Don't know if you'd seen this, but while taking a stroll through the AW neighborhood, I found this thread. Hope it helps.

ERT<ul><li><a href="https://forums.audiworld.com/tt/msgs/434275.phtml">iPod as a Changer (compliments of the TT Cookbook Forum)</a></li></ul>

 

I've ordered an Audi to Panasonic adapter for $20 from Crutchfield. If I can't get that to work as an AUX adapter I'll eat my hat.

But who wants to put their iPod in the trunk?

 

I don't own an iPod, but thanks. I'm an audiophile... want 24bit/96kHz, not MPG!!

 

There is some evidence that 16-bit isn't quite enough at home, but in a car road noise clocks in at 50-60 dB. With the 106dB dynamic range of 16-bit audio that means you can represent sounds from just above background to 20dB below the level of instantaneous permanent hearing damage. That's plenty good enough I would think.

 

if you're in the 1%. :-)

What are you planning for your Nemo A6? I really used to be into car stereos. I'm planning on getting the Phatnoise 30GB MP3 for my allroad. The vast amount of space allows me to carry a crapload of songs all encoded at 256Kbps.

I just sold some of my other toys off and almost have the spare $$$ to dish out the $800 for the Phatnoise. Sucks being married with a baby... financially that is.

 

I'm an acoustical engineer, and have studied work by Floyd Toole and others on listening tests. I've taken part in many.

With a properly revealing setup, well-designed room acoustics, and a bit of familiarity with the system, the vast majority of people agree on, for example, the attributes of sound coming from a variety of speakers or components. Properly prepared listeners can tell the difference between red book CD and 24/96 80% of the time, double blind. The minority that don't hear the differences are the same people that have measurable hearing problems. Its in the Journal of the Audio Engineering Society, somewhere.

I'm sorry you haven't had a chance to hear really good systems!

I plan on an audiophile based system, flat, revealing, subtle. I will start with the stock head unit and see if that is good enough for the car (I don't expect as much in that environment, or need that much). I haven't picked the components yet, but few of them can be found in the normal outlets.

However, for now, I'm saving my dimes....

 

I work on the iPod at Apple. We have a few people who can tell the difference between CD and ANY mp3, no matter what the bit rate. They also can discern other attributes etc.

We call them "golden ears" and they have to listen to our stuff before we release it. I am close to one of these, I can tell normal bitrate MP3s apart, and from red book. I call myself a "gilded ear". I can work as a first pass before we bother calling one of the golden ears over.

Anyway, despite all the people we have on the project who know all this, most of the people on our project cannot tell normal bitrate mp3s apart from red book. Most notably is the fellow who wrote SoundJam & iTunes and has been working on this longer than all of us. He has to ask someone else to see how his encoder is doing.

All of this flies in the face of what you assert. I think the research you've seen says that there is an audible difference between normal bitrate mp3s (or even high) and red book. It doesn't mean that most people can hear the difference between them. It may not be because there isn't a difference, but instead because they haven't trained themselves to hear the difference.

And I personally think they are probably better off not doing so. Ignorange is bliss, so to speak. They can carry around 1000 songs on an iPod and enjoy it, while the people who are tuned to the differences are chained to a CD player and 14 songs tops.

So, anyway, I think perhaps you're splitting hairs saying that there are differences when 90% of people can't detect them, even though there is nothing wrong with their ears.

 

&gt; All of this flies in the face of what you assert.

No it doesn't.

One of the first things addressed by Floyd Toole and others in Canada was whether the listener's experience or physiology makes a difference. They found that the room and equipment makes a huge difference. After that, they found that something like 80% of people could hear the same flaws and attributes in reproduction. The other 20% had hearing loss. Listeners only needed modest time to get familiar with the setup. That was just the start of this one research programme.

Speaking generally about the dozens of research efforts I've studied: <b>Most ordinary people can hear the differences between excellent home audio equipment, and among the very best of sources (CD, clean LP, 30 ips, 16/44, 24/96). And they cannot in general tell the difference between live mic feed and 24/96 properly implemented. Those who can't tell the difference in properly designed listening environments (which is the tough part) almost always have hearing abnormalities like a noise notch or HF rolloff. </b>

Your experiences stand on their own with their own validity and applicability. But it has little to do with what I'm talking about. The MPG listening comparisons you mention aren't even on the scale of quality (read expense on equipment) and rigor (experiment design and room acoustics design) of the body of research I am referring to.

And, no, the research I referred to didn't even bother including MPG or AC3 or other compression schemes. The audibility of those was answered elsewhere, definitively.

One reason most people can't tell the difference between MPG sources and CD is the fault of the rest of the equipment and environment. In such MPG comparisons, what is measured is simply that, <i>under poor (ordinary) conditions,</i> people can't tell the difference. That is an important conclusion, and perhaps the relevant conclusion for most people, but it is not what I am talking about. It is not about what people <i>are able</i> to hear.

This isn't splitting hairs. It is pointing out a chasm. There is a split between (mostly older) people who want to recreate the live environment, and a growing crowd of (almost all young) people who want portable "tunes".

Tell me, how do the MPG developers listen... what equipment? What transducers? What acoustical environment? What do you compare it to? Do you compare stage width and depth? Instrumental images? Timbre subtleties? Depth of stage? Space between musicians? Quiet spaces between notes? How much time do you spend with live unamplified music? With $10,000 speakers? With $20,000 Krells and ARCs?

My guess is you listen as the typical user would. You listend with headphones or perhaps a modest pair of speakers in a lab (not a designed listening environment) for tonal balance, harshness, reasonably natural textures, inelligibility, separation of musical lines... but most of all for relative degree of blurring, blunting, smearing, pumping, and other flaws. People tend to listen for the absence of flaws they are used to hearing. That is too narrowly focused.

I have done my own comparisons between CDs and burns of MPGs ... it is pretty obvious within the first minute, depending on source quality. Even in my car.

Bring your best MPGs over and hook them up to my system next to my 10 year old CD player, and I'm sure both of us will hear musically meaningful differences.

Not to put down the iPod... it is the best audio device I've heard of its size. It doesn't beat a top-notch CD portable, however, from my listening (with different headphones, however), much less a Madrigal or Theta. (Maybe I'll take my portable headphones to the Apple store Monday morning... for the flat-panel G4 iMac "digital hub" announcement).

So, referring back to the conversation I was having with Ernesto and Nebuch., when I select a car audio system, I try to emulate the home listening environment, which itself tries to recreate the soundspace of the performance with all its subtleties. I am not trying to get tons of songs conveniently into a small package. Both approaches have their place.

 

First of all, it is MP3, not MPG. MPEG is a group, the Motion Picture Experts Group. It isn't a compression scheme. Using MPG to mean MP3 can in some way be considered to be correct, but it is also unnecessarily inaccurate. It could be construed to mean MP3, or MP2, or MPEG1 (320x240 compressed video), MPEG2 (DVD or DSS quality compressed video), or MPEG4 (futuristic compressed video, good stuff).

Okay, if you really meant what you meant, then I didn't mean to reinterpret you. I guess I meant to say you were wrong or off-base then. I tried to give you the benefit of the doubt.

I cannot understand how you can't distinguish between having the capability to distinguish between two different quality sources and actually having the training or inclination to do so.

Let me give another example. I think we would all agree that most humans could distinginguish between Mandarin, Cantonese, and Japanese. Unless you have hearing problems, we all have the equipment to do so. However, the vast majority of people in North America can't tell the difference.

So, from your angle, a group of experts could put a random person in a room and point out a few of the sonic differences between the three and then ask the person which was being spoken. In this way, they could say that 80% of people can tell the difference between the three.

Another valid point would be to take the people and put them in a room and run the three languages by them with no training beforehand. They could easily conclude that 80% of the people can't tell the difference.

Both are correct. But if you return to the context into which this whole thing started, the more applicable point of view is the first, because whether an individual is capable or incapable of telling the difference between an MP3 and redbook, the fact is that the vast majority of people do not make the distinction. Essentially, they just don't pay attention to the cues or the overall quality much at all.

As to the rest of your message, I already explained I can hear the difference between MP3s. I could pick out the 160kbps mp3 and 128kbps mp3 from a list of sources including higher qualities and redbook. In fact I did so, despite the fact that the material was banjo music, which I never listen to, and the fact that the material was playing on $18 speakers. So your offer of a demonstration to me wouldn't produce any new info.

But that really isn't pertinent to the discussion.

As to you liking the iPod, I couldn't really care less. No portable is going to satisfy the most demanding listeners. In essence, the most demanding listeners don't even WANT to be satisfied by a portable. So we didn't really expect to do so. I would note that you can play uncompressed WAVs and AIFFs on an iPod if you want, although with the current software it is far from battery efficient. I would also note that our headphone amp is 5 or 6 times as powerful as the average mp3 player and 2 to 3 times as powerful as the next most powerful mp3 player. Still, it cannot properly run the Sennheisers we bought for demos at company functions. Our laptop machines (Ti, iBook) cannot do so either.

I dunno about your original discussions with Ernesto, all I know is what Ernesto (and Nebuchadnezzar) posted in this thread.

Now, as to our testing, we didn't test anything of soundspaces and such that you speak of. You may find this crazy, but we tested for accuracy. Those other things you mention are expressions of feelings various changes (presumably inaccuracies) in the sound give to you. If you reproduce the sound accurately, the feeling of the reproduction is the same as that of the recording. We didn't buy any hoity-toity speakers. A few of us bought our own hoity-toity headphones though, but that was mainly to show off. We did run it by a bunch of self-professed experts. But the emphasis was on what people would actually use an iPod for, and all the stuff you talk about simply isn't relevant to our customers for the reasons I mentioned above.

To that extent, it definitely comes back to what you said. Which is, don't send a portable to do a full system's work.

 

Well.