Classic rock CD musings...

[Brian Steele]

I'll try to get to this in the next few days.

My motivation for wanting "content aware" EQ was the frustration with voicing my speaker designs
to sound good on the majority of recordings - I found, banging my head against the wall, that it was
not possible.

You should give the software I suggested a try. The results were pretty impressive, for the brief time that I tried it.

[philthien]

I'll try to get to this in the next few days.

My motivation for wanting "content aware" EQ was the frustration with voicing my speaker designs
to sound good on the majority of recordings - I found, banging my head against the wall, that it was
not possible. So I just chose 10 or so of the best recordings for voicing, then the idea for content
aware EQ came to me.
It even drove me to purchase really excellent commercial speakers to use as a reference, if a CD
sounded bad on my speakers I got another opinion on the reference and headphones.

I have a feeling this is going to be hugely educational for me.

[Pete Basel]

I'll try to get to this in the next few days.

My motivation for wanting "content aware" EQ was the frustration with voicing my speaker designs
to sound good on the majority of recordings - I found, banging my head against the wall, that it was
not possible. So I just chose 10 or so of the best recordings for voicing, then the idea for content
aware EQ came to me.
It even drove me to purchase really excellent commercial speakers to use as a reference, if a CD
sounded bad on my speakers I got another opinion on the reference and headphones.

[philthien]

Hey Pete, is it possible to explain in a few non techno terms how your method worked?

[Pete Basel]

This article provided some ideas for that patent:

http://www.aes.org/e-lib/browse.cfm?elib=1850

[Pete Basel]

Good question, I've not been in touch with LSI Logic who originally owned the patent, however,
I asked the VP legal dude who asked us to produce patents if they would ever build it and he
said probably not, they just wanted as many patents as possible in their portfolio in case of
patent wars.

I've never tried to find out if anyone implemented it.

It was cited in 59 new patents so there seems to be a lot of interest.

[Geoff Millar]

I have a patent on "content aware" EQ, applied for in 1997 and granted in 2002:

https://patents.google.com/patent/US6341166

I've probably mentioned it 3 or 4 times in the last 20 years or so.

As a matter of interest, has anyone made this commercially? 

Geoff

[Pete Basel]

I have a patent on "content aware" EQ, applied for in 1997 and granted in 2002:

https://patents.google.com/patent/US6341166

I've probably mentioned it 3 or 4 times in the last 20 years or so.

It was completely re-written and mangled by the patent attorney who handled it, LOL!

[Brian Steele]

Sounds interesting: you could play the EQ'd recording through your PC, capture the recording as a file (eg with "Audials") and then burn it to a CD, without of course infringing copyright...

Geoff

The software actually has a batch process mode to something like that, I believe. Basically record the CD to disk, then run the batch processing on the WAV or MP3 files. It will create new ones with the selected processing.

[Geoff Millar]

It does look like a fun utility (it made a very positive difference to the tracks that I tested it with). However it gives me the impression that it's really designed for use on the PC dedicated to audio playback. I can see it being used for example for processing music for PA or a radio station.

Of course using these types of tools runs contrary to being an audio reproduction "purist", but some of those old productions really need help, LOL

Sounds interesting: you could play the EQ'd recording through your PC, capture the recording as a file (eg with "Audials") and then burn it to a CD, without of course infringing copyright...

Geoff

[Brian Steele]

Brian I’ll have to look into that, auto EQ might be a fun diversion.

It does look like a fun utility (it made a very positive difference to the tracks that I tested it with). However it gives me the impression that it's really designed for use on the PC dedicated to audio playback. I can see it being used for example for processing music for PA or a radio station.

Of course using these types of tools runs contrary to being an audio reproduction "purist", but some of those old productions really need help, LOL

[philthien]

Brian I’ll have to look into that, auto EQ might be a fun diversion.

[Brian Steele]

I did some searching around on the 'net to see if there was already a software solution to the "content-aware EQ" that I proposed, and I found one that looks pretty interesting: PAS Graphic Equalizer Studio Pro, available at http://www.pas-products.com/eqstudio.html. The trial version turns off and on the EQ at random times, but it's enough to convince me that if you have a PC devoted to playing music, even a real-time stream (e.g. from Deezer), this solution works pretty well. If offers real-time "corrective" EQ, and a couple of enhancements that, used well, can make a positive difference. I tried it out on a few tracks and the improvement was very audible. For BOC's "Fire of Unknown Origin" for example, it not only removed the impression that the recording was made through a toilet-paper tube and passed through a high-pass filter to kill all the bass, the enhancements feature allowed me to give the drums in the recording a little more heft. It's worth a try if you're looking for something like this.

[Geoff Millar]

I've been thinking about the concept of a "rock CD" the last few days. I started out my recording days in the analog world. There, it was just standard practice to saturate the tape when you were mastering any recording except the lightest ballad. We did it because--in its own special way--it sounded cool. It made the recording "hotter," "more intense," but in a way that wasn't displeasing.

This ties back into the thread about "rock speakers," because again, it goes against what "audiophile purist" recordings strive for. A set of "audiophile-endorsed" speakers was voiced for the good stuff, the Mapleshades and Telarc recordings where the idea of "saturating the tape" was essentially heresy. ("How dare you add content to the sound!" "How dare you squash the dynamic range!"). Again, play a normal tape-saturated rock recording on one of these speakers and all the warts will show; that tape saturation starts sounding far more messy and fatiguing when the mids are brought forward. It's a horses for courses situation.

Now, since digital recording took over, tape saturation isn't an option anymore due to clipping. However they figured out a much more lethal weapon: lookahead compression (ie: Waves L2). As we all know, this has squashed the dynamic range in ways tape saturation couldn't even touch. Record companies love the hard compression because it makes a recording easier to hear in a cheap car stereo or boombox. But again, play these digitally-squashed recordings through "audiophile-grade" speakers, and it's enough to make you want to tear your ears out.

BUT... I have to argue that that compression, be it tape saturation or Waves L2, is inherently part of the sound of rock music (and pop, and rap, and country...). It may not be good, but it is what it is. So either you throw away your favorite music, or you find a pair of speakers that sounds good playing it.

This has been a great discussion, with (as usual) great ideas and cool articles such as post 31. 

What comes out from this post is that I need two sets of speakers in my stereo system and switch between them for different recordings.  Slapshot MTMs for 'good' rock recordings, jazz and classics, and Classix 2.5s for the rest.  This would mean that the Classix IIs from my workshop would have to be re-built as Classix 2.5s to match the volume output of the MTMs (OK as I have the parts).

Now there's a project!  However, I suspect even the Classix 2.5s will have a struggle to make highly compressed and harsh sounding records like the Chili Peppers sound good.


Geoff

[Sydney]

... CD’s were not really available here till 1985....

emp mine
Being pressed elsewhere - ie CBS/Sony Japan, Polygram West Germany (Philips)
17 August 1982. - Polygram, Hanover, West Germany: CD pressing plant in Langenhagen, near Hannover, Germany.
began, the world's first mass production of Compact Discs.

https://en.wikipedia.org/wiki/Compact_disc

I remember when they opened the 1st US press in Terre Haute.
Didn't get my player until later ( 85 or 86? ) so many of my initial CD purchases were pressed Japan and Germany
a side note: my dad knew Phillips engineers ( in Fort Wayne ) working on aspects on it as early as 76 along with Video Laser Disc projects