For the record, that was closer to a -120dB nonlinearity measured as HD, but listened to as IMD of music that has a lot of different frequencies at once. A lot tougher for a reproduction system than a 20-tone IMD test.
Regarding a number of -130dB or lower, that was speculative number for a possible limit.
Would be a loss to drop this line as it is at the core of the topic.
Don't be afraid of the grumpy ol' cats in these threads, usually it is the best to ignore the personal stuff - most of us had our share, too
- and to concentrate on the pieces in each post that help to further the discussion.To find causes for certain percepted impressions is difficult as (beside carefully desgined, controlled and executed experimets) differences can be measured in several dimensions.
Krivium already mentioned another important fact, namely that we have to consider that our hearing sense is time-frequency-analyzer which enables us to decode complex signals by auditory scene analysis. Abraxalito posted the title of Bregmann's book, a milestone.
I was just quoting Earl's statement from another thread.
Don't take "we" or "you" literally it usually means "some" or "at least one" .
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We measure EEG, which is nonlinear, time variant, and non-stationary. Why not? Its a valid measurement.
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Not entering anything if we don't want it: it's called differential attention.
Have you heard?!
Hi Jakob2,
How would a variable, incredibly subjective EEG relate to a piece of equipment or system? Its more a reflection of that individual and really hasn't much to do with the equipment involved.
It might be very interesting, but for audio it is a distraction. I imagine it changes with volume level as well. You may as well describe the look of the clouds outside when listening to something. It is just as relevant.
How would a variable, incredibly subjective EEG relate to a piece of equipment or system? Its more a reflection of that individual and really hasn't much to do with the equipment involved.
It might be very interesting, but for audio it is a distraction. I imagine it changes with volume level as well. You may as well describe the look of the clouds outside when listening to something. It is just as relevant.
I would not want others to suffer for helping me understand. Actually I can accept his response if I try to push a point, but I was told to leave for asking.
If not EEG, how about fMRI? If we want to know what audio reproduction equipment tends to make most listeners happy, might that not be important for moving our understanding of audio forward? There might be some correlation between things we can measure and and audio reproduction quality. We won't find out if we don't look.
It seems like some of us are limited in how we think about doing research to find problems. It doesn't have to be only about measuring volts, amps, Hz, etc., things guys mostly focused on electronics tend to think in terms of.
It seems like some of us are limited in how we think about doing research to find problems. It doesn't have to be only about measuring volts, amps, Hz, etc., things guys mostly focused on electronics tend to think in terms of.
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Regarding 'expectation bias,' a definition can be found in the list of cognitive biases: List of cognitive biases - Wikipedia
"The tendency for experimenters to believe, certify, and publish data that agree with their expectations for the outcome of an experiment, and to disbelieve, discard, or downgrade the corresponding weightings for data that appear to conflict with those expectations."
Yes, true. Expectation bias may have caused later published studies of audibility to repeat errors of earlier researchers.
"The tendency for experimenters to believe, certify, and publish data that agree with their expectations for the outcome of an experiment, and to disbelieve, discard, or downgrade the corresponding weightings for data that appear to conflict with those expectations."
Yes, true. Expectation bias may have caused later published studies of audibility to repeat errors of earlier researchers.
Hi Andrea,
This is actually my preferred amplifier, I have others I put in from time to time, some tube. I have worked on all of them and enjoy all of them. They are driving a pair of PSB Stratus Gold (original) speakers, so they have to work a little. Even the 35 watt tube amps do fine. The amplifier in question is a Marantz 300DC, its rated at 150 wpc and is a perfect match. The woofers bottom at about the same time that the peak lights flash. The person who discovered this is no longer allowed to touch any of my systems. There was no excuse to see how loud it would go. For completeness, the preamp is a Marantz SC-9 (modified) with a Revox B261 tuner and Thorens TD-126 MKII and Ortofon 540 MKII cartridge and a modified Denon DCD-S10 CD player. Its a wonderful system that I have had for years. I don't have any urge to change anything (but would love a new Thorens TD-1601 table and maybe Ortofon Black cartridge).
-Chris
I can only post the after responses for THD and IMD for you. They are good, but not spectacular. The right channel is pretty much the same so I won't waste the space by posting those.
This amplifier has separate voltage regulators for each channel voltage amplifiers. I improved the performance of these regulators for increased noise rejection from the line and overall lower ripple. The 60 Hz components are actually noise pickup from the test setup. The other modifications are from some circuit and component changes I make, plus matching transistors. Since I get paid to do this, I am not going to detail everything I do. One thing I will say is that I do not increase teh size of capacitors at all.
This is actually my preferred amplifier, I have others I put in from time to time, some tube. I have worked on all of them and enjoy all of them. They are driving a pair of PSB Stratus Gold (original) speakers, so they have to work a little. Even the 35 watt tube amps do fine. The amplifier in question is a Marantz 300DC, its rated at 150 wpc and is a perfect match. The woofers bottom at about the same time that the peak lights flash. The person who discovered this is no longer allowed to touch any of my systems. There was no excuse to see how loud it would go. For completeness, the preamp is a Marantz SC-9 (modified) with a Revox B261 tuner and Thorens TD-126 MKII and Ortofon 540 MKII cartridge and a modified Denon DCD-S10 CD player. Its a wonderful system that I have had for years. I don't have any urge to change anything (but would love a new Thorens TD-1601 table and maybe Ortofon Black cartridge).
-Chris
Attachments
Your pov N101N.
We already know we don't share a 'common ground' about technology and physics ( as in your vision of things electronic and commonly accepted science is invalid) so discussion is very limited and won't lead to something interesting.
That said if you think there is no time domain in our preception there could be no movement... so we are in a static world ( which at universe scale may be true but not in a human life scale).
It counteract the feeling most of our fellow humans have: time limited life.
Not talking about the fact that DC to a loudspeaker won't make a sound... ( except a click at the onset due to motion of cone).
We already know we don't share a 'common ground' about technology and physics ( as in your vision of things electronic and commonly accepted science is invalid) so discussion is very limited and won't lead to something interesting.
That said if you think there is no time domain in our preception there could be no movement... so we are in a static world ( which at universe scale may be true but not in a human life scale).
It counteract the feeling most of our fellow humans have: time limited life.
Not talking about the fact that DC to a loudspeaker won't make a sound... ( except a click at the onset due to motion of cone).
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Well, 'expectation' can be found in the writings of [the man who gives the name to the bass reflex functioning ] and can be applied to almost everything.
The attention that a human 'gives' to his surroundings is determined principally by his state of mind, occasional or persistant
thoughts, interest in the thing and many more ( being in love, being hungry, being in a rush etc.), You may say that in a 'test' this should be avoided, but...The attention is sort of masking effect produced by the mind. The masking effect makes you hear everything confused, like you are in a disco. On the other side, the differential attention might let you hear someone talking to you ( or anybody else) in that scenario.
In music is different, there's a sequence...
Hi picowallspeaker,
Well, I agree. In any test you want to control all the variables except for the factor or effect you want to investigate. Maybe a black, quiet room is a step in the right direction - I don't know.
So many complications. Subjective testing is so ... subjective. Maybe the most valuable test is one that takes place over a week or month to average out experiences so you end up with an index of how enjoyable a system is. E.I. Enjoyment index.
-Chris
Well, I agree. In any test you want to control all the variables except for the factor or effect you want to investigate. Maybe a black, quiet room is a step in the right direction - I don't know.
So many complications. Subjective testing is so ... subjective. Maybe the most valuable test is one that takes place over a week or month to average out experiences so you end up with an index of how enjoyable a system is. E.I. Enjoyment index.
-Chris
Funny way we do things in audio, producers measure everything except the resulting acoustic output. Not going to change anytime soon for various reasons. While customer talks about sound quality, not amplifier quality or speaker quality.
I don't see things this way: each time i had to learn something i was happy someone already asked the question and there is a record of it ( why i like fora as writing stays and can be remembered/accessed easily).
The issue i see with your question is that it is wide and leak on many subjects which interact so it's difficult for me to explain easily and clearly without being too much off topic.
I'm sure other could do it but from me expect a mess giving reference to a lot of things which you'll have to digest and make links between them.
^ I'm not sure we all see measurements the same way: from some technical parameters measurements you can deduce/expect a behavior about sound quality but nothing more.
There is too much things involved ( with unknown variable to give 'acoustic output') to give a set of defined measurements you could always trust.
But the measurements will give clues.
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Hi indra1,
That's because an acoustic measurement swamps out many tiny changes that we can hear. There is probably value in measuring an entire system, but it is specific to a single customer.
When you buy an amplifier or other component, you want to know how it performs. The only way to compare equipment is to look at each piece, then hear them in a system. Lately I have been buying things "on spec." and am getting what I expect. The last four speaker systems I bought were on spec., one I listened to on an inferior receiver. But I was able to hear what I needed to hear. They sounded a great deal better when I got them here. Two pair were for the bench (I upgraded after a few months). The others were for other systems I have here and were upgrades for very old systems. Kept the PSBs where they were.
-Chris
That's because an acoustic measurement swamps out many tiny changes that we can hear. There is probably value in measuring an entire system, but it is specific to a single customer.
When you buy an amplifier or other component, you want to know how it performs. The only way to compare equipment is to look at each piece, then hear them in a system. Lately I have been buying things "on spec." and am getting what I expect. The last four speaker systems I bought were on spec., one I listened to on an inferior receiver. But I was able to hear what I needed to hear. They sounded a great deal better when I got them here. Two pair were for the bench (I upgraded after a few months). The others were for other systems I have here and were upgrades for very old systems. Kept the PSBs where they were.
-Chris
Indra1,
I've read the paper from M. De Lima.
Very interesting and clever approach. But limited to full rangers use as i see it (and stated by the author).
In a multiway system once you have more than 2 ways*, bandpass allowed for each way won't have the benefits of the approach. And you can achieve more or less the same effect by bandpass limit each way in their 'best range of application/interest' - no more than 2 octave and a half if possible especially for low and mids -for each drivers and the use of a current drive amplifier ( Firstwatt F1 iirc is an example of such solidstate amp).
In fact this is what i've seen used with some ATC monitors for their dome mid in studio ( with active filtering).
My own bias led me to something like that with my own main but without the current drive amp ( 3 ways dsp filtered and multiamp). I have achieved good results regarding perceived harmonic distortion ( being 3 ways and dsp filtered with an amp dedicated to each way and few things except cable to drivers the system is very 'clean' sounding even when you push it a bit and is stable between low volume and higher ones).
* and if you stay to the ubiquitous 6,5"+1" given the xover freq you'll have limited interest as the distortion cancellation won't happen in the most sensible range of our hearing ( between 1k and 6k with a xover usually in the 2,5k range).
I've read the paper from M. De Lima.
Very interesting and clever approach. But limited to full rangers use as i see it (and stated by the author).
In a multiway system once you have more than 2 ways*, bandpass allowed for each way won't have the benefits of the approach. And you can achieve more or less the same effect by bandpass limit each way in their 'best range of application/interest' - no more than 2 octave and a half if possible especially for low and mids -for each drivers and the use of a current drive amplifier ( Firstwatt F1 iirc is an example of such solidstate amp).
In fact this is what i've seen used with some ATC monitors for their dome mid in studio ( with active filtering).
My own bias led me to something like that with my own main but without the current drive amp ( 3 ways dsp filtered and multiamp). I have achieved good results regarding perceived harmonic distortion ( being 3 ways and dsp filtered with an amp dedicated to each way and few things except cable to drivers the system is very 'clean' sounding even when you push it a bit and is stable between low volume and higher ones).
* and if you stay to the ubiquitous 6,5"+1" given the xover freq you'll have limited interest as the distortion cancellation won't happen in the most sensible range of our hearing ( between 1k and 6k with a xover usually in the 2,5k range).
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@Krivium,
my background is electronics but went off doing work in prepress business for 25+ years. Post retirement I open a small food stall at home and have time to again play around with my audio hobby. So I don't expect to need much help in electronics. My know how in electromechanical and acoustic side is rather limited. Again, thank you for the pointers you gave me.
About my coming multiamp system, I'm trying to put my crossover points away from the phase sensitive 500-2kHz range, perhaps at 200-250 and 3500-4000 Hz. I am hoping to be able to acquire a pair of Satori 6" for my mid woofer driver in a few weeks. I'd appreciate any suggestion that you may have.
@Chris,
As I said, not going to change anytime soon.
I know for a fact that compared to a low THD amp mated with a low THD speakers, I can get lower acoustic distortion by using amplifier with a very specific amount and phase of 2nd harmonic, something still on the bench coming along at a snail pace due to my current budget situation. Not a single driver system, but a multi low power amp system with each amp directly driving a single driver and a LLXO. I'd like to optimize the setup as much as I possibly can as I go along. Thank you for your generous help.
my background is electronics but went off doing work in prepress business for 25+ years. Post retirement I open a small food stall at home and have time to again play around with my audio hobby. So I don't expect to need much help in electronics. My know how in electromechanical and acoustic side is rather limited. Again, thank you for the pointers you gave me.
About my coming multiamp system, I'm trying to put my crossover points away from the phase sensitive 500-2kHz range, perhaps at 200-250 and 3500-4000 Hz. I am hoping to be able to acquire a pair of Satori 6" for my mid woofer driver in a few weeks. I'd appreciate any suggestion that you may have.
@Chris,
As I said, not going to change anytime soon.
I know for a fact that compared to a low THD amp mated with a low THD speakers, I can get lower acoustic distortion by using amplifier with a very specific amount and phase of 2nd harmonic, something still on the bench coming along at a snail pace due to my current budget situation. Not a single driver system, but a multi low power amp system with each amp directly driving a single driver and a LLXO. I'd like to optimize the setup as much as I possibly can as I go along. Thank you for your generous help.
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