Hi,
I've been lurking in the full range speaker forums for a little while looking at speaker projects. When I do finally build, I will use my Ubuntu laptop as a source. Things will be added as I feel the need, assuming I have the cash/time.
I quite like the idea of using brutefir to crossover between supertweeters at some point (I believe it is the best way to do that, yes?).
This therefore boils down to a USB DAC question. I was thinking I could just get a couple of separate stereo USB DAC's and run the main drivers off one and the tweeters off the other, assuming I can convince the software to do that. I am worried that the timing will be off between the two DAC's and it will sound awful (phase problems etc...). Will this be a problem? Can this be avoided in software for reasonable stereo DAC's? Is the solution to get a 4+ channel output soundcard? I need a little guidance here, someone must have done this before.
Oh yeah, and this is on a mere mortal's budget!
Thanks,
Mark
I've been lurking in the full range speaker forums for a little while looking at speaker projects. When I do finally build, I will use my Ubuntu laptop as a source. Things will be added as I feel the need, assuming I have the cash/time.
I quite like the idea of using brutefir to crossover between supertweeters at some point (I believe it is the best way to do that, yes?).
This therefore boils down to a USB DAC question. I was thinking I could just get a couple of separate stereo USB DAC's and run the main drivers off one and the tweeters off the other, assuming I can convince the software to do that. I am worried that the timing will be off between the two DAC's and it will sound awful (phase problems etc...). Will this be a problem? Can this be avoided in software for reasonable stereo DAC's? Is the solution to get a 4+ channel output soundcard? I need a little guidance here, someone must have done this before.
Oh yeah, and this is on a mere mortal's budget!
Thanks,
Mark
It will be no problem to get alsa to see the 2 usb dacs as one - there is documentation on how to combine 2 soundcards as one on the alsa wiki. The problem will be when the stream is processed at the usb dacs. if you simply use 2 seperate dacs they will be running on two seperate clocks which will not be synced. You could try using one clock to feed both dacs, although there may still be other ways in which the chips will not be synced internally.
I read a post on another forum (can't remember where) and someone reported that using seperate usb dacs for left and right speakers worked well - but I can imagine listening over longer periods the 2 clocks would drift from one another and cause the issues you mentioned in your post.
Its not that easy to find good and cheap multichannel soundcards that are compatible with linux. perhaps the EMU 1212m is one of the better cheap ones. M-audio, RME (more expensive) and Terratec cards are other options. ESI Juli@ is also mentioned a lot.
Cheers,
Ross
I read a post on another forum (can't remember where) and someone reported that using seperate usb dacs for left and right speakers worked well - but I can imagine listening over longer periods the 2 clocks would drift from one another and cause the issues you mentioned in your post.
Its not that easy to find good and cheap multichannel soundcards that are compatible with linux. perhaps the EMU 1212m is one of the better cheap ones. M-audio, RME (more expensive) and Terratec cards are other options. ESI Juli@ is also mentioned a lot.
Cheers,
Ross
I asked around some time ago looking for a multi channel usb dac. The m-audio fast track pro is a usb soundcard that has 4 outputs and seems to work with linux. as to the sound quality Im not sure. The emu 0404 usb looks good, but has no linux support although there seem to be people working on it.
Hi Ross,
The M-audio looks like a well made piece of equipment. It says in the manual it can only do 2 channel 24/96khz output. Otherwise it is 24/48khz for four outs. How important is the sample rate to quality, is 48khz ok?
Have you seen the ESI Gigaport-AG? It is an 8-out usb card, but it seems that the dac is the only part that is 24 bits and it is really a 16 bit
card.
M
The M-audio looks like a well made piece of equipment. It says in the manual it can only do 2 channel 24/96khz output. Otherwise it is 24/48khz for four outs. How important is the sample rate to quality, is 48khz ok?
Have you seen the ESI Gigaport-AG? It is an 8-out usb card, but it seems that the dac is the only part that is 24 bits and it is really a 16 bit
card.
M
Mark,
The gigaport looks like a good option in terms of something that has the required no. of channels, affordable and works with linux. It may be difficult to modify the device to the level of high end usb devices which usually have their own power supplies, low jitter clocks and flexibility to upgrade the converter chips (i2s output). It may be a one chip solution. The maudio may well be the same.
In this thread soundcheck has talked about offline sample rate conversion i.e. not doing it during playback and using a high quality conversion programme. He resamples "offline" from 44.1khz to 48khz as the clock of his usb dac is 12mhz - the 12mhz clock is divided by the usb dac chip down to whatever samplerate the audio is running at, the idea is that the division is more accurate when the clock frequency is divided by a whole number. I think 12mhz is pretty standard for usb, but not sure whether all audio devices use this.
If your source material is 44.1khz I see no other reason (than soundcheck's) to change the sample rate. If the files on your laptop are 16bit 44.1khz and you set your dac to playback at 48khz, samplerate conversion must be done in real time (by software or hardware) and therefore most certanly sub optimally. So check that the gigaport can actually do 44.1khz.
You seem to subscribe to the fullrange approach. Would a good 2 channel dac with the right full range design not be the best way forward? It seems you may lose more by compromising the quality of the dac just so you can use brutefir for the tweeter crossover, than you would if you choose a fullrange driver that doesn't need a tweeter or requires only a minimal single capacitor crossover. Most people using pc crossovers are using them for subs or multiway speakers with crossovers well inside the crucial listening frequencies. You could do room correction on 2 fullrange channels.
The gigaport looks like a good option in terms of something that has the required no. of channels, affordable and works with linux. It may be difficult to modify the device to the level of high end usb devices which usually have their own power supplies, low jitter clocks and flexibility to upgrade the converter chips (i2s output). It may be a one chip solution. The maudio may well be the same.
In this thread soundcheck has talked about offline sample rate conversion i.e. not doing it during playback and using a high quality conversion programme. He resamples "offline" from 44.1khz to 48khz as the clock of his usb dac is 12mhz - the 12mhz clock is divided by the usb dac chip down to whatever samplerate the audio is running at, the idea is that the division is more accurate when the clock frequency is divided by a whole number. I think 12mhz is pretty standard for usb, but not sure whether all audio devices use this.
If your source material is 44.1khz I see no other reason (than soundcheck's) to change the sample rate. If the files on your laptop are 16bit 44.1khz and you set your dac to playback at 48khz, samplerate conversion must be done in real time (by software or hardware) and therefore most certanly sub optimally. So check that the gigaport can actually do 44.1khz.
You seem to subscribe to the fullrange approach. Would a good 2 channel dac with the right full range design not be the best way forward? It seems you may lose more by compromising the quality of the dac just so you can use brutefir for the tweeter crossover, than you would if you choose a fullrange driver that doesn't need a tweeter or requires only a minimal single capacitor crossover. Most people using pc crossovers are using them for subs or multiway speakers with crossovers well inside the crucial listening frequencies. You could do room correction on 2 fullrange channels.
Hi Ross,
As you probably have already realized, putting together this stereo is part for listening and part for fun DIY. I am young enough to be able to hear quite high so I might get some supertweeters along the way. I will eventually probably want to make some subwoofers too. You are right though, initially the money for the dac will go further on a nice two channel one. I might get a really cheap 5.1 to play with digital XO as well though.
Changing sample rate by weird ratios seems like a bad idea. I think I have seen some dacs doing 88.2khz though. Ill have a look around.
Mark
As you probably have already realized, putting together this stereo is part for listening and part for fun DIY. I am young enough to be able to hear quite high so I might get some supertweeters along the way. I will eventually probably want to make some subwoofers too. You are right though, initially the money for the dac will go further on a nice two channel one. I might get a really cheap 5.1 to play with digital XO as well though.
Changing sample rate by weird ratios seems like a bad idea. I think I have seen some dacs doing 88.2khz though. Ill have a look around.
Mark
Hi Mark,
If you want to try out digital crossover with a PC, you can do this for about 60 Euro if you use the Club3D -Theatron-DTS soundcard.
Sound wise it is better than my DDDac and all my other tweaked sources, if some caps are changed and the whole active stage gets bypassed .
I keep on repeating this on a few forums, but no one seems to try it out to verify my findings.
You can find the detailes of the mods here:
http://picasaweb.google.de/Klaus.Freis/Audio
Greets,
Klaus
If you want to try out digital crossover with a PC, you can do this for about 60 Euro if you use the Club3D -Theatron-DTS soundcard.
Sound wise it is better than my DDDac and all my other tweaked sources, if some caps are changed and the whole active stage gets bypassed .
I keep on repeating this on a few forums, but no one seems to try it out to verify my findings.
You can find the detailes of the mods here:
http://picasaweb.google.de/Klaus.Freis/Audio
Greets,
Klaus
FWIW, the 1212m is not multichannel - only left and right analog audio, the rest of the '12' channels are available on digital. 8 on ADAT and 2 on SPDIF.
Also I've been running a software resampler in Windoze (built into Foobar) and I find that the 48KHz software resampler gives much better results than running 44.1 KHz signal into the card and having it do the upsampling to 48KHz (only valid for Creative products).
I would say that using a software resampler is a must for low-end cards.
The better cards will work without resampling, AFAIK.
Also I've been running a software resampler in Windoze (built into Foobar) and I find that the 48KHz software resampler gives much better results than running 44.1 KHz signal into the card and having it do the upsampling to 48KHz (only valid for Creative products).
I would say that using a software resampler is a must for low-end cards.
The better cards will work without resampling, AFAIK.
It is identical to the Bluegears B-inspirer and I run it with their driver under XP. On their site they also have an ALSA download but I don't know if it works with Linux. I would really like it to, because I
want to switch finally. I am a bit crippled when it comes to Linux. I could not even install my graphics card.
Greets,
Klaus
want to switch finally. I am a bit crippled when it comes to Linux. I could not even install my graphics card.
Greets,
Klaus
some notes,
OpenOffice is NOT 100% compatible with MS Office. i don't know who told you that line.
second point, make sure the hardware is supported. does it have real drivers, or ones coded by a kid during his spare time? my printer and video card only have partial support.
linux works for me, with a dash of Win and a sprinkle of DOS. i can't justify spending $3000 for Windows server, maybe you can.
OpenOffice is NOT 100% compatible with MS Office. i don't know who told you that line.
second point, make sure the hardware is supported. does it have real drivers, or ones coded by a kid during his spare time? my printer and video card only have partial support.
linux works for me, with a dash of Win and a sprinkle of DOS. i can't justify spending $3000 for Windows server, maybe you can.
Notagenius said:
OpenOffice is about as compatible as most users actually need, though you're right it's not 100%.
Your second point is a good one: on my ubuntu install, I found my wireless network card is not supported. Video proved to be a bit tricky too, though I managed to figure it out finally. The step-by-step guide to installing Ubuntu Studio I linked to in this thread and the wiki was invaluable for me.
Still, I'm still not 100% certain of switching over totally. For now I will stay dual-boot, as I'm really comfortable now with XP.
BTW I gave Vista my first serious attention during the summer, on a Dell laptop I got for my in-laws. I absolutely hated it.
off topic (WiFi NIC)
that's kind of strange... indeed sometimes it may be tricky but most of the wireless NICs can be made to work, one way or the other (i.e. either with native Linux drivers or at worst using the windoze drivers with ndiswrapper). AFAIK as of today the only notable exceptions are a few USB-wifi "dongle" adapters.
Fell free to email me with your NIC model, perhaps I can give you some hints.
About Vista: stay away from it!
What's wrong with Windows Vista
ssmith said:
that's kind of strange... indeed sometimes it may be tricky but most of the wireless NICs can be made to work, one way or the other (i.e. either with native Linux drivers or at worst using the windoze drivers with ndiswrapper). AFAIK as of today the only notable exceptions are a few USB-wifi "dongle" adapters.
Fell free to email me with your NIC model, perhaps I can give you some hints.
About Vista: stay away from it!
What's wrong with Windows Vista
linux 2.6.20 or 2.6.22?
Hello all,
In June I installed the realtime kernel in my Ubuntu Feisty with the Con Kolivas CK2 patch in order to run brutus for playback of CDs in realtime. This works fine with excellent sound quality.
Recently I decided to replace my laptop with a desktop with much more processing power, faster memory, quiet fans and a large internal harddisk. I installed Ubuntu very easily and then followed the Wiki from this thread.
The first step was to download the package libncurses5-dev. Then get the 2.6.22 kernel and de Con Kolivas ck2 patch. I adjusted all parameter settings and compiled the kernel. It worked well so I downloaded schedtool and libc6 as indicated.
After 'dpkg -i schedtool ....' I received an error message. I could not resolve it and asked about it on a Ubuntu forum. The reply was that kernel 2.6.22 cannot be combined with Ubuntu 7.04, I should have used 2.6.20. (The working kernel on my laptop is 2.6.21). Kernel 2.6.22 should be combined with the newer version of Ubuntu which is to be released by the end of this month.
The problem seems to concentrate around the package libc6 which is different in both kernels. The Con Kolivas webpage only has 2.6.22 available. So I copied the bz2 files from my laptop and tried to make a 2.6.21 kernel. This attempt stopped already at the first step 'make menuconfig' with a long list of errors.
Did anyone of you recently install these programs and encounter the same problems yes or no? Any help is welcome.
Kind regards,
Eddie
Hello all,
In June I installed the realtime kernel in my Ubuntu Feisty with the Con Kolivas CK2 patch in order to run brutus for playback of CDs in realtime. This works fine with excellent sound quality.
Recently I decided to replace my laptop with a desktop with much more processing power, faster memory, quiet fans and a large internal harddisk. I installed Ubuntu very easily and then followed the Wiki from this thread.
The first step was to download the package libncurses5-dev. Then get the 2.6.22 kernel and de Con Kolivas ck2 patch. I adjusted all parameter settings and compiled the kernel. It worked well so I downloaded schedtool and libc6 as indicated.
After 'dpkg -i schedtool ....' I received an error message. I could not resolve it and asked about it on a Ubuntu forum. The reply was that kernel 2.6.22 cannot be combined with Ubuntu 7.04, I should have used 2.6.20. (The working kernel on my laptop is 2.6.21). Kernel 2.6.22 should be combined with the newer version of Ubuntu which is to be released by the end of this month.
The problem seems to concentrate around the package libc6 which is different in both kernels. The Con Kolivas webpage only has 2.6.22 available. So I copied the bz2 files from my laptop and tried to make a 2.6.21 kernel. This attempt stopped already at the first step 'make menuconfig' with a long list of errors.
Did anyone of you recently install these programs and encounter the same problems yes or no? Any help is welcome.
Kind regards,
Eddie
Hello Tom,
Thanks for your reply, good to know that its not the kernel version. Indeed the problems started with point II.6 of the Wiki: How to setup schedtool.
I downloaded schedtool_1.2.9-4_i386.deb and received a package with the correct number of bytes (23752). Next step: "apt-get install libc6" responded with: "already the newest version".
Then: "dpkg schedtool_1.2.9-4_i386.deb": gives the following messages:
-error processing schedtool (--install)
-dependency problems - leaving unconfigured
-errors were encountered while processing: schedtool
-schedtool depends on libc6(>=2.5-5)
-however: version of libc6 on system is 2.5-0ubuntu14
It seems that my dependencies are wrong but I have no idea how to fix it. Any suggestions?
Kind regards,
Eddie
Thanks for your reply, good to know that its not the kernel version. Indeed the problems started with point II.6 of the Wiki: How to setup schedtool.
I downloaded schedtool_1.2.9-4_i386.deb and received a package with the correct number of bytes (23752). Next step: "apt-get install libc6" responded with: "already the newest version".
Then: "dpkg schedtool_1.2.9-4_i386.deb": gives the following messages:
-error processing schedtool (--install)
-dependency problems - leaving unconfigured
-errors were encountered while processing: schedtool
-schedtool depends on libc6(>=2.5-5)
-however: version of libc6 on system is 2.5-0ubuntu14
It seems that my dependencies are wrong but I have no idea how to fix it. Any suggestions?
Kind regards,
Eddie
Hmmm. I did this before the wiki was made, think I downloaded it from http://packages.debian.org/unstable/utils/schedtool . I downloaded the tar file and unzipped it with the
'tar xvvf schedtool_1.2.9.orig.tar.gz' command,
cd to schedtool dir, then
'make', and
'make install'.
Perhaps you can try to do it the make way?
Error msg during make will tell you if you need more libs...
Btw, I hope you did 'dpkg -i' on the deb package, if not, try this first...
Cheers,
Tom
'tar xvvf schedtool_1.2.9.orig.tar.gz' command,
cd to schedtool dir, then
'make', and
'make install'.
Perhaps you can try to do it the make way?
Error msg during make will tell you if you need more libs...
Btw, I hope you did 'dpkg -i' on the deb package, if not, try this first...
Cheers,
Tom
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