Live Sound quality

aviavi · Post by **aviavi** » Tue Jun 08, 2004 5:56 am

God, it's so fantastic to read such a clearly stated explanation and debunking of a myth in the world of digital audio.

I also have my suspicions about certain AD/DA converters being audibly better than others.

Avi

Vercengetorex · Post by **Vercengetorex** » Tue Jun 08, 2004 6:52 am

Jitter is your enemy there Aviavi. It really comes down to how much a manufacturer is willing to spend on and audio interfaces clock source...
The more accurate the clock, the less jitter, and therefore the less listener fatigue plays a part in that DAC's output. Jitter is inevitable, no matter who manufactures your audio interface... It is just a matter of how much jitter it will produce. I only wish I had access to an RME Multiface and a decent osilloscope so I could debunk the "My RME sounds better than everything else" myth. Ah well...

raapie · Post by **raapie** » Tue Jun 08, 2004 7:03 am

I'm using my RME's Hammerfall line-out at the front panel. the sound is fantastic.

Vercengetorex · Post by **Vercengetorex** » Tue Jun 08, 2004 7:14 am

Please dont misunderstand me Raapie, I have no doubts that the RME cards perform exceptionally well...
I am just curious whether they truly perform better than any of the other pro interfaces on the market today. It seems to be a common sentiment among users that they do, so my interest in the matter is peaked.

BTW: Nice studio/ Live tour with SpeedyJ

raapie · Post by **raapie** » Tue Jun 08, 2004 8:06 am

if you are comparing ADDA-convertors in this pricerange you can't talk about better or worse. you might hear differences, sure, but you can hardly say one is better than the other because: what does 'better' mean?

cmusicmaker · Post by **cmusicmaker** » Tue Jun 08, 2004 8:48 am

Great stuff Robert...very detailed.

Vercengetorex · Post by **Vercengetorex** » Tue Jun 08, 2004 9:34 am

In this case I am speaking solely in terms of performance of digital to analog converters. As most up to date converters in this price range have approximately the same performance regarding attributes such as sample rate, bit depth, and signal to noise ratio the primary concearn becomes Total Harmonic Distortion. THD is a function of not only the electrical design of a DAC but also the accuracy of its clock source. When a DAC uses an inaccurate clock to determine exactly when a single sample should be converted into an analog voltage that sample can be converted several microseconds early or late. This is jitter. Obviously this variation is not perceivable by human directly, but since this is happening continously, and several thousand times per second it can have a psychoacoustic effect on how we perceive a sound produced by that DAC. The most common description for the effect of this jitter is listener fatigue, where one can find discomfort in listening to this digital audio source regardless of how high quality the monitoring system and listening environment is. This is what makes one DAC of near exact specifications to another inherently superior. This is waht I am curious of regarding the performance of the RME manufactured DAC's.

bedhead · Post by **bedhead** » Tue Jun 08, 2004 9:54 am

Oddly enuff, my ears translated the Ableton sound engine treatment to my trax as very warm sounding, in fact whenever i preach the Live testament to friends (who end up usually buying Live), thats one of the things ill tell them- the only sound engine that sounds close to analogue. They seem to agree.

Whatever, i learned something 2nite, but i still think it sounds warm......

BedHead

raapie · Post by **raapie** » Tue Jun 08, 2004 9:55 am

jitter can be detected by good monitoring. it harms the stereo-image and depth in a mix. in my opinion the best thing you can achieve is a mix where for the instruments are no longer sitting in the speakers, but have a 3d depth. the voice is the best source, if you are able to make a voice 'jump' out of the mix, in general it's a good one

yes, I love the RME for mixing and mastering.

Vercengetorex · Post by **Vercengetorex** » Tue Jun 08, 2004 9:57 am

indeed

ethios4 · Post by **ethios4** » Tue Jun 08, 2004 1:11 pm

is this jitter problem only a problem at the monitoring level or does it carry over to rendered files also? If its a problem with D/A convertors wouldn't the problem be limited to any particular listening environment and not to the actual rendered audio?

markdawes · Post by **markdawes** » Tue Jun 08, 2004 1:28 pm

This is great Robert. Can we have more good night science lessons please? It is great to read a well expressed argument about the invisible factors of audio, written by someone who knows their stuff. Keep it coming!
Thanks
Mark

raapie · Post by **raapie** » Tue Jun 08, 2004 1:56 pm

as far as I know it's only a hardware issue, caused by a badly clocking/synching ADDA-convertor.

Guest · Post by **Guest** » Tue Jun 08, 2004 6:02 pm

Being vinyl junkie myself I found that a very interesting read by Mr Henke. I'm pleased it cropped up as I've recently been toying with the idea of setting up my own Vinyl Pressing plant. I didnt know much about the topic (and still dont) but from the Internet I've managed to pick up some good info. on the subject.

1. I'll probably never own my own vinyl pressing plant

why? well, the equipment is very old, difficult to acquire, and very expensive.

There was a Neumann VMS 70 Lathe on Ebay the other day and it had a Buy It Now price of $17,999 ...and thats just the lathe. You would also need all the correct mastering equipment and computers, solutions and equipment for plating and laquering and the actual vinyl press itself. It would probably come to around at least £20,000 GBP to get a reasonably good working system.

So, for this reason I think a vinyl pressing plant will probably never materialise for me unless I win the lottery or marry a rich woman.

Interestingly, I recently learned that CD's only have a lifespan of around 10 years. I didnt believe this at first but apparently they do 'wear out'. Compare this to some records I own which are 30 to 40 years old and still sound good. I think that maybe vinyl is still alive and well!?

I did find out that Vestax and Vinylium sell DubPlate cutters, but these are only good for dubplates and so will wear out more quickly. Also, I think the frequency response on these machines is not as good as on the Neumann, but of course they are a fraction of the cost.

I found a good site that overviews the process here:-

http://www.capsulelabs.com

bye for now

David

this looks like a nice setup....

dpel · Post by **dpel** » Tue Jun 08, 2004 6:30 pm

Robert Henke wrote:I would like to add something which goes pretty much into the opposite direction but tells very much about the perception of audio:

A lot of people say, vinyl sounds better then CD.
A lot of people say, the acoustic image and the way instruments can
be located within the stereofield is much better then on CD.

So, lets have a brief look at how vinyl works:

A cutting needle cuts a groove into wax. The music is coded into
a horizontal and a vertical displacement of the groove.
The needle of your turntable has to trace that recorded curve.
In order to stay in the groove the needle needs to apply a force to the groove. Since applying a force to an infinite smal area would lead to an infinite force at that area the force of the needle has to be distributed. This is why the needle has an eliptical shape and this is why your record is destroyed it your needle breaks and leaves a sharp spike.

And here comes in one of the most fascinating miracles of vinyl:

The needle is not tracing the bottom of the grove but the two walls.
Even if the record only contains a single sine wave, recorded in mono,
which leads to a pure horizontal movement of the cutting head, the needle of the record player while tracing the walls of the groove also
creates a bit of a vertical movement. This is simple geometry.

This vertical movement translates into a signal of twice the frequency of the original sinewave but 180 degrees out of phase, added to that original
signal. These distortions are called "geometric distortions".

If you do this with music you get amazing artificial stereo effects.
Just listen to high hats on 12 inches. They all sound like someone did
apply a wierd stereo distortion effect on them, and the louder the record the more stereo and the more distorted it gets. Now you know why.

So, what is the conclusion:

a) records do sound fantastic.
b) records do not reproduce at all any "natural" stereo image.

This was my good night science lesson

Good night.

Professor Robert

Robert,

thank you for the romantic lecture re-visiting the pleasure of vinyl.
you forgot to mention, but please allow me, that a pennie on top of the needle head makes the record sound even better! (the extra weight allows the needle to pick up more of the good vibrations)

funny.

dp

Live Sound quality

Right On!

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jitter...

Thanks Robert

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