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aeolus: editing the synthesis parameters

by Paul

How do I start the synthesis parameter editor in Aeolus 0.9.0? -- P.

10 years, 4 months

Fw: Re: [maybe OT] question regarding the FIL equalizer

by Fons Adriaensen

Date: Thu, 26 Feb 2015 22:04:39 +0000 From: Fons Adriaensen <fons(a)linuxaudio.org> To: Cedric Roux <sed(a)free.fr> On Wed, Feb 25, 2015 at 11:46:37PM +0100, Cedric Roux wrote: > can someone explain to me what this bandwidth computation means? There is nothing magical about it, it's just a pragmatic approximation that results in the 3dB BW (for high + or - gain) being expressed in octaves. Expressing the BW in a logarithmic unit (such as octaves) make sense because the magnitude response of a second order parametric is symmetric on a log(f) scale but not on a linear one. An absolute value in Hz or even a relative one (the same divided by center frequency) is informative only for small BW, where the linear distance to the -3dB points left and right would be more or less equal. For large BW values (as often used in sound engineering) this is no longer true. For example for a center frequency of 1 kHz and two octaves BW the -3dB points are at 500 Hz and 2 kHz. For four octaves that would be 250 Hz and 4 kHz, giving a -3dB BW in Hz that is larger than twice the center frequency, which is somewhat counter-intuitive. The 'mathematical' way to define the BW of an second order allpass would be at the +/- 90 degree phase points. This also corresponds to the -3 dB points for an infinite notch, as used by M & R. But keeping this value fixed in a parametric results in curves that are not even symmetric for + and - gains. The 'bumps' would be much wider than the 'notches'. The sqrt (gain) factor restores this symmetry. But using this means that there is no longer any simple relation to what looks like bandwidth on a frequency response plot and the actual 'mathematical' value. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow) ----- End forwarded message ----- -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow)

10 years, 4 months

Detecting 'ready' status of JACK-aware applications in Python

by Jonathan E. Brickman

What are good ways to pull a list of JACK ports in python and detect their readiness to accept connections? And/or, is there a better way to detect 'ready' status of JACK-aware applications? -- Jonathan E. Brickman | jeb(a)ponderworthy.com | (785)233-9977 Ponderworthy | http://ponderworthy.com Music of compassion; fire, and life!!!

10 years, 4 months

[maybe OT] question regarding the FIL equalizer

by Cedric Roux

Hi LAD, I have a technical question regarding the FIL equalizer (by Fons Adriaensen). The code uses Mitra-Regalia lattice filter (as described in [1]). After reordering things here and there I see it's indeed the case (surprise!). [1] might be hard to get, but there is [2] with a lot of details too, especially for bandwidth. The only remaining point that I don't get is the bandwidth manipulations. [1] uses for its parameter 'a' ('_s2' in FIL) the formula: a = (1 - tan(Omega/2)) / (1 + tan(Omega/2)) 'Omega' being I don't really know what (-3dB notch bandwidth for a gain of 0 maybe, if I read the paper correctly). FIL uses bandwith expressed in octave and does: _s2 = (1-b)/(1+b) with: b = bandwidth * 7 * (f0/fs) / sqrt(gain) ('f0' is the center frequency of the equalizer, 'fs' is the sampling rate) Reading [2] we see the factor 'sqrt(gain)' ('gain' is 'K') that we find in the FIL's formula (specifically the formula for k2 at page 13, after equation (17)). But the "bandwidth * 7 * (f0/fs)" remains a total mistery to me. It seems to be 'gamma' as found in [2], but 'gamma' is way more complicated than what we see in FIL's code. So the questions are: - can someone explain to me what this bandwidth computation means? - how it is derived starting from a bandwidth expressed in octave? - And if we use the notations of [1] and [2] how do we relate it to Omega or the various versions found in [2]? (which one is it by the way? I thought it was the "at the bandedge frequencies the gain is 'gain/2 dB'" one but it's not the case) (I wrote a little program to plot things and as far as my program is correct bandedge frequencies don't have a gain of 'gain/2 dB') Regards, Cédric. [1] P. A. Regalia and S. K. Mitra, “Tunable Digital Frequency Response Equalization Filters,” IEEE Trans. Acoust., Speech, Signal Process., vol. ASSP-35 (1987 Jan.). [2] http://www.musicdsp.org/files/EQ-Coefficients.pdf

10 years, 4 months

ams-lv2 1.1.0

by Aurélien Leblond

Hello all, The version 1.1.0 of ams-lv2 is now available: The two main "features" of this version are: - Ported tons of additional plugins from AMS (VCEnv & VCEnv II, Multiphase LFO, VC Organ, etc.) - Ported the changes from version AMS 2.1.1 (Bit Grinder, Hysteresis, the bug fixes, etc.) In addition, this release sees a lot of bug fixes or optimization. As a reminder, ams-lv2 are plugins to create modular synthesizers ported from Alsa Modular Synth. Here is a demo of an older version of these plugins. http://www.youtube.com/watch?v=LWfF71NerkQ ams-lv2 1.1.0 can be downloaded here: https://github.com/blablack/ams-lv2/releases/tag/v1.1.0 enjoy :) Aurélien

10 years, 4 months

Re: [LAD] [LAU] Graphic designer wanted

by Hermann Meyer

Thanks, I've created a job-page on the github job-board now. Sounds like it be a good place. regards hermann Am 13.02.2015 um 12:44 schrieb Cillian de Róiste: > Hi, > > You could try posting the details on: > https://github.com/opensourcedesign/job-board or asking on freenode > #opensourcedesign > > Good luck! > Cillian > > 2015-02-12 7:13 GMT+01:00 Hermann Meyer <brummer-(a)web.de>: >> Hi >> >> The topic say’s it all, any Graphic designer around here, who like to create >> a new, overall design for the guitarix project? >> If so, please contact me. >> >> regards >> hermann >> >> _______________________________________________ >> Linux-audio-user mailing list >> Linux-audio-user(a)lists.linuxaudio.org >> http://lists.linuxaudio.org/listinfo/linux-audio-user > >

10 years, 4 months

Graphic designer wanted

by Hermann Meyer

Hi The topic say’s it all, any Graphic designer around here, who like to create a new, overall design for the guitarix project? If so, please contact me. regards hermann

10 years, 4 months

Problems with time-scaling on records

by Álvaro Canelo Noriega

Hi! My name's Álvaro, from Barcelona [it's my first post to this list, so I say hello :) ]. I'm dealing with some issues with time-scaling and I'm a little bit lost trying to find the problem. I'm trying to record an analog audio input using *arecord*, in order to do some fingerprinting (features extraction). The problem is that after every reboot of the recording machine, the record has a different time scale so, as the fingerprint algorithm works with the relative position of energy peaks for different frequencies and the time them happen, the algorithm sometimes works, but sometimes fails. Could you give me any guidance to know where to search a possible solution for the time-scaling issue? Thank you very much in advance! Álvaro --- Forza saluti a tutti bacioni auguri in boca di lupo arrivederci ea presto pino

10 years, 4 months

a LAD survey (I need you !)

by e-rouge

Hello guys, I've followed this community for a while now and this is my contribution : a survey about LAD. *Why ?* I've made this survey to get a snapshot of what LAD community is, and to help understand how it works. This community has always worked in an informal way with ups and downs, and I thought it would be really useful to look at it with objectivity. *Who ?* It is open to any contributors of any Linux Audio Sofwares. *Who/What's for**?* This study aims to stay within LAD community and to provide very practical information. It does not intend to be part of a essay or any academic work. Actually its only purpose will be to provide a solid ground for further discussion about LAD's future. I've already started to gather qualitative data (as some of you know) an, while you answer this, I'll collect some more data about the projects themselves. Once all put together, we should get a very precise overview of what this community actually is. *How ?* *The survey itself takes around 30minuts to complete and they will be anonymized *before any publication (if you wonder why I ask for your name : it's to help me to build a projects-interactions graph as well as few other things). *When ?* Hopefully, I hope to get most answers within 2 or 3 months. After that it'll take a couple of weeks to analyze the data and write something about them. I'll keep you informed. . *Where ?* *Here's the link : * http://tumulte.me/lime/index.php/survey/index/sid/174631/token/bcdqg4tww7n6… I've made my best to think about the most relevant questions and possible answers, but if you thinks something is missing, wrong or whatever please contact me Thanks in advance, Etienne/Tumulte

10 years, 4 months

[LAU] [LAA] Guitarix 0.32.3 release

by Hermann Meyer

Release 0.32.3 is out, Guitarix is a tube amplifier simulation for jack (Linux), with an additional mono and a stereo effect rack. Guitarix includes a large list of plugins[*] and support LADSPA / LV2 plugs as well. The guitarix engine is designed for LIVE usage, and feature ultra fast, glitch and click free, preset switching and is full Midi (learn) and remote (Web-interface/ GUI) controllable (bluez / avahi) Changelog: * fix some rc-style bugs for KDE Qtcurve engine * add 2 new rc-styles (flat and green) * replace old outdated factory presets * add some new plugin presets * add jack midi out port to report state (CC messages) and control multiple instances with one interface * set engine.mute to default midi controller 120 (All Sounds Off) * add new command-line options -L start with Live Play GUI and -M start with engine muted * fix some issues with remote control GUI and external plugs Guitarix is free, open-source software, distributed under the terms of the GNU General Public License (GPL) version 2 or later. Please refer to our project page for more information: http://guitarix.sourceforge.net/ Download Site: http://sourceforge.net/projects/guitarix/ regards hermann _______________________________________________

10 years, 5 months

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Linux-audio-dev