SH Spotlight I was asked "Why do recordings need compression/limiting during recording, mastering?"

Discussion in 'Music Corner' started by Steve Hoffman, Dec 13, 2016.

  1. mavisgold

    mavisgold Senior Member

    bellingham wa
    No Yolk! Scientists Unboil an Egg Without Defying Physics

    No Yolk! Scientists Unboil an Egg Without Defying Physics

    By Tanya Lewis, Staff Writer | January 28, 2015 11:41am ET

    Think you can't unboil an egg? Think again, scientists say.

    Credit: Steve Zylius / UC Irvine

    Scientists have figured out a way to do something that seems impossible: unboil an egg. But strange as it may sound, the feat doesn't defy basic laws of science.

    When you boil an egg, the proteins unfold and refold into a more tangled, disordered form. But in a new study, a group of researchers found a way to pull apart the proteins in cooked egg whites, and allow them to refold into their original shape.

    The finding could dramatically reduce the cost of cancer treatments and food production, the scientists reported yesterday (Jan. 27) in the journal ChemBioChem. [Science You Can Eat: 10 Things You Didn't Know About Food]

    "Yes, we have invented a way to unboil a hen egg," study co-author Gregory Weiss, a biochemist at the University of California, Irvine, said in a statement.

    In their experiment, Weiss and his colleagues started with an egg white that had been boiled for 20 minutes at 194 degrees Fahrenheit (90 degrees Celsius), until its proteins became tangled clumps. Then they added a substance that ate away at the egg white, effectively liquefying it. Next, they used a machine called a vortex fluid device, designed by Weiss' colleagues at Flinders University in Australia, which used the shearing forces in thin, microfluidic films to shape the egg white proteins back into their untangled form.

    Physicists often use cooking eggs as a metaphor to explain the second law of thermodynamics, which states that the degree of disorder, or entropy, in a system of the universe will always increase. For example, once you scramble an egg, it's basically impossible to separate the yolk from the egg white again, because it would be going from a less ordered state to a more ordered one.

    At first glance, Weiss' experiment may appear to defy this law, because an unboiled egg is more ordered than a boiled one, so the entropy should be decreasing. But in fact, the process of unboiling the egg produces entropy in the form of heat, offsetting the decrease in entropy, Weiss told Live Science. So the entropy of the universe still increases, he said.

    Physics aside, the unboiling technique could be useful in a lot of pharmaceutical and biomedical applications, the researchers said. Proteins often "misfold"into useless shapes when they are formed, but if scientists could refold them again, it could save money for drug development.

    Traditional methods of recovering the misfolded proteins are expensive and time-consuming, Weiss said. By contrast, his unboiling technique takes only a few minutes — thousands of times faster than what was possible before.

    For example, drug companies often make cancer antibodies in expensive hamster ovary cells, because they don't often create misfolded proteins. If, instead, these companies could use proteins from cheaper yeast or E. coli cells, it could make cancer treatments more affordable, the researchers said.

    But the medical industry isn't the only one that stands to gain from the findings. Cheese-making and other industries could also benefit from the unboiling technique, the researchers said. UC Irvine has filed for a patent, and is working with potential commercial partners, they added.
    Cracklebarrel likes this.
  2. mando_dan

    mando_dan Forum Resident

    Beverly, MA
    I've had decent luck with gaining a small but noticeable improvement as well.
  3. showtaper

    showtaper Concert Hoarding Bastard

    Yes, but I think that type of recording ended with the introduction of the electrical process
    around 1925.......
    violetvinyl likes this.
  4. Grant

    Grant Life is a rock, but the radio rolled me!

    These programs will visually restore the look of an unclipped file, and perhaps may sound unclipped, but it cannot restore the sound of the original file before the limiting.
  5. showtaper

    showtaper Concert Hoarding Bastard


    Avast blocks the download of the WinAmp version as containing malware. Could be a false positive
    but I'd proceed with caution.
  6. Wugged

    Wugged Forum Resident

    Warsaw, Poland
    So, you've met my wife ?
    EVOLVIST and JamesD1957 like this.
  7. Yost

    Yost “It’s only impossible until it’s not”

    There was a time I would totally agree with you, but now I'm no longer sure. Of course it will never restore the original sound 100% accurately. But understanding the statistical analysis techniques it is using, the software should me able to come close to the original.

    I still didn't test this particular software myself, but I'm using ClickRepair software from an Australian friend of him. And that software really removes clicks and pops from vinyl rips like magic.
  8. Yost

    Yost “It’s only impossible until it’s not”

    Thanks for the warning. I can only say that the site doesn't look suspicious. It's a Dutch site and he shows a proper Chamber Of Commerce ("KvK") Business Register Number. Still, his download files might have been hijacked.
  9. I had read @Interlude65 post, but then I read yours, so I just wanted to add a few comments, in support, and a little against. I mean, yes, you're right; often the art of a studio performance is lost to a lot of today's musicians because they have a crutch to fall back on with studio trickery to get the job done. Yes, that sucks. Regardless, even with the best musicians (and I've had studio sessions with many top-fight musicians), sometimes you're simply going to get that odd note here and there that needs some compression - analog compression, only, as the invention of the digital compressor is a horrid, horrid thing. Digital is not the enemy, though often digital tools are.

    There is another thing that's often lacking in the studio, as well, and it especially comes in to play with amplified instruments, but it also applies to acoustic and synthetic instruments, to be judged depending on how many instruments you have going on at once. That thing is a sound knowledge of what instruments produce what frequencies and how to work with said frequencies in the mix. Not just in the mix, but as an instrument is being recorded as an overdub. In other words, if you have a backing track already laid, whether it was done live, or in overdubs, you gauge those frequencies, then you make sure that your overdubs doesn't have too many conflicting frequencies before you lay it down. The best way, of course, is during the actual recording, and if it's an amplified instrument, you mess with the tone controls on the amp, itself, thus minimizing any mix EQing. You can't ever get this method down pat, because it's all an approximation, even using the best of tools, but it always makes a difference in the amount of work done in the mix.

    That said, I wish this thread was made sticky again, especially with the Sgt. Peppers threads going bonkers. Then again, this type of thread doesn't generally attract a certain group of people who might be really keen on the new remix. That's not to say that elements of the remix don't sound good. I'm merely saying that the mastering choices for the remix was incredibly misguided and unnecessary.
    telepicker97 likes this.
  10. telepicker97

    telepicker97 Got Any Gum?

    [QUOTE="EVOLVIST, post:16543357, member: 46928]That's not to say that elements of the remix don't sound good. I'm merely saying that the mastering choices for the remix was incredibly misguided and unnecessary.[/QUOTE]
    At first I didn't realize what you were talking about...then I realized you must be talking about the CDs, because the LPs sound great...then I had to wonder why anyone would buy the CDs over the LPs and expect anything different than what you've described...
  11. Right. The CDs. I haven't heard the LP, but I have a buddy who is sure to do a neddledrop on one. He has this needledrop down to a science. I'd love to hear it.
  12. Steve Hoffman

    Steve Hoffman Your host Your Host Thread Starter

    Opening by request.
    Front 242 Addict and CrazyCatz like this.
  13. McLover

    McLover Senior Member

    Is Dave D, Dave Dintenfass by chance?
    CrazyCatz likes this.
  14. CrazyCatz

    CrazyCatz Great shot kid. Don't get cocky!

    Maybe they don't.. ..
  15. Terrapin Station

    Terrapin Station Master Guns

    NYC Man/Joy-Z City
    What if you like when it sounds like a bunch of separate things?

    I know that a lot of stuff that sounds like a bunch of separate things to me still has compression on it, but (a) I've done plenty of my own recording where I've not applied any compression aside from whatever might be inherent in the equipment I'm using (it's hard for me to say just how much compression that might amount to--I don't know technical stuff well enough to say, but in any event, I'm simply talking about not applying any compression per say as a plug-in, rack-mount unit, etc.), and I've liked the sound of it, too, and (b) not only that, but I much prefer the sound of my own compression-free recordings to the contemporarily-in-vogue sound where everything is kind of blended/smooshed together. I kind of hate that sound, rather, but I'm used to it enough at this point that I can "listen through it."

    I also don't agree that there can be "too much dynamic range," as long as we're not talking about stuff clipping/being the the red and distorting.

    Ideal mixes to my ear tend to be where you can clearly hear every instrument as a separate thing. It's always seemed pretty easy to me to mix things, without using compression per se, so that they're balanced--so that one part isn't way louder than another part when you don't want it to be, and so that relative volume levels are consistent (relative to whatever dynamics might be in the piece), and so that nothing is clipping, too. Part of it is due to performances, too, of course. As long as you have good dynamic control on your instrument and a good ear to adjust to the other instruments' dynamics, that makes it even easier.

    Maybe what we should do is present an example of something that was mixed with no compression applied?

    Also, re demos, I typically think that there was no reason to rerecord them, as long as the performances and arrangements are there. In other words, I can't remember ever hearing a demo where I thought, "Whoa, this really needed to be rerecorded to fix the overall sound quality/the mix/etc.", though I've thought "Hmm . . . well, this was pretty sketchy in this demo form; it's a good thing they fleshed it out better and/or tightened up the performances." (Of course, I might think sound quality needs to be fixed if we're talking about a demo that was recorded on a boombox with a Certron cassette, but that's not usually what you find released anyway . . . maybe for bootlegs, though)


    Hopefully I didn't simply repeat stuff I already said, lol. I forgot I responded to this thread last year.
    Last edited: Sep 14, 2018
  16. yasujiro

    yasujiro Senior Member

    From : SH Spotlight - Old 78 RPM records: FATS WALLER/BUNNY BERIGAN, etc. sound so amazing 75 years on...
    I understand that 15db refers to RMS while 52db does to peak to peak value. Am I right?
  17. painted8

    painted8 Forum Resident

    So does the difference in compression approaches the reason why I favor the richness and depth of early to mid 70s Who recordings over those made in 65-67?
  18. varispeed

    varispeed what if?

    Los Angeles Ca
    Well, an example off the top of my head is the old single na na na hey kiss him goodbye... That record by Steam. Squashed and lifeless...I put the blame squarely on the compression/limiting choices. I envision every instrument was being squashed going on to tape, squashed on the submix bounces, and squashed on the way to the 2-trk. My opinion.

    On the other hand, it was a hit.

    Orleans by David Crosby. Same thing. I even somewhat complained to whats-his-name, the engineer about that years ago. He agreed that the limiting was over the top. But again.... Who am I to complain on too many levels. The track is cool....even as squished as those gtrs & voices are on it.

    I think templeman really went way too far with compression/limiting on stuff like "Toulouse street". On the other hand, maybe some of the early Doobie Bros..... Hmm....even van halen stuff...wouldn't have the same charm if templeman had backed off on the compressors.
    Last edited: Oct 5, 2018
  19. misterdecibel

    misterdecibel Bulbous Also Tapered

    I dunno, that squashed sound from the compressed-to-death overhead mics on Alex Van Halen's kit just sound like constant white noise, like steam escaping. To some I suppose it adds "Hollywood glitz" to those tracks, but to me it's headache inducing noise.
  20. Which album(s)?
  21. ajawamnet

    ajawamnet Forum Resident

    manassas va 20109

    From the IEEE:
    The Cool Sound of Tubes

    ""In Atwood's opinion, "Some of the differences in the audio qualities between tubes and transistors have to do with the inherent physical properties of the devices and with the circuit topologies and components used with each type of device. There is no way around it: linear [triode] vacuum tubes have lower overall distortion than bipolar transistors or FETs, and the distortion products are primarily lower-order...the clipping characteristic of tubes is actually not much softer than transistors, but feedback tends to 'square-up' the clipping. Thus, the heavy feedback in most solid-state designs gives them worse overload performance.""

    Also see this from:
    The Cool Sound of Tubes

    Typical tube topologies for a 6AU6A and a 6SN7GTB:
    Note where it states:
    "6SN7GTB medium-mu triode: Noise floor is about 130 dB below the fundamental; second harmonic is 52 dB down [blue curve, above]. Operating conditions were taken from the resistance-coupled amplifier tables in RCA tube manual RC-21, 1961, p. 439. Note: the voltage gain of this device is much lower than that obtained with any of the transistors or the pentode.

    6AU6A pentode: Noise floor is about 120 dB below the fundamental; second harmonic is 48 dB down [red curve, above]. Operating conditions were taken from the resistance-coupled amplifier tables in RCA tube manual RC-21, 1961, p. 438. "


    As compared to this:
    Some typical transistor topologies using a bipolar 2N2222 and a common 2N5457 JFET:
    Note where it states:
    "2N2222 low-voltage bipolar transistor: The noise floor is about 125 dB below the fundamental; the second harmonic is -30 dB. The circuit was taken from the output stage of "High-Fidelity Preamplifier," p. 609 of RCA transistor manual SC-14, 1973, with a 2N2222 substituted for the (similar) 2N3242A. A 1-k(omega) resistor was used to match the 20-(omega) output impedance of the generator to the transistor.

    2N5457 low-voltage junction FET: Unlike the high-voltage MOSFET, the JFET has excellent noise performance (-140 dB) but poor distortion (second harmonic is only 30 dB down). Because of the lower I dss of available junction FETs, the drain resistor was raised to 10 k(omega); the bias was adjusted to give about 1/2 V DD at the output."


    For comparison - MJE2361 bipolar and an IRF822 MOSFET transistor
    Note where it states:
    "MJE2361 high-voltage bipolar transistor: In this test, the transistor was substituted for the 6SN7GTB triode, and the bias was chosen to give the same operating point as the tube. A 1-k(omega) resistor was used to match the 20-(omega) output impedance of the generator to the transistor. The result: a noise floor at about -110 dB, and a second-harmonic level of -46 dB.

    IRF822 high-voltage enhancement MOSFET: When substituted for the 6SN7GTB, with bias adjusted to give the same operating point as the tube, the MOSFET exhibited excellent distortion characteristics, which were compromised by its noise floor of -100 dB--about 30 dB above the tube's. Second-harmonic distortion is 41 dB down, which is only 59 dB above the noise."


    And for reference - a Triad audio transformer
    Note where it states:
    "HS-11 transformer;-90 dB Triad HS-11 input transformer: Source impedance was set to 600 (omega). The transformer was loaded by the 100-k(omega) input impedance of an Audio Precision analyzer. This test was included because some professional audio experts commented on the unusual behavior of audio coupling transformers in tube circuits--specifically, that the odd harmonics tend to be stronger than the even ones. The HS-11 is typical of small input transformers used to couple a 600-(omega) balanced line to a tube grid. Residual noise plus distortion of the analyzer, with only a 600-(omega) resistor in series, is at least 118 dB down."

    Note that the spikes at 3, 5, 7 are higher than the ones at 2, 4, 6.

    So a lot of the more pleasant harmonic distortion of tube circuits might be due to the use of coupling transformers that are usually required.

    I say usually. Sometimes they are just coupled with large plate blocker caps.
    Terrapin Station and owsley like this.
  22. ajawamnet

    ajawamnet Forum Resident

    manassas va 20109
    As i mentioned not all tube topologies are transformer coupled

    For instance:
    Not all tubes are glass - This is the type of tubes I worked with - a 15,000 watt tetrode:
    Old datasheet:
    Newer datasheet - shows specs for use in AB1 audio

    These type of tubes in an RCA BTF are cap coupled

    BTW a "UUF" is a "micro-microfarad" another way to notate a picofarad
    the definition of micro-microfarad
    ALSO - 2L6 and 2L7 are sliding fingerstock tuning elements - one for tuning and one for loading.

    Yea - I've overloaded them... not pretty at 15,000 watts @ 90.3 MHz
    Here's what can happen:

    BTW this is not one of the transmitters I worked on (thank God):

    The RCA BTF's were nicknamed "the flamethrower"
    Last edited: Oct 6, 2018
  23. misterdecibel

    misterdecibel Bulbous Also Tapered

    The first three or four I guess, I certainly don't own any of them.
  24. McLover

    McLover Senior Member

    aka Belch-Fire and "Combustible". Big issue with these was the Rexine used inside the PA cavity. Which liked to easily flash over and arc over. This series had no issues with the 10,000 watt and smaller models in the series. BTF 20E series and combined versions of same (BTF 40E) is where problems were not unusual. Tune them for minimum smoke. Very finicky to tune and load right, get them very much out of the parameters they like, that is where a lot of their problems occurred. I used to be a caretaker to a BTF 40E combined installation, so that's why I knew these rigs well. Good transmitters if ran conservatively. The BTF10E was a very excellent transmitter. But we're getting off topic. Quite a few other engineers had the same experiences with the RCA BTF transmitter line.
  25. ajawamnet

    ajawamnet Forum Resident

    manassas va 20109
    We had a real problem with the tuning and loading due to the noxious environment it was in - steel mills in Pgh. - the sulfurous air pollution. trashed the silver on the tuning and loading inductors. Lots of sparks when adjusting them

    Never saw any Rexine (imitation leather) in ours. Tho that would be cool.

    The shelf was funky once-clear Rexolite ... very flammable. Silly decision on RCA's part.
    See the PDF where I got those photos - it's from the guy that worked at RCA and took the 10kW and made the 20 -
    McLover likes this.

Share This Page