[leeperry]

traditional chinese music has all those very clear/percussive and bright sounds that are very hard to reproduce IMO...like this song on the "Enter The Dragon" OST, I always use it to test tweaks/hardware improvements: http://www.youtube.com/watch?v=OhQUjF-78fo

 

[hodgjy]

Good point.  I think digital sources really have the most trouble with this, whereas true analog, like vinyl and reel-to-reel tapes are better at it.
 
Quote:

traditional chinese music has all those very clear/percussive and bright sounds that are very hard to reproduce 

 

[Headlab]

Not exactly a musical instrument, but: a few years ago I started an engineering project that aimed to use acoustic analysis to detect operational abnormalities in small jet engines. It was mostly for "fun" but I learned a lot about sound and its behaviour - the way air molecules act when they're being slapped around by bits of metal spinning at 10 000rpm is pretty damn fascinating. There was a boatload of interaction and harmonic activity.
 
Reproducing these sounds accurately proved to be extraordinarily difficult to say the least, but it was an enlightening experience.

 

[Anaxilus]

Quote:

Not exactly a musical instrument, but: a few years ago I started an engineering project that aimed to use acoustic analysis to detect operational abnormalities in small jet engines. It was mostly for "fun" but I learned a lot about sound and its behaviour - the way air molecules act when they're being slapped around by bits of metal spinning at 10 000rpm is pretty damn fascinating. There was a boatload of interaction and harmonic activity.
 
Reproducing these sounds accurately proved to be extraordinarily difficult to say the least, but it was an enlightening experience.

 
Now thats a good one.  Didn't think about mechanical noises.  F1 cars rev to 18-20k rpm.  An M1A1 tank might be good too. Jet turbine, trackpads clomping, metal squeeling, hydraulics pumping, weapons firing all at the same time.  That's a pretty complex sound signature.
 

 

[SP Wild]

We can't even accurately recreate the sound of an 18 wheeler let alone a Raptor jet.  As an auto technician, listening to an engine throughout its rev range is a key part of diagnosis of possible problems - Let me say accurately recreating the sound of a high performance V12 is next to impossible.  That is why I say - there is a lot more bass in reality than what most headphones will have you believe.

 

[santacore]

Pipe organ and harp come to mind. Along with piano and acoustic guitar or similar stringed instrument.

 

[khaos974]

The most difficult sound to reproduce faithfully is pink noise

.
But wait, I'm only half joking, a deviation from a flat frequency response is the most easily perceptible in pink noise track, since very few transducers have a flat response, pink noise is indeed very difficult to reproduce.
 

 

[JB197]

Quote:

pink noise

 

 
khaos974, I think the OP meant natural, voice, and instrument sounds!
 
 
If talking about loudspeakers, I think the answer would depend on the speaker system being used. Surely it is hard to stop and reverse a large mass speaker driver when it is accelerated fast towards it's specified maximum excursion? I think that it's inertia is going to want to keep it going until it runs out of suspension with a distorting bounce and shudder. So my vote goes for "any very, very large amplitude signal at the top of the frequency range of the largest mass speaker in your loudspeaker box".
 
As for single driver systems, such as headphones, at any point in time it can never be in more than one place at once, but it has to get there relative to where it was at the previous point in time, so it would have to be sounds with very large contrasts of frequency and amplitude which require drastic dynamic changes of position. Heavy bass drum combined with a hard hit cymbal? That would require large low frequency displacement combined with tracking small harmonics up to 20+ kHz.
 
I'm just guessing.
 
J.
 
 
 
 

 

 

[Prog Rock Man]

Devin Townsend's, power metal/prog wall of sound.

 

[oqvist]

Even though it´s probably technically piano... I have not heard a headphone coming close to the KeeS modded Pro 900 in that regard. Though I wonder if not voice is a better measuring stick. We hear the human voice every day in all kind of variants. We don´t hear piano every day or to the same degree. So it should be a better reference that way even though it doesn´t include all ranges. If you are mid range focused anyway.

 

[SP Wild]

Simple speech is a good test to gauge midrange tonal balance and phasing anomolies.  Hard transients are more able to stress test driver capability to it's upper limit.
 

 

[magicalpig]

It depends. If your question means "what type of sound is usually butchered by sound techs?" I'd say upright bass and tenor saxophone. No, really.

 

[brconner]

In terms of recording and playback, I find that a distorted electric guitar is one of the hardest things to faithfully reproduce. The range of harmonics in vocals and a purely acoustical instrument are rather small in comparison. The distorted electric guitar has all of the mid frequencies that the non-distorted version has and then it also has all of the distortion harmonics added in! Whenever I compare audio equipment, distorted guitar is always a reference for me because of how drastically the sound of the distortion changes.

 

[Anaxilus]

Quote:

In terms of recording and playback, I find that a distorted electric guitar is one of the hardest things to faithfully reproduce. The range of harmonics in vocals and a purely acoustical instrument are rather small in comparison. The distorted electric guitar has all of the mid frequencies that the non-distorted version has and then it also has all of the distortion harmonics added in! Whenever I compare audio equipment, distorted guitar is always a reference for me because of how drastically the sound of the distortion changes.

Nice one.

 

[LFF]

I have heard it from many, many recording engineers and mastering engineers that the most difficult sound to get right is the piano. I would agree.