Audiocontrol has released a new in-dash processor, that, in addition to it's other features, is supposed to make MP3's sound better. From what I understand, Audiocontrol has a pretty decent reputation, but I can't help but think this might just be marketing hype.

Some product info is http://www.audiocontrol.com/caraudio.htm
There's also a product flyer in PDF at http://www.audiocontrol.com/techpapers/hpx.pdf

Anyone have any thoughts on this?


Bill

I think this just makes sound (not only mp3) sound better. In what I see it's something like a sound-processor which is able to filter noise and so on. (Do you know WaveLab? I think it's something like that but as hardware)

TeeMcBee

> Audiocontrol has released a new in-dash processor, that, in addition to it's other features, is
> supposed to make MP3's sound better. From what I understand, Audiocontrol has a pretty decent
> reputation, but I can't help but think this might just be marketing hype.

> Anyone have any thoughts on this?

Sounds like your average spatial (stereo) enhancement, although they hint at dynamically altering the frequency response too. Personally, I view this kind of processing as corruption of the audio stream. Once information in the sound has been lost, by compression or otherwise, there is no way of recovering what was intended with absolute certainty.

However, you can predistort the audio so that when it comes out of the speakers and reaches your ears, the distortion caused by the car enclosure is cancelled. An equaliser will do the most for you money. Compensating for any parameters other than frequency response is extremely difficult, computationally intensive, and very critical on listening position and components used.

Personally, I'd spend the extra those marketing gimmicks would have cost on some other part of your system.


- John (from empeg)

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

Speaking of that, there's an intriguing piece of software, a plug-in for winamp, called Arboretum Realizer. In their own words , "Arboretum Realizer solves all that by expanding the stereo image, adding missing low end frequencies and synthesizing new overtones. It restores the sizzling realism and immediacy of the original recording."
Well, I haven't tried it yet, but has anyone?
It would be cool if it worked... Then my next dream would be An empeg runnig some Linux-version of Realizer. Ok ok, I know Empeg already sounds great, but I'm a bit of a perfectionist.

"...expanding the stereo image, adding missing low end frequencies and synthesizing new overtones."

This is your idea of perfection? Taking the original sound and synthesizing and adding stuff to it that the original artist did not intend to include?

Hmmm... I think we have different priorities here, reggie. My idea of perfection is to have the sound reproduction be indistinguishable from the original. That's not to say that my preference is necessarily superior to yours... I know what you're trying to say. It just tickled my fancy to see what I would consider mutilation described as "perfectionist".

To each his own.

tanstaafl.

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

This is your idea of perfection? Taking the original sound and synthesizing and adding stuff to it that the original artist did not intend to include?

True, but keep in mind that some of these audio enhancement technologies are meant to help properly reproduce what the artist intended. For example, the stuff that BBE does.

The whole idea is that between the time the artist lays down the master tape, and the time those sounds get to your ears, there are many steps in between. There's the mastering (which we all know can get butchered sometimes), there's the inherent differences between the artist's reference equipment and your playback equipment, there's the overall limitations of your playback equipment, and there's the limitations of your listening environment. These things can't always be corrected by equalization.

Little things like phase-correcting individual frequencies can go a long way towards restoring that "sitting at the mixing desk next to the artist" sound that everyone craves. Just hearing the difference between the original Hemispheres CD and the remastered version, you can understand what they're trying to accomplish with these technologies.

I'm not saying they're always successful, or that they're always the right technology for every situation, but taking a purist "don't ever post-process my sound" approach isn't 100 percent realistic, either.

___________
Tony Fabris

Wait a minute. First, to get sound equal (or at least as equal as possible) as the one that was recorded, first you need topnotch equipment. Preferently, you need the very same equipment used for the recording. That's the only way to maintain sound close to what it is expected to sound. Be real: am mp3 file at 128 kb/s doesn't come close to what the engineer wants us to listen. Plug an mp3 player at a third-octave analyser and compare the spectrums to the ones from a top-of-the-list cd player, reproducing the same song. There's no match. That's why I was thinking at the possibilities of enhancing somehow my mp3s. As for real audiophile sound, yes I consider myself a perfectionist and that's why I stick to vinyl. Period. Ok, Cds are nice too. But please don't come with that stuff about preserving sound as indistinguishable from the original. In such a compressed format as mp3, that's not possible.
Please pardon me if sometimes my english isn't clear; it's far from being my native language :-)

Is there a way to play some vinyl on the empeg, too? ;-)

TeeMcBee

Well put, Reggie -- I concede the point!

But.... vinyl? How do you keep the needle from skipping when you run over bumps in the road? ;-)

And I really like your point about the third-octave analyser. Have you actually done this? What differences do you see, that is, do you lose frequency response on the low end, or the high end, or is the loss randomly distributed? How about at different encoding rates -- say AudioCatalyst VBR at the High quality setting?

I have gotten conflicting reports about whether an MP3 recorded at a high bitrate can be made indistinguishable from the original CD. The consensus of opinion from empeg users seems to be that it can be done with the empeg, which seems to have unusually high quality audio output.

If you're talking about third-octave analysers, it sounds like you are familiar with IASCA competitions. Have you participated in such? I am hoping that by the time I get my empeg installed I will be able to put the tracks from my IASCA disk into it uncompressed, and play them back as such. And I am really hoping to be able to equalize each track individually. Talk about an unfair advantage...

Oh -- no need to apologize for your English! It is better than many of the native-born English-speakers I deal with on a daily basis.

tanstaafl.





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

And I really like your point about the third-octave analyser. Have you actually done this? What differences do you see, that is, do you lose frequency response on the low end, or the high end, or is the loss randomly distributed? How about at different encoding rates -- say AudioCatalyst VBR at the High quality setting?

I've seen the graph outputs of these tests, and they all show what our ears already hear: The differences get worse as you get closer to the high frequencies. They also show that as you get past 128kbps encoding rates, the differences start to decrease to negligible levels. Almost all MP3 encoders roll off the ultra-high frequencies above 16khz no matter what encoding rate you use, but as long as you're still in the non-canine range, the differences are negligible at rates of 160kbps and above. Honestly, though, trained human ears are infinitely more sensitive than one of those graphs. A good audiophile will hear differences that those graphs won't show.

I've never seen one of those graphs comparing VBR with CBR though. They always seem to do the comparisons as apples-to-apples constant bitrates between different encoders as compared to the original waveform.

I have gotten conflicting reports about whether an MP3 recorded at a high bitrate can be made indistinguishable from the original CD. The consensus of opinion from empeg users seems to be that it can be done with the empeg, which seems to have unusually high quality audio output.

Keep in mind that there is a difference between the sound output quality of your playback hardware, and the compression quality of your MP3 encoder. Those are two completely different and unrelated steps in getting the sound to your ears.

The Empeg has great audio output, but it's still at the mercy of your MP3 encoder. It's definitely a GIGO system.

The test graphs I refer to are completely independent of any audio output hardware, they only tested the encoder. How do they do this? By working only with the wave data directly on the hard disk. It goes like this:

- Original wave file is analyzed.
- Wave file is used as the source for the MP3 compression.
- Compressed MP3 file is "played to disk" using the WinAmp disk writer plug in. It goes through all the decompression steps, but the output is a new disk file instead of the sound card.
- The resulting "play to disk" wave file is analyzed the same way the original wave file was analyzed, and the results are compared graphically.

This way, you get an apples-to-apples comparison, so to speak, without the audio amplification hardware muddying the waters.

___________
Tony Fabris

Thank you very much, yes I am somewhat in touch with the IASCA standards as I am a suscriber to many car sound reviews, and my car system was built keeping in mind al I have learned from reading them. Competition? well, as I live in Chile, until now I've decided that getting my Golf into the USA for a IASCA sound off isn't worth it, even as I think that with some tweaks I could make some damage in the amateur categories. As for the third-octave analyser,I've got a friend who owns a studio and car sound shop and he did all the tricks and they turned out exactly as Tony Fabris has stated. My advice would be using space-unfriendly 190 Kb/s mp3, as much of my music is now recorded at that bitratre and it sounds more than satisfying for in-car stuff.
As for the vinyl not skipping at bumps, as the folks at Crewe usually said, "Don't worry. We're working at it" :-)

It's been done... =)
They used 5 lasers to read the record, and if I could remember the name of the company, I'd give you a link... =)

Not quite ready for in car use yet though... =)

Jazz
(List 112, S/N 00030, 4 gig blue)

It's been done... =) They used 5 lasers to read the record...

AFAIR, that was a ~$5000 unit intended for professionals like radio-stations and such. The main advantage would be avoiding the damage the stylus inflicts on vinyl (especialy hi-freq part) after a playing or two.

....and if I could remember the name of the company, I'd give you a link... =)

You mean they are still around?

Cheers!

Dragi "Bonzi" Raos
Zagreb, Croatia
#5196

This all has been covered several times, but I have to work on my rating here :

While comparing original and processed (e.g. MP3-compressed) signal using spectrum analyser will reveal obvious shortcomings, it is far from being the whole story. We sometimes don't hear seemingly obvious differences; in other situations, the signal that looks almost perfect on the analyser will have, for example, phase distortions ruin the stereo image etc...

I think the only way to tell whether the signal processed in a particular way sounds indistinguishable from the the original is by listening (of course, in blind tests). (Then again, one can always tell vinyl from CD in blind listening test by hissing, clicking, shaved high freqs, lower dynamic range... :)
BTW, one can find interesting listening test rant here.

Regarding 'repairing' the signal, I understand that one can correct for differences in frequency or phase response between mastering and our own system, or 'undo' intentionally introduced known changes (Dolby, dynamic range compression). However, I think that, if we knew how to 'repair' poorly compressed MP3 signal, we could simply make better decoder....

Cheers!

Dragi "Bonzi" Raos
Zagreb, Croatia
#5196

I stumbled onto a company making a similar device last year, whilst I was just looking round the net for something unrelated...
I'll have a look through the bookmarks file I archived... =)

Jazz
(List 112, S/N 00030, 4 gig blue)

Try $12,000 USD for the base model (30 - 50 RPM continuously variable) and $21,000 USD for the high performance mode (30 - 50 and 60 - 80 RPM). One laser tracks the outside ridge, one tracks the inside ridge, one tracks the middle, and the other two do left and right. One neat feature is that you can read the inner or the outer track separately; this comes in very useful when transcribing very old gramophone records where the whacking great stylus has been pushed around by the outer groove - the inner groove is often much clearer in these cases.

I hate to say it, though, but I have yet to see any objective, statistically significant, double-blind test that proves that vinyl is better than CD. As far as I'm concerned the CD format can record everything there is in a vinyl record and still have 12dB (or more) of headroom left over. Not that vinyl is dead - I certainly wouldn't devalue those that have invested hundreds of thousands of dollars in their vinyl collection. But the argument that CD is somehow inferior seems to only be pushed by those who have big vinyl collections...

But this flame war has been done to death before...

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

I hate to say it, though, but I have yet to see any objective, statistically significant, double-blind test that proves that vinyl is better than CD.

Well, probably because the complaints levied upon CDs by vinyl enthusiasts aren't based on the technology. The technology of CD is provably superior to vinyl. What they really complain about is the way some CDs are mastered. Before CDs became the primary target platform for music, everyone mastered for vinyl, making sure to compress and EQ the music with vinyl in mind. Essentially, CDs were the for-vinyl analog masters that were sloppily digitized then unconditionally normalized, and that was the extent of their mastering process. So what you got was a bunch of mediocre-sounding CDs that didn't take advantage of the format.

There is a trend towards re-releasing some of those older CDs in "remastered" versions. So far, what I've heard is pretty good. Although I have one remaster (the Fixx's "Shuttered Room") that is too bright and tinny, so even that's not a guarantee that you'll get a good-sounding product.

___________
Tony Fabris