You guys are in for another treat.

zafreemusic said:
@FractalAudio is there any way to calculate the time constant for the speaker compression, from data available online (like Jensen has lots of info)?

I think the speaker compression was the magic final 5% of my tone, it really gets the feel. I spent a couple days just redialing in my amps in beta 8 and most of that was the time constant and now the whole algorithm has changed! 🙃
My old values ranged from 40-300ms, now you can't even go below 100ms.
I dialed it in by ear last time and that took a while. So I'm wondering if you have any tips for dialing the time constant for say Fender vs Marshall etc...?

Just wanna be clear I'm not complaining I'm positive the new algorithm is better, but I'd just like to save some tweaker time if possible. 🤪
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Ideally, there could eventually be updated default values that could vary by amp. One step at a time... still in Beta. For now, I have found it more than worth the time to dial it in.

I’ve also found my new settings are radically different from my old ones so I would recommend starting from scratch and not mentally limiting yourself to settings close to what you had before.
 
FractalAudio said:
It doesn't do anything until the power amp clips. You could crank it up 'til the cows come home and if the power amp isn't clipping it won't do anything.

I could elaborate on this but then I'd have to kill you.
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I get it. I'm dumb as a post regarding the actual algorithm and I'm fine with that. I'm fine with being killed if I learn too much.

But I imagine there's a way (in your Cliff brain) to get speaker compression going before the power amp clips (e.g. a "headroom" sensitivity offset or some clever trick).

Can't loud clean amps produce speaker compression?
 
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Speaker compression, as I understand it, is the speaker being told by a big clean power amplifier to move farther and faster than the coil and cone are physically capable of moving. That delta between the actual movement and what the amp said to do, results in some heat in the coil and even flexing and distortion of the cone. If the amp is putting out more power than the speaker's rating, then it will slam the speaker to either end of its full range and the coil will heat.

If there is distortion in the power amplifier, it can cause a problem because it clips the top and bottom of the waveform, telling the speaker to go to full excursion while the amp pours pure DC voltage into the voice coil. That causes the coil to heat and repeatedly pushing the coil and cone to their full throw will break them down.

That's all from the dim recesses of my mind and might be totally off, and I'm happy to be corrected if so.

Years ago I sold high end stereo systems. Periodically we'd grab returned car stereo speakers and hook them to one of the big power amps in the sound room and slowly turn up the volume to see how long the little speaker would survive. Pink Floyd's Dark Side of the Moon's opening heartbeat and chimes would make them hop, start to sputter, then let the sparks out. And, if they survived that, the opening chords would do them in. It was speaker cruelty and I hang my head.
 
Greg Ferguson said:
Speaker compression, as I understand it, is the speaker being told by a big clean power amplifier to move farther and faster than the coil and cone are physically capable of moving. That delta between the actual movement and what the amp said to do, results in some heat in the coil and even flexing and distortion of the cone. If the amp is putting out more power than the speaker's rating, then it will slam the speaker to either end of its full range and the coil will heat.

If there is distortion in the power amplifier, it can cause a problem because it clips the top and bottom of the waveform, telling the speaker to go to full excursion while the amp pours pure DC voltage into the voice coil. That causes the coil to heat and repeatedly pushing the coil and cone to their full throw will break them down.

That's all from the dim recesses of my mind and might be totally off, and I'm happy to be corrected if so.

Years ago I sold high end stereo systems. Periodically we'd grab returned car stereo speakers and hook them to one of the big power amps in the sound room and slowly turn up the volume to see how long the little speaker would survive. Pink Floyd's Dark Side of the Moon's opening heartbeat and chimes would make them hop, start to sputter, then let the sparks out. And, if they survived that, the opening chords would do them in. It was speaker cruelty and I hang my head.
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Lol

Flashback to my high school electronics class. Applying destructive testing to old car speakers was both educational and fun. :)
 
Rex said:
Lol

Flashback to my high school electronics class. Applying destructive testing to old car speakers was both educational and fun. :)
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We'd just join hands and the two at the end would hold onto the terminals of an old crank telephone's generator while someone cranked away, and watch our muscles twitch until someone broke rank.
 
Greg Ferguson said:
Speaker compression, as I understand it, is the speaker being told by a big clean power amplifier to move farther and faster than the coil and cone are physically capable of moving. That delta between the actual movement and what the amp said to do, results in some heat in the coil and even flexing and distortion of the cone. If the amp is putting out more power than the speaker's rating, then it will slam the speaker to either end of its full range and the coil will heat.

If there is distortion in the power amplifier, it can cause a problem because it clips the top and bottom of the waveform, telling the speaker to go to full excursion while the amp pours pure DC voltage into the voice coil. That causes the coil to heat and repeatedly pushing the coil and cone to their full throw will break them down.

That's all from the dim recesses of my mind and might be totally off, and I'm happy to be corrected if so.

Years ago I sold high end stereo systems. Periodically we'd grab returned car stereo speakers and hook them to one of the big power amps in the sound room and slowly turn up the volume to see how long the little speaker would survive. Pink Floyd's Dark Side of the Moon's opening heartbeat and chimes would make them hop, start to sputter, then let the sparks out. And, if they survived that, the opening chords would do them in. It was speaker cruelty and I hang my head.
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^^^ absolutely correct, sir — esp. about square-waving the coils when the cone hits Xmax. I used to do an annual seminar — “How To Blow Up Your Speakers” — to show failure modes, and a Crown M600 into anything will eventually produce said “heated coil” effect. What fun!
 
Greg Ferguson said:
We'd just join hands and the two at the end would hold onto the terminals of an old crank telephone's generator while someone cranked away, and watch our muscles twitch until someone broke rank.
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We didn’t go in for the masochistic stuff. But sadistic? All day long. If you want to piss someone off, wrap a couple of turns of solder around the contacts of a power plug, and wait for some poor slob to plug it in.
 
Neat to see the (old?) audio folks jumping in on this one. I think another factor is that speaker freq. response is rarely linear across all power/volume levels. All sorts of complex interactions going on.
 
touch33 said:
Neat to see the (old?) audio folks jumping in on this one. I think another factor is that speaker freq. response is rarely linear across all power/volume levels. All sorts of complex interactions going on.
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Yes. And those interactions were part of Cliff's epiphany in this last beta.

This beta and upcoming firmware are the most significant I've ever heard in the oh... 8-ish years I've dabbled with modelers. I think this firmware is going to firmly plant Fractal as the leader in modeling. My Helix sounds like a distortion pedal in comparison.
 
State of Epicicity said:
I've had my AxeFX III Mk II for about six months now, and I'm still feel like I'm only scratching the surface with it. I've spent up until now just reveling in the authentic pages of amps, pretending I own all the most sought after amps in the world, but today and last night I started really messing with the ideal pages of mid gain amps, really dialing them in to fit my guitar and my playing style. Holy crap, how incredibly awesome. I've always had my vision of what particular amps would be capable of, and it's just so easy to dial in with the AxeFX. Now, on top of that, there is a goddamn barrage of improvements hitting me in the face. I'm not at all stuck to presets, so for me, I'll just update all day long and see it as a fun thing rather than a hindrance. I can always spend a minute turning knobs and pretty much get there.

I never want to spend money on myself, but I'll never hesitate on spending whatever money we have on my wife and whatever she needs for tools or whatever. So I could never justify buying the Axe. But after talking about everything I read on this forum for so long, she finally started harping on me to buy it, and I'm just constantly feeling so glad she did. I really thought 15.01 was the bees knees, but Cygnus really did further dimensionalize the amps, and I can't imagine what else is on the horizon. Cliff doesn't approach his products like an executive, nickel and diming every ounce of profit out of a product, he approaches his products like an artist; if the inspiration of an idea moves him, he implements it. I feel nothing but respect for that.
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Goes on my list of famous quotes of the 2020's "Cygnus did further dimensionalize the amps". EPic. That one quote right there may be the one that causes me to spring from II to III.
 
FractalAudio said:
Just finished coding it. Sounds much better than the old algorithm. I put in a switch in the debug build to switch between the new and old algorithms and it's noticeably better.

What I realized with this epiphany is that tube amps are better for HiFi as well. I'm not a HiFi person but now I know why HiFi people prefer tube amps. They probably don't understand why it sounds better, they just know it sounds better.

This leads to a potential improvement for solid-state HiFi amplification: Current-mode Class-D. If you could make a Class-D amplifier that works in current mode instead of voltage mode you would get the same benefits as a tube amp for HiFi applications.
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I once had a 295 simulclass and on instinct plugged my turntable into it - and was like "WHAT IS THAT"??? Not sure if related - but it sounded frickin' amazing.
 
DLW said:
I was completely joking when I said could we have the ability to adjust the voice coil radiation in real time with a parameter that could work with an expression pedal.

It would not surprise me though if it one day it happened with all the crazy things this unit can already do.
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Wonder if Cliff could model the Game Changer Audio pedals...
 
Rex said:
We didn’t go in for the masochistic stuff. But sadistic? All day long. If you want to piss someone off, wrap a couple of turns of solder around the contacts of a power plug, and wait for some poor slob to plug it in.
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Charge up a filter cap to 500VDC and then toss it to some unsuspecting sap....
 
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