Home |
Search |
Today's Posts |
#41
Posted to rec.audio.pro
|
|||
|
|||
Kahn Symmetra-Peak
On 18 феб, 14:29, "Arny Krueger" wrote:
"Scott Dorsey" wrote in message In article , hank alrich wrote: Bill Graham wrote: Scott Dorsey wrote: Bill Graham wrote: Yes. - I wonder if my horn can do something like this....There are many different sounds that some people can get out of it. I will have to think about it for a while..... Yup. *Trumpet is one of the most asymmetric waveforms there is, with positive-going peaks that are enormous compared with the negative-going ones. Correspondingly you can use aggressive limiting on trumpet without changing the tone all that much. I have a suspicion that while the positive part of the wave might not look like the negative part, the area between the two curves and the base line should be the same. For an "engineer" you are remarkably prone to guessing, and guessing wrong. Again, put the music into a DAW and take a look. If the wave were directly measuring air pressure, it would have to be that way because the total pressure has to be the same before and after the note. The thing is... what a cardioid microphone measures isn't direct air pressure or anything much like it. Thing is that a velocity microphone like a cardioid is by definition a high pass filter with zero gain at DC. But, forget about the mic, the mic preamp is AC coupled. *So, the following must always be true no matter what the microphone: Without DC coupling and with reasonable linearity, the integral of the voltage in the recording above zero *must* *be equal to the integral of the voltage below zero. Or as Bill correctly said: "...while the positive part of the *wave might not look like the negative part, the area *between the two curves and the base line should be the same." A tragic example of an attempt by a mob to mis-define technical truth by political means. Bill is unpopular with some people, so an apparent error is created out of a true thing that he said. Sad. :-(- Сакриј наведени екс - - Прикажи екс између наводника - DNFTT |
#42
Posted to rec.audio.pro
|
|||
|
|||
Kahn Symmetra-Peak
On 19 феб, 06:55, "Bill Graham" wrote:
Arny Krueger wrote: "Scott Dorsey" wrote in message In article , hank alrich wrote: Bill Graham wrote: Scott Dorsey wrote: Bill Graham wrote: Yes. - I wonder if my horn can do something like this....There are many different sounds that some people can get out of it. I will have to think about it for a while..... Yup. *Trumpet is one of the most asymmetric waveforms there is, with positive-going peaks that are enormous compared with the negative-going ones. Correspondingly you can use aggressive limiting on trumpet without changing the tone all that much. I have a suspicion that while the positive part of the wave might not look like the negative part, the area between the two curves and the base line should be the same. For an "engineer" you are remarkably prone to guessing, and guessing wrong. Again, put the music into a DAW and take a look. If the wave were directly measuring air pressure, it would have to be that way because the total pressure has to be the same before and after the note. The thing is... what a cardioid microphone measures isn't direct air pressure or anything much like it. Thing is that a velocity microphone like a cardioid is by definition a high pass filter with zero gain at DC. But, forget about the mic, the mic preamp is AC coupled. *So, the following must always be true no matter what the microphone: Without DC coupling and with reasonable linearity, the integral of the voltage in the recording above zero *must* *be equal to the integral of the voltage below zero. Or as Bill correctly said: "...while the positive part of the *wave might not look like the negative part, the area *between the two curves and the base line should be the same." A tragic example of an attempt by a mob to mis-define technical truth by political means. Bill is unpopular with some people, so an apparent error is created out of a true thing that he said. Sad. :-( Well, another way to look at it, is where would you draw the baseline given any random audio waveform? You could put it halfway between the peaks, or at the average voltage point, or where the areas below it and above it are equal. I believe a scope puts it, defacto, at the average voltage point, since you set it yourself based on no voltage input at all, and the scope deflects it up or down based on voltage input.- Сакриј наведени екс - - Прикажи екс између наводника - I used to use some VST (or DX) plugin, supposed to emulate tube distortion, it'd make waveform (on screen, in DAW) totaly asymetical, as if whole thing slided down across zero line. |
#43
Posted to rec.audio.pro
|
|||
|
|||
Kahn Symmetra-Peak
On Thu, 17 Feb 2011 14:04:44 -0500, Peter Larsen wrote
(in article ): nterestingly positive sounds slightly sharp while negative sounds slightly flat. Really!? Peter, Not that I doubt you, but do you have a more detailed source for this? I'm a negative peaker. Does that mean I should try to go over the note intended to hit pitch? Regards, Ty Ford --Audio Equipment Reviews Audio Production Services Acting and Voiceover Demos http://www.tyford.com Guitar player?:http://www.youtube.com/watch?v=yWaPRHMGhGA |
#44
Posted to rec.audio.pro
|
|||
|
|||
Kahn Symmetra-Peak
Ty Ford wrote:
On Thu, 17 Feb 2011 14:04:44 -0500, Peter Larsen wrote (in article ): nterestingly positive sounds slightly sharp while negative sounds slightly flat. Really!? That's my guideline to rapid perception of the polarity of vox humana, another is the continuity of the stereo image across the center, also the perceived length of the delay between sound and reverb seems to me to be too short in case the polarity is wrong. Peter, Not that I doubt you, but do you have a more detailed source for this? This goes way back to when late Steen Duelund taught me to listen for loudspeaker oddities way back 1975-ish when he was modifying 8" loudspeakers to tame their requency response and delayed resonances for use in his rear loaded horn designs. I have seen some reference of it in the newsgroups, possibly in the context of a debate I had with Arny about this way back, probably between 1999 and 2001 over in rec.audio.tech. It was Arny who explained how equal harmonic acts as a detection bias by adding asymmetry to the waveform. That correlates very well with the importance attributed to the effects of polarity when using rear loaded horns with their asymmetric loading of the loudspeaker membrane. Consequently as Arny stated back then it is not in itself a positive quality for a transducer system, aka loudspeaker or headphone, in case polarity is easily audible. I'm a negative peaker. Does that mean I should try to go over the note intended to hit pitch? Nobody is purely "positive" or "negative". I think you should just "be the pitch" and not worry, it is very subtle and more about the colour of the chord than about the intonation, trusst your brain. It is the death metal music guys that have to worry because pitch perception is influenced by level in sones. Some albums are fun to use for listening practice because of polarity oddities, they are just never right. Elton John's Brown Dirt Cowboy is one of them. Listen also for center image stability and whether sources are "inside the stereo image" or "on the outside of it". In case someone wants to attribute the latter to channel inversion, yes they are right, it sounds somewhat similar, but to a lesser extent. This is about subtleties and not about shiploads and it may not matter to some, not all hearing faculties work in the same manner. Ty Ford Kind regards Peter Larsen |
Reply |
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Co-Founder Of Electro-Voice: Albert Kahn, 1906 - 2005 | Pro Audio | |||
DIY peak or VU meter | Pro Audio | |||
FS: Electra Glide Ultra Kahn Power Cables(s) x4 | Marketplace | |||
FS: Electra Glide Ultra Kahn Power Cables(s) x4 | Marketplace | |||
Anyone using Peak 3.0 or 4.0 for Mac OSX? | Pro Audio |