Linux-audio-dev August 2010

linux-audio-dev@lists.linuxaudio.org

42 participants
40 discussions

Re: [LAD] mudita24 1.02 -- improved envy24control mixer/router for ice1712-based sound-cards

by Niels Mayer

On Sat, Aug 7, 2010 at 6:10 PM, Geoff Beasley <geoff(a)laughingboyrecords.com> wrote: > Niels, great that you and Tim have fixed this app ;) One thing, can you > explain what those 'profiles' are for and how to use them? Envy24control uses the same mechanism as your system does (see /etc/asound.state and amixer(1)) to save the state of your ALSA devices between boots. The difference is this mechanism puts the file under your control at ~/.envy24control/profiles.conf and allows you to set eight different profiles: allowing you to save or restore up to eight different "asound.state"-like configurations per card. The different profiles are most useful for storing routings set in "Patchbay/Router" panel, as well as "Hardware Settings" panel clock rate, or external SPDIF/wordclock sync. On cards with switchable spdif/optical ins (Terratec/Terrasoniq), you can persist this extra level of "routing" -- which is useful for "matrix routing" between two digitally-interconnected and sync'd computers. ( I use profiles named: 44dmix-to-1&2&spdif, 48dmix-to-1&2&spdif, spdmix-to-1&2&spdif, 44all-outs-pcm, 48all-outs-pcm, spdif-all-outs-pcm, 96dmix-to-1&2&spdif and 96all-outs-pcm. ). When you have a combination of settings in envy24control that you want to return to, just go to the "Profiles" panel, enter the name of the profile into the first free text field (initially these will be numbered "1" through "8"). After entering a descriptive name, click "Save active profile." To restore a given profile, just click on the "button" area surrounding the text field, or even click within the text field. You'll notice the selected profile "button" indicates activation via coloration. After changing profiles, go to, for example, Patchbay/Router or "Hardware Settings" panels,and note that the previously saved state was restored. Note that significant amounts of setting data gets saved in these files: > ll ~/.envy24control/ -rw-r--r-- 1 npm npm 115253 2010-08-07 23:10 profiles.conf For comparison: > ll /etc/asound.state -rw-r--r--. 1 root root 128079 2010-08-07 18:15 /etc/asound.state (That's for a system with two envy24-based cards installed, thus size is large, causing "save" to produce a brief but noticeable pause in the metering on a slower system or "ondemand" throttled system). Niels http://nielsmayer.com PS: speaking of envy24 anybody know whether this will work in standard alsa/linux: http://www.lionstracs.com/store/msaudio-board-envy24-p-122.html and are those i2s connectors, or ttl-level spdif? i guess if it's i2s you have to get: http://www.lionstracs.com/store/mixer-board-p-210.html (which looks pretty cool, esp w/ the onboard dream-based hardware synth w/ large sample ROM).

15 years, 6 months

[LAD] mudita24 1.02 -- improved envy24control mixer/router for ice1712-based sound-cards

by Niels Mayer

The "Mudita24" package is a modification of alsa-tools' envy24control: an application controlling the digital mixer, channel gains and other hardware settings for sound cards based on the ice1712 chipset ( http://alsa.cybermirror.org/manuals/icensemble/envy24.pdf ). It also displays a level meter for each input and output channel and maintains peak level indicators. This utility is preferable to alsamixer(1) for those with ice1712-based cards: M-Audio Delta 1010, Delta 1010LT, Delta DiO 2496, Delta 66, Delta 44, Delta 410 and Audiophile 2496. TerraTec EWS 88MT, EWS 88D, EWX 24/96, DMX 6Fire, Phase 88. Hoontech SoundTrack DSP 24, SoundTrack DSP 24 Value, SoundTrack DSP 24 Media 7.1. Event Electronics EZ8. Digigram VX442. Lionstracs, Mediastaton. Terrasoniq TS 88. Partial support for Roland/Edirol DA-2496. Now available, version 1.02: source: http://nielsmayer.com/envy24control/mudita24-1.0.2.tar.gz binary: http://nielsmayer.com/envy24control/mudita24-1.0.2.x86_64.tgz patch: http://nielsmayer.com/envy24control/mudita24-envy24control-0.6-to-1.0.2.pat… 'envy24control' is part of the "alsa-tools" package. For example, under CCRMA's Fedora repos, it's part of alsa-tools-1.0.22-1.1.fc12.ccrma.x86_64. This "mudita24" package updates/replaces the alsa-tools /usr/bin/envy24control application. The default "./configure ; make ; sudo make install" process on the source-code leaves a binary in /usr/local/bin/envy24control and places the man-page in /usr/local/man/man1/envy24control.1 . This means you can still use the standard alsa-tools version in /usr/bin/envy24control . Screenshots (controlling either Terratec DMX6Fire or M-Audio Delta 66): http://nielsmayer.com/envy24control/Mudita24-102-Monitor-Inputs.png http://nielsmayer.com/envy24control/Mudita24-102-Monitor-Outputs.png http://nielsmayer.com/envy24control/Mudita24-102-Patchbay+Router.png http://nielsmayer.com/envy24control/Mudita24-102-Hardware-Settings.png http://nielsmayer.com/envy24control/Mudita24-102-Analog-Volume.png http://nielsmayer.com/envy24control/Mudita24-102-About.png Changes since recent 1.0.0 and 1.0.1 releases: * Peak-meter display is in dBFS, corresponding to displayed dBFS peak-meter value and scale-widget dB labeling. * Hardware mixer input attenuators provide more precise control to the 0 to -48dB range of adjustment, turning the associated input "off" when the slider is moved to bottom of the scale. External MIDI control of the hardware mixer via --midichannel and --midienhanced options unaffected by this change. * For M-Audio Delta series, add display of "Delta IEC958 Input Status" under "Hardware Settings." * Command line options --no_scale_mark, --channel_group_modulus affect layout and presence of dB markings for sliders. --channel_group_modulus allows override of Left/Right grouping of dB labels for multichannel applications. * Control of peak-meter coloring via --lights_color and --bg_color options. Reasonable default colors used when these options are not set. (1.0.1's use of Gtk skin to provide an automatic color choice didn't work out that well on some systems.) * Fixed command-line options --card and --device to allow valid ALSA card and CTL device names ( https://bugzilla.redhat.com/show_bug.cgi?id=602900 ). * Profiles created in ~/.envy24control and not "~/envy24control" ( http://bugtrack.alsa-project.org/alsa-bug/view.php?id=4738 ). Summary of previous updates from envy24control 0.6.0 (GIT HEAD) to "1.0.2": (1) Implemented "Peak Hold" functionality in meters; reimplemented meters to do away with inefficient "faux LED" peak-meter display. (2) Significantly reduced the number of timer interrupts generated by this program by slowing down all updates to 10 per second -- previously meters updated 25x/second! (3) All volumes are represented as decibels, including the 0 to -48dB range of the hardware peak-meters, the 0 -to- -48dB&off attenuation for all inputs to the digital mixer, the 0 -to- -63dB attenuation of the analog DAC, and the +18 -to- -63dB attenuation/amplification of the analog ADC. (4) All gtk "scale" widgets have dB legends; the "PageUp" "PageDown" keys allow rapid movement between the marked levels, and "UpArrow" and "DownArrow" allow fine-adjustment. Niels http://nielsmayer.com PS: Why "mudita24" ? An alternate name to avoid confusion with "envy24control 0.6.0" until changes in this version propagate upstream. See http://en.wikipedia.org/wiki/Envy#In_philosophy "In Buddhism the third of the four divine abidings is mudita, taking joy in the good fortune of another. This virtue is considered the antidote to envy and the opposite of schadenfreude."

15 years, 6 months

Re: [LAD] [alsa-devel] announcing envy24control, mudita (*) edition.

by Niels Mayer

On Wed, Aug 4, 2010 at 1:20 AM, Raymond Yau <superquad.vortex2(a)gmail.com> wrote: > The "-D" option seem to be used similar to "amixer -Dabc" > ctl.abc { type hw , card 2 } Raymond -- Thanks for the clarification regarding the use of the -D argument for alsa control devices. I've updated my code to handle things in the same way that amixer does. The diffs for this change are at the end of this message, and attached. ALSA names for examples/tests below from http://nielsmayer.com/npm/dot-asoundrc.txt .... ......................................... gnulem-277-~> /usr/bin/envy24control -D66 ##behavior on current head and latest stable release Segmentation fault (core dumped) gnulem-278-~> envy24control -D66 ##behavior using this patch ... using --- input_channels: 4 gnulem-279-~> envy24control -D666 ALSA lib control.c:902:(snd_ctl_open_noupdate) Invalid CTL 666 envy24control: cannot open mixer: No such file or directory - '666' gnulem-280-~> envy24control -Dhw:66 envy24control: invalid ALSA audio device, invalid index or name for card: hw:66 gnulem-281-~> envy24control -Dhw:M66 using --- input_channels: 4 gnulem-282-~> envy24control -Dmulti invalid card type (driver is HDA-Intel) gnulem-283-~> envy24control -Ddefault invalid card type (driver is USB-Audio) gnulem-284-~> envy24control -c default envy24control: invalid ALSA index or name for audio card: default gnulem-285-~> envy24control -c SB invalid card type (driver is HDA-Intel) gnulem-286-~> envy24control -c multi envy24control: invalid ALSA index or name for audio card: multi gnulem-287-~> envy24control -c M66 using --- input_channels: 4 gnulem-299-~> amixer -Dhw:/dev/snd/controlC2 >! /tmp/foo gnulem-301-~> amixer -D/dev/snd/controlC2 > ! /tmp/foo ALSA lib control.c:902:(snd_ctl_open_noupdate) Invalid CTL /dev/snd/controlC2 amixer: Mixer attach /dev/snd/controlC2 error: No such file or directory gnulem-290-~> envy24control -D/dev/snd/controlC2 ALSA lib control.c:902:(snd_ctl_open_noupdate) Invalid CTL /dev/snd/controlC2 envy24control: cannot open mixer: No such file or directory - '/dev/snd/controlC2' ......................................... diff --git a/envy24control/envy24control.c b/envy24control/envy24control.c index 0b2749e..e5d89d0 100644 --- a/envy24control/envy24control.c +++ b/envy24control/envy24control.c @@ -2084,3 +2166,3 @@ int main(int argc, char **argv) view_spdif_playback = 0; profiles_file_name = DEFAULT_PROFILERC; default_profile = NULL; while ((c = getopt_long(argc, argv, "D:c:f:i:m:Mo:p:s:w:vt:", long_options, NULL)) != -1) { switch (c) { case 'D': - name = optarg; - card_number = atoi(strchr(name, ':') + sizeof(char)); - if (card_number < 0 || card_number >= MAX_CARD_NUMBERS) { - fprintf(stderr, "envy24control: invalid card number %d\n", card_number); - exit(1); + /* NPM: old code assumed ':' present, e.g. "-Dhw:66", + * (w/ .asoundrc "ctl.66 {type hw, card M66}") and would + * coredump if given "-D66". Prevent the coredump and even + * handle latter case even if keying off ':' is not a + * good way to do this. Note that for snd_card_get_index() + * "The accepted format is an integer value in ASCII representation or the card + * identifier (the id parameter for sound-card drivers). The control device + * name like /dev/snd/controlC0 is accepted, too." */ + if (!index(optarg, ':')) { + /* NPM: unlike old envy24control code, but behaving like amixer et al, + "-D66" is valid. Handle it. */ + snd_mixer_t *mixer; + struct snd_mixer_selem_regopt selem_regopt = { + .ver = 1, + .abstract = SND_MIXER_SABSTRACT_NONE, + .device = optarg, + }; + if ((err = snd_mixer_open(&mixer, 0)) < 0) { + fprintf(stderr, "envy24control: cannot open mixer: %s - '%s'\n", snd_strerror(err), optarg); + exit(1); + } + if ((err = snd_mixer_selem_register(mixer, &selem_regopt, NULL)) < 0) { + fprintf(stderr, "envy24control: cannot open mixer: %s - '%s'\n", snd_strerror(err), optarg); + exit(1); + } + name = optarg; /* NPM: now that device name validated, e.g. pass "-D66" unaltered to snd_ctl_open()... */ + } + else { + /* NPM: handle e.g. optarg == "hw:M66" */ + card_number = snd_card_get_index(strchr(optarg, ':') + sizeof(char)); /* NPM: use correct ALSA-specific call to fix https://bugzilla.redhat.com/show_bug.cgi?id=602900 */ + if (card_number < 0) { + fprintf(stderr, "envy24control: invalid ALSA audio device, invalid index or name for card: %s\n", optarg); + exit(1); + } + name = optarg; /* e.g. optarg == "hw:M66" passed to snd_ctl_open() below */ } break; case 'c': - i = atoi(optarg); - if (i < 0 || i >= MAX_CARD_NUMBERS) { - fprintf(stderr, "envy24control: invalid card number %d\n", i); + card_number = snd_card_get_index(optarg); /* NPM: use correct ALSA-specific call to fix https://bugzilla.redhat.com/show_bug.cgi?id=602900 */ + if (card_number < 0) { /* NPM: code orig from alsa-utils/alsamixer/cli.c */ + fprintf(stderr, "envy24control: invalid ALSA index or name for audio card: %s\n", optarg); exit(1); } - card_number = i; - sprintf(tmpname, "hw:%d", i); + sprintf(tmpname, "hw:%d", card_number); /* e.g. "hw:M66" for arg "-cM66" passed to snd_ctl_open() below */ name = tmpname; break; case 'f': ......................................... --Niels http://nielsmayer.com

15 years, 6 months

[LAD] [ANN] Nano-Basket v0.1

by Roy Vegard Ovesen

Hi Nano-Basket v0.1 has been released. Source files are available from http://github.com/royvegard/Nano-Basket Nano-Basket is a configuration software for the Korg nanoSERIES MIDI controllers. It's intended to run on operating systems where the official configuration editor is not available (i.e. Linux). It's written in Python, using pygtk for the GUI. This is the first release. The feature set is limited to storing scenes to the nanoKONTROL device. Simple usage instructions are available from the wiki page: http://wiki.github.com/royvegard/Nano-Basket/use -- Roy Vegard Ovesen

15 years, 6 months

[LAD] announcing envy24control, mudita (*) edition.

by Niels Mayer

Summary of updates from envy24control 0.6.0 (GIT HEAD) to "1.0.0": (0) After a decade, incremented version to 1.0.0 (**) (1) Implemented missing "Peak Hold" functionality in meters and reimplemented meters for increased efficiency and lower X resource usage. (see http://www.linuxaudio.org/mailarchive/lad/2010/7/12/171535 & https://bugzilla.redhat.com/show_bug.cgi?id=602903 ) (2) All volumes are represented as decibels, including the 0 to -48dB range of the hardware peak-meters, the 0 -to- -144dB attenuation for all inputs to the digital mixer, the 0 -to- -63dB attenuation of the analog DAC, and the +18 -to- -63dB attenuation/amplification of the analog ADC. (3) All gtk "scale" widgets have dB legends; the "PageUp" "PageDown" keys allow rapid movement between the marked levels. (4) Got rid of myriad compile warnings and other minor fixes across codebase. Some screenshots: http://nielsmayer.com/envy24control/Screenshot-Envy24Control-AnalogVolume.p… http://nielsmayer.com/envy24control/Screenshot-Envy24Control-MonitorInputs.… http://nielsmayer.com/envy24control/Screenshot-Envy24Control-MonitorPCM.png ------------ To the ALSA project: please consider this patch to alsa-tools' envy24control (**): http://nielsmayer.com/envy24control/envy24control-0.6-to-1.0.patch (patch to 'envy24control' from GIT trunk/head of alsa-tools) http://nielsmayer.com/envy24control/envy24control-1.0.README (summary of changes from 0.6.0 to 1.0.0) ------------ Those wanting to compile directly, or run a 64 bit linux binary I've built: http://nielsmayer.com/envy24control/envy24control-1.0.tar.gz (full directory, just follow README directions to build/install) http://nielsmayer.com/envy24control/envy24control-1.0-fc12-x86_64.tar.gz (x86_64 binary that should work on fedora12 and equivalent OpenSuse release) I'd appreciate any testing results or comments on this "1.0.0" release. In particular, I'd like some assurance that the dB markings on sliders in "Analog Volume" panel are correct (compared to values reported by 'alsamixer'). I'm looking for testing with following devices (as I think my testing covers code for M-Audio Delta 44 & Delta 66, Terratec Dmx6fire & EWX2496) specifically: M-Audio Delta 1010, M-Audio Audiophile 2496, M-Audio Delta 1010LT TerraTec EWS 88MT, TerraTec EWS 88D, TerraTec Phase 88, Hoontech SoundTrack DSP 24 (all variants). Thanks, Niels http://nielsmayer.com PS: (*) http://en.wikipedia.org/wiki/Envy#In_philosophy :: "mudita, taking joy in the good fortune of another. This virtue is considered the antidote to envy and the opposite of schadenfreude." (**) http://git.alsa-project.org/?p=alsa-tools.git;a=tree;f=envy24control;h=d5a5…

15 years, 6 months

Re: [LAD] [alsa-devel] announcing envy24control, mudita (*) edition.

by Niels Mayer

On Tue, Aug 3, 2010 at 10:38 PM, Raymond Yau <superquad.vortex2(a)gmail.com> wrote: > 2010/8/4 Niels Mayer <nielsmayer(a)gmail.com> >> * fixed --card and --device to allow valid ALSA names and numbers >> ( https://bugzilla.redhat.com/show_bug.cgi?id=602900 ). > > ./envy24control -Ddefault > > card_number = atoi(strchr(name, ':') + sizeof(char)); > > This bug seem still occur when name does not contain ":" since ctl device is > "hw:n" where n is card number I used similar code to what's in alsamixer to perform the same functions as the old broken code. Now the code behaves as follows: gnulem-238-~> envy24control -Dhw:default envy24control: invalid ALSA audio device, invalid index or name for card: hw:default gnulem-239-~> envy24control -Dhw:M66 using --- input_channels: 4 --- output_channels: 4 --- pcm_output_channels: 8 --- spdif in/out channels: 2 gnulem-240-~> envy24control -Dhw:M66.0 envy24control: invalid ALSA audio device, invalid index or name for card: hw:M66.0 gnulem-241-~> envy24control -Dhw:M66,0 envy24control: invalid ALSA audio device, invalid index or name for card: hw:M66,0 gnulem-242-~> envy24control -DM66 envy24control: ALSA audio device syntax expects ':' character: M66 Current code: while ((c = getopt_long(argc, argv, "D:c:f:i:m:Mo:p:s:w:vt:ng:", long_options, NULL)) != -1) { switch (c) { case 'D': name = optarg; if (!index(name, ':')) { fprintf(stderr, "envy24control: ALSA audio device syntax expects ':' character: %s\n", optarg); exit(1); } card_number = snd_card_get_index(strchr(name, ':') + sizeof(char)); /* NPM: use correct ALSA-specific call to fix https://bugzilla.redhat.com/show_bug.cgi?id=602900 */ if (card_number < 0) { /* NPM: code orig from alsa-utils/alsamixer/cli.c */ fprintf(stderr, "envy24control: invalid ALSA audio device, invalid index or name for card: %s\n", optarg); exit(1); } break; case 'c': card_number = snd_card_get_index(optarg); /* NPM: use correct ALSA-specific call to fix https://bugzilla.redhat.com/show_bug.cgi?id=602900 */ if (card_number < 0) { /* NPM: code orig from alsa-utils/alsamixer/cli.c */ fprintf(stderr, "envy24control: invalid ALSA index or name for audio card: %s\n", optarg); exit(1); } sprintf(tmpname, "hw:%d", card_number); name = tmpname; break; -- Niels http://nielsmayer.com

15 years, 6 months

[LAD] [LAA] [ANN] guitarix-0.11.0 released

by Andreas Degert

On behalf of the guitarix team I'm proud to announce Guitarix Version 0.11 Guitarix is a simple Linux Rock Guitar amplifier and is designed to achieve nice thrash/metal/rock/blues guitar sounds. Guitarix uses the Jack Audio Connection Kit as its audio backend and brings to the jack audio graph a mono amplifier input/output port, and a FX mono input with two (stereo) output ports. Guitarix provides a jack midi input port to connect a midi controller (midi learn) and a (3 channel) jack midi output port, feed by a (scalable) mix of the tuner and a beat-detector. Release 0.11.0 comes with following changes : Users visible changes: - new version of the impulse response parameter editor. You can now graphically define a gain line to be applied to the IR data, e.g. emphasize a part of the early reflections or damping the reverb tail to make it fit to your guitar sound. - the multi-line distortion effect now has 4 frequency bands and is better optimized - fix regression from version 0.10.0: now the default preset file is created again if it doesn't exist (e.g. in new installations). Changes that might be interesting for Developers: We put the Guitarix widgets into a library, with the goal of making them usable independently from Guitarix. You can build it as shared library and there's a c++ (gtkmm) wrapper, a python wrapper and glade support. Check it out and look for examples in those directories, or just build a nice looking display with the glade editor, and of course ask in our Guitarix forum (it's still alpha). As a side note, Guitarix is now in debian (unstable), of course at the moment still the previous version 0.10. have fun _________________________________________________________________________ guitarix is licensed under the GPL. Project page with screenshots: http://guitarix.sourceforge.net/ download: http://sourceforge.net/projects/guitarix/ please report bugs and suggestions in our forum here: http://sourceforge.net/apps/phpbb/guitarix/ ________________________________________________________________________ For capture, guitarix uses the great 'jack_capture' (version >= 0.9.30) written by Kjetil S. Matheussen. If you don't have it installed, you can look here: http://old.notam02.no/arkiv/src/?M=D For extra Impulse Responses, guitarix uses the zita-convolver library, and, for up/down sampling we use zita-resampler, both written by Fons Adriaensen. If you don't have it installed, get it here: http://www.kokkinizita.net/linuxaudio/index.html We use the marvellous faust compiler to build the amp and effects and will say thanks to : Julius Smith http://ccrma.stanford.edu/realsimple/faust/ : Albert Graef http://q-lang.sourceforge.net/examples.html#Faust : Yann Orlary http://faust.grame.fr/ ________________________________________________________________________ For faust users : All used Faust dsp files are included in /guitarix/src/faust, the resulting cc files are in /guitarix/src/faust-generated The tools we use to convert (post-processing and plot) the resulting faust cpp files to the needed include format, stay in the /guitarix/tools directory. ________________________________________________________________________ regards Hermann Meyer, James Warden, Andreas Degert

15 years, 6 months

[LAD] Document on using Jack Apps

by Arvind Venkatasubramanian

Hello: I am very much new to Linux and Linux audio. I am trying to measure audio IO latency for my system. Jdelay seems to be the right tool but when I run it on the terminal, I am getting message "Signal below threshold..." which probably might be because Jack is trying to capture audio and ends up getting the low noise floor because I do not have meaningful signal source connected. But then I tried to patch the this App to the qJACKctl app but the settings console is not straight forward to interpret. as it involved many parameters. I guess there are # of frames per period that may eventually be used to calculate the target latency but *is there a step-by step document description for Jdelay and any other JACK tools and also using JACK audio server in an effective manner*? Also, qJACKctl console does not offer options for very low sampling rates like 8 KHz. With ALSA, this should be possible but may be this particular tool does not support it. Can anyone help here? Thanks, -F

15 years, 6 months

Re: [LAD] [LAA] announcing envy24control, mudita (*) edition.

by Niels Mayer

[trimmed down reply-to linux-audio-dev(a)lists.linuxaudio.org] On Tue, Jul 27, 2010 at 8:25 AM, john ffitch <jpff> wrote: > Any chance of an option to envy24control to allow colour blind people > to see three zones? I had been using it for years before I was told > that there is a red section at the top and green below > ==John ffitch John -- Thank you for writing and you'll be happy to know that the new "mutida24" (to avoid confusion with the old and overly colorful envy24contol) does not use coloration in the same way, and yes, I'd imagine the old choice of colors would be particularly bad for http://en.wikipedia.org/wiki/Color_blindness#Red-green_color_blindness . Although there's been some recent minor changes, this is the look of the new meters: http://nielsmayer.com/envy24control/Screenshot-Envy24Control-MonitorInputs.… http://nielsmayer.com/envy24control/Screenshot-Envy24Control-MonitorPCM.png Hopefully, at least for any colors at issue, there is enough contrast against the background to make it properly visible. Please let me know of any specific issues w/ the simplified, and more X-efficient meters in this version, which try to be less eye-candy, and more useful for making a visual level determination of inputs, outputs, or digital mixer inputs. The peak metering features a green/white/orange/red progression of the peak color (the thin band that stays fixed while the meter below bounces around). But in addition, and more helpful to you, are he peak-level readouts in dBFS from -48 to 0dBFS for all inputs and outputs, including in the "Analog Volume" panel. The 0dBFS label is red with white background, whereas the other levels remain black with white background. That should provide enough redundancy in the metering to not hide important information from you. However, I'm not sure of the perceptibility, of the red "0dBFS" marking. On the other hand, it does say "0dBFS" (in red) which is quite different-looking than, say "-5.02" (in black) In http://nielsmayer.com/envy24control/Screenshot-Envy24Control-AnalogVolume.p… the green (at 0dB) and red (+6 +12 +18) markings on the ADC would not be very useful for you; fortunately, the "+" should be visually distinctive from all the other "-" markings in blue. Other alternatives would be Bolding amplification values, and underlining unity gain. Thanks, Niels http://nielsmayer.com

15 years, 6 months

Re: [LAD] what does "full range" mean with regard to ambisonics and speakers?

by Martin Leese

"Bearcat M. ?andor" <hometheater(a)feline-soul.com> wrote: > Thank you. I think i understand all that, but let me take this apart to > make sure. What you're [J?rn Nettingsmeier is] saying is that having full range speakers only > effects the playback quality of the music not the ambisonics and > that ambisonics itself does not *need* full range speakers, but that > having full range speakers is better than not. Is that correct? There are (at least) two things to reproduce: the frequency range and the localisation. Ambisonics satisfies localisation cues up to about 5 kHz, and down to very low. (There is evidence that humans can localise frequencies below 20 Hz using things like chest cavities. Ambisonics can reproduce such localisation cues if these frequencies are in the source.) So, for localisation, the speakers can top out at 5 kHz. However, music played though such speakers is unlikely to sound very good. At the low end, lower is better. However, it is a law of diminishing returns, limited by the standing waves in your listening room which will interfere with the localisation of subwoofers. > I think part of my confusion is that i'm still thinking of it as having > 6 or 8 or more *channels* when that is not the case. The speakers are > not steered, they are driven. So you are not going to have a situation > where the speakers behind you are only reproducing high to midrange > information as was the case with Dolby pro-logic or something. Right? Right. With Ambisonics, all the speakers cooperate to localise a sound. While the speakers on the left push, those on the right pull. (This is less pronounced with frequencies above 400 Hz and less important with higher-order Ambisonics, but ignore this.) Regards, Martin -- Martin J Leese E-mail: martin.leese stanfordalumni.org Web: http://members.tripod.com/martin_leese/

15 years, 6 months

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Linux-audio-dev August 2010