2. misc-audio
  3. 154369-20253

Toole and why I like Tone Controls

In another thread I was pointed to a really excellent paper by Dr. Floyd Toole (he doesn't use the Dr. but it is well earned) on getting to neutral.

So I want to go back with a little history. In all of audio reproduction theater sound reproduction is among the most rigidly controlled areas of audio. From the needs of Dolby Surround playback, to introduction of acoustic decay requirements introduced by THX, and more, the attempt to deliver a uniform theater experience has been a subject of serious effort by many, and continues to be so.

That's in sharp contrast to consumer music.

So while this article focuses heavily on theater sound, it also touches on just how difficult it is for even theater sound experts to get to neutral. If they can't do it, imagine how hard it is for music!

And, yes, I'm going to hijack Dr. Toole's paper to plug tone controls. With all the guessing that goes on, not using tone controls, and not having great tone controls to use is folly.  Quote me. I said FOLLY!

http://www.aes.org/tmpFiles/elib/20200201/17839.pdf

Also, personal request, if anyone knows how I can get in touch with him and be a fan boy, please let me know. :) I'd love to hang with him, and it turns out he's a local.
erik_squires
tomic601's avatar
tomic601
13,092 posts
 
No Eric, I have the original issue CD and an incredibly vivid memory of Biamping the BIG ADS 2030 with 4 Hafler power amps ( because we could ! )....
erik_squires OP
16,416 posts
 
Thanks @tomic601 I'll take a listen ...


mijostyn's avatar
mijostyn
8,570 posts
 
erik, I am certainly not the one to argue as I use the best tone controls ever made, full spectrum room control. I can adjust the frequency response any way I want and see the actual results on the computer that controls the system by impulse test. It gets even better. I have dynamic loudness compensation. The system will follow the appropriate loudness curve depending on the actual volume so no matter what the volume the music sounds exactly the same. Various curves are stored in memory to cover specific problems. As an example I have a curve with a notch filter centered on 3000 Hz. I use it for sibilant voices and such. The unit is a Tact 2.2X. Tact went out of business. Trinnov and Anthem make units that are good but do not quite make it to the level of the TACT. I could never live without it. Fortunately the Tact is very well made but if it died I would probably go with the Trinnnov Amethyst.    
noble100's avatar
noble100
2,419 posts
 
mijostyn: "The system will follow the appropriate loudness curve depending on the actual volume so no matter what the volume the music sounds exactly the same. Various curves are stored in memory to cover specific problems."

Hello mijostyn,

     As I stated earlier in this thread, it’s my experience that good quality class D amps (Currently very noticeably present on my pair of class D DSonic M3-600-M monoblocks), do this naturally with all source content. I use a Levinson 326S ss balanced preamp with no tone controls.
     I have no idea how technically this happens but I’m suspecting it’s been incorporated into the comparator circuitry of the class D power modules, that are constantly comparing the inputted signal to the outputted post amplified signals to make sure they match, then making any necessary adjustments to the signals prior to releasing them to the speakers. It seems to me that this would be the logical circuitry to insert some sort of automatic, algorithm based loudness control.
     I’ve noticed this very unusual but obvious characteristic on all of the good quality class D amps I’ve owned or listened to thus far. I’m not stating this as factual, rather as a possible explanation for what I know I perceive.  I haven’t heard any other class D amp users discuss this trait but I’d still be very interested in asking Bruno Putzeys and other class D amp power module designers about this phenomenon.

Tim

erik_squires OP
16,416 posts
 
I have dynamic loudness compensation. The system will follow the appropriate loudness curve depending on the actual volume so no matter what the volume the music sounds exactly the same.


Very nice! Reminds me of the Yamaha/Denon loudness dials.  Loved those too.
More to discover