Ok, you can probably use these as a quick test until you can make up your own.
"sub-low" is 70Hz down.
"main-low" is 70Hz->3Khz.
"main-high" is 3Khz up.
All for 48Khz sampling rate, and each 2048 in size.
"sub-low" is 70Hz down.
"main-low" is 70Hz->3Khz.
"main-high" is 3Khz up.
All for 48Khz sampling rate, and each 2048 in size.
Oh, and youll probably want these as well... my brutefir config files.
You might have probs with the "jack-jack" config as i had to modify the BruteFIR source to get that working correctly (modified so BruteFIR doesnt try to connect output ports).
[edit]
Oops... youll also have to remove the "powersave" setting as thats only supported in the BruteFIR V1.0 beta that Anders sent me.
You might have probs with the "jack-jack" config as i had to modify the BruteFIR source to get that working correctly (modified so BruteFIR doesnt try to connect output ports).
[edit]
Oops... youll also have to remove the "powersave" setting as thats only supported in the BruteFIR V1.0 beta that Anders sent me.
Tweeters
Beware of the turn-on / turn off thump of your soundcard / amplifier frying your tweeters !
Operator error (ie. loading the lowpass coefficients for the tweeters) will also fry them.
May I strongly advise putting a capacitor in series for the tests ?
Headphone-check each output before connecting !
Have fun !
Beware of the turn-on / turn off thump of your soundcard / amplifier frying your tweeters !
Operator error (ie. loading the lowpass coefficients for the tweeters) will also fry them.
May I strongly advise putting a capacitor in series for the tests ?
Headphone-check each output before connecting !
Have fun !
Re: Tweeters
Yep, thats very good advice.
I accidently gave my tweeters a few large PC power-off thumps 🙁
They now have a couple of large caps in series to help protect them.
You shouldnt have to worry about Gainclone power on/off thumps though due to the built-in undervoltage protection.
peufeu said:
Yep, thats very good advice.
I accidently gave my tweeters a few large PC power-off thumps 🙁
They now have a couple of large caps in series to help protect them.
You shouldnt have to worry about Gainclone power on/off thumps though due to the built-in undervoltage protection.
MWP said:
V1.0 GA release came out a couple weeks back, so powersave should now be mainstream. I've grabbed the V1.0 source but haven't run it yet. Having @$@#$@# problems with my Delta 1010 spdif output......
Thanks all!
You guys are great! Good advice on protecting tweeters. I'm always careful and even wear ear protectors as well. You get careful in the process of setting up 7kW home theater🙂
I'm starting with brutefir v1.0 btw.
-Robert
You guys are great! Good advice on protecting tweeters. I'm always careful and even wear ear protectors as well. You get careful in the process of setting up 7kW home theater🙂
I'm starting with brutefir v1.0 btw.
-Robert
for those interested in the VIA boards, there is a new one out with onboard power supply, it only requires 12V and can supply HDD/optical drive.
you just need a 12V/6A power brick.
http://www.techseekers.net/modules.php?name=Reviews&rop=showcontent&id=76&page=1
you just need a 12V/6A power brick.
http://www.techseekers.net/modules.php?name=Reviews&rop=showcontent&id=76&page=1
Progress report
I have successfully played 4-ch music (left hi and low and right hi and low) through BruteFIR/ALSA on Linux 2.6.5.
It was not easy
and it is not yet ready for prime-time.
The issue of the moment is to produce a good crossover FIR for each left and right speaker. I can't find any literature on generating the coefficient files for these filters, although google told me that both MWP and peufeu have been here before me asking the same questions.
Anyway, I can report that latency is not an issue with 2.6.5 as long as you compile the pre-emptive kernel, make sure the soundcard is on a priority IRQ (mine is on 9), set the latency timer for the soundcard pci slot to F8 (max) and nice the audio stuff to outrank the desktop stuff.
The main headache was to configure ALSA for my M-Audio Delta 410 and then to configure BruteFIR to handshake with the alsa device. VERY TOUGH!!!
But there were no blown tweeters and I can tell the system has lots of sound potential.
How do you guys generate FIR coefficient files?
-Robert
p.s. - Oh, I'm away next few days so keep the thread alive! When the project reaches a useful point of performance, we should capsule it all to make it easier for people to follow. Nobody should have to go through this just to make a good music player.
I have successfully played 4-ch music (left hi and low and right hi and low) through BruteFIR/ALSA on Linux 2.6.5.
It was not easy
and it is not yet ready for prime-time.The issue of the moment is to produce a good crossover FIR for each left and right speaker. I can't find any literature on generating the coefficient files for these filters, although google told me that both MWP and peufeu have been here before me asking the same questions.
Anyway, I can report that latency is not an issue with 2.6.5 as long as you compile the pre-emptive kernel, make sure the soundcard is on a priority IRQ (mine is on 9), set the latency timer for the soundcard pci slot to F8 (max) and nice the audio stuff to outrank the desktop stuff.
The main headache was to configure ALSA for my M-Audio Delta 410 and then to configure BruteFIR to handshake with the alsa device. VERY TOUGH!!!
But there were no blown tweeters and I can tell the system has lots of sound potential.
How do you guys generate FIR coefficient files?
-Robert
p.s. - Oh, I'm away next few days so keep the thread alive! When the project reaches a useful point of performance, we should capsule it all to make it easier for people to follow. Nobody should have to go through this just to make a good music player.
Re: Progress report
I use Matlab (filter design toolbox) under Windows.
Its not the best, but its doing the job at the moment.
Im still looking for a better way of doing it.
I should really pull out my old DSP textbooks and write my own apps to do it.
Its like anything else DIY... if you want it to be the best, youve gotta put the time in.
BTW, i thought you wanted to make the "Worlds best music player", not just a "good music player" 😉
RFScheer said:
I use Matlab (filter design toolbox) under Windows.
Its not the best, but its doing the job at the moment.
Im still looking for a better way of doing it.
I should really pull out my old DSP textbooks and write my own apps to do it.
Its like anything else DIY... if you want it to be the best, youve gotta put the time in.
BTW, i thought you wanted to make the "Worlds best music player", not just a "good music player" 😉
It will be done
I do and I will
Just didn't expect this phase to be so murky. We're not past mid-field yet.
-Robert
I do and I will
Just didn't expect this phase to be so murky. We're not past mid-field yet.
-Robert
have any of you tried asioXO before?
http://www2.gol.com/users/pcazeles/asioxo.htm
is it really that inferior to BruteFIR??
thanks in advance,
http://www2.gol.com/users/pcazeles/asioxo.htm
is it really that inferior to BruteFIR??
thanks in advance,
Re: Progress report
Tools for this is definitly in demand !
One way is to take the impulse response of the corresponding analog filter and use this as the coefficents propably combined with windowing.
Another way is to take the measured impulse response from a given driver and compare( in frequency domain) the response to a desired filter response ( as per above)
Morten
RFScheer said:
Tools for this is definitly in demand !
One way is to take the impulse response of the corresponding analog filter and use this as the coefficents propably combined with windowing.
Another way is to take the measured impulse response from a given driver and compare( in frequency domain) the response to a desired filter response ( as per above)
Morten
Filters
I use Octave which is a free Matlab clone (and it crashes as often as the original).
Basically :
- read a book on digital signal processing
- create a vector with your complex frequency response (start simple with a phaseless (real) linkwitz-riley 4th order)
- plot it
- do an inverse fourier transform
- multiply it with a time window (hamming, blackman, whatever)
- take the real part
- normalize it so sum( square( all coefficients )) = 1
- plot it
- use it.
Create the highpass first, then for the lowpass take frequency response = (1-highpass)
not that simple ?...
I use Octave which is a free Matlab clone (and it crashes as often as the original).
Basically :
- read a book on digital signal processing
- create a vector with your complex frequency response (start simple with a phaseless (real) linkwitz-riley 4th order)
- plot it
- do an inverse fourier transform
- multiply it with a time window (hamming, blackman, whatever)
- take the real part
- normalize it so sum( square( all coefficients )) = 1
- plot it
- use it.
Create the highpass first, then for the lowpass take frequency response = (1-highpass)
not that simple ?...
hello all
Could you not use filter maker at
http://www.pvconsultants.com/audio/dsp/dplay.htm
I haven't looked into if the coefficents could be used for brutefir as I am just a simple thread lurker at the moment.
The program is probably too simple but, it makes at least a starting point.
Cheers
Andreas
Could you not use filter maker at
http://www.pvconsultants.com/audio/dsp/dplay.htm
I haven't looked into if the coefficents could be used for brutefir as I am just a simple thread lurker at the moment.
The program is probably too simple but, it makes at least a starting point.
Cheers
Andreas
Hi guys,
Great thread! I too think the PC can be used as a good input source (when modified, of course 😉 )
I saw this on ebay and thought it might be relevant? Perhaps it can be heavily modified for our uses:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=3701&item=4129852991&rd=1&ssPageName=WDVW
regarding keeping the PC quiet (assuming you are not using mini-itx) how about total immersion?
http://www.liquidninjas.com/reviews.php?op=showcontent&id=15
Great thread! I too think the PC can be used as a good input source (when modified, of course 😉 )
I saw this on ebay and thought it might be relevant? Perhaps it can be heavily modified for our uses:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=3701&item=4129852991&rd=1&ssPageName=WDVW
regarding keeping the PC quiet (assuming you are not using mini-itx) how about total immersion?
http://www.liquidninjas.com/reviews.php?op=showcontent&id=15
Progress report
I'm back after a few days away and have some progress to report.
1. As stipulated by peufeu, I have read 1 book on digital filters (mostly iir though).
2. Loaded and played with Octave (no crashes btw).
3. Searched around and found gmeteor and used it to design low and high pass FIR filters for a prototype crossover. 1024 taps.
4. Successfully executed BruteFIR using the new filters.
HOWEVER, the sound is not so good
because ALSA isn't configured right for the soundcard yet. The same high-pass stream is playing in both tweeter and mid even though BruteFIR is producing both low and high and sending them to the ALSA device.
I found a thread in the ALSA site on the ICE1712 series of soundcards, which I believe the M-Audio Delta 410 belongs to and have still had trouble configuring ALSA for it.
But, even without documentation, persistence will prevail.
Regarding some of the latest posts:
It would be nice to get a report from someone on asioXO. I'm thinking WinXP is looking better and better for a platform. There are lots of open-source tools for Windows and multimedia is just easier to set up.
But don't worry, I won't give up on Linux/BruteFIR quite yet.
Very funny, tifosi_f1; it has occurred to me to resort to immersion for my pc on several occasions recently, but not so much for the purpose of cooling it but more for killing it. On the ebay usb unit, it's not something that I'll be investigating but if you want to go for it, good luck and report back the good results.
Now, back to the ALSA config mess.
-Robert
I'm back after a few days away and have some progress to report.
1. As stipulated by peufeu, I have read 1 book on digital filters (mostly iir though).
2. Loaded and played with Octave (no crashes btw).
3. Searched around and found gmeteor and used it to design low and high pass FIR filters for a prototype crossover. 1024 taps.
4. Successfully executed BruteFIR using the new filters.
HOWEVER, the sound is not so good
because ALSA isn't configured right for the soundcard yet. The same high-pass stream is playing in both tweeter and mid even though BruteFIR is producing both low and high and sending them to the ALSA device. I found a thread in the ALSA site on the ICE1712 series of soundcards, which I believe the M-Audio Delta 410 belongs to and have still had trouble configuring ALSA for it.
But, even without documentation, persistence will prevail.
Regarding some of the latest posts:
It would be nice to get a report from someone on asioXO. I'm thinking WinXP is looking better and better for a platform. There are lots of open-source tools for Windows and multimedia is just easier to set up.
But don't worry, I won't give up on Linux/BruteFIR quite yet.
looks promising if you are using Windows. You could build several simple filters and cascade them. Didn't take the trouble to see if it works or not though.
Very funny, tifosi_f1; it has occurred to me to resort to immersion for my pc on several occasions recently, but not so much for the purpose of cooling it but more for killing it. On the ebay usb unit, it's not something that I'll be investigating but if you want to go for it, good luck and report back the good results.
Now, back to the ALSA config mess.
-Robert
Thanks Andreas
Looks like a good pkg for designing filters, viewing and analyzing them and outputting coeff's for BruteFIR. If gmeteor doesn't quite go far enough for me, then I'll look into it, even if it is for Windows.
-Robert
Looks like a good pkg for designing filters, viewing and analyzing them and outputting coeff's for BruteFIR. If gmeteor doesn't quite go far enough for me, then I'll look into it, even if it is for Windows.
-Robert
it came from the last posts in this thread
"very low Q woofer" in the loudspeaker forum
cheers
andreas
"very low Q woofer" in the loudspeaker forum
cheers
andreas
What probs are you having with the ALSA setup?
After the last few months of trying to get ALSA working correctly here (ive been hacking kernels/drivers/brutefir to fix a noise problem), ive got a fairly good understanding of how it all works.
Ive also been using an ICE1724... the drivers are similar to the ICE1712.
After the last few months of trying to get ALSA working correctly here (ive been hacking kernels/drivers/brutefir to fix a noise problem), ive got a fairly good understanding of how it all works.
Ive also been using an ICE1724... the drivers are similar to the ICE1712.
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