Do Audio CD copying "DEGRADES" the sound? A Blindfold Test

[kbhuvi]

So can we take from your comment above that from copy 0 onto copy 6 the sound quality remains CD like and needs multiple listening to ascertain the difference between 0 n 6.
But from copy 6 to copy 9/10 there's drastic deterioration, as far as that 9/10 sound as bad as 128kbps mp3?

Just articulating what i heard. I am not implying anything. Apart from listening I have not examined the files in any way.

 

[Nitin K]

Have heard the wav files on the headphones & then on my modest system. I couldn't find any difference between the wav files. Maybe I don't have the "golden ears"

 

[hector2013]

Anirban...Thanks a lot for conducting this blind test. I have also listened to all the files several times & could not find any noticeable difference. Hence voted for all are same sounding. I believe now these test results will finally conclude all the difference of opinions on this subject of degradation of sound on CD copying...

 

[anirban420]

I want to summerise the result as follows.

There are three groups of people.
1. Group A: This group have found a notable difference (10 people out of 28, 35.71%)
2. Group B: This group did not found any difference (11 people out of 28, 39.29%)
3. Group C: This group can not conclude because of the small difference (7 people out of 28, 25%)

The goal of this test is to address a notable degradation of sound during CD copy. From a general perspective, the files sounded same/similar to Group B & C. They did not perceive any notable degradation in sound among files. Therefore, collectively they represent a category where sound degradation was not notably perceived. Therefore, by summing Group B & C, we can re-sort the result as follows.

1. Group A: 10 people out of 28, 35.71%
2. Group B + C: 18 People out of 28, 64.29%

Therefore, on a general perspective, people who did not perceive a notable difference is roughly double (actually 1.8 times) than the people who marked the difference. That means the majority of the participants (roughly 2/3rd people) can not hear any notable difference, even after 10th copy and in spite of read error in some rips. This can be noted as the outcome of this test.

 

[anirban420]

I want to thank all the participants who voted in this poll, followed the thread and made comments. Also, many thanks to all FMs for appreciating my effort regarding the test.

I want to acknowledge the following FMs who helped and inspired me to design the test.
@haisaikat @subhashis_1980 @bhaskarcan and @hector2013

And last but not least. I want to thank HFV and the team of moderators for giving me such a platform to perform the test.

 

[haisaikat]

Here is my experience, and I would be frank that I felt it difficult comparing all 4 files together at one go. Then I had to request @anirban420 to help me with 2 files the original and the 10th copy (3.wav and 4.wav) but did not tell me which is what.

In my limited capability system, not sure if it's placebo effect, I liked 3.wav more. The main difference I felt was that the high notes were coming up as more smooth sounding and also the female voices sounded more airy. The difference was evident in listening first 2-3 minutes itself.

The rest is history, 3.wav is the 10th copy. I am not sure if others who voted for 3.wav have had similar observation but I felt that a lot many who could not end up finding difference between 4 files, may have been able to make a distinction if 2 files were presented, probably our brains job becomes easier that way. Even now if they do a blind test between the original and 10th copy may end up hearing some differences. Also systems with initial brightness like mine has tendency to produce more prominent highs and that is why any difference at those bands are more easier to perceive.

This experiment also proves, since waveform of the files were observed different, that at times degradation and losses can end up on the positive side too.

 

[prem]

I thought I would just share my experiences regarding an original and a copy made from it.
These experiences relate to the time when I only had a digital rig. So we are talking around 2012. Again these experiences are only related to what I heard in my rig which was Esoteric P 70 transport and Esoteric D 70 dac.

I will first share my experience with a copy made from a master in a studio. The master was on a CD. And the copy was made from the master in the studio itself. When I heard both in my rig, I couldn’t hear any difference. They both sounded same to me.

Many times I have also heard copies made from my original CDs. These copies were made using dB power amp. Here I could clearly hear a difference. The original always sounded more relaxed. I always got the feeling something was wrong in the highs of the copy. I have no idea why this happens. Maybe because of some errors in copying or maybe some jitter or electrical interference finds its way into the copy. The highs in the copy for lack of a better word sounded a bit compressed. Some may hear this compression as highs getting sharper or more defined. Or some may even hear it as more details. And some may not perceive any difference. So I guess different people are going to hear it differently

 

[anirban420]

I will first share my experience with a copy made from a master in a studio. The master was on a CD. And the copy was made from the master in the studio itself.

Just a curiosity that is nothing related to this thread. What was the DAW in which the files were prepared and the master disk was made? And also, what was the copy software?

 

[prem]

I have no idea what was used in the studio. I used the DB power amp software for copying. I don’t remember if the copy was made at home or in my office. In those days I used to have a Mac Pro at home. At office we use DELL

What might also interest you is if you compare the original master CD with a commercially available original CD, the difference is huge. The master CD is way way better.

 

[Deleted member 15865]

The original always sounded more relaxed.

A term rarely used in audiophile sites/forums, but makes a world of difference to the listening.

 

[alpha1]

I want to summerise the result as follows.

There are three groups of people.
1. Group A: This group have found a notable difference (10 people out of 28, 35.71%)
2. Group B: This group did not found any difference (11 people out of 28, 39.29%)
3. Group C: This group can not conclude because of the small difference (7 people out of 28, 25%)

The goal of this test is to address a notable degradation of sound during CD copy. From a general perspective, the files sounded same/similar to Group B & C. They did not perceive any notable degradation in sound among files. Therefore, collectively they represent a category where sound degradation was not notably perceived. Therefore, by summing Group B & C, we can re-sort the result as follows.

1. Group A: 10 people out of 28, 35.71%
2. Group B + C: 18 People out of 28, 64.29%

Therefore, on a general perspective, people who did not perceive a notable difference is roughly double (actually 1.8 times) than the people who marked the difference. That means the majority of the participants (roughly 2/3rd people) can not hear any notable difference, even after 10th copy and in spite of read error in some rips. This can be noted as the outcome of this test.

You also need to come out with which wave file was the original. Was it 2.wav?

 

[anirban420]

What might also interest you is if you compare the original master CD with a commercially available original CD, the difference is huge. The master CD is way way better.

I think I will get the oppertunity to check it. Presently I make cover version of popular songs with my voice by using available karaoke tracks. During the song production, I do the recording, mixing and mastering by myself. Its just a home-brew hobby of mine. Recently, I wanted to make a cover of such a song whose karaoke track is not available. I talked to one of my musician friend regarding this. This friend owns his own orchestra party and I performed many times with them on-stage. He told me that he will make the track electronically. He will make individual instrumental soundscape which I have to downmix. Since the track used very less instrument, it can somewhat be done on experimental basis. He will send me the files over internet.

Right now, everything is in planning situation. If the project happens ever, I will check whether the copy from the project master has any difference or not.

 

[anirban420]

You also need to come out with which wave file was the original. Was it 2.wav?

04.wav was the file ripped from the mother CD.

 

[keith_correa]

Rips are only going to be as good as the CD transport and the way the ripper is configured. Period!

 

[subhashis_1980]

I missed voting - majorly due to electricity and network issue in my area post cyclone in Kolkata. I had performed this test twice before and results were 1st time i guessed it right. In the 2nd time I choose the 10th copy as the best sounding .

But one thing I felt then is that we had 4 files from repetitive rips which we were comparing and were trying to guess the best sounding one but assume had it been only 2 rips - the 10th and the original - most probably we would have a larger audience voting for group B and C.

Also it disperses another myth that original cd is "better" sounding than the copy/rip.

Thanks @anirban420 for doing this and also thanks to everyone who participated.

 

[tuff]

maybe you need to add +/- error to your stats... like say 30%

 

[anirban420]

Also it disperses another myth that original cd is "better" sounding than the copy/rip.

Superlike

Thanks @anirban420 for doing this and also thanks to everyone who participated.

You are most welcome bro

 

[crowdme2]

dint know copying digital files affected the sound

 

[alpha1]

04.wav was the file ripped from the mother CD.

so I can think of only two scenarios:
- either all the copies were bit perfect and folks are unable to distinguish but still cock-sure about their choice
- or the copies are not bit perfect and people seem to prefer the deteriorated sound

 

[anirban420]

@alpha1 Please check the previous posts of this thread for the conclusive explanation of the poll.