It's a very obscure local joke. I live in Nova Scotia, and we are called "Bluenosers" (something to do with the North Atlantic climate I suppose). There was a famous fishing schooner called the Bluenose that sailed out of Lunenburg and won many races against American vessels (they used to race the fishing boats, and she won the International Fishermen's Trophy in 1921 and kept it for 17 years of races). So for a screen name I chose something to celebrate my heritage, with a nod to the French Acadians who first settled here (until the British threw them out and stole their land in the 1750's), but which would not mean much of anything to anyone else.
Ed’s targeted questions helped me learn a few things and I thank him for that.
Speakers and acoustics are his fields of activity, he knows what he is talking about.
Acoustics in small spaces is still a big issue for me and any essential info provided by the old hats is welcome.
I ask for your understanding if I have consumed some bandwidth here with things that are trivial to the majority of the participants.
Then, we may have a different understanding of the meaning of troll
Hint: Ask any German, they will provide another interpretation of the meaning
(‘Ich bin blau’)
George
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It's a very obscure local joke. I live in Nova Scotia, and we are called "Bluenosers" (something to do with the North Atlantic climate I suppose). There was a famous fishing schooner called the Bluenose that sailed out of Lunenburg and won many races against American vessels (they used to race the fishing boats, and she won the International Fishermen's Trophy in 1921 and kept it for 17 years of races). So for a screen name I chose something to celebrate my heritage, with a nod to the French Acadians who first settled here (until the British threw them out and stole their land in the 1750's), but which would not mean much of anything to anyone else.
I thought there might be a story behind the nickname. Thank you for telling it. Names are funny, they sometimes tell interesting stories. For example, my family name "Veselinović" roughly translates as the son of a joyful person, if somewhat styiized it could be translated as "Joyson". I think it describes me reasonably well, I might not be laughing all the time, but I am never gloomy or surly. Or am perhaps once every 10 years or so.
OK, but we need some numbers. Well designed power amplifier will have almost no measurable distortion above -100 dB at say 2Vrms output voltage. I have done quite a lot of distortion measurements with speakers. Typical midrange, 5", at 2Vrms, measures like the one attached. Yes, 2nd and 3rd harmonics dominate. But it has higher harmonics as well and they are huge compared to distortion of well designed amplifier.
Though I agree with you that amplifier's sound may be quite easily distinguished through speakers, harmonic distortion of the amplifier is definitely not the case of perceived difference.
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I am not sure where all this talk of how something was recodred, whene and using which mikes is of ayn practical use here, nor does it make sense to me. As far as I could tell, none of us here is engaged on such activities. How do we improve on what's already been done, under DIY conditions?
I'm sure each and every one of us has a few recordings, on LP, CD or even master tape, he considers to be excellent in technical terms. Using these sources helps us identify audio gear we feel is good in some proportion that source material helps us achieve a believable illusion of "being there", or the performers "being in the room". If we now change a part of our system and the illusion is lost or sigificnatly changed, we have proof of the pudding that not all audio gear sounds the same, no matter how it measures. Which in turn means that not everything is well in the elctronic side of the audio world.
As for speaker designers, my feeling is that far too many of them do not think about how their speakers will interact with the power amps driving them, they assume far too many wrong things, so we end up with speakers only the exalted few can actually drive. Remember the Infinity reference speaker set, two mammoth boxes per side, but with a twist of evil, if memory serves its impedance dropped below 2 Ohms and with a solid -45 degree phase shift, presenting a load which could be driven only by Levinson amps, as recommended. With all respet to Infinity, I would call that a reckless design.
But the key point here is that by introducing such subjects we widen the selection of topics to the point where no single engineer is likely to be truly competent any more, let alone the non-engineers. To what end? Are we now to supply proof of various theses put forth by supplying our own recordings to prove our point? On a matter which to us is a fit accompli, it's already done, all we can do is make wild guesses how it might have turned out better?
I'm sure each and every one of us has a few recordings, on LP, CD or even master tape, he considers to be excellent in technical terms. Using these sources helps us identify audio gear we feel is good in some proportion that source material helps us achieve a believable illusion of "being there", or the performers "being in the room". If we now change a part of our system and the illusion is lost or sigificnatly changed, we have proof of the pudding that not all audio gear sounds the same, no matter how it measures. Which in turn means that not everything is well in the elctronic side of the audio world.
As for speaker designers, my feeling is that far too many of them do not think about how their speakers will interact with the power amps driving them, they assume far too many wrong things, so we end up with speakers only the exalted few can actually drive. Remember the Infinity reference speaker set, two mammoth boxes per side, but with a twist of evil, if memory serves its impedance dropped below 2 Ohms and with a solid -45 degree phase shift, presenting a load which could be driven only by Levinson amps, as recommended. With all respet to Infinity, I would call that a reckless design.
But the key point here is that by introducing such subjects we widen the selection of topics to the point where no single engineer is likely to be truly competent any more, let alone the non-engineers. To what end? Are we now to supply proof of various theses put forth by supplying our own recordings to prove our point? On a matter which to us is a fit accompli, it's already done, all we can do is make wild guesses how it might have turned out better?
I understand the criticism from a couple of folks who do it professionally concerning the room treatment, etc. but I have heard few audience recordings as clear as the one we did. Ordinary stuff, something any DIY'er could duplicate on a marginal budget. Before I forget those nasty little eight legs were right there too.
I think PMA's point applies equally well to a microphone diaphragm at high SPL.
[QUOTE
What fascinated me personally was an effect I could never explain. A taped song from a quality LP was in all respects like the original, but somehow, the bass lines tended to be more forceful, better defined, almost palpable, so much so that no cartridge I ever tried could match. It was so with my older Uher tape deck, it was so with the Philips, and it was so with a reVox A and B series decks.
Jesus, I loved those years.[/QUOTE
Copy better than original? Mona Lisa copy with more vivid colours than original painting? Some sort of distortion reducing effect? Or useful coloration.
What fascinated me personally was an effect I could never explain. A taped song from a quality LP was in all respects like the original, but somehow, the bass lines tended to be more forceful, better defined, almost palpable, so much so that no cartridge I ever tried could match. It was so with my older Uher tape deck, it was so with the Philips, and it was so with a reVox A and B series decks.
Jesus, I loved those years.[/QUOTE
Copy better than original? Mona Lisa copy with more vivid colours than original painting? Some sort of distortion reducing effect? Or useful coloration.
I really don't know, but my guess would be coloration. Subtle in every sense except on deep bass lines, where it was hardly subtle, more like towering. And yes, I did prefer the tape to the orginal LP track. It simply sounded better to me.
Pavel,
The loudspeaker distortion curves are interesting. The issue is how much is the microphones contribution. If I got those curves I would check for dust in the microphones grid or on the diaphragm. (Typical of a used precision microphone!). You might want to measure a hot wire to see what harmonic structure you get.
The loudspeaker distortion curves are interesting. The issue is how much is the microphones contribution. If I got those curves I would check for dust in the microphones grid or on the diaphragm. (Typical of a used precision microphone!). You might want to measure a hot wire to see what harmonic structure you get.
George,
You win the prize again. Some use cosine others cosine squared to modify the absorption based on angle. Now the values given by manufacturers often do not include measuring methods. Around here it is mostly done is special echoic chambers and assumed to be random incidence. When a small sample is used for one off measurements the the tube method is often seen.
My field measurements regularly do not agree with the commonly accepted values. Most if the software uses those values. One program expects you to insert the value for each surface.
The result is that mapping a loudspeakers coverage for the direct field can be quite accurate. Much work needs to be done before similar accuracy will happen for the final acoustic field results.
This is biggie when you design systems that have to meet speech intelligibilty standards for life safety requirements.
Now have you observed what happens you you ask an instructional question on this thread?
The folks who have uniformed opinions, just want to spout and trolls go silent! Really is a noise reduction method.
You win the prize again. Some use cosine others cosine squared to modify the absorption based on angle. Now the values given by manufacturers often do not include measuring methods. Around here it is mostly done is special echoic chambers and assumed to be random incidence. When a small sample is used for one off measurements the the tube method is often seen.
My field measurements regularly do not agree with the commonly accepted values. Most if the software uses those values. One program expects you to insert the value for each surface.
The result is that mapping a loudspeakers coverage for the direct field can be quite accurate. Much work needs to be done before similar accuracy will happen for the final acoustic field results.
This is biggie when you design systems that have to meet speech intelligibilty standards for life safety requirements.
Now have you observed what happens you you ask an instructional question on this thread?
The folks who have uniformed opinions, just want to spout and trolls go silent! Really is a noise reduction method.
Pavel,
Almost forgot to mention the proper way to clean a microphone.
For Scott and SY I recommend compressed air. SY I know has lots of it.
However to avoid damage the best method is on a precision microphone to unscrew the protection grid which can be cleaned with compressed air if removed far enough to avoid the diaphragm. Once the grid is off you can see the diaphragm and the dirt. I use a sable makeup brush to clean it. If there is oily stuff on a metal diaphragm then high purity alcohol can be used to remove it. If there is oil also clean the grid.
Almost forgot to mention the proper way to clean a microphone.
For Scott and SY I recommend compressed air. SY I know has lots of it.
However to avoid damage the best method is on a precision microphone to unscrew the protection grid which can be cleaned with compressed air if removed far enough to avoid the diaphragm. Once the grid is off you can see the diaphragm and the dirt. I use a sable makeup brush to clean it. If there is oily stuff on a metal diaphragm then high purity alcohol can be used to remove it. If there is oil also clean the grid.
No reason for underestimations, Ed, I have cleaner measurements of different drivers as well. However, it makes no sense to exaggerate amplifier distortion and to argue with crossover distortion. I am more and more disappointed here. Would you show some speaker distortion measurements with same resolution as I did.
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My common measurements are of noise level, frequency response and intelligibilty. If I get the chance I will measure a small driver and send it to you for comparison.
A past project that needs to be updated was a standard chamber for testing loudspeakers. I think I did post a picture of it.
Do have some interesting stuff to post when I get the chance.
My microphones have lots of GNFB, op-amps too, that makes the difference.
120dB SPL with no distortion from the electronics. That was from a 9V battery for portable applications, from 48V phantom power 150dB SPL is no problem.
Pavel,
Almost forgot to mention the proper way to clean a microphone.
For Scott and SY I recommend compressed air. SY I know has lots of it.
However to avoid damage the best method is on a precision microphone to unscrew the protection grid which can be cleaned with compressed air if removed far enough to avoid the diaphragm. Once the grid is off you can see the diaphragm and the dirt. I use a sable makeup brush to clean it. If there is oily stuff on a metal diaphragm then high purity alcohol can be used to remove it. If there is oil also clean the grid.
I threw out the capsules that were filthy, two had chewing tobacco spit dried all over the grid.
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