Axiom Home Page Forums General Discussion The Water Cooler Fun with Audacity - Dynamic Compression

Mark, that's cool. I really appreciate your perspective. I was thinking about the same thing.

I think the difference is that the clipping we're seeing in the Audcacity analysis is caused by over-saturating the recording medium. I should think it would still be possible to record a "distorted" guitar without the recording causing additional distortion.

Very true Tom,
If you had a SA in a studio, you could see this. I have a couple friends who do. Trust me, its both science and art.

I mean, just changing the speaker, though same specs, can cause a change in compression in live amplified music. I tired hunting it up but couldn;t find it; but a studio friend of mine had a SA chart (what we are working with here) of the same guitar, amp but a different speaker, though it was same size, same RMS, same ohm, etc. It was pretty obvious the compression difference. (FYI: An Alnico Blue against a Jensen.)

Going to see how a modern day "Grammy" winning CD stacks up. Subject Jeff Beck Guitar Shop.

From Jeff Beck's Grammy Award winning Guitar Shop we bring you Where Were You. This is one of my fav tracks.
It provides I think for an interesting observation on what was voted best instrumental album of the year.

Jeff is known for dynamics (trust me, I have see him live multiple times and it shocks you that a musician other than one in the classical genre understands this and uses it so much. The last time I saw him, I walked out and thought the guitar lesson to me was - my god man, use DYNAMICS when you play.)

This track is odd though in the fact it is well known that the guitar is HIGHLY compressed before being amplified and recorded. (FYI: So much so that it can not be performed live in the same rendition).

Hmm:
Clipping is not there - so good mastering. We do see less definition between peaks/valleys which illustrates the compressed nature of the music.

Oh, and I guess you can tell I am a JB fan.

I finally took some time before heading off to bed to scan the 2 copies of Holst - The Planets, well only Jupiter, the Bringer of Jollity. It does show the difference in loudness very well. The top is the Andre Previn version apparently done as all digital(DDD) according to the jacket. The bottom is from Mehta's version which was Analog to Digital(ADD). Other than needing to turn up the volume on the Previn version I can't tell any difference.



I had my SPL meter out to check for any difference in Dynamic range while listening on the M80s and they both run in the mid 50 db range for the most part.

Thanks for the explanation Mark. I got to wondering after noticing that the Zeppelin song seemed more compressed then the Knopfler song I was looking at.

The upshot of all this for me is that most of the stuff I plan to re-acquire is probably going to be ok because it will be earlier productions of late 60s to early 80s music.

I think I will stay away from re-mastered productions if I can.

Fred

Very interesting, Jason; in addition to the overall higher level at which the Mehta disc was mastered, it can be noted how the two conductors, although working with the same score, occasionally applied different dynamic gradations. For example, about 4-5% in, Mehta applies a crescendo earlier than Previn does at the same point.

I had noticed the timings were a little off from each other and I guessed it was due to the different conductors. I really can't say I can hear much difference between the 2 other than the loudness factor, then again I have only listened to each one about 3 times.

Here is the 1994 remaster of Pink Floyd - Wish You Were Here from The Wall.



They stretched it to the limits, but I couldn't find anything going beyond the borders

I agree jakewash, that looks pretty good- but I was more surprised to hear this track was on The Wall album