Head-Fi.org › Forums › Equipment Forums › Headphones (full-size) › mp3 quality
New Posts  All Forums:Forum Nav:

mp3 quality - Page 7

post #91 of 138
Quote:
Originally Posted by Febs View Post
And if so--and I've said this before--that means that Rockbox's decoder is broken. But that is irrelevant to your other assertion, which is the one that I was responding to: you claimed that one can tell that lossless is different from .wav by looking at the bitrate displayed in playback software. That statement is wrong. It doesn't matter what the bitrate of the encoded lossless file is prior to decoding. When decoded, the data from a lossless file is bit-for-bit identical to the original file.
Thats not wrong like you say, it depends on how you measure the data. The decompressed data is 1440kbps but compressed not.

Is the same with mp3, this is a compressed format too, not only lossy. When you decode a 192kbps mp3 you take more raw data back. Dont know if you understand me.
post #92 of 138
Quote:
Originally Posted by LFF View Post
Well....here is one of my MP3's for all you non-believers:

http://www.sendspace.com/file/6i9zup

Enjoy!

For the record - I have played these MP3's for many headfiers at meets and they all believe they are listening to lossless.
this is because aslong as you rip it from cd you do genuinly get a good sound its when you have an mp3 and downgrade it further that it meks a bad result
post #93 of 138
Quote:
Originally Posted by LFF View Post
Well....here is one of my MP3's for all you non-believers:

http://www.sendspace.com/file/6i9zup

Enjoy!

For the record - I have played these MP3's for many headfiers at meets and they all believe they are listening to lossless.
Someone should quote that in their signature.
post #94 of 138
Quote:
Originally Posted by LFF View Post
Well....here is one of my MP3's for all you non-believers:

http://www.sendspace.com/file/6i9zup

Enjoy!

For the record - I have played these MP3's for many headfiers at meets and they all believe they are listening to lossless.
AHA! Your encoder just doesn't encode past 20KHz. (Which, therefore wouldn't make any difference in SQ to our ears.)

post #95 of 138
An easy way for me to relate sound reproduction and quality is to go visual. We have all seen photos in the newspaper. They are not very detailed even thou the original photo may have had a lot of detail. In fact if you look at one under a magnifying glass you can easily see the individual pixels or color dots. It is easy to understand that it would be impossible to recover the detail by taking a photo of the news print - or any other method. (Converting a 128k mp3 to a higher rate will never result in more accuracy/better sound than 128k!)

Using low bit rates to encode music is a bit like copying a painting using crayons. You can certainly recognize the painting but if the original had a lot of "detail" the difference between the copy and the original would be easily seen. Now if you use a fine tipped brush or pencil (high bit rate) the copy would be harder to discern from the original.

We know detail can at best only be maintained but how well depends on the encoder and the bit rate. If you are copying a photo with a crayon, which details do you copy and how? The better encoders will capture the details that matter, to the limits of the encoding rate.

Lossless encoders use some sophisticated math to capture all the information but encode it in a file size that is smaller than the original. How much smaller depends a lot on the complexity of the original. (It doesn't take much info to describe a simple blue wall but much more to capture the same wall covered with a floral design.) The process in reverse returns the sound to its original form. But since a player converts the info to sound waves in real time, I can see how some less capable decoders might be overloaded with certain types of music.

Something that wasn't mentioned is the best CD can never be an "exact copy" of the music being recorded. It is a digital representation of an analog sound. But while we could tell the difference with an oscilloscope and/or other instruments, we normally can't tell the difference with just our ears. And isn't that what is important to us?

Hope this was understandable and not too long!!
post #96 of 138
Quote:
Originally Posted by jclinton46 View Post
...

That was a great explanation.
post #97 of 138
Quote:
Originally Posted by DavidMahler View Post
My understanding of Lossless is this (I may be totally wrong so don't quote me haha)

A sound wave is a vibration. A vibration is a movement that has a center which you can call the "resting place". A sound wave looks like this:



The vibration is "vibrating" around that center straight line. It is scientific fact that any sound made vibrates equally distant both north and south of the resting position. Meaning if something vibrates at exactly A 440 (440 vibrations per second), then there will be, without variation a wave that both peaks and dips symetrically around the resting place.

Now a wave file copies the vibration exactly (all the peaks and dips).....

The gift about sound though and compressing sound is that you can use only half the represented vibration and have a program read it back to you by playing both the parts of the vibration above the resting place and mirroring it exactly to play what's below the resting place. This concept is exactly like those paintings you did when you were a child and your teach had you paint on one half of the paper and then fold the paper in half and press to have a symmetrical painting!

Therefore you will not hear any differences between flac or alac and a wav file. You may think you hear a difference, but it would be scientifically impossible unless the flac file is corrupt or your reader is working improperly.
Err...you are comparing an analog sinus wave to a WAV file which is already digital. I think you're cutting a few corners here...
post #98 of 138
Someone can correct me, but I believe that vertical symmetry only appears with a theoretical sine wave. Real music is quite different, and often radically asymetrical. You need only take a piece of music and look at the wave form to observe this.
http://www.audiomisc.co.uk/asymmetry/asym.html
post #99 of 138
Quote:
Originally Posted by AS1 View Post
Err...you are comparing an analog sinus wave to a WAV file which is already digital. I think you're cutting a few corners here...
I understand that, but I was trying to explain it in the simplest terms, otherwise the lingo gets too technical
post #100 of 138
Quote:
Originally Posted by mdarnton View Post
Someone can correct me, but I believe that vertical symmetry only appears with a theoretical sine wave. Real music is quite different, and often radically asymetrical. You need only take a piece of music and look at the wave form to observe this.
http://www.audiomisc.co.uk/asymmetry/asym.html
That is true, sound is not continuously symetrical, BUT in order for a sound make, well "sound" it has to peak and dip symetrically at least once......What I mean is for everything audible that we hear there is a positive and a negative. So while an A 440 may not be 440 exactly ,sometimes may waver off to 439 or 442 or whatever, every single vibration has a symetrical positive and negative. This is my understanding.
post #101 of 138
I think you're missing something. There is no centerline in nature.
post #102 of 138
Quote:
Originally Posted by mdarnton View Post
I think you're missing something. There is no centerline in nature.
It's like the equator...a center line which isnt really there, theoretically with every vibration there is a center, but its not visible, but its there.
post #103 of 138
Quote:
Originally Posted by DavidMahler View Post
It's like the equator...a center line which isnt really there, theoretically with every vibration there is a center, but its not visible, but its there.
Stop talking about something you dont understand. you are confusing people
post #104 of 138
Quote:
Originally Posted by Alatriste View Post
Stop talking about something you dont understand. you are confusing people
When I went to audio engineering school it was taught to me that all vibration has an intuitive resting place and the vibration moves away from this spot equally distant in a positive and negative movement. I don't believe science has changed in 10 years.

I also master wav files every day and see this visually everytime I do it. Maybe you don't feel I've explained the science of a sound wave perfectly, but it is scientific truth that a vibration is moving around an invisible center line
post #105 of 138
Quote:
Originally Posted by DavidMahler View Post
It's like the equator...a center line which isnt really there, theoretically with every vibration there is a center, but its not visible, but its there.
That's basic sinus vibrations. How could one symmetrical vibration tell us of so many instruments and sound signatures at the same time? (perhaps I understood you wrong. The center you mean of is probably simply 0 db.)
.....

My dad taught me the basic theoretics about basic analog ->digital conversion.

Before you read this, I suggest you pay a quick visit to wikipedia... I'm just blurting things from memory, I might be wrong at times


I'll try to merely explain where you were wrong, but don't kill me if I'm wrong at some parts... I'm still under-age : D

The graph you showed us is a graph of a perfect SINGLE sinus. It DOES produce a certain sound, but only a single frequency, and textured/pronounced exactly the same, always.

Even single frequency sounds, are produced by many different harmonics of the same sound. Meaning, when you hear a single sound, you hear a certain range of harmonics (Sounds which are multiples of the original frequency). Many harmonics\at produce different sound colors\textures of sound. (harmonics meaning many many sinuses being played simultaneously, until the sinus sound is forgotten, and you hear a sound produced by many sinuses "data" in addition to one another.

As the different sinuses peak and tide at different times, and other instruments are added at time to time, what you eventually get is a "Randomly" Changing graph of all the hundreds and thousands of sinuses added to one another. So you can say the graph is basically a graph of thousands-perhaps millions (I have no idea actually)of different sinuses.

So the graph you showed us isn't merely but a single 440HZ frequency sinus sound, which sounds rather dull and lifeless on it's own.


Now to the subject...

I just tried different mp3 bitrates compared today for the first time. A 128kbps song, and the same one ripped at 192kbps mp3. Both through my zen microphoto+etymotic er-6i.

There was a definative and highly effective difference between the low bitrate version to the high bitrate one. The low, sounded muffled and un-present, while the 192KBPS sounded just, there, present, punchy, better!

I'm going to try some of my other CD's, I think I'm switching to 100% 320KBPS MP3...



What about WMA? Will 320KBPS WMA sound better then 320KBPS mp3? (I don't understand all that much about encoding.)
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphones (full-size)
Head-Fi.org › Forums › Equipment Forums › Headphones (full-size) › mp3 quality