I downloaded emplode in the hope I could have a play before getting a player, but no .... ;-(

A couple of questions:

1. Does the empeg have the ability to rip direct from CD, or is the sequence to rip onto the PC hard drive and then copy the files across?
2. Does emplode hook into CDDB to get the track listings, genre, year, etc?

J.

Unfortunately, Emplode is not a ripper. It's just the program you use for transfering files to the Empeg and managing your playlists. It assumes you've already got MP3s on your hard disk waiting to be uploaded.

If you don't already have a ripper program, try Audiocatalyst. Everyone says it's very easy to use, and has CDDB support, etc. (I personally don't use it yet but I have been considering switching to it.)

Tony Fabris
Empeg #144

I already have a licensed version of Jukebox. Seems like a good reason to start ripping those CDs!

Thanks Tony. Seems like just you and me on the BBS. I assume the Brits are all at the pub already (those of us that aren't in the US!)

Blimey mate, yet another national stereotype trotted out!

I'm off 'ome. Now where's me whippet and me flat cap?

In the pub? No, still quite a lot of work to do...

Hugo

I already have a licensed version of Jukebox. Seems like a good reason to start ripping those CDs!

It's actually a good thing to have your collection ready before the Empeg arrives on your doorstep. I spent a few months ripping my collection in anticipation of getting an Empeg. I was glad I did it.

Some tips:

- Make sure your tags are filled out on all your MP3s. If they're not, you have to enter the track data by hand in Emplode.
- Make sure they're regular ID3 tags. Emplode does not yet support the ID3v2 standard (as far as I know... Any word on this, Hugo?). This might be an option somewhere in your software.
- Make sure to fill out the "Year" field in the tags. I love being able to play all the songs from a given year on the Empeg.
- If you have any trouble getting accurate data for your tags (for example, if you are ripping a soundtrack album and you want to enter the original year and and album for a given song), look it up at www.allmusic.com. Their database is very comprehensive.
- Try to organize a directory structure on your PC's hard disk that mirrors (as close as possible) the playlists you intend to create in the Empeg. That way, your uploading process will be very simple when you get the Empeg.
- Make sure your USB and serial ports are working properly on the PC, and make sure you're running Win98 or Win2000. Nothing would be more disappointing than to get the Empeg and be unable to put your tunes into it because of Windows problems.


I assume the Brits are all at the pub already (those of us that aren't in the US!)

Actually, you'll notice that the Empeg folks will post to the BBS at very odd hours sometimes. I've seen Rob post to the BBS from home at 3am (UK time) before.

And we have pubs here in the US, too, I'll have you know. There's one right down the street from where I work called "Mad Dogs and Englishmen".

Tony Fabris
Empeg #144

Thanks for the tips. I'll have to check the ID thing - I have no idea. I'm running Windows 2000 Advanced Server on both desktop PCs, and Win98 on the laptop. They're all networked, so hopefully not an issue to txfer. Did I see some mention ogf RJ45 support for the Mk2?

I'll have to check the ID thing - I have no idea.

If you have a binary editor program such as UltraEdit, you can check if your files have a regular ID3 tag by looking at the last 128 bytes of the MP3 file. There should be a 128-byte block at the end of the file starting with the ASCII characters "TAG", followed by several fixed-length fields containing the tag data in ASCII. This is the data that Emplode will use to extract the song information. If it's not there, then there's nothing for Emplode to read from the file and you'll be forced to enter the tags by hand when you add them to the Empeg.


They're all networked, so hopefully not an issue to txfer.

In theory, you should be able to upload songs into the Empeg even if they're not stored on the local PC hard disk. Although I seem to remember some folks reporting problems when trying to synch files from a shared network drive, I'm pretty sure the problems were not network-related. So, in theory, you could have one of your server drives storing the MP3s, and use a client workstation to do the Emplode uploading.

Another nice thing about the Empeg is that everything is stored on the unit itself. Emplode doesn't read any local PC data files. It downloads your playlists from the Empeg when you start it up. It's sort of like a dumb terminal program. What makes this cool is that you can manage your Empeg playlists from any PC just by installing Emplode. You don't need to worry about synching data files between your home and work PCs, for example.


Did I see some mention of RJ45 support for the Mk2?

They said that it would be an option. I'm not sure how they plan to implement it. I don't know if the Mk2 Emplode will upload over ethernet or not. They said that they intended it to be for developers only (i.e., you can telnet into the box over ethernet if you like). Hugo, what's the latest word on this? Did I miss a meeting?

Tony Fabris
Empeg #144

OK, I'm ripping! MusicMatch supports both V1 and V2 tags, so I've selected both. What fields will empeg read? I've added year to the list, will it read 'mood' and 'preference' and all the others?

Can't wait to get the empeg now!!

OK, I'm ripping! MusicMatch supports both V1 and V2 tags, so I've selected both. What fields will empeg read? I've added year to the list, will it read 'mood' and 'preference' and all the others?

Empeg makes use of the following fields in the V1 tag:

- Track Name
- Artist Name
- Album Name
- Year
- Genre

I believe it stores the "Comment" field and displays it in Emplode, but I've never seen it displayed or used on the Empeg itself.

There is a V1.1 standard where they sacrifice the last byte of the "comment" field to store the track number. This is not used by Emplode. Instead, order your tracks by hitting view/details in Emplode and sorting by the sequence number, then dragging your tracks around until they're in the desired order. (One day, when you actually get your Empeg, remind me to teach you a trick that lets you drop groups of tracks onto the Empeg so that they appear in the correct order.)

Note that in V1 tags, there is only a specific list of about 128 genres that it will accept- you can't roll your own genre. Also note that all the name fields are limited to 30 character. This is a pretty severe limitation because you outrun it very frequently. This is one reason why I refuse to depend upon the CDDB to fill out my tags-- when there's an overflow, I want to be sure that I abbreviate it my way rather than just truncating it.

Also, I'm pretty sure that the CDDB doesn't store the year, so it'll be up to you to enter the year when you're filling out your tags.

Tony Fabris
Empeg #144

Maybe I won't bother with 'mood' then. I've only done 4 Depeche Mode albums so far and they're all 'morose' ;-)

I'm adding the year manually, so no probs there.

Rip ... rip ... ripping away ... I assume 128kbps is the right sample speed?

I had one minor problem with syncing from the network in W2000. The network cable became slightly loose, and it disconnected the drive. Emplode immediatly freeked out and had a sync error, as where most programs just start a timeout timer at that point and will retry to get the file. (A broken network cable and an x-jack PCMCIA card don't mix well).

Also, The ethernet port on the MkII will be standard if I remember some of the recent more semi-official notices about it.

My empeg site is:http://24.236.3.131/empeg/

Here's a question for the gallery ... given you're all happily MPEGing your audio ... how many others are MPEGing video? I've had a Philips TiVo for about a year and couldn't live without it now. (www.tivo.com) And no, I've nothing to do with them apart from being another gadget loving geek. ;-)

Rip ... rip ... ripping away ... I assume 128kbps is the right sample speed?

---

It really depends who you ask. Personally, I regret having ripped my music at 128kbps, and have lately been ripping the new one at 160kbps variable... (high-quality variable in some programs...) - I think there is a difference between these two - as the 128kbps sounds like it's coming out of a tin-can for me.. You might want to rip your lesser cd's at 128, and your better cd's at 160 variable...
-mark

...proud to have one of the first Mark I units

Hmmm ... my new car's a convertible .... I think 128 will be fine! ;-)

Mk2's will open a socket listener and synchronise over this connection - we've not yet quite sorted the IP address stuff, but I suspect it will be along the lines of: if there's a link light on power up, it will use DHCP to get an IP address, otherwise it won't configure eth0.

Hugo

I hope this doesn't mean you will only work in a dynamic address allocation scheme ? What about statically allocated network address schemes? What if there is no available IP lease on the DHCP managed subnet you connect to? There are a number of DHCP-related issues that many people will not want to have to deal with.

I don't use DHCP in my network due to the difficulty of operating within a suitable DNS scheme, so it would be infinitely preferable if I could use the conventional ipconfig method to attach IP parameters to the eth0 NIC from the command line.

This does imply that this would only be available to system images with a command shell available via serial, ie. Developer. The Consumer image would not provide any way of getting to ipconfig.

Could you consider the idea of setting the IP address/subnet mask/gateway via Emplode? This would make it infinitely more flexible (and useful).

Also note that all the name fields are limited to 30 character.

Just to make it crystal clear, this is an ID3V1 limitation, once the files are in emplode each can be up to 255 characters long.

--
Mike Crowe
I may not be speaking on behalf of empeg above :-)

I suspect we'll use a bit of flash to store IP parameters for those who want static addresses: our DHCP client on the empeg does uPnP (universal plug & play) like win98, so that you can just slam an ethernet card into your unit and not even open the network control panel - but still have it work.

Hugo

I don't use DHCP in my network due to the difficulty of operating within a suitable DNS scheme.

DHCP doesn't necessarily mean the IP addresses that are handed out are dynamic. We use DHCP with statically assigned IP addresses by MAC address here for laptops and prototype Mk2 players without problems. This is compatible with DNS.

--
Mike Crowe
I may not be speaking on behalf of empeg above :-)

Yup, that's right - but it does mean that the administrator of the DHCP server has to decide that IP leases are attached to MAC (policy issue). If addresses were assigned from a pool, then they are effectively randomly assigned within the pool limits if the policy does not attach MAC to IP. This second form is not compatible with older DNS servers that do not include a DHCP server. If you use the first policy (effectively what BOOTP has been doing for years), then you are effectively using static assignment scheme anyway, so why bother with DHCP? (spot the gross oversimplification coupled with bullspeak in an attempt to pull a suitable amount of wool...)

I know - I'm only pointing out the obvious; I was just scared from the way Hugo framed it that there would be no other method of assigning NIC attachment data other than DHCP. He has explained a little in an adjacent post.

Believe it or not, I am actually a closet fan of DHCP (you'd never guess though), but it's frequently badly administered and under used/used incorrectly, and somewhat awkward to integrate into a useful DNS-based address scheme. I learnt the hard way about DHCP working overnight to configure a network of around a 130 PCs, finishing just about half an hour before the bash started (shudder - never again)

Whether or not your car is noisy isn't really the question. The question is whether or not you're an audiophile. My car is very noisy, but I also listen to my stereo very loud, so I can still hear compression artifacts when they're there.

At 128kbps fixed bitrate, you will lose some high-frequency content, and cymbals will sound a bit "swishy". It's very subtle, but if you're an expert in audio stuff and you know what to listen for, you can hear it.

Remember that it's always a quality-for-file-size tradeoff. If your software gives you a variable bitrate option, you can try using that to cheat the tradeoff curve a little bit. I've only just bought AudioCatalyst, and I'm very impressed with its variable bitrate encoding at the higher quality settings. In fact, I'll probably re-rip some of my more beloved albums with this new encoder.

Tony Fabris
Empeg #144

I have seen the Tivo boxes, and they look tempting. Especially since they're supposed to integrate with my DSS dish really well. Still, it's one of those things that I don't really need- I can work my VCR just fine and can't justify the expense at this time.

Oh, and a more on-topic note... Jens, since you're new to this board, I think something should be made clear to you. When you see posts by "Altman", "Rob", or "Mac", you're talking directly to the Empeg folks:

"Altman"- Hugo Fiennes (did I spell that right?), Founder and owner.
"Rob"- Rob Voisey, customer service.
"Mac"- Mike Crowe, programmer.

I wonder how much they communicate with each other in-person vs. posting on this bbs...

Tony Fabris
Empeg #144

.... I think 128 will be fine!

You'll regret ripping at 128bps once you get your Empeg and try things out. I bet you'll hear the difference even while cruising in your convertible at 80MPH with the top down! I recommend to rip at Variable Speed medium-high quality(Audio Catalyst supports this). In practice it averages out at 130-140bps, but sounds much better. Well worth the extra 5% in file size.

Henno
# 00120 (6GB+18)

OK, I've found VBR - what setting should I use? It's currently set to 6%

Thanks for the heads up on the 'empeg' boys ... I'd already sussed them out!

J.

I wonder how much they communicate with each other in-person vs. posting on this bbs...

Can someone put the kettle on please - I could do with a cup of tea. :)

--
Mike Crowe
I may not be speaking on behalf of empeg above :-)

OK, I've found VBR - what setting should I use? It's currently set to 6%

I have no idea. I'm not familiar with the software you're using. AudioCatalyst has nice little descriptions to accompany each setting, and they sound accurate. Perhaps your software has a similar set of descriptions?

You might have more than one setting to determine the quality, too, so look for it... One level of quality will always be the bitrate: i.e., the more bits per second of data, the more high frequencies and better stereo separation they can play back in a given frame. But another level of quality might be: How hard do you want the CPU to work to get the optimum compression? Some encoders let you adjust this, so that the compression can be done either quickly or carefully, or somewhere in between. Fraunhofer's command-line encoder offers both, but AudioCatalyst doesn't offer that option, it just has a single quality slider (plus a high-frequency checkbox buried in the advanced options).

Again, keep in mind that it's always a quality-for-filesize tradeoff. When deciding how to encode your music, decide what kind of disk space you're willing to pay for to store those 400+ albums. You might discover that you'd need a pricey 50gb to store all your albums at the highest quality settings, and you'll have to compromise a bit. Listen carefully to the albums you've encoded so far and see how much space they take up.

Tony Fabris
Empeg #144

Well, I've done some at 6% compression, and the files are about the same size, but I have no speaker in the office PC, so I'll just have to wait until I get home and see what they sound like. I was just taking advantage of the 2x400 machine I have here.

Thanks for the intro to the 'guys'. Nice to 'meet' you. And if you're looking for a 'demo car' for the UK, I have a 1990 TVR 400SE back in the old country that you're welcome to use (if it means me getting a freebee empeg!)

J.

There is a very good article that has been posted a couple of times to this board, which documents a blind listening test conducted with the popular compression formats.

The article made a pretty compelling argument that on most types of music, hardcore audiophiles can not reliably distinguish a 128K-bit MP3 file from the master recording.

After reading that article, I find it hard to believe that most people are going to hear the difference cruising in your convertible at 80MPH with the top down. I'm usually happy when I can make out the lyrics under such circustances. :)

You and Tony seem to be identifying a discernible difference that doesn't seem to be supported by the study. Why is this?

Corby
6-Gig Blue, #320, 128K VBR

You and Tony seem to be identifying a discernible difference that doesn't seem to be supported by the study. Why is this?

Good question. Hopefully I can provide a good answer...

I just got done commenting in a different thread that I can only hear a difference on certain songs. On most material, I can't distinguish a 128kbps MP3 from the original wave file. But there are a few songs where I can hear definite aliasing on very high frequency material. It's subtle, but it's there. The general effect is a certain harshness to cymbal crashes. In some passages with very complex material (multiple cymbal hits combined with vocal sibilance combined with high-frequency guitar notes, a surprisingly common occurence in Rush songs, go figure), I can hear the cymbals actually break down and begin to show obvious aliasing artifacts. It's sort of a swirl and chatter sound. If you're familiar with guitar effects, it's like having a very subtle flanger effect applied to the cymbals. The effect is similar to what you get when you listen to a casette tape that's wearing out, only more subtle.

Another very specific example I can cite is at the beginning of the song "All the way from Memphis" on Brian May's "Another World" album. The song has a section in the beginning where there is some recorded crowd cheering that fades into the song. The cheering was added into the recording as an effect (it's not a concert album), and they've already processed the cheering sound with some delay-based effects such as chorus and detune. Actually, it's the sound of whistling wind, combined with a car engine, combined with the cheering fading in as the song starts. It has a very specific sound that's nice and smooth on the original recording. But when I encode it at 128kbps-fixed with Fraunhofer, the resulting MP3 file very clearly demonstrates aliasing. The cheering, as it peaks in loudness, sounds staticy and harsh instead of smooth. There's also more "pink" to the white noise, making it sound more like a jet engine than a crowd cheer. The same thing can be heard at the end of the song, since the same cheer recording is used there. It's subtle, but audible if you know what to listen for.

The reason this happens is because of the nature of data compression. High frequency sounds and white noise translate into digital numbers that are almost completely random from a compression algorithm standpoint. Compression depends upon repeating patterns, and these sounds are the exact opposite of what the compression algorithms like. It's the same problem with video compression, except with video, high frequency is defined as high contrast. That's why you always see odd artifacts around sharp edges in compressed video. The audio artifacts are exactly the same, they're just interpreted through a different one of our senses (hearing instead of sight).

But like I said, in order to hear the artifacts, you have to know exactly what to listen for, and you have to know the song well, and you have to directly compare it to the original material.

Unfortunately, I happen to know my Rush material so well that those kinds of things stick out like a sore thumb when I do hear them. It's kind of ironic: You only notice it on your favorite songs, but you notice it precisely beacuse they're your favorite songs. So it makes it that much more annoying.

That's why I bought AudioCatalyst the other day. So I could do the extra high-quality VBR encoding on those particular albums to take care of it. The rest of my collection is fine at 128k, and I intend to leave it that way.



Tony Fabris
Empeg #144

hardcore audiophiles can not reliably distinguish a 128K-bit MP3 file from the master recording

Don't believe everything you read, Corby . Most people can easily hear the difference between a CD master recording and any MP3 copy if they compare on a decent stereo system. The MP3 theory that it can eliminate certain frequency bands without anyone noticing the difference is grossly exaggerated: the difference is significant: It is as if the leading tunes eat into the sounds that are not in the foreground - I find that there are 'dips' in the background music lines, whereas on decent playback systems, all music lines are autonomous; not affected by other sounds played at the same time. MP3s also combines lower frequency left and right channels on the assumption that the lower tones don't contain directional info - the same theory that Bose uses to market small speakers with a single bass box that's supposed to be hidden behind a couch. Well, the stereo image of MP3 is affected, for which the mono lower frequencies contribute. But with 90% reduction in file size, the results are remarkably good and Emma does a great job in reproducing vast CD collections from such a small box. If you don't believe that the differences between CD and MP3 are significant, you're invited and I'll demonstrate on my home system: It 'll tell you know how well CD's can sound. MP3 are no comparison for serious listening.

I agree with you that the differences are only distinguishable at home: the car is such a bad listening environment (shape / size / speaker placement / speaker quality / electrical noise) that the differences are probably hardly noticeable even if one were able to eliminate engine and traffic noise (even tanstaaf may agree . . . do you Doug?). Also, the amps and the speakers are much less refined than at home. So if you'd play Emma in the car only, normal compression may well suffice. But as a somewhat of an audiophile I believe that higher quality should be up the chain in any audio chain: amp should be better than speakers - pre-amp better than amp etc. so I don't mind to have 10% larger MP3s that sound a tiny bit better. Moreover, I also use Emma at home: it provides very decent background music and when played over the home stereo system, the better quality of normal/high encoding clearly shows.

But for close listening, nothing beats a properly mastered CD played on a good system (yet?) - There is so much potential left, that I doubt if DVD (or whatever) can improve on it, as longs as the basic technology (high sampled wav) remains unchanged. I can recommend to carefully listen to a good stereo set-up and then try to find a system that you can afford that sounds like it. Well recorded MP3s then prove worthwhile.

Henno
# 00120 (6GB+18)

Thanks for the intro to the 'guys'. Nice to 'meet' you.

And in the interest of reciprocity, why not fill out your BBS user profile so we can "meet" you, too?

Tony Fabris
Empeg #144

I suspect we'll use a bit of flash to store IP parameters for those who want static addresses: our DHCP client on the empeg does uPnP (universal plug & play) like win98, so that you can just slam an ethernet card into your unit and not even open the network control panel - but still have it work.

Hmm, time to read man dhcpd etc....

How about another (admitedly primitive) protocol: put manually empeg's desired MAC to IP mapping to your Linux arp table, than access empeg. It will grab the target IP address from the first packet whose ethernet frame has its MAC as target and assign it as its own. (Those cigarette-pack sized print servers often use this scheme - OK, I admit it is a relic from times before DHCP, but I still find it convenient.)

Cheers!

Dragi "Bonzi" Raos
Zagreb, Croatia
#5196

Since you put it so nicely, how can I refuse? ;-)

Hey Tony,

My friend Ash and I (check out his two car computers ) have had an on-going debate regarding the quality of 128kb mp3's vs. higher.. I forwarded your post to him, check out his response:

---

This makes sense to me. Because higher frequencies have more waves per
second, it seems that the repetitiveness of these high frequencies are
harder for the compression algorithm to recognize and therefore you have
some degree of alternating sources of the repeat which will cause you to
hear a flanger-type effect in cheering, and most other high frequency
sound sources. But what this document doesnt explain is why some come
out sounding different whereas other cd's compress fine. 95% of music
is going to have low, mid, and high range frequencies. The high range
is the one in question because according to this, those high
frequencies are what create these anomolies but, all songs have high
frequencies. It may have to do with the CD itself and how purely those
high frequencies are recorded. Our ears may hear a perfect 8th octave
C note but the digital transcript on the CD would show some
inconsistencies in the wave pattern that the MP3 encoder will see and
translate that small inconsistent section as another repetitive cycle,
but unlike the moment before as a perfect 8th C. Therefore creating a
flanging effect by switching from one repetitive clip over to this short
inconsistent clip that almost sounds the same, but different, and then
back to the first clip once more. Imagine this happening at say, 20
times per second on one note. This will create a 20Hz flange that will
be audible. Of course, what I have said to be the source of this
(inconsistencies on the CD) is only a theory. I dont know if this is
actually the cause, but I think I'm on to something. BTW: 8th octave C
is actually the highest note on a piano at the far right. It is at
16KHz, pretty damn high.
Ash

---

-mark

...proud to have one of the first Mark I units

Tell your friend his car computers look sweet. The fabrication of the replacement dash plate on the Z is particularly nice.

As far as the quality discussion goes... I actually commented on this in another thread with Mike... When I talk about high-frequency artifacts, they always seem to manifest themselves in high-frequency noise. In other words, the very thing that's hardest to compress. And the kinds of artifacts I notice happen in parts of the music that are particularly saturated with high-frequency noise. It seems that a 128kbps encoder can handle some high-frequency noise reasonably well, but not too much of it. So you only end up noticing it on certain songs.

Your friend's theory of the possible inconsistencies in a digital sample is known as jitter correction and it's already taken into account at each stage of the MP3 creation process: By the digital master of the original CD, by the drive mechanism you ripped the CD with, by the encoder, and by the playback firmware. Note that "jitter correction" is used two different ways: The first (and the correct usage), refers to the time-base correction of digital samples and their relative accuracy to a given wave. The second (and technically incorrect usage) refers to the ability of a CD ripper to sector-synchronise and correct errors when performing Digital Audio Extraction from a CD. Bad jitter correction can, as he predicted, cause artifacts that sound similar to compression artifacts. But that's not what's happening with a 128kbps MP3.

Here is a very well-informed discussion about jitter correction as it relates to digtally-sampled waveforms, and here is a discussion about jitter correction as it relates to ripping audio data blocks from a CD.

I have heard that data-compressed music fails to capture certain subtleties that audiophiles can notice. For example, the phrase "not enough air around the instruments" keeps coming up. I can't hear this myself-- perhaps it's the nature of the music I listen to. But that same phrase seems to get used in reference to jitter correction problems, too, so there's some sort of parallel going on. In the end, both jitter problems and data compression can make the final output sound slighty different from the original source, and therefore might induce the same sorts of audible artifacts.

Tony Fabris
Empeg #144

MP3s also combines lower frequency left and right channels on the assumption that the lower tones don't contain directional info

I'm going to pick a small nit here -- this is misleading. Lower channel frequencies can be combined in Layer III for better compression, but there's no loss of stereo imaging here; essentially the channels are encoded as L+R and L-R. This is called middle/side or M/S joint stereo. Both channels can be reconstructed perfectly.

Layer III can also optionally use something called intensity joint stereo, in which some high frequencies are encoded as mono plus some stereo imaging information. In this case you can't always reconstruct both channels perfectly. This might be what you're thinking of, as it's the only joint stereo option for Layer I and Layer II. However, it's not very common in Layer III.

For Layer III, either of these joint stereo options, both, or neither are possible. M/S is probably most common, as there's usually little reason not to use it. I have found inconsistencies, however, in the way some decoders handle a combination of M/S and intensity joint stereo, so I don't recommend anyone use both.

-v

errr.... mainly because we have had experience with bad RIPs carried out on music we are familiar with?

Plus, the open-top argument carries weight, yes - but don't forget you can use the box at home when you definitely will hear cracks, pops, and compression artifacts on high frequency stuff.I don't know about you, but this sets my teeth on edge....

Can, but in all honesty, probably won't. I have a top of the line a/v setup (52" projection TV, DVD, LD, CD, AC3, external DA converter, etc) and the 40 CDs are in a rack right next to it. I might use it at the office, though, but that'll be through small ear-plug headphones, which combined with office noise, and given I can't have it so loud that I can't hear the phone ring, it'll probably do.

I started ripping at fixed 128, then went to VBR 75% and am now down to VBR 50% and still can't tell the difference. The file sizes are good, and looking at the actual rates on VBR, I see everything from 192 (electronic trance with lots of precise high frequencies - little harmonics) down to 96 (acoustic guitar with background vocals).

---

You're saying that now:) but you'll use it indoors... I have a 200disc changer that I never use anymore; the empeg's just alot more effecient at swapping cd's (instant - in place of the 4-5 second pause most changers have..), and it's alot easier to use/control then disc changers; it's very easy to make playlists with the emplode software, something that's typically a pain to do on disk changers...
-mark

...proud to have one of the first Mark I units

Tony,

Thanks for the tip on www.allmusic.com! I just checked it out, and wow! ... Great resource! Now i can fix my year tags, and learn more about my favorite artists! I didn't know some of these albums exsisted!

thanks again.


-CHiP

Yeah, allmusic.com is one of the best resources on the net, if not THE best. Try allmovie and allgame.com too. allgame isn't that great, but allmovie is really good. I've used allmusic for years, and even used it in a school report :) They've got books in print but for some reason they list free, updated information on the internet. Who knows...

Anyway, I've got an interesting link about bitrates. It's mostly a review/comparison of about 4 encoders, but there's alot about different bitrates.
http://arstechnica.com/wankerdesk/1q00/mp3/mp3-1.html

I don't know who said that even audiophiles could not tell the difference between 128 and wav. I'm no audiophile but if I listen to a file encoded at 128 and an original CD. There's no question. I even did one of my CDs at 320 once just to check, and the difference is unmistakeable. I haven't done alot of testing at only slightly higher bitrates, but I imagine it could make some difference.

By the way, what do you mean your Variable Bitrate is set at 6%? All my AudioCatalyst has is 5 settings from low to high. what exactly is the VBR?

Thanks for the tip on www.allmusic.com!

Yeah, it's a great resource for people making MP3s. I use it when I rip soundtrack/greatest-hits/compilation albums. I can tag the MP3s with accurate year and album info. I mean, how silly is it to tag The Beach Boys' "Don't Worry Baby" with the date of 1999 and the album name of "Never Been Kissed Soundtrack"? With a few minutes of research, I can pull the correct date and album.

Although, for some pieces of music, it's a little difficult to look up those particulars. The way their search feature is laid out, it takes a little work on the users' part. Especially if the song is published by more than one artist, or was published by the same artist on more than one album. Still, great site.

Tony Fabris
Empeg #144

...definitely will hear cracks, pops, and compression artifacts on high frequency stuff.

Just to be painfully clear here (since Jens is new to this black art of MP3 creation)...

If you encounter cracks and pops (or instrument sounds shifting suddenly between the left or right channels), you're encountering issues with the Digital Audio Extraction from the CD-ROM drive, and these have to be fixed by activating the "sector synchronization" feature of your ripping software.

Compression artifacts are unrelated to those things, and are a lot more subtle.

Remember that ripping a CD is two distinct steps: 1) The digital extraction of the audio from the CD, and 2) the data-compression of that full-bandwidth audio into MP3 format. Things can sometimes go wrong in both sides of that equation, but the problems manifest themselves differently.

Tony Fabris
Empeg #144

Dionysus is right, Jens. I've scrounged up three extra power supplies for the Empeg, and I now have little pre-wired "stations" that I plug the Empeg in at: My desk at work, my desk at home, and the stereo in my living room at home. I understand that you've already got a high-end stereo system in your living room, but if there's a free set of inputs on your tuner, you'll really enjoy plugging the Empeg in there and having it shuffle-play. I haven't put in a real CD in months (except to do A/B comparisons or something).

Tony Fabris
Empeg #144

I would agree that 128K files can lack a lot of detail with certain genres however I seriously doubt whether the difference is "unmistakable" at 320K. If this is the case then I suspect your PC audio system is the cause. The empeg sounds an order of magnitude better than most PC systems.

I haven't heard of anyone consistantly identifying an MP3 track at 256K/sec in a controlled blind test against the CD original. A number of tests have yielded similar results at lower bitrates but I suspect that these are very genre specific.

In practice the majority of our clients report that 128K is satisfactory for them and a significant minority (myself included) encode at 160K. My experience has been that whenever I note a track with poor quality, I later discover that the original CD was dirty or worn. In other words, ripping was the problem, not encoding.

Rob

There seems to be some confusion about the style of compression mp3 uses. It isn't based on repeating clips or any such time-domain analysis. All the work gets done in the frequency domain, in a sequence (1 per frame) of spectra.

My understanding of how it works is it splits the wave into its frequency components by a DCT (discrete cosine transform). A DCT is like an FFT (fast fourier transform - which gives you a spectral display) but with the nice property that there are no imaginary numbers floating about. It then takes into account a property of the ear: you cannot hear quiet frequencies which are close to loud ones. This effect is called 'psychoacoustic masking'. For these masked frequencies, it can use less accuracy. All the coefficients are then quantised (have bit accuracy reduced) depending on their required accuracy, and huffman coded. Quantisation means that there are less 'symbols' for the huffman code to deal with, so the data compresses. It's quantised by an amount which makes the compressed data the correct size.

Ok, that description was properly full of technical inaccuracies, seeing as I'm not completely clued up on all aspects, just the basics :)

At any rate, high frequencies are no more difficult to compress than low frequencies. It's the quantity of frequencies which are loud in relation to each other that determine how well it compresses. The absolute worst case, as somebody else here pointed out, is white noise, which contains all frequencies in equal measure - which is remarkably similar to a cymbal crash.

The effect you hear when mp3 compression doesn't work is 'noise modulation'. Imagine standing a distance off from a waterfall. After a while, your ear will filter out the sound and you won't be concentrating on it. If however the waterfall was turning itself on and off, you would be most alarmed. Quantisation gives this effect, but mp3 attempts to get around it by quantising masked frequencies more than those which aren't. But if there's white noise all it can do is quantise everything - so you get that weird 'swishing' noise (very technical term).


- John.

(The above may not represent the views of empeg :)

that's exactly what it does. it's also just what the link I posted says:

http://arstechnica.com/wankerdesk/1q00/mp3/mp3-1.html

I'm still wondering about that VBR thing everybody here's been talking about. It appears we have either different encoding programs or different Audiocatalyst versions.

I'm still wondering about that VBR thing everybody here's been talking about. It appears we have either different encoding programs or different Audiocatalyst versions.

If you're referring to that "6%" thing, it's because that's an option found in a completely different piece of software (not Audiocatalyst). I believe it was MusicMatch, although I'm not sure.

That link to the Ars-technica article is good (especially in terms of explaining the nature of compression and describing the compression artifacts well), but the article makes one big mistake: It makes its final conclusions based on only fixed-bitrate compression.

You see, the article praises the Fraunhofer encoder for its ability to reproduce the music well at fixed bitrates, and complains about Xing because it doesn't sound quite as good as the Fraunhofer encoder at the same fixed bitrates.

While I agree with the article's conclusions on that level (and agree that it's necessary to compare apples to apples in such tests for accurate results), it doesn't take into account that the Fraunhofer encoder (as far as I know) currently only offers fixed bitrate encoding, whereas Xing will do VBR.

His complaints about the Xing encoder seemed to only apply at low bitrates. But the space-cost of cranking the bitrate on a VBR file is a lot less than the cost of cranking the bitrate on a fixed-rate file. What we really need is a comparison of the sound at a given file size rather than a given bit rate. For instance, if you encode something at a fixed bitrate with Fraunhofer, and compare it to a Xing VBR file that's the same size, I'd bet that the VBR file will probably sound a tiny bit better. This would be a more accurate "real-world" comparison, since the end-user mainly cares about the size/quality tradeoff.

Tony Fabris
Empeg #144

Cool, sounds interesting.

So just some clarifying questions:
a) Did we all decide that that 6% rate was good?
b) If so, what is the comparable rate in AudioCatalyst (in terms of low->low/medium->medium->medium/high->high)?
c) How does the 6%/comparable bitrate compare to the 128 bitrate?

I dont use music match or what ever it is, so no, i dont know what 6% means. Since I have no idea what it means, I cant tell you if its good or not. I use hycd to encode my cds - it uses the xing encoder. I use the high quality vbr setting on the songs that i listen to frequently. Although this is an interesting subject, i think that which setting is the best is entirely dependent on each individual listener and what quality they expect in their music. I suggest you try some different settings with your encoder and figure out what sounds the best for you based on how much hard disk space you have to give. Good luck

Term

Perhaps I'd better explain the 6% thing!

According to the help file, "Choose a VBR setting from 1 to 100, low end being the lowest quality/highest compression and high end being the highest quality/lowest compression, to customize your recording." So 6% is decidedly bad! I ended up choosing VBR at 65%.

I've had varying results (all sound good) with this setting, some files are encoded at 190 (mostly electronic trance and techo), but most are around the 150 mark. I've actually had some files encoded as low as 34 on this setting and they still sound fine (some tracks from Bryan Ferry's 'Boys and Girls').

Remember I'm listening through the PC speakers (middle of the line, with subwoofer) so not the same quality as the empeg or home setup. I've encoded over 2Gb now, which will be enough for me to start with when I get the empeg and not too many that it'll p*ss me off to have to do them all again!

What I'll do (when I get time) is to encode the same track at different rates and make them available from my FTP site - perhaps you guys could then do me the favour of testing them 'in the field' as it were?

J.

What I'll do (when I get time) is to encode the same track at different rates and make them available from my FTP site - perhaps you guys could then do me the favour of testing them 'in the field' as it were?

Um, don't do that, please. We just got done talking about the RIAA in another thread.

Besides, it's totally up to you as to whether the stuff sounds good or not. Just encode them so that they sound OK to you. If you ever reach a point where you're listening to the Empeg, and you dislike the compression on one particular song, it's not so tough to re-rip that song from your original CD (now that you've seen how easy it is with the proper software).

Tony Fabris
Empeg #144

I'll second that study - I read it too and it seemed on the money.

I'll concede that 128kbit might have some artifacts in certain parts of certain songs. I can hear it quite clearly as a digital processed sound on the snares on New Order's Blue Monday. High frequencies, white noise and other near random sound, and sharp attacks such as kick drums or explosions all suffer the most under MP3.

However, firstly, the encoder you use makes a big difference. A recent article on Ars Technica studied the frequency response of various players. While the Fraunhofer encoder reproduced the sound all the way up to 20 or 22KHz (I can't remember exactly), AudioCatalyst and BladeEnc (and another I can't remember) all dropped off at around 16KHz in standard 128kbit mode. People with good hearing can hear these tones directly, but there's plenty of evidence to suggest that the rest of us can still notice if a cymbal is lacking the really high frequencies. Most of this frequency loss went away as you increased the bit rate - the spectrum would return to normal at 160kbit or 192kbit.

Secondly, double blind is the only way to accurately determine real results. I've seen too many 'experts' able to tell the difference between a well encoded JPEG and a TIFF ten times its size when they know which is which, but very few can identify them when they don't know. And hearing is much more subjective - the memory is not very good at remembering precise tones or sound characteristics over time, and by the time you've loaded up that next track you've probably forgotten the exact details of the comparison part you wanted to look at.

Try things out before you commit to someone else's ideas.

Save the whales. Feed the hungry. Free the mallocs.

Good, now I have a justification for ripping all my music at 192 via Audio Cataylist. I'll have to dig through some book marks, as I know a site had the same song in 96, 128, 160 and 192. All of them I herd differences in, and would never encode that particular song any lower then 192.

My empeg site is:http://24.236.3.131/empeg/

Okay, I think I'm going against what I've said before, but I'll say it anyway.

I've decided that 128 is fine (for me). My reasoning is that I recently got the Klipsch ProMedia's, and now I can actually HEAR my music. Considering I'm listening to Candlebox's "You" at 112 right now and it sounds fine, I've decided I'll be fine in a car setting with 128.

It seems to me from reading this thread that pretty much everybody finds 128k indistinguishable from a CD for most of the time. Doesn't this mean that a good VBR is the way to go? That way you get much higher bitrates for the (apparently) problematic cymbal crashes and so forth, without blowing your whole file size out.

Personally, I've been encoding my stuff with lame, with VBR, at a nominal bitrate of 64k. I think in general the file sizes come out to an equivalent bitrate of around 140k. I haven't checked individual frame bitrates yet. So far, listening in the car, I haven't found any audible artifacts. If the psychoacoustic model in your VBR encoder is good, then that's how it should be. I really like the idea of being able to fine tune your psychoacoustic model, so that it knows just what YOUR thresholds for distortion at various frequencies are. Once you've got that, then you can be pretty much assured of getting the smallest possible file size that won't give you any audible problems.

Richard.

Jens --

Listen to Dionysus and tfabris.

All you have to lose by encoding at a higher bitrate is disk space, and you have everything to gain. From the reviews I've been reading, 160 is good, but 192 seems to be the sweet spot beyond which diminishing returns takes effect. Disk space is cheap. The difference in cost of an empeg with enough space to hold all your music at 128 Kbps compared to one big enough to hold the same music at 192Kbps is only going to be a few hundred dollars. Believe me, after you've had the empeg for a year you'll never miss that couple hundred bucks.

Anybody who can afford a Mustang Cobra can afford enough hard drive space to encode his music for optimal playback!

tanstaafl.

"There Ain't No Such Thing As A Free Lunch"

I agree with you that the differences are only distinguishable at home: the car is such a bad listening environment (shape / size / speaker placement / speaker quality / electrical noise) that the differences are probably hardly noticeable even if one were able to eliminate engine and traffic noise (even tanstaafl. may agree . . . do you Doug?)

Not really, Henno. Yes, the typical slap/dash car installation, put the CD player in, play it through the miserable factory speakers, then crank the bass up as high as it will go so the subwoofers in the trunk can annoy the neighbors.... you're right.

But I have seen cars in competition with incredible sound systems -- one Lexus that I know of has a system that we onlookers estimate at over $40,000 (the owner won't say one way or another) and while my own system is pretty good, the Lexus puts it to shame. You've told me a little bit about your own home system, and yes, it probably is better than even the Lexus... but from your description, there probably aren't very many stereos on the whole planet to equal yours.

A car can be an excellent listening environment IF PROPERLY CONFIGURED for the very reasons you cite as making it a poor environment. The fact the the environment is so.... finite means that you can do some very specific tuning without having to deal with the variables involved in a large, unsealed room. It just takes a bit more work to find the right speakers to work with the amount of air volume in your car; the right locations for the speakers to work with the shape of the interior and the rake of the windshield and the different materials and reflective surfaces; some of the best quality speakers available are made for in-car audio, such as MB Quart; the same could be said about amplifiers. One of the things that is driving the push towards quality car audio is the audio competition environment; many cars do a quite respectable job of filtering out road, engine, traffic, and electrical noise, and by the time you have the volume cranked up to 90 decibels or so (for some reason the very ambience of a moving car seems to encourage playing the music louder than you would at home, irrespective of any external noise) all you'll hear is the music, you won't hear anything else, and that music can sound very good.

Whether you'd pick up on the subtleties of 192Kbps vs 128 Kbps.... I have no first hand experience on that. I think I would. Little things like the brightness of the treble might give it away. Toni (oops, pardon me, Tony) might be able to verify an analogy: is a comparison between 128 and 192 Kbps similar to a comparison between the original Rush CDs and the re-masters? If so, then I can absolutely promise and guarantee that I will be able to tell the difference, at least in my car.

tanstaafl.

ps: sorry to be so slow in responding to this -- I've been "off-line" for the past two weeks...

"There Ain't No Such Thing As A Free Lunch"

Especially anyone who can afford the parking prices in NY. They're INSANE!

A car can be an excellent listening environment IF PROPERLY CONFIGURED for the very reasons you cite as making it a poor environment.

Yeah, Henno, I gotta go with Doug on this one. It depends on the car and the stereo system, but in some cases, the car can be a better listening environment than a living room.

For me, the biggest advantage to listening in the car is the fact that I can concentrate more directly on the music when I'm driving. If I'm at home, it's hard to just sit there and listen, I always end up doing something else at the same time and not listening closely. When I'm driving, I am already occupied on a focused task (watching the road, etc.), leaving the other 75% of my brain in the perfect state to absorb the music properly.

When I consider how much time I spend on the road every day, it makes sense to spend the money on a really good car stereo system. I'm especially happy since I traded my GTI in on an Accord, and the car interior is so much quieter and makes for an even better listening environment.


is a comparison between 128 and 192 Kbps similar to a comparison between the original Rush CDs and the re-masters?

While I know that you'd have no trouble distinguishing 128 from 192 for certain material, the comparison is not quite like the original/remaster thing. The differences in bitrates are more subtle than the obvious improvements made on those remasters, and they're different kinds of differences, if you know what I mean.

Doug, have you discussed this topic with the CE at your radio station?

Tony Fabris
Empeg #144

I also have a question about emplode. How does the transfer of music to the empeg work? Can you do it incrementaly? I'm currently ripping my collection to jaz disks. I'm considering getting the 12gig empeg but I won't be able to have 12gig of music on my computer at one time. Will this be a problem or can I download songs in batches? Thanks.

no problem..You can transfer as many or as little songs at a time as you want..
-mark

...proud to have one of the first Mark I units

There doesn't have to be a 1:1 correspondence between your hard disk and your Empeg. So you can drag the songs from the Jaz onto Emplode, hit the "Synch" button, wait for Emplode to send those songs to the Empeg, then swap in another Jaz cartridge, and repeat the process. Emplode is like a "dumb terminal". It can only organize data on the Empeg itself, and send new songs to the Empeg. It doesn't care where the song files come from, or how many different times you send new songs to the Empeg.

Still, since you can't easily copy songs directly off of the Empeg, I recommend keeping your MP3's backed up somehow. I have an 8-gig hard disk on my computer where I store all my MP3's. If something ever happens to the Empeg's hard disks, I can simply re-send all the songs. But you don't have to do that.

Tony Fabris
Empeg #144

Doug, have you discussed this topic with the CE at your radio station?

Yes and no. He's listened to my stereo, thinks its the best he's ever heard, but he is not an audiophile. He is very hardware oriented, and music is music to him -- an AM station playing oldies through the single speaker in the middle of the dashboard of his pickup truck keeps him just as happy as my [he says, bragging] superb car stereo playing re-mastered Rush CDs.

He would love the empeg -- but only from a technical point of view. He'd be entranced by the idea of 50 GB of storage in a standard DIN sized box. He'd salivate over the specifications ("115 dB signal to noise ratio -- that's fantastic. What kind of circuitry do you suppose they used for that? Did they couple the inverse capacitance bias modulation rectifiers directly to the tertiary output channels, or did they ...") You get the idea.

Go figure.

tanstaafl.



"There Ain't No Such Thing As A Free Lunch"

"Did they couple the inverse capacitance bias modulation rectifiers directly to the tertiary output channels, or did they ..."

So, what you're saying is, all Chief Engineers are alike, whether they run radio stations or starships?

Tony Fabris
Empeg #144

So, what you're saying is, all Chief Engineers are alike, whether they run radio stations or starships?

Being one, I can authoritatively answer "yes".

-- Bleys

"If you would judge, understand." -- Seneca