These remind me of the Magnetic Floaters sitting on my bookshelf for close to a decade...
I tend to find the opposite, but then I know my ears are lying to my brain, or is it the opposite?
Originally Posted by DF96
The evidence is that ears are easily fooled. For example, a small increase in loudness is perceived as a big increase in quality.
The evidence is that ears are easily fooled. For example, a small increase in loudness is perceived as a big increase in quality.
But it's so easy to do. Just use a voltmeter to match the levels.
Perceptual level matching is not necessarily exactly the same as electrical level matching.
Also, preference level matching is very different, it's not matching to get the same peak, average, RMS, or other power or voltage level. If one DUT sounds better than another, it is adjusting levels until both sound equally good or likable. That can be done even if they sound very different and have very different waveforms. By such means it is possible to get some estimate to quantify how much more likable one DUT is than the other.
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This has confused me for some time. In DB testing, much is made of the importance of level matching, and understandably so. But what I usually hear is "matched to within 0.1 dB @ 1 KHz." This of course makes no allowance for perception, as you mention. For two DUTs with enough of a difference in tonal balance, I could see where a match at 1K might not have much of a correlation with the perceived loudness.
But if we then switch to some sort of perceptual measure of equal loudness, is the test no longer blind/accurate/valid? How is this done?
As usual, I fear the answer will make me smack myself in the head, but it won't be the first time or the last.
I would like to thank the two physicists who contributed to giving us physics books to look up. I tried to buy Dugdale's book, but it was just too expensive, $160 for a new paperback, but Kittel's book is free on the net. I got Kittel's book, and if I ever really had to research wire conduction again, I would probably buy Dugdale's book as well. I have a selection of these books available already, but trying to understand precisely how electricity flows and how resistance in metals is produced is still a challenge. For example, WHY is gold so much different than silver in resistance, but yet the same in so many ways? Why is copper so similar to silver in resistance, yet a very different color and with different internal parameters, like atomic size, V(Fermi), and many other factors?
Green and blue are mental experiences, not exactly properties of objects. The mental experiences are triggered by certain frequencies of light or certain combinations of frequencies of light.
A separate question would by why particular objects emit or reflect certain frequencies of light. Hate to say it, but quantum mechanics is involved.
What to use depends on what we are trying to measure. Measuring mental experiences is harder than measuring voltages. Often its done by asking somebody to rate DUT 1 and DUT 2 on a scale of 1-5 or 1-10 for this or that characteristic. But, some people rate everything close together and some people rate vary wide. In other words, people have different gain and offset factors for how they rate. People can be trained to rate in a way to compensate, such as what JBL does with their trained listeners.
Anyway, when testing some audio processing plugins I just decided to try perceptual likability level matching. It turned out for one compressor plugin it's matching factor was about 3dB. I had to turn it down 3dB for it to sound equally good as uncompressed audio. But, when I did I discovered there were some things I really didn't like about the sound of it. So it was a useful experiment which I learned from.
It seems to me in a forum like this we don't have a way to communicate how much we like the sound of DUT 1 compared to DUT 2. If we could say DUT 1 needs 1.5dB boost to sound as good as DUT 2, when measured SPL is 70dB at the listening position. Now we have some numbers instead of words that don't have clear meaning and for which we don't have any idea of perceptual gain and offset factors. Like anything else, if we can find a way to measure something, then we can do science on it. First we need to get to understanding our measuring tool characteristics, properties, limitations, etc., then we can use it for stuff.
You're welcome.
Sincerest wishes of good luck here. It's definitely tougher stuff to really get at the equation level, and I apologize that I don't know of more approachable material.
That said, once you get a better feel for band diagrams and density of states, a lot of the other stuff (optical properties, thermal conductivity, electron transport, etc) becomes much more intuitive.
(albeit not at a level that lets me compute it quickly, that math gets really hard really fast)
Intra-atomic stuff past the basics is just straight up mystifying, haha.
I appreciate where you're going, Mark/ScottJ(at least moniker), but my caution is that it'd have to be in a large composite of perceptual factors as any one metric will poorly describe the entirety. Which unfortunately makes it too complicated to be useful, and we're back to square one. :/
So this would apply to unit with different frequency response curves?
As there is no way to match levels across the band. (without using EQ).
So you look for levels that sound the most alike?
But why would you even be AB testing two pieces of electronics (as opposed to transducers) with dramatically different frequency response? If an amplifier has significant FR errors it should be disqualified from further testing.
When told that, for listening tests to be meaningful, playback levels must be matched to <0.1dB, some ask "How can I catch levels that closely?". The answer is, adjust levels until they sound the same, then you know level is within 0.1dB!
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