RIAA Equalization Curve -Sound Forge - PC - MAGIX Community Forums Archive

Subject:RIAA Equalization Curve Posted by: RickD Date:8/27/2004 3:23:44 PM Can anyone suggest a method of implementing the old RIAA equalization curve for phonograph records in SoundForge?
Subject:RE: RIAA Equalization Curve Reply by: Snappy Date:9/29/2004 6:11:15 PM A way that's not totally hackish? No. But... for experimental purposes, I would try: Use audio plugin chainer and string together 62 parametric EQs, each one representing one of the frequencies found in the table here: http://www.tanker.se/lidstrom/riaa.htm I'd start with an output gain of -18dB on all of them, to try to ensure adequate headroom, adjusting level downward if necessary. Band-notch/cut filter type. .2 octave bandwidth, (based on the assumption that a 31-band EQ has 1/3 octave bandwidth, so a 62 would need 1/6 octave bandwidth, or .15, which we can only approximate because the bandwidth control is limited to one decimal place.) Also, the gain control only provides one decimal place, so here we are approximating as well. Accuracy set to 'high', of course, unless this makes my computer crawl. Creating a template preset can expedite the setup of this idea considerably. i.e. -- set up the first one, then save that as parametric EQ preset 'temp', then load it in to the next one and you will only have to set the frequency, instead of doing the whole thing from scratch. etc. (apologies if this is obvious to you) If you know of some hot EQ plugin that could do any aspect of this better than the built in Sonyc Foundry ones, you would probably improve your results by using it. Or, you could just plug values into that formula and solve it for each frequency band 'f' that your EQ plugin supports. It seems you could APPROXIMATE the curve, even with something as simple as a 5-band eq(?) Like I said, hackish. At best. If you intend to use that curve as a 'special effect', then an approximation is probably sufficient. If, on the other hand, you are trying to do accurate reproduction, I'm sure this is going to cause some unexpected results... Maybe somebody with a real clue wants to offer some insight on what kind of nastiness such an unorthodox approach would yield... In the meantime, have fun... I'm going to! =)
Subject:RE: RIAA Equalization Curve Reply by: Snappy Date:9/29/2004 6:28:31 PM ------------ follow up... the 'ouch' part was when I realized that the chainer will only let you string together 32 plugins... so... need to break this up into a 2-part operation, or use an eq plug with more than one band. I wanted to try to do this all with built-in components, and all in one chain, but it doesn't appear possible... the sonyc paragraphic and graphic EQs have even less configurability than the parametrics, so I'll probably try a 3rd party plugin first. Then again, like I said -- if you're just going for the 'effect', not accuracy, 'close' is probably still going to be pretty cool! ;-) also, save your master chain often! & maybe even re-save your template periodically as you move up the scale, to avoid having to adjust it so much each time... fun, fun!
Subject:RE: RIAA Equalization Curve Reply by: Geoff_Wood Date:10/5/2004 3:52:58 AM Forget it. You will be sacrificing 40dB of headroom before you start. Not to mention that your TT catridge will be operating into the wrong impedence and/or level input - and this is a critical factor. geoff
Subject:RE: RIAA Equalization Curve Reply by: captn_spalding Date:10/5/2004 6:43:29 AM Look here: http://www.kabusa.com/frameset.htm?index.htm you will find what you need (hardware wise) and can pay as little as $20 or as much as $1200. There are other such devices, but this is who built the EQS MK12 that I use ...spalding

Subject:RIAA Equalization Curve

Posted by: RickD

Date:8/27/2004 3:23:44 PM

Can anyone suggest a method of implementing the old RIAA equalization curve for phonograph records in SoundForge?

Subject:RE: RIAA Equalization Curve

Reply by: Snappy

Date:9/29/2004 6:11:15 PM

A way that's not totally hackish? No.

But... for experimental purposes, I would try:

Use audio plugin chainer and string together 62 parametric EQs, each one representing one of the frequencies found in the table here: http://www.tanker.se/lidstrom/riaa.htm

I'd start with an output gain of -18dB on all of them, to try to ensure adequate headroom, adjusting level downward if necessary.

Band-notch/cut filter type. .2 octave bandwidth, (based on the assumption that a 31-band EQ has 1/3 octave bandwidth, so a 62 would need 1/6 octave bandwidth, or .15, which we can only approximate because the bandwidth control is limited to one decimal place.)

Also, the gain control only provides one decimal place, so here we are approximating as well.

Accuracy set to 'high', of course, unless this makes my computer crawl.

Creating a template preset can expedite the setup of this idea considerably. i.e. -- set up the first one, then save that as parametric EQ preset 'temp', then load it in to the next one and you will only have to set the frequency, instead of doing the whole thing from scratch. etc. (apologies if this is obvious to you)

If you know of some hot EQ plugin that could do any aspect of this better than the built in Sonyc Foundry ones, you would probably improve your results by using it.

Or, you could just plug values into that formula and solve it for each frequency band 'f' that your EQ plugin supports. It seems you could APPROXIMATE the curve, even with something as simple as a 5-band eq(?)

Like I said, hackish. At best. If you intend to use that curve as a 'special effect', then an approximation is probably sufficient. If, on the other hand, you are trying to do accurate reproduction, I'm sure this is going to cause some unexpected results... Maybe somebody with a real clue wants to offer some insight on what kind of nastiness such an unorthodox approach would yield...

In the meantime, have fun... I'm going to! =)

Subject:RE: RIAA Equalization Curve

Reply by: Snappy

Date:9/29/2004 6:28:31 PM

------------
follow up... the 'ouch' part was when I realized that the chainer will only let you string together 32 plugins... so... need to break this up into a 2-part operation, or use an eq plug with more than one band.

I wanted to try to do this all with built-in components, and all in one chain, but it doesn't appear possible... the sonyc paragraphic and graphic EQs have even less configurability than the parametrics, so I'll probably try a 3rd party plugin first. Then again, like I said -- if you're just going for the 'effect', not accuracy, 'close' is probably still going to be pretty cool! ;-)

also, save your master chain often!

& maybe even re-save your template periodically as you move up the scale, to avoid having to adjust it so much each time...

fun, fun!

Subject:RE: RIAA Equalization Curve

Reply by: Geoff_Wood

Date:10/5/2004 3:52:58 AM

Forget it. You will be sacrificing 40dB of headroom before you start. Not to mention that your TT catridge will be operating into the wrong impedence and/or level input - and this is a critical factor.

geoff

Subject:RE: RIAA Equalization Curve

Reply by: captn_spalding

Date:10/5/2004 6:43:29 AM

Look here:

http://www.kabusa.com/frameset.htm?index.htm

you will find what you need (hardware wise) and can pay as little as $20 or as much as $1200. There are other such devices, but this is who built the EQS MK12 that I use

...spalding