[slim] Re: Crossfeed Plugin
I'm not aware of anything. I still would be interested in this, enabling crossfeed out the analog RCAs would be great. -- schalliol schalliol's Profile: http://forums.slimdevices.com/member.php?userid=1854 View this thread: http://forums.slimdevices.com/showthread.php?t=16068 ___ discuss mailing list discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
[slim] Re: Crossfeed Plugin
InguzDSP does crossfeed (on the server, using FIR filters). I've been using this for stereo-width enhancement with loudspeakers, but it would work great for headphones too. http://inguzaudio.com/usage/plugin/settings/enhanced-stereo-filters/ -- inguz inguz's Profile: http://forums.slimdevices.com/member.php?userid=1139 View this thread: http://forums.slimdevices.com/showthread.php?t=16068 ___ discuss mailing list discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
[slim] Re: Crossfeed Plugin
Thanks for the link. Does it work with flac files? Cheers Richard -- magnanimous magnanimous's Profile: http://forums.slimdevices.com/member.php?userid=8977 View this thread: http://forums.slimdevices.com/showthread.php?t=16068 ___ discuss mailing list discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
[slim] Re: Crossfeed Plugin
It plays basically all the Squeezebox file types (but Internet Radio doesn't work -- hopefully that's temporary; and SHN is not tested). I posted some sample headphone matrix filters to try (http://inguzaudio.com/usage/plugin/settings/enhanced-stereo-filters/). Two fairly striaghtforward crossfeeds, and a third with a tiny bit of real living-room ambience (which is fun, or not, depending on the type of music you're listening to...) -- inguz inguz's Profile: http://forums.slimdevices.com/member.php?userid=1139 View this thread: http://forums.slimdevices.com/showthread.php?t=16068 ___ discuss mailing list discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
[slim] Re: Crossfeed Plugin
Perhaps someone could persuade Michael Rhoades to contribute to Slim Server in some fashion. He is the author of the crossfeed plugin for Foobar200. http://www.naivesoftware.com/software.html -- dwc dwc's Profile: http://forums.slimdevices.com/member.php?userid=1892 View this thread: http://forums.slimdevices.com/showthread.php?t=16068 ___ discuss mailing list discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
[slim] Re: Crossfeed Plugin
When circuit that perform the desired function are used for loudspeakers they are commonly called cross-talk cancellers. With speakers in a normal room, both ears hear both speakers. By crossfeeding and inverting the phase of the crossfeed signal and adding a slight delay and attenuation to compensate for interaural spacing, the result is that with some recordings the sound of the instruments and voices can appear to come from locations other than the speakers. It works great with some recordings and not so great with others. Carver made a device called a C-9 Sonic Hologram processor for this purpose. It worked well if you were in the right position and your speakers were placed symetrically in your room. It is pretty easy to implement this sort of thing with a few op-amps. You can play with that sort of circuit and hear its effect using SwitcherCAD, the spice based circuit simulator you can DL from Linear Technology for free. SWCAD has .wav file input and output functions, so you can specify a .wav file to process and it will generate a .wav file with the crossfeed/crosstalk cancelation. It is NOT real time! It can take a long time to process the .wav input file, so short snippets are best. The circuit pictured does simple crossfeed with no delay, but will give you a taste of the possibilities. It is easy to add an all-pass filter to generate a little delay. If such a circuit were included in the SB, either as hardware or software, I recommend that the remote include a button to switch it on and off with a single press. TD +---+ |Filename: crossfeed.jpg| |Download: http://forums.slimdevices.com/attachment.php?attachmentid=1420| +---+ -- tyler_durden tyler_durden's Profile: http://forums.slimdevices.com/member.php?userid=2701 View this thread: http://forums.slimdevices.com/showthread.php?t=16068 ___ discuss mailing list discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
[slim] Re: Crossfeed Plugin
I don't suppose anyone had progress since this thread slowed down. With regards to the first comment, I did suggest this as a nice addition a long time ago on the developer and standard SlimDevices lists. I have a couple pairs of wireless Sennheiser headphones that operate through my receiver, and it would be ideal to offer crossfeeding like I have on my headphone amp driving the corded pair I use too. I'd be happy to help, though I don't think I'm technically proficient enough to do a whole lot... -- schalliol schalliol's Profile: http://forums.slimdevices.com/member.php?userid=1854 View this thread: http://forums.slimdevices.com/showthread.php?t=16068 ___ discuss mailing list discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
[slim] Re: Crossfeed Plugin
bjackson Wrote: http://headwize.com/projects/showfile.php?file=meier_prj.htm The guy who wrote this article (Jan Meier) is the father of the Corda headphone amps which are indeed well known for their crossfeed circuit. Some more info is available on his web site (look at the link crossfeed filter in the left pane): http://www.meier-audio.homepage.t-online.de/ bjackson Wrote: Maybe call it something like: Expand Soundstage (Off, Low, Middle, High) or something? And why not Crossfeed :-) Michel -- Michel Fombellida ___ Discuss mailing list Discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
Re: [slim] Re: Crossfeed Plugin
That's interesting, but what we really need is a DSP guru to design an IIR (or FIR, if necessary) filter that does the same thing. Anybody? On Sep 2, 2005, at 4:57 AM, Michel Fombellida wrote: bjackson Wrote: http://headwize.com/projects/showfile.php?file=meier_prj.htm The guy who wrote this article (Jan Meier) is the father of the Corda headphone amps which are indeed well known for their crossfeed circuit. Some more info is available on his web site (look at the link crossfeed filter in the left pane): http://www.meier-audio.homepage.t-online.de/ bjackson Wrote: Maybe call it something like: Expand Soundstage (Off, Low, Middle, High) or something? And why not Crossfeed :-) Michel -- Michel Fombellida ___ Discuss mailing list Discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss ___ Discuss mailing list Discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
Re: [slim] Re: Crossfeed Plugin
On 9/2/05, Michel Fombellida [EMAIL PROTECTED] wrote: And why not Crossfeed :-) I'd say that would be a bit too easy to confuse with crossfade (as in song transitions). But really, as long as it's not called SlimDSP X-TREME-HeadphoneMAGIC 2000++,(*cough*X-Fi*cough*), I won't mind. :) - Jacob ___ Discuss mailing list Discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
[slim] Re: Crossfeed Plugin
bjackson Wrote: Why are you coughing X-Fi? I have no idea if Creative's new soundcard has this, but it's definatly not their idea. Anyway, would an FIR filter work? I've been told before by people more knowledgable than I that an FIR filter would not work and the reason given was that an FIR filter doesn't mix channels with delay (i.e. it's impossible), any ideas on this? Mixing channels with some delay is a very simple time-domain operation. You just look backward in the buffer by x samples, attentuate by y decibels, then add to the other channel. Filters only come into play when you want to change the frequency content of the mixed-in channel. -- seanadams ___ Discuss mailing list Discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
[slim] Re: Crossfeed Plugin
A fine idea - please file a request at bugs.slimdevices.com. It's something we'd need to do in firmware, right at the end of our audio process. What kind of delay would you want? Obviously the delay and mix levels would be configurable but I'm guessing you'd want a range of 0 to 1000uS or so? Also isn't there another name for this besides crossfeed that wouldn't be confused with the crossfade feature? -- seanadams ___ Discuss mailing list Discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
Re: [slim] Re: Crossfeed Plugin
seanadams wrote: A fine idea - please file a request at bugs.slimdevices.com. It's something we'd need to do in firmware, right at the end of our audio process. Actually, you could do this on the server by piping the audio stream through the appropriate processing program. What kind of delay would you want? Obviously the delay and mix levels would be configurable but I'm guessing you'd want a range of 0 to 1000uS or so? There is a whole load of research on this, but I can't find the links right now. I'll have a scout around. Also isn't there another name for this besides crossfeed that wouldn't be confused with the crossfade feature? I'm sure the work to which I refer is called something other than crossfeed. Again, I'll see what I can find. R. -- http://robinbowes.com If a man speaks in a forest, and his wife's not there, is he still wrong? ___ Discuss mailing list Discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
Re: [slim] Re: Crossfeed Plugin
Robin Bowes wrote: seanadams wrote: A fine idea - please file a request at bugs.slimdevices.com. It's something we'd need to do in firmware, right at the end of our audio process. Actually, you could do this on the server by piping the audio stream through the appropriate processing program. What kind of delay would you want? Obviously the delay and mix levels would be configurable but I'm guessing you'd want a range of 0 to 1000uS or so? There is a whole load of research on this, but I can't find the links right now. I'll have a scout around. Also isn't there another name for this besides crossfeed that wouldn't be confused with the crossfade feature? I'm sure the work to which I refer is called something other than crossfeed. Again, I'll see what I can find. OK, I've not found the links I was looking for, but this technology is related to Head Related Transfer Functions (HRTFs). Somewhere I've seen a site that demonstrates a pseudo-HRTF, i.e. an artificial approximation and provides a couple of sample files illustrating the effect. If only I could find it ... R. -- http://robinbowes.com If a man speaks in a forest, and his wife's not there, is he still wrong? ___ Discuss mailing list Discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
Re: [slim] Re: Crossfeed Plugin
On Thursday 01 September 2005 09:32, Robin Bowes wrote: Robin Bowes wrote: seanadams wrote: A fine idea - please file a request at bugs.slimdevices.com. It's something we'd need to do in firmware, right at the end of our audio process. Actually, you could do this on the server by piping the audio stream through the appropriate processing program. What kind of delay would you want? Obviously the delay and mix levels would be configurable but I'm guessing you'd want a range of 0 to 1000uS or so? There is a whole load of research on this, but I can't find the links right now. I'll have a scout around. Also isn't there another name for this besides crossfeed that wouldn't be confused with the crossfade feature? I'm sure the work to which I refer is called something other than crossfeed. Again, I'll see what I can find. OK, I've not found the links I was looking for, but this technology is related to Head Related Transfer Functions (HRTFs). Somewhere I've seen a site that demonstrates a pseudo-HRTF, i.e. an artificial approximation and provides a couple of sample files illustrating the effect. If only I could find it ... if what you are referring to is the cross-feeding stuff to make headphones sound nicer, then HeadRoom has some docs here: http://www.headphone.com/products/faqs/about-headroom-crossfeed/ but it doesn't actually tell you exactly how to do it (obviously). My iriver hd140 also includes something similar named SRS (http://www.srslabs.com/) but it generally sounds horrible (to my ears). However they have many demonstration files available (http://www.srslabs.com/Demonstrations.asp) that I haven't had a chance to listen to yet in a controlled environment. Alex ___ Discuss mailing list Discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
Re: [slim] Re: Crossfeed Plugin
Alex Twisleton-Wykeham-Fiennes wrote: if what you are referring to is the cross-feeding stuff to make headphones sound nicer, then HeadRoom has some docs here: http://www.headphone.com/products/faqs/about-headroom-crossfeed/ but it doesn't actually tell you exactly how to do it (obviously). Well, it comes pretty close: The current HeadRoom crossfeed circuit uses a two-stage active filter that provides about 400 uSec of delay and a gentle frequency response roll-off starting at about 2 kHz. The left crossfeed signal is mixed in with the right channel’s direct signal (and vice versa) at a level about 8dB lower. However, that's not the link to which I was referring. My iriver hd140 also includes something similar named SRS (http://www.srslabs.com/) but it generally sounds horrible (to my ears). However they have many demonstration files available (http://www.srslabs.com/Demonstrations.asp) that I haven't had a chance to listen to yet in a controlled environment. That's not it either - this is going to bug me! R. -- http://robinbowes.com If a man speaks in a forest, and his wife's not there, is he still wrong? ___ Discuss mailing list Discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
[slim] Re: Crossfeed Plugin
(1) Doing it on the server is probably not the right thing for anything other than a PCM stream because it would require a decode-encode step. (2) I'm no expert, but it's more complicated than just a delay and gain adjustment. The process is usually frequency-dependent. (3) One could make up a name like headphone virtualizer instead of crossfeed. -- ephemere ___ Discuss mailing list Discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
Re: [slim] Re: Crossfeed Plugin
On Thursday 01 September 2005 17:32, ephemere wrote: (1) Doing it on the server is probably not the right thing for anything other than a PCM stream because it would require a decode-encode step. Agreed. (2) I'm no expert, but it's more complicated than just a delay and gain adjustment. The process is usually frequency-dependent. The previous quote from headphone.com is frequency dependent because the crossover for the feed into the delay line is described as a gentle frequency response therefore the amount of delayed signal will increase as the frequency increases. Or are you suggesting that the delay time would alter with frequency as well? (3) One could make up a name like headphone virtualizer instead of crossfeed. would it not be a speaker virtualiser because it makes headphones sound like speakers? :-) Alex ___ Discuss mailing list Discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
[slim] Re: Crossfeed Plugin
I don't know if this would help anyone, but this is my favorite crossfeed CIRCUIT I've heard, but it might give some insight into the proven methodologies. http://headwize.com/projects/showfile.php?file=meier_prj.htm and this one isn't too bad: http://headwize.com/projects/showfile.php?file=cmoy1_prj.htm Maybe call it something like: Expand Soundstage (Off, Low, Middle, High) or something? -- bjackson ___ Discuss mailing list Discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
[slim] Re: Crossfeed Plugin
I'd really like a crossfeed feature. I'm guessing there's not a huge demand for it, though. I wouldn't mind implementing one myself, but I assume there's no SDK for the DSP. -- ephemere ___ Discuss mailing list Discuss@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/discuss
