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Step Response: Does It Really Matter?

j_j

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I wonder how you do that.
Well you can start with the impulse response. Go to www.aes.org/sections/pnw and then in "meeting recaps" or something like that to tell you how.

if you have the impulse response, you can just sum along the axis adding one sample at a time, there's your step response.

Note; using an actual impulse is a bad idea. Use an allpass sequence. Look at the site, find the talk, you'll see. There is even a test signal and a matlab script there for you to use if you have that, or instructions on how to get octave if you don't spend for matlab.
 

j_j

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"Microphones work on the principle of pressure, pressure gradient, or velocity. If you don't know the difference, then you can't yet call yourself a sound engineer."

Whoa, dodged that bullet...

More at https://www.audiomasterclass.com/ne...re-pressure-gradient-and-velocity-microphones
There are inexpensive soundfield mikes out there. Just use one. :) While ambisonics is NOT the holy grail of stereo capture despite what its proponents think it DOES capture the entire soundfield at one point.
 

DonH56

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I haven't tried to do pressure/velocity measurements for ages. When I did, I used my old B&K or Sennheiser (forgot model, their equivalent of the Earthworks M30 omni measurement mic I have now) for the pressure mic and a large-frame condenser (but cheap, e.g. AKG C3000) for the "velocity" sensor since I didn't have a good ribbon mic at the time. I did borrow a friend's ribbon and IIRC the results weren't much different (a ribbon is not a true velocity mic but about as close as it gets). I have a vague memory of papers trying to use the plasma driver approach in reverse as a mic to achieve a true velocity mic, and even got pinged on the idea back in the early 1990's to help a startup working on the approach, but it never really became a commercial success AFAIK.

I do not recall the results ever being that useful except as a laboratory exercise; maybe @j_j could comment on the practical use? I graduated and moved on shortly after doing the measurements (for a grad class project) away from audio research.
 

j_j

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I do not recall the results ever being that useful except as a laboratory exercise; maybe @j_j could comment on the practical use? I graduated and moved on shortly after doing the measurements (for a grad class project) away from audio research.
If you're trying to measure acoustic impedance, it's very useful. This is somewhat esoteric, unless you build mikes, or speakers, or measure soundfields.
 

DonH56

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If you're trying to measure acoustic impedance, it's very useful. This is somewhat esoteric, unless you build mikes, or speakers, or measure soundfields.
Yes, and that's what I was doing at the time, just was not sure of it's application to consumer measurements. Does not seem like something the average audiophile needs to muck with (or worry about)...

Thanks JJ! - Don
 
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I agree. Someone else who says the same thing:
I can unfortunately add nothing of technical interest to this thread, and even though I own Thiel (time/phase coherent) speakers I remain agnostic about the case for time/phase coherency, given I see arguments from knowledgeable people on both sides of the debate.

But I can't help remark on the paper above. Many of the listening impressions purported for time/phase coherence seems to align so well with what I hear from the Thiel speakers (2.7 with coax mid/tweeter).

One really stuck out in the paper:

"3.Separation of ambience. With loudspeakers whose stereo image is slightly blended because of time-smear, any hall ambience or reverberation in the recording tends to become slightly mixed with the instrumental sounds, causing coloration of those sounds. Consequently, with such speakers closely-microphoned recordings tend to sound better because of their distinctly defined sound. But with time-corrected loudspeakers, the ambience is resolved as a separate sound, and larger amounts of hall ambience in recordings can be enjoyed.......”

That is EXACTLY one of the attributes that stick out every time I compare my Thiels directly to my other speakers - MBL omnis, Waveform Mach MC, Spendor, Hales and others - or to other non time/phase coherent designs.

Recently I've been switching in a variety of my other speakers and have truly enjoyed them - each brings something I like, sometimes that aspect a bit more than the Thiels. But what always sticks out is the relative lack of imaging precision. It's not like my other speakers don't soundstage and image impressively - they do so like gangbusters. But I can't help but note how the sonic image of a voice, sax or any other instrument on the other speakers seems to be blurred or mixed in with the surrounding reverb or acoustic. It gives a sort of flattened or see-through quality to the sonic images. Every time I go back to the Thiels, images seem to "snap" in to focus, as if all the sonic energy coming from a sound source which goes astray in other designs has been organized and lined up properly. The effect is that sonic images seem more solid, dense, dimensionally 'round' and separated from the reverb and acoustics. So they sound like solid acoustic sources IN a reverberant space.

Again, I can't speak to whether this is due to their time/phase coherence, or perhaps to some other attribute of their engineering. But it is a constant impression I have every time I go from listening to a higher order non time/phase coherent design to the Thiels.
 
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Also, I have to hop on the earlier conversations about electrostatic speakers. One poster said he'd moved on from them, finding them dynamically unconvincing - not 'pressurizing the room' the way box/dynamic speakers do. I moved on from electrostatics (Quade ESL 63s) for the same reason! I was for a while seduced by that particular boxless 'transparent-sounding' aspect of the electrostatic sound. But it seemed after a while to have a sort of ghostly, removed character, as if I were listening to a performance happening through a window in a different room.
When I'd throw in my older smaller box speakers (a pair of old Thiel 02s) it's like the room came alive with the energy of musicians. Drums, bongos just seemed to "whap!" the air right there, like someone was in the room playing the instrument. It just seemed more palpable and dynamic and affecting.

I added the gradient sub to the Quads - some may remember it was a dipole sub designed specifically to match the radiation pattern of the Quads, and the Quads sat on top making for a seamless monolith. They remain to my ears the most seamless combination of dynamic sub with a panel that I've heard. Yet, I still found the 'problem' above persisted and I moved on to box speakers, never looking back.

I've heard a great many Martin Logan hybrids over the years, and my friend owns a pair of ML hybrids as well. Every time I'm struck by the same impression: wow at that cool electrostatic presentation in the mids up, but that same old weightlessness. I get why some people think that adding a dynamic driver in to the design for the lower frequencies gives back some dynamic palpability. But what I always hear is a discontinuity: instruments ranges covered by the dynamic driver have some weight and air-moving drive - e.g. bass instruments - but as the range moves to higher frequencies there is that weightless quality. My friend thinks his MLs rock just fine because once he feels those bass notes hitting from the woofer section, well....there you go! They rock! But for me, it just doesn't work as I find the rest of the spectrum dynamically bereft. Put on Rush and geddy lee's bass can be felt, but Lifeson's guitars don't seem to have the same drive - they are more like a sonic mist you could just walk through rather than the killer impact you hear from a guitar through their cabinet amplification.

So, I get both the anti-panel and pro panel opinions. I enjoy visiting panels - and in fact would own Quad ESL 57s if I had the room to store them when not listening. But it's more a nice place to visit than a place to stay for me.
 
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