In my experience some drivers can measure well in a particular cabinet but not sound good while other drivers (in the same cabinet) can measure very similar and sound great! It seems that broadband resonances/hash/diffraction resulting from the cabinet/waveguide/damping scheme (or bleed through the driver diaphragm) can occur without much peakiness being apparent in the FR.
Obviously this topic drifts into another thread, but these days I wouldn't conclude a good looking FR indicates fidelity. All a good looking graph tells *me* is that the speaker+alignment is performing reasonably and deserves a serious listen... Similarly, polars don't tell me much about diffraction, but in some topologies/waveguide schemes diffraction is noticeable and I don't enjoy it.
I saw someone questioning peoples ability to notice +/-1.5dB changes in FR... FWIW, trained ears are capable of noticing > .5 to .8dB changes in amplitude over pretty narrow bandwidths. Mastering engineers routinely work up into this threshold of audibility.
As far as comparing the Behringers to the Orions... Was the spirit of that test reasonable? One speaker interacts with the room across it's BW and the other across what, half?... IDK, I couldn't read more than 20 pages of this thread, but I would not expect a definitive result from a test of different topologies that have different room interactions... I *can* see shooting out Summa's against the Behringers as they are *almost* in the same species. The Orions would need to go against Alons or some other OB design no? Otherwise what are we comparing?-listeners preferences for different types of delayed room reflections? I'm probably repeating some previous post so I'll bow out now.
Obviously this topic drifts into another thread, but these days I wouldn't conclude a good looking FR indicates fidelity. All a good looking graph tells *me* is that the speaker+alignment is performing reasonably and deserves a serious listen... Similarly, polars don't tell me much about diffraction, but in some topologies/waveguide schemes diffraction is noticeable and I don't enjoy it.
I saw someone questioning peoples ability to notice +/-1.5dB changes in FR... FWIW, trained ears are capable of noticing > .5 to .8dB changes in amplitude over pretty narrow bandwidths. Mastering engineers routinely work up into this threshold of audibility.
As far as comparing the Behringers to the Orions... Was the spirit of that test reasonable? One speaker interacts with the room across it's BW and the other across what, half?... IDK, I couldn't read more than 20 pages of this thread, but I would not expect a definitive result from a test of different topologies that have different room interactions... I *can* see shooting out Summa's against the Behringers as they are *almost* in the same species. The Orions would need to go against Alons or some other OB design no? Otherwise what are we comparing?-listeners preferences for different types of delayed room reflections? I'm probably repeating some previous post so I'll bow out now.
Last edited:
Hi Anthony
My experience is quite contrary to yours and it is contrary to all of the work of Toole and Olive. We believe that measurements tell us a lot about a system and that the confidence in looking at measured data outweighs the lower confidence of using personal non-blind subjective data. People hear what they want to hear, but microphones measure only what really is.
Polar maps miss a few things, like dynamics, but they about 90% of the important aspects of a loudspeaker. A few more measurements of dynamics and we will be much closer then even 90%.
My experience is quite contrary to yours and it is contrary to all of the work of Toole and Olive. We believe that measurements tell us a lot about a system and that the confidence in looking at measured data outweighs the lower confidence of using personal non-blind subjective data. People hear what they want to hear, but microphones measure only what really is.
Polar maps miss a few things, like dynamics, but they about 90% of the important aspects of a loudspeaker. A few more measurements of dynamics and we will be much closer then even 90%.
Fully with Earl on this one, if that wasn't obvious already. Just one additional remark.
Taking measurements and interpreting them is not the same thing as knowing how to use the equipment. It takes effort and study to translate measurements into actionable information. For example, one of the problems is that three different issues: diffraction, internal standing waves and driver behaviour, all may show up as almost the same kind of wriggles on a Bode plot. To know how to dissect the data takes some skill.
I just received d'Appolito latest book on measurement (for sale at Parts Express), and while I was waiting for the order, I sort of regretted to have spent the money. What a foolish, pompous *** I was to think that I already know it all! There is always more to learn, or to relearn, even on such a limited area as measuring a loudspeaker. Buy the book, I would say, money well spent.
Taking measurements and interpreting them is not the same thing as knowing how to use the equipment. It takes effort and study to translate measurements into actionable information. For example, one of the problems is that three different issues: diffraction, internal standing waves and driver behaviour, all may show up as almost the same kind of wriggles on a Bode plot. To know how to dissect the data takes some skill.
I just received d'Appolito latest book on measurement (for sale at Parts Express), and while I was waiting for the order, I sort of regretted to have spent the money. What a foolish, pompous *** I was to think that I already know it all! There is always more to learn, or to relearn, even on such a limited area as measuring a loudspeaker. Buy the book, I would say, money well spent.
Hi Gedlee,
The intent of my post was not to dismiss measurement as an important tool but to add some perspective about what measurements aren't telling us. I was cavalier and over-emphasized my point in hope of shaking people out of their exaggerated trust in measurement (some were talking as if systems could be evaluated/compared without listening).
Consider this perspective. Graphs do not have the resolution to display to the eye what the ear perceives at > 18,000 times a second (especially if smoothing is applied). A graph 500 pixels wide showing FR gives a nice clue about a systems overall balance. But beyond that, the "tonality" of the system is unknown until we listen. Add to this graph it's underlying fft bin artifacts and visual smoothing and we're starting to talk about painting our reflection *on* a mirror! As we make the first stroke we can't see ourselves well enough to continue.
So we agree measurements are important. Great. My intended point was about data that is psycho-acoustically perceived but simultaneously buried in the visualization.
fwiw, 10% or even 1% is significant when discussing perceptual aspects of an audio signal.
If I could experience perfect synesthesia and just look at graphs to hear Mozart, well, I'd probably do it.
The intent of my post was not to dismiss measurement as an important tool but to add some perspective about what measurements aren't telling us. I was cavalier and over-emphasized my point in hope of shaking people out of their exaggerated trust in measurement (some were talking as if systems could be evaluated/compared without listening).
Consider this perspective. Graphs do not have the resolution to display to the eye what the ear perceives at > 18,000 times a second (especially if smoothing is applied). A graph 500 pixels wide showing FR gives a nice clue about a systems overall balance. But beyond that, the "tonality" of the system is unknown until we listen. Add to this graph it's underlying fft bin artifacts and visual smoothing and we're starting to talk about painting our reflection *on* a mirror! As we make the first stroke we can't see ourselves well enough to continue.
So we agree measurements are important. Great. My intended point was about data that is psycho-acoustically perceived but simultaneously buried in the visualization.
fwiw, 10% or even 1% is significant when discussing perceptual aspects of an audio signal.
If I could experience perfect synesthesia and just look at graphs to hear Mozart, well, I'd probably do it.
Last edited:
I personally think they can be shown. There is so much data to compare and contrast it leads most people to information overload. Where to to even begin or how should the test be setup takes priority. How would one properly test for driver cone transperancy? I know the answer, but it is just that kind of question that will give most pause and a bit of head scratching before proceeding. Even then the results may not be expected, further buried or improperly done. Questioning the results should be second nature and normally leads to the correct conclusion... eventually (or not). For example a loose mounting screw was discovered through the impulse response. Another example is two breakup peaks around 4k and 5k in a 6.5" woofer. These peaks are attributed to the diameter of the voice coil bisecting the cone and downward radiate at the third harmonic.
If a commercial speaker is seen via a picture, knowing crossover points and quality response measurements made get my attention, then it's worth a listen. If the above is known, then generalities of it's performance can be implied to the experienced. How well they pull it off requires an ear or two.
If a commercial speaker is seen via a picture, knowing crossover points and quality response measurements made get my attention, then it's worth a listen. If the above is known, then generalities of it's performance can be implied to the experienced. How well they pull it off requires an ear or two.
What book is that? I have the 1998 version, but I am not aware of a more recent one.
That would be me. I believe that.
I would much rather put my faith in measurements than the well known flawed opinions of listeners.
Mozart has nothing to do with this discussion. We are talking about reproduction here, not music. Noise or swept sine waves, even rain, are valid signal sources for this, but I wouldn't want to sit down and listen to them.
We must learn to separate the emotional aspects of listening with the scientific aspects of reproduction. Mixing up the two will only lead to uncertainty about which is which - "Did I like the speakers or did I like the performance?"
Apparently that would also describe Dr Roger West, designer of the Sound Lab electrostatics, who is almost deaf, I understand, and adjusts his speakers' design mainly from measured data.
o
Wim, your are right, I thought it was a new book, but it was only new to me
sorry for the confuxion, but still a recommendable read.
Wim, your are right, I thought it was a new book, but it was only new to me
sorry for the confuxion, but still a recommendable read.
I think it is more important to find the link between emotional aspects of listening and the scientific aspects of reproduction. Being able to reproduce the emotion the performers put into their performances is a very important aspect of reproduction, and differentiates product quality. This is really being more realistic in audio system design.