BAASnotes.com – Bay Area Audiophile Society

Audio Primer: Training Your Ears

Continuing on our recent technical theme, here’s a great site for training your ears to detect and describe sonic anomalies. It’s harder than you think. If you like what you hear, please support the author by buying one of the products on Quiztones. (The Golden Ears material is the sine quo non of the field – it’s great.)

One more bit of knowledge that you need to make pronouncements like “the lower mids are muddy” is a working definition of “bass/midrange/treble.” I personally use the mental hook of dividing the audio range into three ranges, separated by two easy-to-remember “corner frequencies”: 150hz and 1500hz. Piece of cake. You can find a more elaborate definition in the graphic.

Finally, it’s fair to ask about how these map to the musical concepts that we know or learned in school. The keyboard graphic below helps with this aspect.

Bob

An Engineer’s Comment on the High-Frequency Noise Spike Issue

The professional engineer in question has requested anonymity, but here’s what he had to say:

Studios are full of HF signals that alias back into the audio spectrum.
The guess about a TV monitor
somewhere in the mastering studio is valid indeed, as 15,750 * 4 -
44,100 = 18,900 Hz. It could even be a nearby TV transmitter.

Such “birdies” of constant frequency are relatively easy to trace, but
wideband HF is harder. For example, decent condenser mikes and
preamps go well beyond 100kHz at their output. Feeding them to
poorly-filtered ADCs (nearly all of them are!) can produce -40 to -60
dB of aliasing into the audio spectrum. As a side note, this is a
killer justification for ribbon mikes on “comb-spectrum”, high dynamic
range music such as authentic-instruments baroque.

Studio engineers can shrug and call HF birdies “digital sound”, yet to
me everything is analog: some within the audio band as intended, and
the rest just gets there unintentionally. Higher sample rate (192 or
176.4ksps for baroque, 88.2ksps for everything else) dramatically cuts
most of the latter.

See the comments of the previous post for more ideas.

Bob

Van Gogh + Music + Computer Graphics = Remarkable

Starry Night (interactive animation) from Petros Vrellis on Vimeo.

May not be “audiophile,” but I find it simply remarkable.

(Watch it all…surprising throughout.)

Bob

“Spend on the Room and High Res” Says Alan Parsons

Despite the link-bait title – “Beatles, Pink Floyd Engineer Alan Parsons Rips Audiophiles” – the main message that I got out of the interview had to do with room acoustics and high-resolution downloads. These are where Mr. Parsons recommends spending on home systems. He is also big on surround sound.

Of course, Parsons undeniably knows good sound, having played key roles on Dark Side of the Moon (DSOM) and Year of the Cat (YOTC). Hard to fault the sonics on these babies. To my recollection, the Alan Parsons Project LP’s sounded pretty solid as well.

In any case, while Parsons admittedly is no audiophile, fans of this music will benefit from the read.

Bob

Was Steve Jobs an Audiophile?

Well, well, well.

Audiophile news has all of the sudden risen on the charts of the blog-o-sphere. To what do we owe this honor?

Chalk most of it up to the timeless “Old Man” – Neil Young.

At a recent News Corp media conference, Young described in some detail about his recent dealings with Apple to bring high(er)-resolution offerings to iTunes. He added that Steve Jobs was taking a personal interest in the project.

Young also approached Bill Ford, asserting that MP3′s sound bad, and suggesting hi-rez alternatives for the car. Ford baulked.

So what’s the ideal hi-rez format? Young claimed that he and Jobs agreed on this one: the LP! He went on to say that Jobs, master of the iPod and $1 compressed download, typically listened to vinyl at home.

Thus, audiophile issues have risen, if for a moment, to the popular consciousness – USA Today, Rolling Stone, HuffPo, Washington Post, PCmag. Like most internet news, the half-life of this issue will likely be measured in hours. But perhaps an impression will be made, boomers remembering just how good that record console sounded and kids wondering whether there’s something to this “quality reproduction” thing. Jobs, having immense street cred across cultures and ages, is probably the ideal messiah for such word.

As an aside, I wrote to Mr Jobs about two years ago, suggesting some audio-friendly tweaks to OSX’s Core Audio package. Alas, my note went unanswered. But I’m no Neil Young.

Bob

PS  I can hear PeterT and the legions of BAAS vinylphiles now: We told you so! lol

Resurrecting the First Recorded Sounds

I was just reading the latest Science magazine (here) and ran across an article highlighting the work of Patrick Feaster, audio archeologist.

This, in turn, led me to the First Sounds website, an outpost for the restoration and preservation of our earliest recorded sounds.

It turns out that Cal Berkeley plays a unique role in this process: they have developed a method for digitally scanning fragile wax cylinders to extract the signal without destroying the original.

I find this ironic – recovering man’s original analog signals using digital means. I wonder if they worry about jitter?

Bob

Is Music Math (and vice versa)?

Physicist Glenn Elert has included a nice exposition on the mathematical basis of music in his online physics text (click here).

From Beck "Sea Change" DVD-A

Glenn keeps the tech description at a “Popular Science” level for much of it, but descends to undergrad-college-level in parts. So there’s something for everyone. (nice illustrations too.)

If you think about the content, I believe you’ll emerge with a thing or two to enrich your listening – at home or in live venues.

Bob

PS  The pic at right shows some anamolies I’ve detected on a popular DVD-A. I am shocked and amazed at what I find in some “hi rez” material. (At least this one goes above 22kHz – some don’t.)

Can Androids Create Musical Art? – A Short Story

Fans of music and science fiction can find common ground in this enjoyable, award-winning short story by local software engineer Bill Katz.

In the story, the career of a concert pianist is ended in its prime with sudden onslaught of a debilitating disease. Future science has a “cure” – but can his art survive the process?

Plenty of humanity and neat tie-ins to the world of a classical pianist.

Enjoy,

Bob

The Ultimate Blind Reference Test – Pick the Stradivarious!

I want to introduce you to NPR’s new classical music blog, Deceptive Cadence, and to this article.

The article describes research in which professional musicians could not tell the difference between a centuries-old classic violin and one minted in 1980. In fact, most preferred the sound of the 1980 job!

Based on the sound clips, I don’t know how. I could correctly identify the more sonorous sound of the Strad after 3 seconds of playing. It was obvious. I guess I’m just that good a listener. Or maybe that lucky!  lol

Have fun with it,

Bob

[Thanks to member JeremiahH for pointing this article out.]

Stereo is Evil

Can Loud Music Add Hard Drive Latency? Does it Matter?

Note that this ad hoc demonstration does not represent proof, let alone applicability to home playback environments. Also, extensive use of caching in player software would seem to negate this effect in sound systems.

However, perhaps this is why some austensibly-sensible audiophiles report better sonics with solid state drives (SSDs)?

Thanks to PeterT for pointing this out to me, from reporting in the San Francisco Chronicle.

Bob

Reproducing the Live Event – How Loud is Loud Enough?

We audiophiles are obsessed with frequency response (FR):

• Is that system “flat” to 20hHz?
• How low will these speakers go? I *must* have 20hz!
• There was a “BBC dip” in that Tannoy. No, I would call it a smile.
• Urgh. Those speakers are waaarrrm.
• And so on….

Even looking at the august Stereophile, keeper of the truth of measurements, we see JA focusing primarily on (for loudspeakers) impedance, FR, and time domain criteria.

What’s usually missing, often ignored, is the amplitude response (AR). How loudly will the system play distortion-free, and how softly? As any Lowther or horn fan would say, this dimension is also vital to producing the illusion of a live event.

Wait, you may say, everybody (including JA) publishes sensitivity data (dB/V for speakers, and dB gain for amps) and uses said data for buying decisions. True enough. But our present system of metrics makes it difficult to answer the original question regarding distortion-free amplitude envelope.

More fundamentally, before we even worry about what our own system can do, we might ask the question: how much is enough? How loudly (and softly) must my system play to reproduce “live levels”? (Assuming one cares. And BAAS members seem to have wildly disparate opinions on this point.)

While researching this issue in the context of my own system, I discovered an excellent survey article on the issue of audio dynamic range (click here). The source was a Greek website (unsurprising given the audiophile mania over there). I will warn you that the piece is long, winding, and – given the blazing red background – hard on the eyes. But it rewards the reader with a trove of cool data, from microphones to the digital chain and (eventually) out your speakers and into the room. Along the way, we investigate the noise floor of Davies Hall and Skywalker and more.

I’ll give you the gist. How much dynamic range do I need? More than you think. Can my present system do it? Almost certainly not. What can I do about it? Ummm, 24 bits, 500+ watts, multichannel….

Read the article. It’s a bit of work, but you’ll likely learn something new and useful.

Enjoy your Thanksgiving.

Bob

Where’s the dough in downloads? Ringtones!

Well, it’s nice to be HDtracks, Linn, or some other music download service. And it’s great to be Apple or Amazon – but not for their music download sales.

But being on top of ringtones? Now that rocks!

You may be surprised at the size of this market. Don’t be. Number of buyers is huge, size of sales channels (starting with cellphone companies) is huge, and most buyers just want the latest Ga Ga now and easily.

You might also be surprised at the movie and commercial soundtrack bizes too…but that’s another story.

Bob

How Should Your Room Measure?

Yes, the title of this post is correct.

We audiophiles read a lot about how our components should measure, i.e., how to quantitatively specify system performance. You know the drill: 20-20Khz, 8 ohm, slew rate > 10, noise < 100dB, etc.

But how do we specify correct room behavior? And what are the consequences of poor behavior? Should any of this change with dipole speakers?

Sure, these answers can be found buried in textbooks and AES research papers. But few, if any, easily-accessible references are available.

Now, thanks to BAAS member Nyal Mellor, we have such a document. In fact, he and co-author Jeff Hedback wrote it! And they graciously donated a copy to BAAS for download.

You will need to use FTP to get it. See the new “Downloads” button above for instructions. It’s easy!

Bob

Is the CD Format Good Enough for High Fidelity?

BAAS member Vince S. just sent me this very interesting link from Aussie pub Australian Hi-Fi . Just as interesting was that the article written way back in 1999, an era that I would not equate to superlative digital. (Hint: A DVD-V was used as the hires source.)

The article presents a balanced case for both formats, relying on by objective and subjective measures.

I personally agree with his key conclusions, but the author reached his 12 years ago!

A relevant AES article [1], published in 2007, also seems to support these conclusions. The money line:

The test results show that the CD-quality A/D/A loop was undetectable at normal-to-loud listening levels, by any of the subjects, on any of the playback systems. The noise of the CD-quality loop was audible only at very elevated levels.

Enjoy,

Bob

[1] Meyer & Moran,  “Audibility of a CD-Standard A/D/A Loop Inserted into High-Resolution Audio Playback,” J. Audio Eng. Soc., Vol. 55, No. 9, 2007 September

Alan Parsons Laments Abandonment of High Fidelity

Despite his “normal guy” appearance, discerning eyes would have spotted superstar Alan Parsons on the Exhibit Floor of the recent AES Conference in San Francisco. (I would have missed hgim had the Prism rep not pointed him out to me.)

Writing in the current Wired, he says:

“It’s definitely lamentable that the concept of high fidelity seems to be largely a lost relic. The sad thing is that it seems to be irreversible. People are locked in to the idea that music (and other ‘entertainment’) is now delivered on their computer — instantly — and that’s all that matters.”

Of course, BAAS members join Alan in these sentiments. Parsons goes on to share various interesting tidbits about iPads (“ Why would anyone take recording on an iPad seriously?”, rock (“Talking Heads are a one-hit wonder”), and his own musical development (“ I was coerced into piano lessons by my parents from age 6. I hated it…”).

Recommended reading.

Bob

Audiophile Guide to the Universe

The last truly-new-and-truly-useful web site for audiophiles that I discovered was the now-venerable Computer Audiophile.

Well, here’s another: Audiophile’s Guide to the Galaxy. This isn’t a simple “clipping service” like Daily Audiophile (also useful). Rather, it’s an edited compendium of all-things-audiophile. That is, the site creator attempts to add order (and opinion) to the content. And, I must say, he adds content that I have never seen before.

The proprietor of the site, Mike Davis, is a deep thinker. He tends to seek categories, root causes, hierarchies – to bring order to the chaos that is the 21st-century high end. While he also runs a high-end retail establishment (Audio Federation; it might be moving to North Bay), he does a reasonably good job (IMO) of keeping his writing balanced. Other BAAS members disagree, citing concerns of bias. So YMMV.

Anyway, like him or not, I think that you’ll find this site useful. Dig around…and enjoy!

Bob

Burning Amp 2011 – My Highlight

Here’s my “best in show” award for Burning Amp 2011 (the audio track actually captures the speaker’s audio signature pretty well):

Zenwood Audio speakers – check out Zenwood’s other videos! (They are located in San Francisco.)

Bob

In Audio, Digital is Simply Not Digital

I wrote earlier in this blog about how digital audio signals must ultimately be represented by analog signals – particularly when traversing a cable.

This article in EE Times, while geeky, presents more evidence about the slippery problems of digital audio – this time from the perspective of USB.

Don’t think USB cables matter? Read on – if you dare!

Bob

Psychoacoustics – The Next Frontier for Audiophiles?

Earlier this month, the NYT published an interesting article about the way that the brain hears.

If we can understand the way the brain hears, we can design better, more realistic, solutions to listen to music.

Such is the work of companies like Audyssey, whose work is cited in the article.

I’m not a big fan of surround setups, but I have heard some very interesting sound from 3-channel Meridian setups.

I am a big fan of DSP, though. And as more of our listening becomes computer-based, DSP effects will become easier to implement in home environments.

Those coming to Saturday’s event will get a glimpse of this….

Bob