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ngsm13
08-27-2005, 09:51 PM
Trying to redo this thread since JMAC deleted all his posts...

COPIED from the WHAT.CD Wiki Tutorials:

What is a transcode?


Wikipedia says that "Transcoding is the direct digital-to-digital conversion from one (usually lossy) codec to another." A transcode is any conversion of format.

Why is lossy transcoding bad?


Whenever you encode a file to a lossy format (such as mp3, m4a(AAC), ogg, or mpc) information is permanently lost. It doesn't matter what you do, it's impossible to get this information back without making a new rip from the original lossless source. If you re-encode it to a different format or bitrate, you are reducing the quality. This applies to any lossy to lossy conversion, so even if you convert from 320kbps to 192kbps, the final file will still sound worse than if you had just ripped to 192kbps in the first place.

It's also important to remember to verify that lossless rips actually came from an original source. People that download lossless expect it to be identical to the original. There's no point in people downloading a bigger file just to get another lossy rip.

So how do I verify that my music isn't a transcode?


The simplest way is to rip and encode it from the original source yourself. That way, you know that there has been only one lossy step (or that the rip is truly lossless, if you decided to do a lossless rip).

You should also check it by using a wave editor (such as Adobe Audition) to look at the spectral frequency display.

What is the difference between FhG and LAME?


Most lossy encoders use a low-pass filter when encoding. The filter is set to cut frequencies above a certain point and leave those below. The reason they're doing it is, that high frequencies are more difficult to encode and hearing is less sensitive in higher frequencies. MP3 encoders at 128kbps will typically use a LPF at 16kHz. As you raise the bitrate, the frequency threshold raises. At 192kbps the LPF is usually set at 18kHz or higher.

How can I view the Spectral Analysis of songs using Adobe Audition?


To view the spectral analysis of audio files in Adobe Audition, first ensure you are in Edit Waveform View by pressing the number 8 on your keyboard. Then, go to File > Open and select the file you wish to test. Adobe Audition will open the audio file in the "Waveform View" by default each time, so you'll need to choose View > Spectral View or press F9 to switch to Spectral View.


Common Bitrate Comparisons


The following section contains a list of common bitrates and their audio spectrum. The LAME were all done using dbpoweramp from a flac source, and they are all encoded using LAME version 3.97. The FhG were all done using Adobe Audition 1.5 FhG. The shape of the screen-shots differ due to different screen resolutions.


Original (FLAC):

http://img462.imageshack.us/img462/8946/flacvv2.th.png (http://img462.imageshack.us/my.php?image=flacvv2.png)

128 LAME:

http://img462.imageshack.us/img462/4782/128lamewl3.th.png (http://img462.imageshack.us/my.php?image=128lamewl3.png)

160 LAME:

http://img223.imageshack.us/img223/2971/160lamenf8.th.png (http://img223.imageshack.us/my.php?image=160lamenf8.png)

160 FhG:

http://img462.imageshack.us/img462/3716/160fhgsy4.th.png (http://img462.imageshack.us/my.php?image=160fhgsy4.png)

192 LAME:

http://img160.imageshack.us/img160/5825/192lamejs9.th.png (http://img160.imageshack.us/my.php?image=192lamejs9.png)

192 FhG:

http://img462.imageshack.us/img462/5137/192fhgcf0.th.png (http://img462.imageshack.us/my.php?image=192fhgcf0.png)

V2 (preset standard, aka aps):

http://img473.imageshack.us/img473/77/v2presetstandardxj0.th.png (http://img473.imageshack.us/my.php?image=v2presetstandardxj0.png)

224 LAME:

http://img160.imageshack.us/img160/1255/224lamelr6.th.png (http://img160.imageshack.us/my.php?image=224lamelr6.png)

224 FhG:

http://img160.imageshack.us/img160/5595/224fhgfo8.th.png (http://img160.imageshack.us/my.php?image=224fhgfo8.png)

256 LAME:

http://img160.imageshack.us/img160/783/256lamesq5.th.png (http://img160.imageshack.us/my.php?image=256lamesq5.png)

wrwekjl

ngsm13
08-27-2005, 09:53 PM
Continued...

256 FhG:

http://img160.imageshack.us/img160/8060/256fhgjx5.th.png (http://img160.imageshack.us/my.php?image=256fhgjx5.png)

320 LAME:

http://img462.imageshack.us/img462/6236/320lamelg3.th.png (http://img462.imageshack.us/my.php?image=320lamelg3.png)

320 FhG:

http://img473.imageshack.us/img473/6886/320fhghr1.th.png (http://img473.imageshack.us/my.php?image=320fhghr1.png)

V0 (preset extreme, aka apx):

http://img462.imageshack.us/img462/3979/v0presetextremels8.th.png (http://img462.imageshack.us/my.php?image=v0presetextremels8.png)

Typical Webrip: (notice the gap)

http://img160.imageshack.us/img160/8761/typicalwebripfp7.th.png (http://img160.imageshack.us/my.php?image=typicalwebripfp7.png)
Analysis


As you can see, LAME uses 'full resolution' up to the frequency threshold, whereas FhG, encodes at 'full resolution' up to 16kHz, and uses 'low resolution' at higher frequencies. This is an easy way to tell which encoder was used. At 128kbps, LAME uses a LPF at ~17kHz and FhG at ~16kHz. I have included a screenshot of FhG at 128kbps without the LPF. At 160kbps FhG's LPF is set at 20kHz. At 192kbps, LAME stops at 19kHz and FhG encodes upto 22kHz.

FhG looks like it's not doing its job right, but if you listen to the 192kbps samples, you can hardly tell which is LAME and which is FhG. At 128kbps, LAME sounds a bit better, more 'clear'. FhG encoding at 128kbps without the LPF sounds bad, you can certainly listen to the artifacts.

LAME APS will typically use a LPF at 18.5kHz, whereas APX will go up to 19kHz.

ngsm13
08-27-2005, 10:24 PM
How to view the Spectral Analysis of songs using Adobe Audition



To view the spectral analysis of audio files in Adobe Audition, first ensure you are in Edit Waveform View by pressing the number 8 on your keyboard. Then, go to File > Open and select the file you wish to test. Adobe Audition will open the audio file in the "Waveform View" by default each time, so you'll need to choose View > Spectral View or press F9 to switch to Spectral View.

I've seen a lot of discussion here about how to spot transcodes. Many people have suggested using a spectral analysis from programs like Cool Edit / Adobe Audition / EAC and looking at the 'cut off' point. There is some disagreement about how effective this is, but those who recommend it suggest looking for cut-offs between 1600 Khz as the signature of a 128kbps mp3 source and 2100 Khz as the signature of Lossless.

One counter argument to this 'cut off' level method is that the same cut off which characterises lossy encodes may also be the result of a poor quality recording - a bootleg of a live show or a 'third world' vinyl master.

A number of spectral views have been posted and linked to, but nearly all of these have been analyses of entire tracks... which IMHO is NOT the most effective way to use spectral analysis to detect transcodes.

What I haven't seen anyone discuss is the 'blocky' appearance of the spectral analysis of lossy rips which is noticeable only when you zoom in close enough. IMHO this is a more reliable way to detect whether a file which purports to be lossless has in fact been transcoded from a lossy rip, and may even be a useful way to detect re-encodes from lower to higher bitrate mp3s (although this is much harder whatever method you use).

The image below illustrates what I mean. The track (from an album by Philip Glass) was ripped from CD to flac and a 1 second sample was saved to 320 kbps LAME mp3 and 128 kbps FhG mp3 and then in each case saved again to flac. The spectral analysis was done at full screen on a monitor with resolution of 1280 x 1024. Each of the three strips below is of the same 0.15 of a second.

FLAC / 320 mp3 / 128 mp3 compared

http://img473.imageshack.us/img473/2159/flac320mp3128mp3compareum0.gif

And here are bigger strips of the three spectral analyses. The zoom level is the same - bigger simply means that what is shown here is around 0.5 of a second - and NOT the whole track!

FLAC

http://img473.imageshack.us/img473/6268/flacfn7.gif

320Kbps LAME mp3

http://img462.imageshack.us/img462/9240/320kbpslamemp3ok9.gif

128Kbps FhG mp3

http://img462.imageshack.us/img462/8555/128kbpsfhgmp3wu5.gif

Credits


Adopted from the tutorial by brigetd (http://what.cd/user.php?id=786): forums.php?action=viewthread&threadid=1200 (http://what.cd/forums.php?action=viewthread&threadid=1200)

adam71
08-29-2005, 07:00 AM
Anyone still think MP3s sound just as good as CDs??

theCybe
08-29-2005, 09:17 AM
jMac, please put 'Apple Lossless Encoder' to the test. Contact me for more information if necessary.

ThatDude
08-29-2005, 10:28 AM
Really though, anything above 192 kbps I think sounds just fine. I'm pretty sure most you guys can't tell the difference between them to. Nice data.

tRiGgEr
08-29-2005, 11:25 AM
I went and bought the Tool cd's to compare to all of my 192k files. No audible difference was detected by my ears.

Jmac, can you please explain what diminishes in quality are caused by the compression. Like the drop of frequency above 12k-16k...

hellomota
09-06-2005, 12:14 AM
Question when you burn CD from mp3, will it change the bit rate back to 1411kb/s, or will it just make, lets say, 192kb/s mp3 larger for CD players to recognize them?

HiAmplidude
09-06-2005, 12:37 AM
It changes to 1411kbps, but it samples from the 192kbps clip, so it's only as good as its 192k source.

hellomota
09-06-2005, 12:54 AM
that sux

thch
09-06-2005, 01:25 AM
hmm. why are there differences between the original and the lossless compression. lossless compression should give exact results, anyone disagreeing should look at the proliferation of ZIP, ARJ, BZIP, ect... files out there.

bri487
09-06-2005, 01:47 AM
hmm. why are there differences between the original and the lossless compression. lossless compression should give exact results, anyone disagreeing should look at the proliferation of ZIP, ARJ, BZIP, ect... files out there.

the guy who does the tech article in car audio and electronics did a good job explaining that in this months issue. maybe check that out.

TeenWolf
09-06-2005, 01:52 AM
Good post...really gives you a visual of what happens when you convert to MP3.

Dozy_production
09-15-2005, 01:21 AM
could flac or this mcintosh lossless stuff work for mp3 capable hus?

JLee1469
09-15-2005, 02:10 AM
I remember back in the Napster days when most songs out there were ripped @ 128 kb... especially in rock music the sound is clearly awful!

Reading up on many msg boards... it seems VBR (Variable Bit Rate) is the way to go to compress music.

IamDeMan
09-15-2005, 08:11 AM
Anyone still think MP3s sound just as good as CDs??At 50MPH with windows down, yes. It isn't the format I use at home to listen to music, but in the car, MP3 makes a very nice compromise in convenience/SQ. I rip my MP3s for the car in VB mode 192-256.

adam71
09-15-2005, 04:41 PM
At 50MPH with windows down, yes. It isn't the format I use at home to listen to music, but in the car, MP3 makes a very nice compromise in convenience/SQ. I rip my MP3s for the car in VB mode 192-256.

In that respect I can see where you may not hear a difference. In a quiet environment the difference is night and day. Especially if you were to compare it to vinyl, DVD-Audio or SACD but CD-Audio is a big enough difference for me.

ngsm13
09-15-2005, 04:49 PM
At 50MPH with windows down, yes. It isn't the format I use at home to listen to music, but in the car, MP3 makes a very nice compromise in convenience/SQ. I rip my MP3s for the car in VB mode 192-256.

Agreed.

NG

thch
09-15-2005, 05:49 PM
would it be possible to redo the graphs with log spacing of frequency? and possible give differnecs between the original and compressed (image subtraction).

While the linear spacing does show harmonics very well (the rows of lines), it also favors HF over LF. most of the detail shows up in a very small part of the pics. compression typically favors LF over HF.

Dan5767
11-13-2005, 01:43 PM
Where did you get the program to show the Effects of Compression? Also, what is its name?

Defconx3
11-21-2005, 02:20 AM
I can definately tell a difference between mp3's >320kbps VS CD's. However when your dealing with an mp3 at 320kbps its very close to cd quality, hardly noticable.

_DjScrew_
11-29-2005, 04:46 PM
I remember back in the Napster days when most songs out there were ripped @ 128 kb... especially in rock music the sound is clearly awful!

Reading up on many msg boards... it seems VBR (Variable Bit Rate) is the way to go to compress music.

x2 on the VBR. most music you download online ... that has a -GROUP tag is ripped to that standard.

Jae
01-09-2006, 05:12 PM
wma and apple lossless codecs arent considered true lossless codecs by audiophiles. try flac, wavpack, ape. and all these charts are showing is bits that is being lost when u encode to a lossy format. thats what its suppose to do

ighettoboyi
01-15-2006, 02:23 AM
i've always been able to tell the difference...but like everyone says, it's a good compromise. besides, what's the point of having a head unit that can decode mp3's and continually waste cd's...

yacoub
06-13-2006, 01:39 PM
for some reason 192kbps often sound better than 256kbps mp3s. 320kbps usually sound the best though i've run into some that people have made that have disgusting high-pitched amplification that is terrible. must be the encoding algorythm they use. generally though, a top-quality VBR mp3 wins the day with the best trade-off in filesize and soundquality - normally sounding every bit as good as a 320kbps CBR mp3.

CBFryman2
07-12-2006, 03:19 PM
Ripped CD's at a high bitrate + good quality CD's and burner = no detectiable difference in home or in car.

adam71
07-30-2006, 07:02 PM
Ripped CD's at a high bitrate + good quality CD's and burner = no detectiable difference in home or in car.

I just read this today after going a long time without reading this thread so you'll have to forgive my delayed response (18 days). You are saying that you can't tell a difference between them?? Or are you saying NO ONE can hear a difference.??

TomBrooklyn
07-31-2006, 02:41 PM
What is being lost? It looks to me mostly like highs above 16k.

adam71
07-31-2006, 03:17 PM
What is being lost? It looks to me mostly like highs above 16k.

Whatever part of the signal is being perceived as sounds that we would not hear.

AzzKicker
08-01-2006, 01:34 PM
Like stated, with my good setup I can really hear the difference between ripped and original. With a factory radio you wont notice.

But I'm just going to start hitting up ebay for all my music in original form..

djman37
08-01-2006, 01:38 PM
Anyone still think MP3s sound just as good as CDs??

never did.;)

jmac, is that teh adobe audition? I upgraded from cool edit pro.

TomBrooklyn
08-01-2006, 03:00 PM
Ripped CD's at a high bitrate + good quality CD's and burner = no detectiable difference in home or in car.
Hi CBFryman2,
What bitrate are you using?
Most of my mp3s are at 128mps. I haven't tried any CD/MP3 side by side comparisons yet.

Also wondering, how does mp3 stack up against FM Broadcast?

JimJ
08-01-2006, 03:46 PM
Also wondering, how does mp3 stack up against FM Broadcast?

Even 128K MP3 is an improvement over FM.

When you modulate a signal to RF, the bigger the bandwidth, the more power needed to maintain signal strength. So it makes sense to transmit a really small bandwidth...

The left/right information in an FM signal only covers from about 50Hz to 15KHz - it needs to stop there because the pilot carrier for the stereo encoder is a 19KHz tone, and any musical information that high will result in a "chirp" on the receiving end...because your receiver is looking for that steady 19KHz pilot tone to decode the stereo information. So the top end is automatically lopped off. The bottom end isn't there because modulating strong subbass would simply take too much power than it's worth, and since most radio receivers aren't hooked up to subwoofers anyway, who would ever hear it?

It *****.

Beat_Dominator
08-01-2006, 03:56 PM
AM rox.

gabe8501
08-15-2006, 05:10 PM
Please forgive my elementary question, I'm an audio noob.
But just to make sure I'm reading this correctly..... from the info originally posted.... it looks like WMA Lossless is the way to go?
And the sound quality diminishes and the # of kbps on an mp3 decreases?

Any helpful info or comments would be greatly appreciated.
Thanks.

PRIVATEpastry
08-15-2006, 11:57 PM
Please forgive my elementary question, I'm an audio noob.
But just to make sure I'm reading this correctly..... from the info originally posted.... it looks like WMA Lossless is the way to go?
And the sound quality diminishes and the # of kbps on an mp3 decreases?

Any helpful info or comments would be greatly appreciated.
Thanks.

Yes and yes. If you have enough disk space on your computer/MP3 player, then go with lossless.

mnaines
08-18-2006, 11:51 PM
Can you test the ATRAC3plus format through SonicStage digital music manager and post the test results? I run ATRAC3plus and ATRAC Advanced Lossless, so I am interested in seeing how they stack up to MP3, WMA, and the original source quality. ATRAC3plus and ATRAC Advanced Lossless are both Sony's proprietary formats, and are, from what I understand, supposed to be superior to both MP3 and WMA. According to Sony, ATRAC3plus is to MP3s what CDs were to tapes, so I want to see if that is true. Test the ATRAC Advanced Lossless and ATRAC3plus all the way down to 63.475kbps, which Sony says is the smallest bitrate ATRAC3plus can compress a CD to. The difference between ATRAC Advanced Lossless and WMA Mathematically lossless is ATRAC Advanced Lossless can run as low as 64kbps, while WMA Mathematically Lossless is a minimum of 800kbps. ATRAC Advanced Lossless @ 64kbps makes a file size of 30MB for a 4-minute song, while ATRAC3plus @ 64kbps creates a file size of 1.9MB for a 4-minute song. I have good ears, and it is almost impossible for me to tell the difference between 64kbps ATRAC3plus and the original source CD.

mnaines
08-19-2006, 12:04 AM
According to Sony, MP3 can compress a CD to 1/10 its normal size (down to 141.1kbps) without losing any of the original source quality, while ATRAC3plus can compress a CD to 1/22 its normal size (63.475kbps) without losing any of the original source quality. I want to know if this is true, or if there is loss at those bitrates.

adam71
08-20-2006, 04:49 AM
Can you test the ATRAC3plus format through SonicStage digital music manager and post the test results? I run ATRAC3plus and ATRAC Advanced Lossless, so I am interested in seeing how they stack up to MP3, WMA, and the original source quality. ATRAC3plus and ATRAC Advanced Lossless are both Sony's proprietary formats, and are, from what I understand, supposed to be superior to both MP3 and WMA. According to Sony, ATRAC3plus is to MP3s what CDs were to tapes, so I want to see if that is true. Test the ATRAC Advanced Lossless and ATRAC3plus all the way down to 63.475kbps, which Sony says is the smallest bitrate ATRAC3plus can compress a CD to. The difference between ATRAC Advanced Lossless and WMA Mathematically lossless is ATRAC Advanced Lossless can run as low as 64kbps, while WMA Mathematically Lossless is a minimum of 800kbps. ATRAC Advanced Lossless @ 64kbps makes a file size of 30MB for a 4-minute song, while ATRAC3plus @ 64kbps creates a file size of 1.9MB for a 4-minute song. I have good ears, and it is almost impossible for me to tell the difference between 64kbps ATRAC3plus and the original source CD.

I like you, you're funny.

You look like Snoopy and that makes me smile.

You have smelly dog farts.

Pyro_By_Nature
08-20-2006, 05:24 AM
In a car, you usually can't too much of a difference.But I can hear a night and day difference in home.

adam71
08-20-2006, 05:36 AM
Personally I think mnaines would eat a pile of **** as long as it had a Sony label on it.

axo409
09-15-2006, 01:59 PM
that really *****

axo409
09-15-2006, 02:00 PM
lets try this again.........that really *****

MrLaRotta
09-19-2006, 10:18 PM
hmm. why are there differences between the original and the lossless compression. lossless compression should give exact results, anyone disagreeing should look at the proliferation of ZIP, ARJ, BZIP, ect... files out there.

Hahahaha, do this experiment. Take a 10.0 MB song.mp3, and convert it using winzip. The resulting song.zip is... ta dadadaaaa ... (snare drums...) 9.8 MB!!!

No, the magic of the file compresion doesnt work in the same way with audio

thch
09-23-2006, 09:52 AM
zip, arj, rar, gz. bz2 are all lossless compression.

take file.wav (10M) and compress to zip. (8M?)
that file.zip (8M) and uncompress to file.wav (10M)

files.wav is unaffected by the compression + decompression combo.

thus, if the "zip audio format" (zaf) were to exist, people would be able to make zip files of their wav audio files and the audio codec would simply unzip the file and play it on demand. when tested, file.wav and file.zaf would sound the same and in fact be the same, having all audio properties the same (as well as any other info in the wav format).

any largely compressed format will be more resilient to further, lossless compression.

MrLaRotta
10-01-2006, 04:04 PM
What program did Jmac used to make those graphics? :)

speedracerx
10-03-2006, 05:54 PM
I have spent the last 3 days throwing a study on my Phatnoise media package for my Kenwood 789 hu. I have not allowed myself to explore compressed fileing tell this week so I'm cramming now. I loaded all my WMA files and ripped 80 cds at several speeds and settings the last 3 days (need sleep) and made several discs with samples of each on same disc. Mostly I just have more questions now than before but I dig the voice navigation.

speedracerx
10-03-2006, 06:23 PM
One thing that threw me was the VRP option. Manual says this: Variable Bitrate vs Constant Bitrate Encoding
The PhatNoise Media Manager uses Constant Bitrate Encoding (CBR) by default. Variable Bitrate Encoding (VBR) is a more efficient way of encoding. Variable Bitrate Encoding ensures high audio quality throughout the MP3 file by making intelligent bit-allocation decisions during the encoding process. This means that the encoder will determine what bitrate to use depending on the complexity of the audio signal. It will use more bits when necessary and use fewer bits when appropriate. The VBR Quality setting determines the ratio of high/low bitrate audio frames (a frame is 1/75th of a second of audio data) The higher the VBR Quality, the higher the sound quality of the MP3 file. VBR encoding requires more processing power, so it takes a little longer. When I started useing the VBR at 320 Kbps, it took about 30 sec. per song as apposed to - well alot more with CBR at 190. I never went back to the CBR to side by side check quality - so am I correct in assuming VBR = more quality, cause I understood it said its slower and my ripps were 10x faster.

adam71
10-06-2006, 09:39 AM
One thing that threw me was the VRP option. Manual says this: Variable Bitrate vs Constant Bitrate Encoding
The PhatNoise Media Manager uses Constant Bitrate Encoding (CBR) by default. Variable Bitrate Encoding (VBR) is a more efficient way of encoding. Variable Bitrate Encoding ensures high audio quality throughout the MP3 file by making intelligent bit-allocation decisions during the encoding process. This means that the encoder will determine what bitrate to use depending on the complexity of the audio signal. It will use more bits when necessary and use fewer bits when appropriate. The VBR Quality setting determines the ratio of high/low bitrate audio frames (a frame is 1/75th of a second of audio data) The higher the VBR Quality, the higher the sound quality of the MP3 file. VBR encoding requires more processing power, so it takes a little longer. When I started useing the VBR at 320 Kbps, it took about 30 sec. per song as apposed to - well alot more with CBR at 190. I never went back to the CBR to side by side check quality - so am I correct in assuming VBR = more quality, cause I understood it said its slower and my ripps were 10x faster.


Agreed.

I use EAC with Lame encoding via the Ubernet standard and have never looked back.

Mugen
10-20-2006, 01:55 AM
I just use 192kbps for all my music and it sounds the same to me whether in my truck, on my PC, or on my home speakers (Primus 250s). I can usually tell if a song's at 128kbps, which is why I hate XM, it's really low quality (or my mom's car speakers REALLY ****).

Motovet
11-23-2006, 11:44 PM
I take it XM is 128kbps then. Can one download at higher rates from I Tunes and similar sites? Also can one copy CD's to Ipods at higher rates? I am a total noob with the new stuff. Thanks.

adam71
11-23-2006, 11:53 PM
I take it XM is 128kbps then. Can one download at higher rates from I Tunes and similar sites? Also can one copy CD's to Ipods at higher rates? I am a total noob with the new stuff. Thanks.

I have no clue what XM is. You can't download from them so it doesn't really matter. XM quality depends on the system you're listening to it through.

PRIVATEpastry
11-24-2006, 02:14 AM
I'm not sure what XM is, but I'm pretty sure that its less than 128kbps. Yes, you can download at higher rates on Itunes and other download sites. You can also copy CD's to your Ipod at higher rates, but keep in mind that the higher bitrate the audio file is at, the more space it will take up on both your computer and your Ipod.

Motovet
11-24-2006, 02:49 AM
I wasen't interested in recording xm, just curious what rate they air at as my Alpine XM actually sounds pretty fair. Been considering an Ipod if it can sound better than my XM reception, and tunes can be transferred at higher rates which your telling me is possible. How do you calculate play time for 4g and 8g ipods at different rates? Thanks for the info guys.

adam71
11-24-2006, 02:05 PM
I'm not sure what XM is, but I'm pretty sure that its less than 128kbps.

I seriously doubt that. When I had my system in my recently deceased Grand Am which was nice sounding system the XM sounded really good. Not CD quality like they try to say it is but wayyyy better than 128kbps Mp3 quality.

Motovet
11-25-2006, 04:15 PM
What Mp3 rate do you consider closest to the XM? My XM sounds real nice to me too.

PRIVATEpastry
11-25-2006, 04:53 PM
I seriously doubt that. When I had my system in my recently deceased Grand Am which was nice sounding system the XM sounded really good. Not CD quality like they try to say it is but wayyyy better than 128kbps Mp3 quality.
I'll quote NetPedia (http://www.netipedia.com/index.php/XM_Satellite_Radio):


Audio channels on XM are digitally compressed using the aacPlus codec from Coding Technologies for most channels, and the AMBE codec from Digital Voice Systems for some voice channels. Due to bandwidth restrictions and a large channel load, the maximum bitrate XM broadcast from its satellite per music channel is limited to 64kbps.

And the talk channels are obviously going to be lower quality, I'm guessing 32kbps.

pikers
03-28-2007, 01:41 AM
I seriously doubt that. When I had my system in my recently deceased Grand Am which was nice sounding system the XM sounded really good. Not CD quality like they try to say it is but wayyyy better than 128kbps Mp3 quality.

Just lost a lot of credibility on that one.:laugh:

adam71
03-30-2007, 08:17 PM
Just lost a lot of credibility on that one.:laugh:

Before XM started adding wayyyy too many channels their quality was better than 128kbps. I had no idea they had changed it at the time. I was corrected but hardly at a loss of credibility as you have done to yourself by bringing up a 5 month old post.

Did you even read the date on that last post?? Asshat.:suicide:

sportyaccordy
06-04-2007, 03:02 PM
Can someone put up the original pictures?

Beat_Dominator
06-04-2007, 03:25 PM
You better Jmac :nono:



And to recent questions, I'd say XM is pretty close to 160kbps MP3. A little bit chopped off at the high end and kind of flat through the midrange.

PRIVATEpastry
06-04-2007, 10:56 PM
We already went over that.

I'll quote NetPedia (http://www.netipedia.com/index.php/XM_Satellite_Radio):


Audio channels on XM are digitally compressed using the aacPlus codec from Coding Technologies for most channels, and the AMBE codec from Digital Voice Systems for some voice channels. Due to bandwidth restrictions and a large channel load, the maximum bitrate XM broadcast from its satellite per music channel is limited to 64kbps.

And the talk channels are obviously going to be lower quality, I'm guessing 32kbps.

pinkfloydms
06-06-2007, 12:38 PM
WHat about HD radio?


Also are mp4 or ACC higher quality than mp3?

ShakesAllDay
08-20-2007, 11:10 AM
Most of the time, I can tell when I'm listening to a 160kbps or less mp3/wma. Lower bitrates have a weird *tingy* sound to them... very easy to hear the compression.

192kbps is much better and I believe it to be the best middle of the road bitrate (wrt SQ vs. file size).

Personally, I find gigabytes too cheap to encode at anything less than 320kbps. The only problem w/ that is you can't fit as many files on a CD.

I have yet to try any lossless format.

tcguy85
09-05-2007, 01:47 AM
and this is why i only listen to rap and hip hop in mp3 format. rap and hip hop sounds like **** anyway so it doesn't matter. :-)

jblayz1
10-05-2007, 10:00 PM
.flac and .shn are two more lossless formats but few mobile audio HU's play them.

jamesmington
10-23-2007, 06:02 PM
I've run into a problem recently, in which I think my compression rates may be the source. I just installed an Eclipse CD7000 thats hooked up with a pair of CDT components, and I play my ipod through the headunit's auxillary input.

Many of the songs that I play have an "airy" sound, in which it is dominant more in some songs than others. Is this due to compression rates, faulty wiring, wrong headunit settings or what?

oneiztoomany
11-09-2007, 06:09 PM
where can you find high bitrate songs for IPOD?

Itunes now is offering some of their music at 192kbps which still isn't all that impressive...

tcguy85
12-17-2007, 10:42 PM
what happened to this thread???

oneiztoomany
12-18-2007, 12:27 PM
it was compressed to oblivion

apw122
12-18-2007, 12:45 PM
I like how there is a 5 page thread where each post is a month after the previous, except for now of course

JimJ
12-18-2007, 12:50 PM
where can you find high bitrate songs for IPOD?

Itunes now is offering some of their music at 192kbps which still isn't all that impressive...

Most private torrent trackers such as What.cd, Waffles.fm and STMusic.org require bitrates above 192k CBR, with many things available in 320 CBR or V0/V2 variable bitrate.

oneiztoomany
12-18-2007, 04:55 PM
where can i get these private torrent trackers?

bigbang
04-28-2008, 12:27 AM
Hey, I store all my music in AIFF lossless on my iPod. My question is when I add one of my friends burned CDs to my iTunes library, I don't have a clue what the quality of that burned CD is so I import it with AIFF. Any idea how to know what the bitrate/format is on the burned CD and how to import the format directly without up converting it to AIFF so that I can have a clear picture of the quality of my files without everything in my iTunes library saying "AIFF file" even though some may have been ripped from a low quality audio CD? My friends CD's aren’t MP3, they are audio CD's so does this mean there is no way of determining the true quality of the recording because it has been unconverted by default to play as an audio CD?

I hope for an answer in the next year or so.

joker0907
10-13-2008, 12:50 PM
ok so for someone who downloads everything from limewire and puts them on itunes... how bad is it to do that and once they are downloaded is there a way to make them any better when you put them on a cd or ipod ? or are u just stuck with the compressed version.

ngsm13
10-13-2008, 04:57 PM
Ok, I tried to edit this thread... and refill it with some info...

Check the first page, should help you out some!

nG

Megalomaniac
10-13-2008, 06:48 PM
Wikipedia :/.... your professor would b!tch slap ya if he saw that *****


thanks though :) i pmd jmac about it and he deleted all his post cause of g00b

ngsm13
10-14-2008, 12:43 AM
Wikipedia :/.... your professor would b!tch slap ya if he saw that *****


thanks though :) i pmd jmac about it and he deleted all his post cause of g00b

It's the What.cd Wiki... basically their tutorial section...

I trust it completely, it's a private dedicated music torrent site full of audiophiles... :fyi:

nG

Megalomaniac
10-14-2008, 12:09 PM
Oh those Wikis. I thought it was actually wikipedia. You know how professors hate that. In all my classes there is this bigass sign that says wikipedia with a red circle and a line through it.

shiny2
10-08-2009, 09:33 AM
As the name implies, compression reduces the dynamic range of a signal. It is used extensively in audio recording, production work, noise reduction, and live performance applications, but it does need to be used with care. It's commonly said that compressors make loud sounds quieter, and the quiet sounds louder, but this is actually only half correct.

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neverfinished
02-19-2010, 03:58 AM
no wonder my ipod never sounds as good as my cd's

W124_Man
01-30-2011, 07:50 AM
So... some sound processors apparently have some technology to restore lost dynamic range to compressed music. Sony HU's have DM+, for instance, and Creative X-Fi soundcards have Crystalizer (I think its called). Obviously these can never quite replace what was lost, but how effective are they? Would be interesting to see graphical evidence of their effectiveness, or lack thereof.