Wednesday, 23 October 2013

Show and Tell....

Home sound and video shows are fascinating and even exciting events for those in search of the Perfect Home System (that they can realistically afford!).
At one such expo took place in Melbourne last week-end.  Most of the country's A/V wholesalers and retailers of note had their wares on display and demonstration.  Must admit I didn't attend, but I received a very interesting few comments from a young man who has worked in the industry for quite a few years, both in wholesale and retail "Hi-Fi" and Home Theatre installations.  The company for which he works currently is a wholesaler/importer of several of the better brands of stereo equipment, so he is familiar with a range of very high quality systems, both analogue (record players) and high-definition or CD music sources.
He was "on deck" at his company's display for much of the time, but managed to have an extended coffee break so that he could investigate the very best systems on offer at the show:  stereo systems that frequently cost about the same as the median-priced inner suburban home in Melbourne.  Scary just to think about it.  The "cutting edge" music sources were usually servers (hard drives) playing high resolution 24bit, 192KHz sample rate, hopefully recorded at that resolution, audio files - WAY better than CD standard:  just consider all those extra "bits"!
He listened carefully.  He compared.  Was he "blown away" by the sound of all these state-of-the-art music playing systems?  How impressed was he when he was listening to a set-up that cost 20 times what the average person would be prepared to pay?
Not very.
It's the law of diminishing returns when it come to spending obscene amounts of coin on a stereo.  Impresses the friends, acquaintances and family, but.
He regularly hears live music, performed on real instruments by talented human beings.  This is his "reference" sound experience.
What he heard at the show was impressive in a way - detailed, dynamic and rhythmic....
But not convincing:  very far from "You are there!".  Sterile, clinical, somewhat uncommunicative and uninvolving compared to a real performance of acoustic music - that is the acid test of any recording/replay chain.
The speakers and amplifiers and other non-digital equipment were fine:  a few comparatively subtle differences are evident when comparing "apples with apples", and even some bargains are to be found when you budget is relatively tight.

He was so impressed by the fancy digital players that he is now saving up for a decent record player.

Tuesday, 15 October 2013

"Curiouser and curiouser", said Alice.....

Walked into my favourite record store last week, with, for a change, the intention of not just browsing, but actually seeking some recordings to purchase.  No CD's for me: straight over to the new and second-hand vinyl proudly on display, all in alphabetical or musical genre order.  Half an hour or so later I had made my selections.  I hadn't been in the store for over 6 months, and there seemed to be many more new LP's from which to choose.  When I commented to the sales clerk about the seeming resurgence of vinyl, he remarked that in the last 12 months their LP sales had increased by 50%.
Incident number 2: Last Friday I was in Richmond, passing a well-known Audio/Home Theatre business and what did I notice prominently displayed in their front window? :  a collection of about eight record-players.

The enjoyment of music features significantly in most people's lives in our society.  Today it seems to be all about convenience when it comes to purchasing, storing and playing our favourite tracks (OOPS, I mean songs ).  "Tracks" is so analogue and old-fashioned.  But who would be bothered storing, caring for and going through the rigmarole of playing an LP on a quaint and somewhat complicated mechanical device?  What is so attractive about placing a tiny piece of polished and shaped diamond in a groove of a rotating disc of 12inch wide plastic?

LP quiz question:  How many grooves on one side of a record containing 22 minutes of music?   (Answer given at the end of this post.)

Downloads are so quick, easy to get, convenient to store, fun  to organise and the music can be played anywhere without disturbing anyone nearby.  (Even I take my iPod walking.  Well, I have music on it and I intend to next time, if I remember.)  Digital is so "cool" and immediate.  But something is missing.  Something is not quite right.  Something could be better:  an iTunes song of our fave performer just doesn't seem to be satisfying, involving,...not sure quite what.
It's not all there.  The original recording has suffered data compression.  Subtle and not-so-subtle details have been discarded.  Dynamics have suffered, instruments and voices don't sound quite correct or convincing.  Our brains are trying to find this missing information, and so we may become irritable, mildly stressed and somewhat disappointed with the session of listening.

Yes, LP's suffer from more background noise (although a good pressing played on competent equipment will not have much noticeable "groove noise"), are a pain to keep in good condition and can only be played at specific locations.  But increasingly, it seems, people who love music and enjoy good sound are turning from digital, including CD's and downloads, and investing in a good record player to play their new and old LP's.

It is not my intention to get too "technical" on this or any future post.  Wikipedia is usually a great resource for in-depth information on digital recording and reproduction.  The theory is all there for your investigation, if you have the inclination!  But I will point out a few simple observations about digital recording and replay.
Ignoring the importance of the need for high quality analogue equipment at every stage of the process from microphone to the listener's ears, it is evident that digital technology, both hardware and software, deals with a numeric representation of sound waves:  in other words, sound received by the microphone(s) is converted to a carefully timed string of zeros and ones which can be stored on a computer.  This digital recording process is called "sampling", and is, by nature, not absolutely continuous, but switches on and off thousands of times each second.  For CD quality/standards, there are 88,200 pieces of data recorded every second.  When this digital file is "played", the numbers are retrieved with very precise timing (we hope!) and the audio waveform is reconstructed, more or less accurately, by a "digital to analogue" computer chip which converts the stream of numbers to an electrical signal which can be sent to headphones or an amplifier and speaker system as sound we can hear.
So.....The recorded data is not exactly continuous (like the operation of the ear and brain is), and accurate results, from recording to replay, are very dependent on very precise digital "clocks".  Errors occur.  Tiny, but cumulative.  Even the reading of a CD in  a player would be impossible without a sophisticated error correction system.  Digital audio files streamed from a computer hard drive are far less prone to such errors.  A good analogy for digital sound compared to a live performance would be looking at a scene through a fly-wire screen, in the case of digital.  You can still see quite well, but small details and subtle effects are missing or marred.  The finer the screen mesh, the less it is noticed.  But you know it is there!

What prompted all of the above?

Yesterday I read a couple of internet articles and watched a couple of video presentations on basic PCM (never mind !) digital audio recording and replay.  The message was:  Audio CD standard is, if the engineering is correctly applied, more than adequate for stereo reproduction of music, with no perceivable degrading of the original musical signal:  no noticeable difference between input and output would be evident to the average listener.
Wishful thinking, I'm afraid!  And definitely not in my experience.

My point to this post?  Educate your ears:  listen to a good pressing played on reasonably competent gear, and compare it to the .mp3 file, or even a CD of the same LP.  No contest, when it comes to enjoyment, emotional impact, satisfaction and involvement.

Yes, great quality digital audio is available and can sound quite "analogue" to our ears.  But don't discard your LP's for CD's or mp3's.  In any case, some of them may have disappeared from the commercial music catalogue by now.

Nearly forgot:  the answer to the LP quiz question above is one.

Wednesday, 2 October 2013

Now You Hear It -- Now You Don't

When I was a kid in Primary School, I had a few good friends whose homes I would visit from time to time to play.
I enjoyed music:  my parents were both good singers and my dad played piano as well.  He also had a record player.  It could only play " 78's ", but he had ingeniously connected the pick-up output to a nice cabinet-style radio set on which it was perched.  Most days after school saw me sitting under the dining-room table, which was quite close to the radio/record player, listening to one of my favourite Radio Serials.  Anyone remember Superman, Biggles, Hop Harrigan or The Lone Ranger?

At that time I was the proud possessor of a small collection of 78's - a couple of jazz numbers and 2 or 3 story records.  One of my friends occasionally invited me over to her(!) house to play records on her dad's wind-up phonograph:  no electrics here - the sound waves pressed onto the record's surface were traced by a steel needle, which caused a diaphragm connected to the needle at the end of the tubular pick-up arm to vibrate in sympathy, and the resultant sound waves were funneled down an internal horn and emerged somewhat louder through an opening in the lower front of the machine.  Volume could be controlled by adjusting two louvered doors across this front opening.  Close the doors - quieter:  open the doors - louder.  Simple but effective.
Not what you would call "Hi-Fi", but we had fun.

Two main problems with 78rpm records of those days, before the advent of the LP - short playing time and horrendous surface noise, compared to the LP record.  In addition, both the "needles" and the records themselves tended to wear quickly.

Fast forward to today...
I love some of the music and performances on those old 78's, and have in recent years been transferring many a disc to CD format, both from my collection and customers of my little business.

Here is a sample of a 78 side cut in the '40's or early '50's - Al Jolson is in good voice.  The disc was transferred on a modern turntable, with an appropriate stylus, at 33rpm, and the recorded sound file adjusted in the computer to the correct speed and pitch.  No other "monkey business" was employed...

Now for the same song, but with "state of the art" noise reduction applied.  It still isn't "Hi-Fi" quality, but surface noise and much of the damage heard in the "straight" version have largely disappeared.  Further work could have been attempted, but the result is quite satisfactory.  It's amazing what can be done using the right software these days.

Now, where did I put that Enrico Caruso record...?