Hi,

When comparing quality of commercial CDs vs mp3s (even at 192kbps), I notice that the mp3s sound much more dull then the original CD. I also have the impression that the bass frequencies are much louder, too heavy, muddy with mp3s compared to the original CD. Anybody else notices this or is it just my imagination? I listen music mainly on decent hifi speakers.

Since mp3 is a compression format, isn't it so that certain frequencies are being cut out or something?! How does that work with mp3's, like which frequencies exactly are being cut out?! Anybody who knows more about this could please explain this? Also, how come that the bass sounds heavier, or is this just my imagination?

Thanks!

http://www.iis.fraunhofer.de/ *hope I got the url right *

I bet the info is on that page somewere, I wouldn't know myself tbh.

http://en.wikipedia.org/wiki/Mp3

That has everything you need to know...

it cuts out alot of audible and semi inaudible frequencies. the extent to which is does this is determined by the bitrate its encoded at.

i think even with 320 kbps mp3 the freq range reproduction is between 15hz and about 15,500hz or something like that. thats why the most noticeable differences between mp3 and CDDA are often in the hihats. or at least, most people notice flatter, tinnier hihats with mp3s because the frequency response doesnt extend that far. it loses some sub bass response too but it depends on the record and the amount of bass presence. at high levels certain bass heavy recordings just lose something noticeably when played on PAs at club levels - even at 320 kbps. even though you cant physically hear ultra high and low frequency sound you can sometimes notice when its not there. case in point - have someone blow a dog whistle near you.

then theres the fact that your speakers/headphones have an effective frequency response too. most people dont have audio equipment sensitive enough to pick up frequencies above 15,000 hz so they wouldnt notice any degradation in sound quality on say most mini hifi systems. i have some sony hifi speakers which are pretty bass heavy and the freq response drops off pretty heavily and sharply around teh upper mids. i reckon 320 kpbs mp3s would be largely indistinguishable from CDDA on these speakers simply because they arent sensitive enough. on monitors you notice the difference more. on really sensitive monitoring speakers and PAs and high levels it is sometimes clearly audible.

If the freq range of mp3s (even at 320kbps) starts at 15Hz, doesn't give you that enough subbass frequencies? I actually got the impression that with mp3s the bass is too heavy (or more muddy) compared to the original CD.

Also, is it really so that mp3s only go to 15khz?! It would explain why mp3s don't sound so bright as CDs when listening on some decent hifi speakers, however isn't it so that mp3s are also very weak in the mid frequencies. Isn't it so that mp3's cut frequencies in the entire frequency range in order to make the file smaller (compression)or how does that work?

I'm sure it cuts a little from the entire spectrum but it concentrates on the high frequencies for sure. Listen to a 96 kbps mp3, bass will generally sound fine, albeit a bit muddy, but anything over like 5 khz is completely shot. Anyways, a lot of dj's play 192 to 320 kbps mp3's, and they sound fine at the clubs. The only way you hear the difference is if you put them right next to eachother, A/B, but for all practical purposes a well mastered hi fi mp3 will suffice behind the decks just as well as any wav.

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you know comparing cd to vinyl tho you loose even more sound... honestly the best sound youll ever get is from vinyl. not even dvd sound can compare to vinyl look at chart below:





so really if your going to take a quality loss why not just use mp3 becuase they all loose quality when compared to a vinyl heres the full report below..... taken from how stuff works





Is the sound on vinyl records better than on CDs or DVDs?

The answer lies in the difference between analog and digital recordings. A vinyl record is an analog recording, and CDs and DVDs are digital recordings. Take a look at the graph below. Original sound is analog by definition. A digital recording takes snapshots of the analog signal at a certain rate (for CDs it is 44,100 times per second) and measures each snapshot with a certain accuracy (for CDs it is 16-bit, which means the value must be one of 65,536 possible values).

Comparison of a raw analog audio signal to the CD audio and DVD audio output



This means that, by definition, a digital recording is not capturing the complete sound wave. It is approximating it with a series of steps. Some sounds that have very quick transitions, such as a drum beat or a trumpet's tone, will be distorted because they change too quickly for the sample rate.

In your home stereo the CD or DVD player takes this digital recording and converts it to an analog signal, which is fed to your amplifier. The amplifier then raises the voltage of the signal to a level powerful enough to drive your speaker.

A vinyl record has a groove carved into it that mirrors the original sound's waveform. This means that no information is lost. The output of a record player is analog. It can be fed directly to your amplifier with no conversion.

This means that the waveforms from a vinyl recording can be much more accurate, and that can be heard in the richness of the sound. But there is a downside, any specks of dust or damage to the disc can be heard as noise or static. During quiet spots in songs this noise may be heard over the music. Digital recordings don't degrade over time, and if the digital recording contains silence, then there will be no noise.

From the graph above you can see that CD quality audio does not do a very good job of replicating the original signal. The main ways to improve the quality of a digital recording are to increase the sampling rate and to increase the accuracy of the sampling.

The recording industry has a new standard for DVD audio discs that will greatly improve the sound quality. The table below lists the sampling rate and the accuracy for CD recordings, and the maximum sampling rate and accuracy for DVD recordings. DVDs can hold 74 minutes of music at their highest quality level. CDs can also hold 74 minutes of music. By lowering either the sampling rate or the accuracy, DVDs can hold more music. For instance a DVD can hold almost 7 hours of CD quality audio.

CD Audio DVD Audio
Sampling Rate 44.1 kHz 192 kHz
Samples per second 44,100 192,000
Sampling Accuracy 16-bit 24-bit
Number of Possible Output Levels 65,536 16,777,216


DVD audio discs and players are rare right now, but they will become more common, and the difference in sound quality should be noticeable. To take advantage of higher quality DVD audio discs, however, you will need a DVD player with a 192kHz/24-bit digital to analog converter. Most DVD players only have a 96kHz/24-bit digital to analog converter. So if you are planning to take full advantage of DVD audio be sure to look for a 192kHz/24-bit DAC.

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wow, I really hate it when websites that people use as a resource are full of crock.

Where does the actual waveform being cut onto the record come from huh? Usually DAT or CD. Both digital formats. Plus you get the fact that mastering engineers have to cut high end before the record can be cut to avoid problems such as the needle being too big to handle a super narrow groove. In practice, this cut is lower than the specs of CD. Oh, and the actual waveform is cut on the record, uhh whatever.

Sprry vinyl freaks. I love vinyl too. But it's not because of scientific bullshit. It has a specific nice sound to it. But it's by no means a more accurate representation of an original master, than, say, CD.

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show me stats and where you find them then lets see this.... i hate when people post replys and cant even included any facts kinda like trying to smoking a joint without having weed

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ok here's an internet source backing me up:

www.whiteroachproductions.nl/FAQ.html

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All rhythm evolves around a kick...

ZxZDeViLZxZ: I have one important question in regards of your fabolous explanation, when a tune is "burned" onto a vinyl.. wouldnt that tune be burned right off the CD and the vinyl would get the same quality as the CD? (confuses me)

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What I really would like know: what's the maximum frequency of mp3s (any difference in this between a 192 and 320kbps files) and vinyl. Anybody knows those numbers?!

Isn't it so that a CD sound brightest because it goes up to 22kHz and people can hear frequencies up to 20Hz (correct me if I am wrong) which a decent pair of hifi speakers can reproduce.

Anyway, I always get the impression that a 192kbps mp3 sounds less bright then a CDs, but I still don't know why that is!

Last edited by Dance123 on Dec-28-2004 at 05:42