Re: Music on the XO
Seth Woodworth wrote: Slightly off of the conversational thread here but: Information on the specific output spectrum capabilities might improve transcoding of audio files into smaller file sizes. If there is no, or poor quality, auditory response below or above a given threshold, it might be worth snipping off various frequencies, or otherwise optimizing how materials are encoded to take advantage of this. The speakers start rolling off at about 600 Hz and are virtually worthless below 400 Hz. The hardware has a one-pole highpass filter at about 400 Hz (I forget the exact frequency but it doesn't matter much) in order to reduce the amount of useless LF energy that is presented to the speakers. The rolloff is only in the speaker path; the headphone path has flat response across the audio band. In my experience, equalization doesn't improve the sound from the speakers very much. They sound tinny and weak no matter what you do. Taming the big peak in the 4 Khz range is of some value, but most program material has little information in that region, so the perceived improvement is small. Boosting the bass makes things worse - the speakers don't have enough air-moving capacity (cone diameter times linear motion range) to render low frequencies, and sending them more signal just slams the mechanical structure against its physical limits, causing distortion and possible damage. Bottom line - don't sell your Klipschorns. Is Jamendo, or anyone else, studying this? And Re: above conversation. Yes, I would love to see ethnologists get involved. The at the moment I don't believe is a lack of effort on anyone's part, but a lack of available material. Go to most university's music libraries and you will still find plenty of content in vinyl format as opposed to cd-audio or digital formats. Getting recordings made or existing recordings released into the public domain is an important project, and one of the main topics of a What should Wikipedia do with $100 Million dollars thread about a year back. I believe that just about everyone is on the same page here as far as what they would *like* to see on the OLPC. In the meantime I think that the current selections are far better than nothing.. Seth On 10/28/07, *Jean Piché* [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: If I may summarize, what you are saying is that: a) Given that this is about education, OLPC should be taking the cultural high road in terms of bundled music. yes. b) The perception that acceptable licensing terms will be difficult to impossible to obtain should not get in the way of a) yes. ___ Devel mailing list Devel@lists.laptop.org mailto:Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Music on the XO
On Tue, Oct 30, 2007 at 08:04:22AM -1000, Mitch Bradley wrote: The speakers start rolling off at about 600 Hz and are virtually worthless below 400 Hz. For your collective interest, the speakers can reproduce DTMF tones reliably provided the levels are set down from maximum. At lunch today on a B2 with build-debian, the dtmfdial package was used to transmit tones over a ham radio for making an IRLP request. The DTMF tones include 697 Hz for the top row. In listening to podcasts, certainly headphones sound better. -- James Cameronmailto:[EMAIL PROTECTED] http://quozl.netrek.org/ ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Music on the XO
Mitch Bradley writes: The speakers start rolling off at about 600 Hz and are virtually worthless below 400 Hz. Music activities should thus default to a bassoon. The odd thing about a bassoon is that the fundamental frequency is nearly absent. The ear-brain system fills in this frequency, making the bassoon sound very low pitched without actually containing much of the very low frequencies. At the other extreme, a sine wave is worst case. Recorders produce this, and flutes nearly do. ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Music on the XO
Slightly off of the conversational thread here but: Information on the specific output spectrum capabilities might improve transcoding of audio files into smaller file sizes. If there is no, or poor quality, auditory response below or above a given threshold, it might be worth snipping off various frequencies, or otherwise optimizing how materials are encoded to take advantage of this. Is Jamendo, or anyone else, studying this? And Re: above conversation. Yes, I would love to see ethnologists get involved. The at the moment I don't believe is a lack of effort on anyone's part, but a lack of available material. Go to most university's music libraries and you will still find plenty of content in vinyl format as opposed to cd-audio or digital formats. Getting recordings made or existing recordings released into the public domain is an important project, and one of the main topics of a What should Wikipedia do with $100 Million dollars thread about a year back. I believe that just about everyone is on the same page here as far as what they would *like* to see on the OLPC. In the meantime I think that the current selections are far better than nothing.. Seth On 10/28/07, Jean Piché [EMAIL PROTECTED] wrote: If I may summarize, what you are saying is that: a) Given that this is about education, OLPC should be taking the cultural high road in terms of bundled music. yes. b) The perception that acceptable licensing terms will be difficult to impossible to obtain should not get in the way of a) yes. ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Music on the XO
Hello Antoine, Like I outlined in my previous response to SJ, I am not so worried about cultural dominance/imperialism. People are too aware for this to happen as a matter of course. I am concerned with quality. Quality measured locally. If there is condescension to be had, it will be local. Cultural condescension is complicated. It is not a east-west thing. It happens in every society: consider older kids commenting on younger kid's musical tastes. Culture, by definition, is built on the rarification of talent and expression. As you grow more sophisticated, you understand more. The examplar in any culture is what has value. Not the common denominator. jp _ http://jeanpiche.com On 28-Oct-07, at 6:32 AM, Antoine van Gelder wrote: Jean Piché wrote: I am perhaps not in a position to be an arbitrer any more than the undoutedly generous and sharp young minds at Jamendo but I suggest OLPC thread VERY carefully here. Even when there is quality, I am not certain what to think of Nigerian children being fed a diet of DJ Spooky, no matter how much I personally enjoy his work... Dear Jean, Also being a member of the so-called 'dominator culture' I can appreciate where these concerns are coming from as there is much ill-will between people of all countries - richpoor - regarding things that have happened in the past and fears of what might still happen in the future. I would however like to comment that it is at our peril that we tread on egg shells or - even worse - be _perceived_ as treading on egg shells as there is only one sin which is considered more vile than cultural imperialism and that is the sin of cultural condescension!!! :-D I'd like to quote an email I received this morning from Ron Wertlen, one of the folk involved with grassroots olpc here in South Africa, written on his return from a TV shoot for Swiss national television. While reading it, please bear in mind that the area they visited is one of the poorest and most remote of any district in South Africa. (or Africa for that matter!) Ron wrote: the shoot went very well! The main thing is we got on well, the kids had a great time (unfortunately only 20 out of 722). And the highlight was how surprised Cristina was by the kids - they danced for us after the shoot and there was some modern and ballroom dancing there complete with costumes. We decided that would be great as a final scene, to show that there should be no fear of cultural imperialism via the digital content. The people are seeking new inputs for growth wherever they can and OLPC can definitely make a big difference. We overnighted at Bulungula, which is very scenic and it really requires 4x4 driving, which they promptly also filmed to get a good feel of the Wild Coast. After that there was a short interview in the car and then we filmed at the school. 722 kids, 18 educators and I think about 8 classrooms. They have to have classes out of doors. Because of a roaring wind, the interviewing was done in one of the two good classrooms (which also has a principal's corner). that's also where the kids used the computers. I let them play with block the most. They really enjoyed that. Then I switched on the video camera on one, and they figured it out themselves on the other one. These were fairly young kids Gr. 5. - a ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Music on the XO
SJ, Two things. More important: Free music is a great concept... for people who have global access to ineternet-based music pools. Given enough community mass and discernment on the part of the listener, one can get to the subjective and elusive concepts of quality and exemplariness. The problem here is that OLPC, by the very fact it will include collections of music by curated artists out of the free music ethos, gives a value imprimatur where perhaps none is warranted. We dont need a discussion about music's influence on culture but I think everyone will agree its serious business in the education and socialising of a child, increasing manyfold in adolescence. Alas, much of the music that is presently included in the Jamendo collection is, to be honest, dreadful in style and of rather poor quality in production. I am perhaps not in a position to be an arbitrer any more than the undoutedly generous and sharp young minds at Jamendo but I suggest OLPC thread VERY carefully here. Even when there is quality, I am not certain what to think of Nigerian children being fed a diet of DJ Spooky, no matter how much I personally enjoy his work... We should be discerning about what we wish for. Open System ia not Open Culture. Less important: A head's up on the XO audio subsystem: The speakers have a severely biased frequency response. We have recently performed a thorough analysis of the audio response curve of the machine and there is a spectacular 12dB peak between 3000 and 4500 Hz, this on all models. I suspect these are mobile phone speakers designed for voice clarity. What this means is kids will likely crank up the volume so that they can hear some of the lower frequencies. Since the physical size of the speakers prohibits any frequencies below 350 HZ, as they try to get a decent bandwidth, they will get the membrane-against-the- casing distortion (which has the merit of making the kids lower the volume but risks killing the speakers if done routinely). Someone on the hardware side really should look at the long term prospects for audio hardware failure and see what correction we can bring, by limiting signal output and/or equalising the output of the AD1888 (we dont know what can be done on chip...) The solution we have implemented in TamTam is to simply apply a reverse notch filter on the audio signals we send to the speakers. This works well and provides a more pleasant listening experience, but inevitably reduces the dynamic range. It does nothing per se to protect the speakers becasue you can still crank up the volume to casing distortion. Furthermore, our solution only works with the speakers of course, since the line out/headphone output produces an acceptably neutral signal. Thus, to make it sound good in the speakers, we make it sound bad in the earphones. Unless there is a signal we can access that tells us when the line out jack is connected Anyone know? jp (ethrop) _ http://jeanpiche.com On 26-Oct-07, at 9:33 PM, Samuel Klein wrote: Jamendo has been hard at work compiling albums of music and confirmations from their artists, coordinating the work of dozens of curators and smaller partner sites. You can see some of the results of their work here: http://www.jamendo.com/fr/olpc There will be a contribute music interface soon; for now, you can send albums and interested artists to Romain directly (cc:ed here). And there will be more information put up about the artists involved. This has come together thanks to many people, but especially the crews at Jamendo, Free Culture, and the Antenna Alliance. You all rock. If you have contributed music in other formats that doesn't currently show up on the page listed above, let us know; and make sure that you have confirmed the license of your works. Cheers, SJ ___ Library mailing list [EMAIL PROTECTED] http://lists.laptop.org/listinfo/library ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Music on the XO
Jean, Free music, like free culture, is not simply a great concept -- it is a reminder and affirmation of the inherent right to cultivate and share cultural artefacts. If as you say choice of music is of fundamental importance in the education and socialisation of a child, I hope you will agree that the right to educate and socialize a child 'properly' should not be owned by a small group of individuals who can choose whether or not to license said music to you. It should go without saying that old yet beautiful recordings of canonical works which have been enjoyed and revisited for centuries should be available for anyone (such as OLPC) to share with millions of children throughout the world. That there is a legal sense in which this is not possible is a testament to deep failings in our conception of how and where culture is created. To your implied criticism of the Jamendo collections: If there are particular pieces you find of poor quality, not merely distasteful, please let me know which they are. The collections posted were selected with care, and none would suggest that low quality works have a place there. If you link to the Jamendo collection, your comments will appear directly on that page[1]. I would like nothing better than to see those collections become better rounded. While we must start somewhere, that is not because we philosophically privilege the first entries over others. I would likewise love to see our collection of sounds grow to include samples from every family of the animal kingdom. You are in a position to help ensure this. Your input, and suggestions of specific works and collections, is most welcome. While we are careful about the licensing of collections we distribute, we can be more flexible about the collections we link to. Thank you for the upate on the audio response; I do not know the hardware details, but often feel I don't have very subtle control of the audio environment. Perhaps there is some way to offer more than linear volume control? SJ [1] the top post right now: http://conley.toejammer.net/blog/?p=201 On Sat, 27 Oct 2007, Jean Pich? wrote: SJ, Two things. More important: Free music is a great concept... for people who have global access to ineternet-based music pools. Given enough community mass and discernment on the part of the listener, one can get to the subjective and elusive concepts of quality and exemplariness. The problem here is that OLPC, by the very fact it will include collections of music by curated artists out of the free music ethos, gives a value imprimatur where perhaps none is warranted. We dont need a discussion about music's influence on culture but I think everyone will agree its serious business in the education and socialising of a child, increasing manyfold in adolescence. Alas, much of the music that is presently included in the Jamendo collection is, to be honest, dreadful in style and of rather poor quality in production. I am perhaps not in a position to be an arbitrer any more than the undoutedly generous and sharp young minds at Jamendo but I suggest OLPC thread VERY carefully here. Even when there is quality, I am not certain what to think of Nigerian children being fed a diet of DJ Spooky, no matter how much I personally enjoy his work... We should be discerning about what we wish for. Open System ia not Open Culture. Less important: A head's up on the XO audio subsystem: The speakers have a severely biased frequency response. We have recently performed a thorough analysis of the audio response curve of the machine and there is a spectacular 12dB peak between 3000 and 4500 Hz, this on all models. I suspect these are mobile phone speakers designed for voice clarity. What this means is kids will likely crank up the volume so that they can hear some of the lower frequencies. Since the physical size of the speakers prohibits any frequencies below 350 HZ, as they try to get a decent bandwidth, they will get the membrane-against-the-casing distortion (which has the merit of making the kids lower the volume but risks killing the speakers if done routinely). Someone on the hardware side really should look at the long term prospects for audio hardware failure and see what correction we can bring, by limiting signal output and/or equalising the output of the AD1888 (we dont know what can be done on chip...) The solution we have implemented in TamTam is to simply apply a reverse notch filter on the audio signals we send to the speakers. This works well and provides a more pleasant listening experience, but inevitably reduces the dynamic range. It does nothing per se to protect the speakers becasue you can still crank up the volume to casing distortion. Furthermore, our solution only works with the speakers of course, since the line out/headphone output produces an acceptably neutral signal. Thus, to make it sound good in the speakers, we make
