signal generator. No sweep function on the free version of this one but it will save wav files.

http://www.dr-jordan-design.de/signalgen.htm

A single executable no installation and it worked first time on my pc.
It appears to offer lots of functions but they are only available on the paid for pro version.

The free version does sine, triangular and square waves at any audio frequency set by numerical input or with a slider. Saving wav files you can certainly save single frequency sine waves of a defined frequency and duration, I haven't worked out if you can save a wav of a manual sweep.

Hope this is useful

Ray

PostPosted: Wed Mar 12, 2008 6:52 pm
by Glenn
Hi guys;

That's the best one I've seen yet. Lots of goodies on that site; too bad I don't have more than 2 loons to rub together at the moment. Poking around I did find this little tidbit:

http://www.selfmadehifi.de/basscad.htm

They didn't have stuff like this when I was in school!

Glenn