Reverse of the old Loudness Control

[Don Hills]

Originally Posted by pheonix358

Most speakers like help to ensure they don't exceed xmax. It allows the speaker to play cleanly at louder levels. My preference is for a shelf filter on the bottom end.

This is Jamikl's target - a way to allow him to apply LF boost to his OB speakers at low listening levels without launching the cones into orbit when he turns up the volume. The loudness compensation circuit I have in mind can be modified to do this, by moving the boost/cut corner frequency lower. It wouldn't be true "loudness compensation", but it would protect his cones.

Originally Posted by pheonix358

If you have kids playing today's music, even softley some form of protection is essential. Your spiders will thank you.
Terry

Any spider dumb enough to build a web across one of my woofers deserves the headache it will get. Oh, wait...

[Pano]

So been thinking about this and I sure like my idea of running the OB woofers on the loudness control and the subs not.

But I have not come up with a wiring scheme for it yet. Pencil and paper are needed. Time to start drawing lines.

As for the tapped pots mentioned earlier - yes, it was done that way. I think I have some motorized Alps pots that are tapped for loudness, will have to check. Had a late 70's Pioneer amp that did it, and still have a 1930s RCA radio with a tapped pot. So not a new idea.

Don - watch those spiders. In your part of the world they are deadly serious. Oh wait, you're in NZ.

[pheonix358]

Originally Posted by panomaniac

So been thinking about this and I sure like my idea of running the OB woofers on the loudness control and the subs not.


Don - watch those spiders. In your part of the world they are deadly serious. Oh wait, you're in NZ.

Yes, it's the sheep that get serious down there.

I don't mind loudness controls but to protect a driver a shelf control makes more sense since it controls all freq below a fixed point. In normal use you could call it a subsonic filter, this is what is needed here. Having a variable one is good. I think it was silicon Chip magazine, yes it was, July '96, that developed a parametric equalizer. This had a very useful shelf filter down the bottom end that worked very well. These things are also useful for helping with room acoustics if used carefully.

Terry

[markus76]

Here are EQ curves based on the "new" ISO 226:2003 (http://www.nedo.go.jp/itd/grant-e/re...pdf/is-01e.pdf):



Best, Markus

[AJinFLA]

Chase RLC-1 might be a cheap solution
TEA6320 pdf, TEA6320 description, TEA6320 datasheets, TEA6320 view ::: ALLDATASHEET :::

[Pano]

Interesting chip. Here is direct link to the datasheet:
TEA6320

[Don Hills]

Thanks for the link. Unfortunately, it's not very suitable.
Reasons:
- It's controlled via I2C bus, rather than direct interface.
- The loudness function mimics the operation and control law of a classic tapped pot, rather than providing a fully progressive boost with level.

I really must get my schematic scanned. I did my design and simulation with AkAbak, which doesn't output diagrams...

[Pano]

Can you just do a screen capture or 2?

[jamikl]

Don Hills, how is it going with your circuit. Don't want to lose track of this. Will you be making available to the forum. I appreciate all the help you have given to date.
jamikl

[pheonix358]

Originally Posted by jamikl

Don Hills, how is it going with your circuit. Don't want to lose track of this. Will you be making available to the forum. I appreciate all the help you have given to date.
jamikl

Would someone please be kind enough to post the first section of the schematic of the July '96 parametric equalizer, it's a shelf/subsonic filter. It's over 13 years old so copyright would have expired.

I can't find mine!

Thanks

Terry