Personally in just hate the soggy sound you get from a good speaker being under driven by a tube amp, the distortion might not sound fatiguing but i still can't listen to it to long.,
Well there is ^that^
Any time one cannot listen to it for long, makes for a telling fact.
I think it's probably just an issue with communicating nuance across a screen and likely different languages.
- Nobody here has disagreed with the importance of time and phase correctness except at frequency extremes. Rob and I only disagreed on terminology for "time aligned". I meant it for the physical and electrical alignment for the drivers on the speaker baffle, Rob meant it for across different physical places in the room.
There is no “absolute phase” everywhere in the room, we agree that that doesn’t make any sense.
Of course the latter is a near impossibility. but the former is speaker design 101 and a basic premise of how to get drivers to work together. I also assert the importance of "time alignment" is frequency dependent. The group delay graph Rob later posted shows this exact phenomenon, so it is in fact relevant. What's critical at 2 kHz is not so critical at 20 kHz or 20 Hz. AFAIK, you haven't clearly stated what you think except for liking 1st order crossovers, and seem to deny that our sensitivity to time depends on frequency, despite that view being contrary to conventional wisdom and scientific studies.
Are you referring to my post #57 where I said:
Assuming that there is PRAT, and that it is something with timing or rise time, or decay time, then I am perplexed as to how people talk about using cables and soft suspensions, or transformer coupled amps with a low damping factor, as if it is anything other than describing the danger fleas and ticks on an attack dog.
Both the box “order” and crossover “order” can store a lot of energy.
When those are hit with some impulse, it takes longer for that energy to decay away.
In a planar speaker we can attribute that to light mass, but it is also a 1st order “enclosure”. A big driver in an open baffle is also a 1st order “enclosure”.
I suppose that one can try to loosen the grip on the driver in a lower order box.
(I am discounting whether that is the right thing to do or not.)
But it is difficult to increase the grip on a driver, when the box and XO are high order. In that case we are gripping onto the XO and the box has largely evaded our grasp.
In any case if PRAT may not be something that is trying to describe transcient and impulse response, so I could be wrong.
I think I was relatively clear, that having the speaker sucking-n-pushing, with an impulse or step function response that is all janky, sort of does not match the outgoing sound wave to that which the microphone recorded.
If there is trident shaped impulse response of correlation peaks, then does that make for a system that has PRaT?
I think that post #133 showed the impulse or step functions:
I don't know who/what you classify as competently designed? Do you consier the big name speakers as competently designed? e.g Magico, WIlson, YG, Avantgarde, Goebel, KEF, B&W ....
I pasted three pictures of impluse response as measured by stereophile. One is almost a perfect triangle. This one is from an old Thiel model. It used a first order crossover and all of the impluses from the various drivers arrived at the same time. But only on one axis. If you shift the axis they won't arrive on time as is shown in the second picture. The third picture shows a well known speaker brand reviewed in 2024. We can see that the tweeter, midrange and woofer arrive at different times. And that the midrange is even out of polarity with the tweeter and woofer.
I don't need to do math. I can hear it. Whether it is the speaker or the room I don't know and it really doesn't matter. The fact is the instruments are either playing together like a band or they are not. This is the definition of praT.
- On distortion, I think it's most likely Ron simply didn't understand how you worded your post. It's not just you and Ralph that have noticed, it's actually a basic concept that nearly everyone in the audio hobby is familiar with to some degree. I think it's fair to assume everyone reading this is familiar with the concept of even and odd order harmonic distortion and its effects.
It might be more nuanced than just even versus odd, and the SS having odd and tubes even..
Some of those amps have just 2nd and 3rd order harmonics, and very little happening in the higher harmonics.
It is not just a hand waving, “these are not the droids you’re looking for,” where everyone is just assumed to know it.
The statement seems like it was couched in terms as some fundamental law that came off the mountainside carved on a tablet, and while I have heard it for decades, some systems just sound scary quiet and relaxed.
(Maybe that is the opposite of resolving? And why a lot of people have other systems.)
Back to
@Robh3606 his cherry picked plots on his post #139.
How is my feeble mind supposed to work out, in real-time, which of those peeks/peaks is/are the one that describes the sound coming in
There are two or more options for that waveform to give me some PRaT, and I sort of need it to be clear, in order for me to get it.
And if the sound is further delayed by a cycle, then that is also making it difficult to line things up.
It might be possible that some people are just better at processing the sounds, and others need some help with an easier and more accurate sound?
Some speakers may use a full 360 out of phase alignment but you're cherry picking examples to make your point.
I don't think the vast majority of speaker manufacturers simply don't know what they are doing wrt to time and phase, and I don't think this subject has anything to do with PRaT either.
I think I poised one of my earlier posts as a question… “as to whether impulse response was what PRaT was trying to describe.”
So I appreciate your response, that you don’t think that it has anything to do with PRaT.
The good news is that almost everyone has gear that they are able to enjoy, and the industry caters to many people.
