John Curl's Blowtorch preamplifier part II

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Really,
I have solid over the ear sound barriers for use at the gun range and yes I can hear the person talking to me if nobody happens to be shooting within a few feet at that moment. At work my tooling guys wore soft foam ear plugs and I could easily talk to them while they had a mill or lathe running.

This isnt the military range is it? You all fire when ordered to fire and stop all at once etc. Or you are in deep s**t with the range instructor.

And, you dont use them in combat, either. Many men have lost thier hearing by going into military service.



THx-RNMarsh
 
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When playing back on a 24 bit system, it is a noticeable improvement in realism/accuracy to the sound. Mo bits is mo betta. No one here has convinced me otherwise.

THx-RNMarsh
Which is because the digital to analogue conversion is doing a better job of what needs to be done, in your system. So, either improve the converter - or upsample all your material to a format where your current converter works better ...
 
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The unwrapping process has actually been studied. It is a series of sharp impulses as bits of the deformed plastic snap back into shape. When you make the noise measurement with a sound level meter you find it reads less than 10 dBA at 1M. Yet this noise can be heard clearly throughout most concert halls, even though the NC rating may be as high as 35 dB.

Now 10 dBa at 1M allowing even for critical distance reverberation levels or room gain will still be below 0 dB at many seats. The peak concert levels on stage have been recorded by others at 137 dB. Front row levels can easily reach 120 dB. (There is a reason why so many concert musicians lose some of their hearing.)

So now that you are arguing research is not needed just judge with your ears, why don't you try your ears in a live concert and then go back and try the same or similar music on a reproduction system and see just how much difference there really is.

ES


This is very true... many musicians loose their hearing because it is so loud in the orchestra. Just a factoid.

regarding hearing very low level sounds and doing it easily.......

I was at a recital at Carnegie Hall. I was on top row front in the back. [free tickets by my host] ---- A single small bell was held in the left hand and struck on stage and it was as crystal clear to me as if it had been next to me..... great hall acoustics. I dont remember anything of the recital but that little bell sound... it so impressed me. But, point remains, very low level signals are easily heard and get recorded.


THx-RNMarsh
 
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If we use studio standards for levels, we can gain 2 bits at the top end of the range. And, if we can get 2 bits more at the bottom of the range. And if we only convert when going down one step -- 32 to 24 bits -- we gain 2 bits. The extra bits add up to greater dynamic range and less added noise. Plus, the deeper bit number (24) puts us in a better digital recording/playback level range for reduced distortion. And we dont need extra gear to make disks and play them back with thier added processing distortions/noise/artifacts.

Like this --- picture time:

fimage002.jpg


Nothing much to change, is there? We can do this now and bypass the CD. Who bysides myself is currently doing this to hear music at its best?


THx-RNMarsh
 
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I don't understand what that diagram has to do with domestic audio levels. I am also somewhat confused how moving the gain structure around actually gains anything.
signal to noise on the line to the amps by lowering the gain amp you run a much hotter signal improving the snr and reducing the problem of hum and emf problem by uping the line voltage to 10 volts or more rather than less than 1 volt . As well as line loss becomes less of a problem .
 
Richard as close as I got to military service was having my draft card and being on list to be called up to go to Vietnam. When the guns get going who is listening to anybody, your just trying to stay alive.

But as I said you can wear hearing protection and still hear someone talking to you even at the gun range with crazies shooting there 50 caliber hand guns, really mini cannons.
 
Thanks for the picture. I have never seen that gizmo before. It is similar to what they tried to use in tanks and airplanes to get the microphones close enough to work in noisy environments. But here used to stabilize level.

Ed, I am most surprised that you have not seen coleselectroacoustics.com/4104-commentators-microphone, though to be fair these are mostly used in Europe, UK and Aus.
This microphone is generally regarded as the leader in its field. Wherever it is essential to single out a speaker's voice without transmitting background noise, this is the choice of buyers from all over the world.
One example application is its use in sports reporting, selecting the spoken commentary and cutting out the roar of racing cars at Brands Hatch or the screams of the little old ladies in the ringside seats at wrestling contests.
They do make the announcers look stupid, but they also work very well in reducing crowd noise and outputting consistent signal level Lip-ribbon_microphone.
One of the fun things in pro audio is cleaning the windscreens... It will not surprise you to learn what they get loaded with. Smokers of course are the worst.
Yeah, like foam windscreens after a KISS concert...real men don't wear make up and lipstick like those guys do.
Hire company standard kit is a can of Glen-20 Aerosol Disinfectant in the mics case.

Dan.
 
In the end it is programming skill and knowledge of the algorithms, ...
Exactly! And the number of people who excel in this discipline in regard to audio processing is very small worldwide :(
I'd love to do my own SOTA oversampling filters or decimators in DSP, but that is way over my head.
(Yes, I've read the literature and have the basic idea what I need, but it looks that to be good in this art I have to dedicate the rest of my life to mathematics..)
 
If I'm not mistaken, one such device was customized hybrid AD by Analogic.

The irony of it all, Bernie Gordon once stated that 12 bits would be all that audio would ever need. If that is the case it would not take an act of God to recreate it.

EDIT - I see they only offer high level solutions these days, an A to D as an individual product is no longer interesting.
 
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on a military firing range

Don't believe I had the pleasure, we did Belgian (semi) automatic shooting fries in my days. I do have really nice bullet hole and knife scars though.

Then again, you wouldn't believe the places I've seen with ear protection.
I've worn ear protection for years on end in various jobs, everything from simple foam plugs to fancy adjustable valve ones.
Machine shops as Mr Soibelman, ship yards, navy frigate and submarine engine rooms.

Even a stint as a quality controller in a glass bottle factory, called a matman, who walks up to the mould man to tell him it's time to exchange/clean a mould.
While both are wearing ear protection, you wouldn't believe the noise and heat level at the moulding position.
Likely the reason my hearing isn't half bad at my current age.

It's been my experience that hearing human voices isn't that hard while wearing ear protection.
Takes a little practice maybe, like shooting.
 
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