Home | Join! | Help | Browse | Forums | NuWorld | NWF | PoPo   
Well Actually....
Counter
About me


jacyhenry
Age. 36
Gender. Male
Ethnicity. White
Location Maysville, GA
School.
» More info.
The Ten Commandments

My Other Favorite Place On The Net


April 2021

  S  M  T  W  T  F  S
              1  2  3
  4  5  6  7  8  9 10
 11 12 13 14 15 16 17
 18 19 20 21 22 23 24
 25 26 27 28 29 30
Subscribe to my nerdy rants
Subscribe to this to blog if you would like to be emailed whenever it is updated.

Your email

The Lie Of Modern Hi-Fi Reiteration
Tuesday. 6.17.08 2:46 pm
Alright first of all let's define High Fidelity. For a system, a stereo system to be deemed HI-FI it must deliver this.

A bandwidth of
-+3Db 20HZ - 20KHZ @ RATED power on both channels.

AND

Total harmonic Distortion is < 1% @ Rated power.

Also the accompaning speakers have to have the bandwidth also.

Now I think I have eliminated about 95% of all modern stereo systems with HI-FI written on them. You find me a system that can deliver 100watts stereo and speakers with these ratings and I will give you a cookie. If you take a close examination of a amplfier box and literature you will see the HI-FI emblem. But if the specs will show some sorry performance. I recently bought a Sony 30 watt desk radio for my mother. It has HI-FI written all over it. If you look in the manual at the specs it shows a bandwidth of 40HZ to 10KHZ under half the HI-FI standard. Also stated that it had up to 10% harmonic distortion. TEN TIMES THE MAX ALLOWED by HI-FI standard. Don't misunderstand. The radio sounds fine but it's not High Fidelity.

CD's have totally disgraced all that is HI-FI. First of all CDs cannot produce the HI-FI bandwidth accuratly. They simply can't.

The Reason? DIGITAL. CD's music is encoded with a digital code. The CD player reads the code and interpets the code into a voltage that is sent to the speaker. In order for proper playback the player reads a code 44,100 times per second. Ok so that is pretty quick right? Not at all. Your computer can read codes at well over 1,000,000,000 times per second. HMMM not so fast after all.

Now the player is 16 Bit. This is the resolution. Like a photo resolution is what determines how clear and vivid a picture is. Now, 16 bit res. What does this mean to a CD player?

A bit is a simple amount of info. The amount of info to tell if somthing is on or off.

0 or 1 Hi or Low

2 bits is more info it can add other possibilities. With 2 bit there is 4 possiabilities.

Nothing Low Medium High or 0 1 2 3

now 3 bits can describe much more info with eight levels.

0 1 2 3 4 5 6 7 or

Nothing
Low
Medi Low
Hi Low
Low Medium
Hi Medium
Low Hi
Hi hi

Ok so whatI have been describing is every bit you add you double the amount of Information available. So in a classic CD player 5V is the high voltage and 0 is the low. If there are sixteen bits then that means it can make 65536 voltages between 0 and 5V.

Let's imagine this on a small scale. Somthing simple like 4 Bits. Including 0 there are 16 possible voltages. And would be this

0.3125
0.625
0.9375
1.25
1.5625
1.875
2.1875
2.5
Look this is the 8th point. We are 2.5 half of 5V
2.8125
3.125
3.4375
3.75
4.0625
4.375
4.6875
5

Ok so a 4 bit CD player could make 16 different voltage levels. What happens though when the sound being recorded to this CD is let's say .2 volts? It won't pick it up. What about if the voltage is 2.6V? It will come out as 2.5V. SO are we seeing some problems with this system?

Maybe it can't reproduce all the sounds. AHHHHHHH

Don't be discrouraged. 16 bits is plenty of voltage levels. 65,536 levels to be exact. So a CD has just OK resolution. It can't totally reproduce all the sounds despite it's high resolution. In fact a CD with digital encoding can never do it. Even with some ungodly number of bits, even megabits.

Ok so we understand the resolution of a CD player. What about the sampling rate.
The best way to describe a sampling rate is like a TV. Have you ever been online and watched a video and it had a low frame rate? How the image seems to jerk and the action doesn't match the sounds. That is the sampling rates fault. The camera took a picture a few times in a second.

When sound is recorded on a CD it works the same way. The recording device takes a sample of the music. It takes a sample 44,100 times a second. So each second of CD music is made of 44,100 parts pieced together. Now this method works great for low frequencies. But as the frequency increases the more it becomes distorted. Just like a camera, the faster the action being filmed the less it captures. What about a normal picture camera. What happens if you move while the pic is being taken. It blurs and distorts.

Likewise with sound, imagine a 20KHZ sound. That means 20,000 movments in a second. The CD recorder can read 44,100 times a second. So it can not acuratly sample the high frequency. So in one cycle of the sound, the recorder will only take 2 samples of the wave. Thus it can not be acurratly reproduced. Inversly a low frequency wave can be very well reproduced. To make it simple a low frequency like 44HZ will have 1100 samples taken in one of it's cycles.

Also in the process of changing a digital code into a analog voltage for the speakers a low pass filter is used. In digital conversion a high frequency clap is created. And is mostly ultrasonic. So a low pass filter is used to cut out the high frequency claps and DC included in the virgin analog signal. The low pass filter workes very well for this application, but unfortunatly it further cuts the upper frequencies of the HI-FI band width.

If you want true Hi-Fi go and find a true HI-FI turntable and an old record in good shape. New records would been recorded by a digital process simular to a CD so only old records from the eighties back can be the true Hi-Fi. Put a true Hi-Fi stereo and speakers with it and enjoy.

In summary Hi-Fi is rare. Stereos are mislabeled to intice you into buying them. CD's and MP3's and other digital music is never HI-FI.
2 Comments.


Records may have better sound quality, but they wear out and most people actually don't care too much, in my experience. As long as he/she can listen to it without mountains of static, the average person is probably fine with our not-so-great digital media. :P

Also I didn't read your whole entry. Mostly I sorta skimmed then looked at the last part. 'Cause it's freakin' LONG, man!

And the IMVU thing... strikes me as a little creepy.
» randomjunk on 2008-06-18 05:09:38

I won't lie
I did read over this before, but I got scared off by the big numbers and complex explanation. I don't know anything about the physics of a stereo, and computing numbers during the summer is COMPLETELY outside of the question :)

I'm with Randy on this one though...my music doesn't need to be Hi-Fi for me to have a good time. As long as the bitrate isn't abysmal and my headphones aren't POS, then I'm good go to. I suppose if I were a high-end consumer interested in this sort of stuff it might be of more use, but all I gather from this is that the market is still full of corruption and falsification despite organizations like the BBB (Better Business Bureau).

I'm pretty sure I can use pieces of this info to throw into salespersons at various stores if they ever try to cheat me into buying junk. I can appear smart without even fully understanding what I'm talking about!
» The-Muffin-Man on 2008-06-18 05:25:22

Sorry, you do not have permission to comment.

If you are a member, try logging in again or accessing this page here.

jacyhenry's Weblog Site • NuTang.com

NuTang is the first web site to implement PPGY Technology. This page was generated in 1.032seconds.

  Send to a friend on AIM | Set as Homepage | Bookmark Home | NuTang Collage | Terms of Service & Privacy Policy | Link to Us | Monthly Top 10s
All content Copyright 2003-2047 NuTang.com and respective members. Contact us at NuTang[AT]gmail.com.