What are transients (the musical kind)?*

No, I'm not talking about people. But I read quite frequently about transients in regards to recordings in these pages and was wondering if anyone could provide a definition or illuminating discussion of what these are. Thanks.

 

In acoustics and audio, a transient is a high amplitude, short-duration sound at the beginning of a waveform that occurs in phenomena such as musical sounds, noises or speech.[1][2] It can sometimes contain a high degree of non-periodic components and a higher magnitude of high frequencies than the harmonic content of that sound[citation needed]. Transients do not necessarily directly depend on the frequency of the tone they initiate.[citation needed]
Transients are more difficult to encode with many audio compression algorithms, causing pre-echo[citation needed].

(( A very loud, short duration sound ))

 

This typically refers to loud musical peaks, such as a drum hit, that are above the average musical level. 1 watt of amplifier power can be loud, but for very dynamic music you must also have the headroom to reproduce the instantaneous blips of loud sound that last for milliseconds or even just one wave cycle.

 

I suppose you are quoting Wikipedia? Cite your sources.

 

This little blurb describing the Sonnox Transient Modulator DAW plug-in describes transient information pretty succinctly:

"As any good engineer will testify, a recording’s transient detail – in other words, the first few milliseconds of sound energy contained in an instrument’s attack phase – forms a defining part of the overall sound quality of a track. This comes as little surprise when you realise just how much auditory information the ear extracts from a transient, with a sound’s complete identity often being formed in a time period as short as three or four milliseconds. "

(from http://www.musictechmag.co.uk/mtm/reviews/transient-modulator)

(In my own words now), this would also help explain why compression may potentially be detrimental to a sound, when in order to make something loud you soften/bring down the attack (changing the transient information) in order to bring up the decay portion of a sound, bringing you closer to that brickwalled-looking waveform. A brickwalled track has REALLY messed with the transients when you consider that snare drum attacks become nearly impossible to locate within the waveform.

 

Our host brought the topic up once in regards to the Beatles, which led to an interesting discussion.

http://www.stevehoffman.tv/forums/showthread.php?t=189997&highlight=transient+attack

 

What many of us are becoming since this godawful economic downturn began five years ago...

 

I think the easiest way to wade through all this technical mumbo jumbo would be to install a DAW on your computer like pro tools, logic, cubase, something that can utilize 3rd party audio plug-ins, then try a demo of the Waves L3 bundle (its a pretty common mastering limiter). Import an audio file into your sequence that seems to have a good amount of dynamic range, where all the attacks are sharp isolated points. Then insert the L3 plug-in onto that same track, and try pulling down the threshold A LOT. You'll quickly hear that you're making the track very loud while obliterating the finer details of the instruments being played.

Okay so not everybody is going to go to the trouble to install these things on their computers, let alone shell out the extra dough when they could just be buying more records, but for me at least this is a very obvious illustration of how things can get brickwalled (in modern music at least), and the sound you achieve by doing so is a familiar one nowadays.

For the Beatles discussion the technology involved would be quite different obviously, but they might have been going for their own version of the "brickwall" by putting condenser mics close the drums and overloading them, hitting the recording levels hard to get natural tape compression, using compressors liberally to achieve creative effects (this is just going off of memory from reading geoff emerick's book a while back).

And I do realize that bringing up the Beatles like this might get me in trouble around here.... but I'd love to see more of a discussion on this tough-to-discuss topic!

 

I was thinking about transients today, how terrible almost all types of sound reproducers are at recreating them, something about frequency and energy or something.

When a drum gets whacked the waves start at there max value and taper off. When a speaker tries to reproduce that wave the start isn't the max, it takes a few cycles to reach max and then tapers off.

 

Thanks all for answering my query on what a transient is. I think I understand, at least I comprehend the definition.

But then I read the entire thread refered to here:

Now I realize that in listening, I wouldn't know a compressed peak from a transient if he was on bath salts and bit me in the a**.

Any soundclips anyone could post that demonstrate a transient and a peak w/o transient?

 

And there I was thinking transients meant cross-dressers, ah well!

JG

 

Transient reproduction is a key reason why Hi-Rez music sounds better than redbook audio. Some believe that DSD handles transients more transparently than PCM.

 

Haha, uh never

 

Ive always found "Low level" sounds to be superior on Higher res, music media, not transients.

Ambiance, and very low level sounds remain intact and do not whither away into digital "noise"....

 

Interesting.
My contribution would be to mention an old BobCarver advertisment. in which he discusses a scisssors snip (transient)
"""Once, Bob Carver visited a famous sound researcher who was attempting to recreate the "snip" of an ordinary pair of scissors. He used no less than TWENTY-FOUR 200-watt amplifiers for playback, yet when viewed on an oscilloscope it was apparent that the top of that instantaneous transient was being distorted. Believe it or not, he needed more power! It was evident that real-world sound occurs very quickly and requires far more power than ANY current amplifier could produce." ""
This quote is so widely disseminated it would be hard to find the original source..
The idea was used in an advertisment for one of his early amplifiers..

 

I owned a Carver 1.5 and I wish I had never sold it. I liked it back in the day..
I replaced the Carver with a Forte'4a. and after using that for 17 years i bought a Bryston 4B-SST2 a few years ago.

 

Transients are the attack, decay is the sound that trails off. For example, pressing a key on a piano creates a transient (the attack or the 1st loudest part of the note you hear) and then a decay (the trailing off, fading out sound of the piano note).

Another example - hitting a cymbal creates a transient (the attack or crash of the cymbal) and then the decay (the trailing off sound of the cymbal).

If you hit the cymbal and then instantly grasped it with your hand you get the transient but your hand stopped the decay.

The reason transients are so important in music is because they give the music dynamics. Dynamics give music feeling, energy and life. With the Loudness Wars of today transients are clipped off and we are left with lifeless distorted music because the Mastering engineer got rid of the nice peaks and valleys in the waveform.

Hope that helps!

 

I was going to try and dumb this down some to explain it, but then I saw this post.

The part about it being the loudest part on the album is annoying when you are trying to deal with overall volume.


Usually, it has something to do with fast moving air hitting a mic and causing a burst. In this case, the guy snapping his fingers - that initial spurt of air shooting out from between the fingers directly hit the mic - probably right next to his hand. On tape, this would just distort for a micro second, and would be covered up - tape cant react that fast, it just records it and it is what it is. On digital, this comes out sounding nasty! This is one of the benefits of tape on things like cymbals and vocals - it blurs over stuff like this pleasingly. SHHHH sounds can do this kind of thing too.

 

This thread popping up again spurred me to reach for my invaluable copy of J. Gordon Holt's pithy little Audio Glossary (1990):

transient 1) A sudden, brief burst of signal energy, characterized by a rapid rise and decay; 2) the attack phase of a percussive sound, such as the striking of a triangle​

 

Not necessarily, but most 1/2 speed cut records generally do a better job of handling transients than do conventional cuts.

A lot of this is due to the increased headroom available for the cutting amplifier. Also avoiding the accelerator limiter can help with transients of conventional cuts but if you're taking that approach you'd better watch your levels.

 

This is new to me. I believe you're talking about saturation which can easily be avoided by lowering levels. I don't think it has anything to do with the reaction speed of tape. I've recorded massive transients on tape with no problems by either using noise reduction techniques or keeping the levels down.

Keep in mind that with some sounds, like a conventional soft flute or synth, the peak versus average level can be about the same. OTOH when you record a glockenspeil or triangle, the peaks can be well more than 10db higher than the average levels and may not even be visible on a conventional vu meter. Those are what I call transients. A good recording engineer keeps this all in mind when setting gain structure.