On Fri, 2014-08-29 at 08:12 -0700, Len Ovens wrote: > On Fri, 29 Aug 2014, Kaza Kore wrote: > > > Anyway it's probably more important to talk about the standardised DV25 and DV50 > > protocol all these commercial/prosumer products use for communication that > > tape/card formats. There are some Sony and Panasonic camera that do this fine > > over USB so it's not impossible or a problem with USB itself. I see yours (and > > apparently many others) claim to have some kind of USB Streaming but for some > > reason it's not usually full quality, as you would get from Firewire. Wonder > > why... > > Intel says that nobody really needs that low of a latency anyway in > response some sound cards problems with one of their implementations of > USB3. (the problem was USB2 cards with USB3 ports which are supposed to be > compatable) > > In recording latency is not the issue it is with live work. For recording > latency needs to known and constant and reasonably low for monitoring. I > have heard/read people who say what does it matter if you move your head a > foot or two closer or father from the speaker? But in live work if the > same audio comes from different places it is called a filter. > Yes if it is coming from two sources of different distances you get a comb filter but that's not what we're talking about with distance/delay here. It's more absolute latency. Examples I was presented at while at college/university were: * A piano player striking a key and hearing a sound, from the downwards motion to hearing the sound is about 6ms. Taking into account both mechanical transference from key to string and the sound to the ear. * For comparison this would be the same as a guitarist standing six feet away from his guitar amplifier if we lived in a ideal world (where electricity travelled the speed of light) but there is obviously propagation delay plus any added by stomp boxes (s)he may have. This is not a distance at which a guitarist finds it difficult to play! I sometimes think the hunt for super-low latency is a bit absurd! 3ms, to give you a 6ms round trip, should be a workable amount for pretty much anybody and most I expect could cope with quite a lot higher (not many working methods require the full round trip!) But full round trip is probably also the time when delay effects (com filter and echo) become important, such as using a PC as an LMS or FOH mixing desk. I would consider these specialist cases though. Just my 2c ;-) _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
