Just saying today's instrumentation could complete PK's study.
BTW, I actually liked some of the single driver setups at Burning Amp. All those horrible direct radiators are still going strong.
Careful that's more like relative pitch. Wait ten minutes and turn the oscillator to 440 without looking then measure it. Try again later.
Well, i got 9 out of 10, but i used the speakers at very low
volume; otherwise, i m sure it would have been 10/10....
I m sorry, but you ll have to add more precision in your
future project calculations...
Right , Scott.
Indeed, the test in SY s link is easier due to the frequency sweep..
Great !!
You are proving to yourself that you did ,intellectualy,understimate yours ears
all these past years.
Chris,
Sorry I missed this, but a nice guess, however the L really is in Henries the C can get close to 1 F (okay .1) so with a pair of 8 ohm speakers playing average level of -20 re full power R would be closer to 40 ohms, so the load does come a little into play, but I see how that is not what it would seem at first look.
I suspect most of your measurement experience is at a well designed and built test bench. So you probably do not have as many motors interacting with your AC line. Which makes it reasonable with all your experience you haven't seen the problem.
Most of my systems are bigger than my shop so I have to do field measurements. They have HVAC systems that can cool an entire city block! Most also can coat the floor with ice.
So you might keep an eye out for it and let me know if it does show up in consumer gear.
BTY my shop is not that large it is only one half of an acre!
ES
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If I'm not mistaken, getting two right out of ten is as statistically significant as getting eight right out of ten.
se
Scott,
That is a test for "Perfect Pitch" and yes there are cases where some folks have demonstrated the ability.
Of course you really could use a function generator, most of the audio band ones can do FM. It is often called "Sweep."
I have done some work vaguely related to this area and will be doing more. I did a brief article for Sound & Video Contractor 20 or more years ago on a useful application related to some of this. Someone else then got a "Protection" patent on the method and never brought it to market.
So I will not be able to add any useful data to this topic.
ES
There is absolute perfect pitch and relative perfect pitch. Which you have or none at all is I think a result of genetics. I think most people have perfect relative pitch. I had a neighbor once who had perfect absolute pitch. You could rap your knuckles on a piece of wood and she knew what key it was.
7 out of 10 right is only slightly more significant than random chance according to the web site with the test. Whatever. 2 out of 10 right may have been because I didn't understand the test. I took it without reading the instructions first.
I'm still not convinced that I can hear FM distortion or sideband distortion in loudspeakers. I'm also not convinced that the horn loaded speaker solves anything. One thing about horns, in addition to the propagation delay (time between electrical excitation of the voice coil and mechanical response of the diaphram, there is a time delay for the compression wave to leave the mouth of the horn. So much for time aligned horns.
I meant wahab switching a generator between 440 and 441 Hz that is relative pitch. If you look hard enough you will find some people with absurdly good abilities for setting an oscillator "cold" to 440 Hz.
Sorry, not the way I read you. Looks like we are in agreement on the point just not the wording.
Hope you have a good new year!
Different issue
Quote From BT Part 1 "Well in the actual power supply box, I use conventional 3 terminal regulators, to remove hum and ultra low frequency (breathing) of the power line. I have found that 2 regulators in series is better than one 'super' regulator. I hope that this makes sense to you."
So apparently my motor question was actually on topic!
I just had 10 minutes of entertainment with those online hearing tests, thanks for pointing them out! If anyone else is interested in the significance of their scores, here's a table of the % chance of getting a certain number n correct by blind/deaf guessing:
{{n, 100*P}, {0, 1.7}, {1, 8.7}, {2, 20.}, {3, 26.}, {4, 23.}, {5, 14.}, {6, 5.7}, {7, 1.6}, {8, 0.30}, {9, 0.034}, {10, 0.0017}}
You could probably say 7 or more right is significant. The distribution is not symmetrical because there are 2 wrong choices and only 1 right for each trial.
{{n, 100*P
}, {0, 1.7}, {1, 8.7}, {2, 20.}, {3, 26.}, {4, 23.}, {5, 14.}, {6, 5.7}, {7, 1.6}, {8, 0.30}, {9, 0.034}, {10, 0.0017}}You could probably say 7 or more right is significant. The distribution is not symmetrical because there are 2 wrong choices and only 1 right for each trial.
It is important to note that horns tend to remove Doppler distortion, but small coned direct radiator loudspeakers can make lots. There is NO solid rule that we hear FM and AM distortion in exactly the same way, or sensitive to the same magnitude.
Doppler distortion is just one of the trade-offs in loudspeaker design.
Usually the horn loudspeaker designers make a big deal about it, and the direct radiator loudspeaker designers like those formerly at AR, tend to attempt to dismiss it. Yet it is real, and often audible.(at least in my opinion)
Doppler distortion is just one of the trade-offs in loudspeaker design.
Usually the horn loudspeaker designers make a big deal about it, and the direct radiator loudspeaker designers like those formerly at AR, tend to attempt to dismiss it. Yet it is real, and often audible.(at least in my opinion)
Simon7000, interesting notes on motors, and in the commercial world HVAC is one of the main causes of EMC mains borne problems. It isn't to bad (a relative bad) where there is a distributed mains systems (though if you are unlucky to be next to a big HVAC installation!!), but if you live where the mains is supplied by local generating set ups it can be horrendus. At a past company making Gen set controllers we had to cater for up to the 13th harmonic on the mains as we were getting false zero crossing detects due to the horrendous non monotonic wave form.
EMC and mains borne is getting worse, and harder to heep out, to add to the problem in the UK we now have BT wanting to transmit EMC in the form of BT vision. Ofcom have even given them a dispensation from the normal CE declaration!!
EMC and mains borne is getting worse, and harder to heep out, to add to the problem in the UK we now have BT wanting to transmit EMC in the form of BT vision. Ofcom have even given them a dispensation from the normal CE declaration!!
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