Audiophile Musings: March 2012

Thursday, March 29, 2012

You know it sounds right when...

I lived in Colorado near where that big fire is going on now just outside of Denver. This is pristine forest area and my heart goes out to those who are enduring the agony of not knowing which way the wind will blow, never knowing if you will return home and still find your house standing. It is truly a strain that many just cannot endure.

But in thinking back of that home, I recall strangers visiting its lush valleys and warm breezes bearing rich pine scents unlike any other in the world. Sitting on the deck and scanning the valley below, one could see tens of miles northward to Rocky Mountain National Park, South Boulder Peak, Mount Audobon, and other spectacular and well known peaks west of Denver, Golden, and Boulder.

Both beautiful and breathtaking, such grand vistas also offer another incomparable feature: quiet unrivaled in most audiophile homes. This view is roughly 7 miles from the main highway at about 9,300 feet in elevation with a National Forest border on the left just out of view. This far from civilization, things get pretty still. Add to that a home built with six-inch studs on 12" centers sitting on an 8" monolithic concrete slab, the basement becomes even quieter. This is where our listening room was located: a place where inner detailing and dynamic range reigned.

Imagine being downstairs in the listening room and being able to hear the refrigerator cycle on and off upstairs at the far end of the kitchen. Imagine lying in bed and hearing twigs snap on the mountainside under the feet of a passing coyote or elk through an open window. Imagine how easy it would be to hear the inner detailing of a good stereo in such a location.

Strangers to the high end would make one consistent comment from the upstairs kitchen before even venturing downstairs to the listening room: "Wow! That sounds great even up here!"

When your stereo is properly matched and voiced, it should sound right even when you are in another room. Being at the "sweet spot" then fetches an experience that is almost as breathtaking as the view from a mountaintop. Everything should come together and provide a psycho-acoustic experience that rivals being at that concert. You should be able to close your eyes and see where in 3-dimensional space a particular instrument was (or was carefully positioned during the final mix).

When finding the right place for your dream audiophile system, begin by searching for the quiet. Once the background noise is gone, you will know when it sounds right.

Yours for higher fidelity,

Philip Rastocny

I do not use ads in this blog to help support my efforts. If you like what you are reading, please remember to reciprocate, My newest title is called Where, oh Where did the Star of Bethlehem Go? It’s an astronomer’s look at what this celestial object may have been, who the "Wise Men" were, and where they came from. Written in an investigative journalism style, it targets one star that has never been considered before and builds a solid case for its candidacy.

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Monday, March 26, 2012

New Vinyl Find

If you've been reading my blog, you know that I listen to digital sources as elevator music and prefer others when critical listening. The problem is that there just s not enough good source material around, even in used record stores.

Last Saturday, a friend drove me to a place in Tampa called Banana Music and my opinion was reversed. Billed as the largest record store in the world, I was skeptical when walking up the creaky stairs to the "warehouse" location, one where after sifting through the oodles of records purchased by their buyers each week they find the true treasures of this medium. I was shocked - in a good way - as to what I found.

First, the store was in an older part of St. Petersburg, Florida, where rent is cheap and things like one-person auto repair shops shared the area. We parked next to such a garage with the only door accessing the business was the garage door, the mechanic dutifully twisting wrenches under the rusty old beater of a car. An overbuilt metal stairway - some Led Zeppelin fans could call this a stairway to heaven - rose from the next door lot like a fire escape in the Bronx. With reservation, I opened the door and went inside.

After winding around a metal floor-to-ceiling scissor gate and around a few hard turns, a long counter appeared similar to that of my memory of my first record store of my childhood. Stacks of jazz albums were everywhere waiting to be sorted and rows of record racks and neatly organized boxes were everywhere. It was unbelievable as to how many pressings were in this facility.

Aisles about two feet wide ran like a shopping market through floor-to-ceiling racks of records, all labeled by category and the portion of the alphabet it represented. The level of effort and persistence it took to organize this was clearly evident, unsurpassed by even the finest book libraries..

Being a classical music lover, I asked for that section. "Over there in the back corner is where the high-end stuff is" a kind salesman replied pausing for a moment while helping another customer. I dashed around the maze and eventually found an unbelievable find.

There, against the side wall in the corner of the building, was boxes and boxes of the best vinyl I have ever seen in one place. The box on the floor in front of me was where I started. I am a fan of Fritz Reiner, the conductor of the Chicago Symphony, during the era when the brass section was unsurpassed. A brilliant conductor, Mr. Reiner and Zubin Meta are at the top of my most sought after conductors.

Flipping through the records there was one, and then another, and then two more of the same recording and then four more in a row, all different pressings. Then I realized the entire box was filled with the RCA LSC-series numbered recordings of this conductor only. The entire box! Pressings that I believed to be lost were there. Pressing I never heard of were there, right in front of my eyes! Carefully removing one disc from its sleeve, the vinyl appeared to be essentially untouched. I nearly fell off my chair.

Now the prices of these rare recordings were also remarkable, but in a world of shrinking resources, they too were reasonable, especially since they were all in one place. Most albums started at $20 and the most rare and in the best condition fetched hundreds. And that was just the Reiner box!

Well, this tale of love could go on for hours but let us say that this is indeed a remarkable place, one that I would recommend to anyone serious about finding and appreciating quality source material as any good analog audiophile should be.

Here is the link: http://musicfinder.com/index.html. Enjoy!

Yours for higher fidelity,

Philip Rastocny

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Thursday, March 22, 2012

Evolution of the High End, Part 3

There is a fact in physics that states "Maximum power transfer between the source and destination occurs when the output impedance of the source matches the input impedance of the destination." This means that if your preamplifier has an output impedance of 100,000 ohms, then the input impedance of your amplifier should also be 100,000 ohms. Anything else creates problems.

Audiophiles love to swap this piece of gear and that piece of gear without a thought of this principle of physics. Changes heard usually describe "the sound is more mellow, or darker" and even "the sound is now quite bright compared to the other." While theree is no doubt that a great difference exists between various types of electronics, what is also heard is the audible effect of this impedance mismatch.

Unbalanced outputs and inputs are notorious for this mismatch. But despite the promise of better audio (and it does deliver on its own merits), this mismatch can still occur in balanced systems.

How can this be? Balanced connections were supposed to be the Holy Grail of audio...what's up with that?

It's the same issue: impedance mismatching causes problems. No one has settled on a standard and I doubt if we ever will. While some companies do in fact match impedance within their own product lines, impedance mismatches can and do occur regularly within the industry. Balanced cables are primarily quieter and do offer much better immunity to electrical noise, however, other issues can also occur in less than optimal designs.

For example, there is no standard for connecting the shield. I don't know about you, but to me, this is a pretty big OOPS. Ground loops are a huge source of coloration and time smearing and interconnect cables are one source of this problem. When more a signal has the opportunity to take more than one path (even when the input and output impedance are matched), it will. Like a overflowing rain puddle, it will travel in whatever direction it can find and in many ways as it can to eventually get to the sea.

.It a balanced system better than a single ended system? Maybe, maybe not. If the engineers have done their homework, it will be far better; if not, it will be mediocre at best despite the effort put into the circuit design.

Another related issue is the characteristic impedance of the interconnect cable (this should also match whatever the input/output impedance is). This is why swapping brand X amplifier with brand Y preamplifier creates changes in sound but then changing cables again changes the sound.

Other issues are going on inside interconnect cables even when impedance is matched and no ground loops are inadvertently built into the electronics. Simple single-pulse tests reveal a myriad of issues with improperly designed cables from ringing to echoes to slew-rate limitations to...well you get the idea. A well designed cable has a lot to consider and a lot to overcome.

So, the next time you swap a piece of gear in your system, think about where the change is really coming from. Is it the new piece of gear? Or is it a better matched input-output impedance? Or is it a better match to the interconnect cable design? Or is it two of these...or all of these...or other issues not mentioned herein?

The answer is in your ears. Trust what you hear and whenever possible compare it to the real thing. Forget the sales hype; it's always a search for new, complimentary adjectives to describe some ethereal property anyway.

Yours for higher fidelity,

Philip Rastocny

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Monday, March 19, 2012

Speak from your Heart

There are many times in life that you do something for the first time like your first cigarette, your first road trip, and your first day in school. But much like your first kiss, there are some firsts that are more memorable than others and last Saturday night was one of these for me.

There are a lot of people in the music industry that sing very well and some of those who sing with heart. There are more of these today than ever before and many choose to drop out of the "competition" before even beginning. It's a hard business and a harder life as a musician, and of the hundreds of millions who try each year around the world to do so, few actually making it to the top.

As it is with musical talent programs today, some of the best of these hopefuls find their way into living rooms through the magic of television, and some faceless others choose a different path and have a different definitions for the word "success." Regardless of how you connect with the latter type of artist, you know it when it happens.

When you hear such a new, promising musician, there is something magical about that time, something that makes a connection with a higher consciousness within you, something that you know to be more than mere entertainment. Such encounters, unfortunately, happen infrequently, but last Saturday night was such a moment for me and my wife.

Within the sea of those struggling artists, there will be a unique occurrence where you understand what they are singing about, something that touches you personally, something that transcends the guitars, the lyrics, and the melody and combines into an emotional crescendo. Susan Enan is such a struggling artist whose heart is not tainted by convention and with her down-to-earth folk style sings of truths that can bring tears to your eyes.

In speaking with her briefly after the concert, I wanted to give her a compliment that could hopefully impart the same feeling she shared with the 40 people attending this particular home concert. I struggled for the words and then said to her, "You perform with heart..." and then realized that this was a cliche. I struggled for a while looking for the right words and then continued, "...the word passion falls far short in describing what I see inside of you..." Tears swelled in her eyes and I knew in for that instant I resonated with that same spot inside of her. She understood that I understood, and that touched her heart.

I reserve such heart-felt compliments only to times when they are well deserved, when what happens inside of me needs to be shared with the one who stirred those feelings. I am a writer and such words are easier for me to find. I encourage you to find your own ways to connect with your own higher consciousness and tell others in your own words exactly how you feel. It is easy to criticise; it is noble to compliment. It is divine to speak words of encouragement from that higher-consciousness part of your being.

Take time in your relationship today to tell that person how you feel. Dismiss your thoughts and speak from your heart. You may fumble at first but the more you do it, the better person you will become. Take the time, don't wait, do it today.

Yours for higher fidelity,

Philip Rastocny

My other titles include:

Saturday, March 17, 2012

Modern-day Minstrels

Tonight, I am going to a new movement around the world; a type of concert, one in which I will be feet from the artist with no artificial enhancing sound system. Like traveling minstrels and kobzars of the past, these contemporary roving musicians perform in people's homes to a small audience with acoustic instruments singing songs and playing tunes. I am fortunate to be able to see the one of the first few people who supported this idea, Susan Enan (http://www.susanenan.com/).

Minstrels of this nature appeal to my spirit as those who seek to retain the purity of the messages conveyed in songs. As a songwriter herself, she has traveled the world performing in some typical and also some rather unusual surroundings. But the real message behind her chosen vocation is that of following your heart and being open to that moment when true inspiration arrives. Unlike those who follow the crowd, Ms. Enan has chosen the road less traveled finding along its path the real meaning to her life.

I admire those who hear the beat of a different drummer for it is from which those hearts, minds, and ears art flows. Her dedication to spreading this movement brings life lessons from which we all can learn. I feel honored to soon be in her presence and share a moment in time I will not soon forget.

Seek out such venues for yourself at websites like http://www.lunazoot.com/, http://www.houseconcerts.us/, http://www.houseconcerts.com/, http://www.houseconcerts.org/, http://www.concertsinyourhome.com/, and the like (search for "house concerts" in your favorite search engine).

Yours for higher fidelity,

Philip Rastocny

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Thursday, March 15, 2012

Sound Pressure Level and NASA

Many audiophiles love to "turn it up" and hear their rigs at the maximum sound pressure level (SPL) that it can achieve within tolerable distortion limits. Car audio has even added contests for the loudest stereo and given awards for the most ear-shattering systems. But what is the theoretical loudest sound that can be achieved?

One may think that this is a never ending possibility; all you need is more drivers, and more power. Not so! The medium we use to hear is air and there is a limit as to how much something can make this elastic gas move back and forth. As it is with flexible things, there is a point to where you can mash and stretch them and then they break. With gasses such as air, the same is true and even if you add more power, the sound doesn't get any louder.

Fortunately, this point is well beyond the threshold of pain and should never be attempted to achieve (such as at ground zero of a nuclear explosion), but just for grins what is the number associated with that sound?

The calculation goes like this for an average air pressure of 101325 Pa :

L = 20 × log (101325 / 0.00002) = 194 dB (RMS)

WOW! now that's loud! Even at the loudest rock concerts, sound pressure levels of this magnitude are only achievable in the minds of fanatics.

A long time back (in the early 1970s) NASA did an interesting experiment in trying to understand the impact of loud noises on things. Rocket launches produce sound pressure levels close to this physical limit and it was their concern that these vibrations could do some real harm, other than deafen an astronaut. They were right. But how did they do this without investing in a jigawatt flux capacitor? Someone came up with a brilliant idea.

Most audiophiles know that horns literally transform whispers into roars. If you go to any concert that uses sound reinforcement, you will see horn stacks suspended along the stage. Horns are acoustic transformers that allow the severe mismatch in power transfer of a speaker driver to better couple it to the characteristic impedance of air. Just like matching transformers on tube amplifiers that match the electrical output impedance of the tube to the speaker impedance, horns do the same for matching acoustic impedances.

A Typical Horn Loudspeaker

Normal acoustic horns use one driver at the small end called the "throat" (the hole at the back of the image above) and sound comes out the front end (called the "mouth"). Horns use an exponential relationship where the area doubles every unit. So at the throat, an area could be two square inches (two to the first power). Moving forward one inch, that area becomes four square inches (two to the second power, or two squared). Moving forward again one inch, that area becomes eight square inches (two to the third power, or two cubed). That's enough of the math for now, let's get back to how NASA did this test.

The great thing about any transformer, electrical or acoustic, is that it is bi-directional, that is, you can use either end as the input and the other end as the output. So NASA used this understanding and instead of driving the acoustic horn transformer using one driver from the throat (small end), they used tens (or was it hundreds?) of drivers at the mouth (large end) and put microphones at the throat.

Great idea. Now you can transform whatever maximum SPL of each driver is and combine that to produce a really loud sound pressure. It worked. What came about from these experiments is the water spray that comes on just before the engines fire and changes the density of air. The water does not keep things from melting down (although this is a side benefit), it actually lowers the maximum SPL created by the rocket engines.

So what should the sights of an audiophile's system be? How loud should it go to achieve realism? Should it be "toned down" so as to not produce pain or introduce instant hearing loss?

All excellent questions since people who own car systems capable of producing extreme SPLs can attest (current world record SPL in a car stereo is 174.1dB). A reasonable assumption would be loud enough to thrill you but not so loud as to harm you. But the maximum recommended SPL varries with time (how long you listen or are exposed to the sound) and how close you are to that sound. Here is a chart of what sounds commonly occur in nature:

dBA	Event
190	Heavy weapons, 10 m behind the weapon (maximum level)
180	Toy pistol fired close to ear (maximum level)
170	Slap on the ear, fire cracker explodes on shoulder, small arms at a distance of 50 cm (maximum level)
160	Hammer stroke on brass tubing or steel plate at 1 m distance, airbag deployment very close at a distance of 30 cm (maximum level)
150	Hammer stroke in a smithy at 5 m distance (maximum level)
130	Loud hand clapping at 1 m distance (maximum level)
120	Whistle at 1 m distance, test run of a jet at 15 m distance
	Threshold of pain, above this fast-acting hearing damage in short action is possible
115	Take-off sound of planes at 10 m distance
110	Siren at 10 m distance, frequent sound level in discotheques and close to loudspeakers at rock concerts, violin close to the ear of an orchestra musicians (maximum level)
105	Chain saw at 1 m distance, banging car door at 1 m distance (maximum level), racing car at 40 m distance, possible level with music head phones
100	Frequent level with music via head phones, jack hammer at 10 m distance
95	Loud crying, hand circular saw at 1 m distance
90	Angle grinder outside at 1 m distance
	Over a duration of 40 hours a week hearing damage is possible
85	2-stroke chain-saw at 10 m distance, loud WC flush at 1 m distance
80	Very loud traffic noise of passing lorries at 7.5 m distance, high traffic on an expressway at 25 m distance
75	Passing car at 7.5 m distance, un-silenced wood shredder at 10 m distance
70	Level close to a main road by day, quiet hair dryer at 1 m distance to ear
65	Bad risk of heart circulation disease at constant impact is possible
60	Noisy lawn mower at 10 m distance
55	Low volume of radio or TV at 1 m distance, noisy vacuum cleaner at 10 m distance
50	Refrigerator at 1 m distance, bird twitter outside at 15 m distance
45	Noise of normal living; talking, or radio in the background
40	Distraction when learning or concentration is possible
35	Very quiet room fan at low speed at 1 m distance
25	Sound of breathing at 1 m distance
0	Auditory threshold

Understand that the longer you listen to music, the quieter it should be. If you work in a noisy environment, use ear protection and do not drown out the ambient noise with loud music from your iPod.

My point is this: It may be nice to drown out the surrounding noise by turning up your music, but know that in doing so you can easily damage your ears. IMHO as an audiophile, absolutely nothing is worth that!

Yours for higher fidelity,

Philip Rastocny

My other titles include:

Wednesday, March 14, 2012

Evolution of the High End, Part 2

Last time, we left off at the introduction of the compact disc and barely mentioned the huge success of this format in passing. Compact discs saved sagging music sales and in general the entire audio industry. So for this, I am grateful!

But now, time has come for this to mature. In my other article about digital format wars, I mentioned that the original 16/44 sampling rate was not exactly perfect audio as almost everyone, myself included, hoped it would be. Everyone pretty much agrees that the dynamic range of a CD is just not enough considering that micing a rim shot on a snare drum produces 135dB at one meter. So to capture life without the problem of the 16-bit word going "deaf" (the sudden disappearance of slowly decaying echos), AT LEAST a larger word size is needed.

But why was the original format chosen in the first place? Two reasons: the original total storage capacity of a compact disc (640MB), the longest performance you want to record uninterrupted before switching discs (about 60 minutes). Adding to these two limitations is the sampling frequency (44.1KHz using the Nyquist Theorum for the minimum number of samples to be able to reconstruct a sinusoid). No one questioned this mathematical proof since it was also confirmed by Shannon as to its accuracy. So 44.1KHz it was.

From here, the math took over to determine the maximum dynamic range (word size) but you were left with an option that did not make the cut: compression. The math calculated a usable dynamic range of 90dB (96dB theoretical maximum) without compression (aka 16 bits, or exactly two 8-bit bytes) and engineers believed that this would be good enough compared to the maximum dynamic range of a vinyl record (78dB was the loudest ever recorded by Sheffield Labs). 16 bits was 12dB greater and people assumed that it would be more than adequate. So the math is:

44,100 samples/(channel*second) * 2 bytes/sample * 2 channels * 60 minutes * 60 seconds/minute = 635,040,000 bytes

Since its conception, CD capacity has grown to about 784Mb increasing the maximum playing time of 16/44 from 60 minutes to 74 minutes, uncompressed.

Marketing of all major record labels insisted that once a decision was made as to the digital playback format that it would not be changed (I forget what the length of time was but 20 years sticks in my gut). All agreed and the rest is history.

So without even listening to their conclusions, engineers went to work cobbling together the entire industry, both record and playback, based on these purely mathematical assumptions (what was it that someone said about assumptions?). And today we are still living with those initial left-brained decisions. If you've been reading my blog, you know how I feel about a decision that is made entirely from your left brain.

But now, the right-brained people are having their say. Musicians, producers, and audiopphiles alike are all about to "spit or go blind" when it comes to the future of digital audio. The Blu-Ray disc, with its infancy in 2002, created a storage medium exactly the same physical size as the CD but with over 7 times the storage capacity. Now that's what I'm talking about!

With 7 times the capacity (4.7GB vs. 640MB), new options present itself. What would be a good choice for the new digital format? If the word size (dynamic range) increased from 16 to 24 bits (2 bytes to 3 bytes), the usable dynamic range will go up from 90dB to 124dB (144 theoretical maximum). So now we can just about capture that snare drum I talked about earlier. So 24/? it is. I have listened to 24 bit recordings and although they are much better, there is still the fact that even this sized word goes deaf.

Great! But how much space do we have left for the increase in sampling frequency? Again here the math takes over and the numbers crunch out for each to be:

24 bits: (3 bytes/sample * 2 channels * 60 minutes * 60 seconds/minute) / 4.7GB = ~192000
32 bits: (4 bytes/sample * 2 channels * 60 minutes * 60 seconds/minute) / 4.7GB = ~128000

So the two possible HD Audio formats on a Blu-Ray disc could be 24/192 or 32/128. My vote would be 32/128.

If we cut the playing time to 48 minutes, we get Ultra HD.

Ultra HD: (4 bytes/sample * 2 channels * 50 minutes * 60 seconds/minute) / 4.7GB = ~192000

BUT - and there is always a but - now the marketing folks want to toss in more than two channels and that is the big gotcha (there is more money behind the marketing types than the audiophile types). If we go from 2 channels to 8 channels (7+1), we are pretty much back at the beginning with 16/88 (same deafness problem but better high frequency resolution).

So it appears that audiophiles will lose again unless we all make our voices heard. This time, we have a chance to make a difference. Contact everyone you can and express your interest in making Blu-Ray High Resolution Audio in the format you prefer. Hopefully, your preference will be like mine: Ultra HD or 32/192.

Yours for higher fidelity,

Philip Rastocny

My other titles include: