Thanks for saying that . The fools gold I am working on would be happy to use that . I can go down to 200 Hz which is daft because I will only get 2 octaves from the bass unit if so . 500 Hz seems better . I wonder if RIAA 318 uS comes into it in 1960 ?
The > 500 Hz will be first order . The bass can be anything I want including brick wall .
If I need HF then 7 kHz is where I set my crossover .
Anyone willing to say if damping factor matters at 200 or 500 Hz ? Perhaps at 500 Hz best to have very little ?
Off to Bert Haynes scrap yard for some plywood tomorrow .
Is it not the ear mechanism can not do other than make it so ? Optical illusion is well understood ( ? ) .
Panel speakers often seem to have more bass except where the really deep bass is a special part of a film for example . Panel speakers are sometimes like a friend who forgets a rendezvous . They make up for it in being genuine and great when they do turn up .
Actually there is a good evolutionary reason for that, which also neatly illustrates how perception works.
As most people here will know, perception is the process of taking in ALL available sensory information, combine it with internally (to the brain) generated info like memories, expectations etc, plus the 'body state'.
This is evolutions' way to minimise the risk from taking a wrong decision in everyday live on the savannah, like failing to run even when you doubt there's a tiger afoot. The veiw of a large predator primes your brain for hearing a low frequency rumbling sound, so much so that in case the large primate is present, but the low frequency sound is not (yet) heard, both the brain and your ears themselves insure themselves by making up the lf rumble so that you give the right response, i.e. get the hell out of there.
It's intriguing that a lot of our questions can be answered with reference to evolution. Or maybe it isn't - we wouldn't be here to ask them if it wasn't for evolution.
jan
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Yes, the Anthropic Principle. Lately I've been considering, as more appropriate, the Misanthropic Principle.
We had this with the new sirens for ambulance . I do find it very useful and always know where to look . All the more remarkable as the sound has bounced around the inside of the car . In the past I would look around and mostly have no idea where the sound was coming from .The blue lights being the first proper sign .
It's said we developed our skills when living in forests . The snap of a twig says danger . The direction might be confused . We at least switch on our eyes and the flight mechanism . Transients thrill as it says danger . Someone said stereo and music relates to jungle sounds . Very beautiful sounds in the mid-range . Our eating instincts are primitive so why not our ears ?
It's said we developed our skills when living in forests . The snap of a twig says danger . The direction might be confused . We at least switch on our eyes and the flight mechanism . Transients thrill as it says danger . Someone said stereo and music relates to jungle sounds . Very beautiful sounds in the mid-range . Our eating instincts are primitive so why not our ears ?
In this case we seem to do the opposite...we perceive something that isn't there.
Obviously evolution has favoured those who are able to distinguish men from women on the telephone.
OTOH, it could just be an unavoidable consequence of how ears work. Can we hear phantom bass lower than the lowest audible real bass? If our ears are damaged so we can't hear real bass, can we still hear phantom bass? Is that why old people like valve amps?
Some interesting demos of psychoacoustic stuff here
I was looking for acoustical scene analysis, in pursuit of Pano's cello.
Wondering if "natural sound" and "close enough to a cello" could sum to "sounds like a real cello", and so grappling with the notion that "natural" and "cello" can be separated. Is there a universal natural, or is every natural different?
So I was looking for evidence of a mental toggle for natural...held on by normality perhaps. Or vice-versa with respect to "unnatural". It could then be possible that "natural sound" (or "not unnatural sound") is a property of some audio systems. If natural is toggled on, then the cello sounds real even if it is not in fact quite like a real cello.
I wonder then what happens if a natural-sounding system is presented with an unnatural input. If input and subsequent transform combine by multiplication, then Bjork could be properly rendered by a natural-sounding system.
The attraction of such an argument, or something similar and better informed by science, is that it holds the prospect of uniting the subjectivists and objectivists. A good system must be both accurate and natural. Everybody's right.
My guess is that engineering now easily achieves the one, but it takes years of design evolution to get the other.
I was looking for acoustical scene analysis, in pursuit of Pano's cello.
Wondering if "natural sound" and "close enough to a cello" could sum to "sounds like a real cello", and so grappling with the notion that "natural" and "cello" can be separated. Is there a universal natural, or is every natural different?
So I was looking for evidence of a mental toggle for natural...held on by normality perhaps. Or vice-versa with respect to "unnatural". It could then be possible that "natural sound" (or "not unnatural sound") is a property of some audio systems. If natural is toggled on, then the cello sounds real even if it is not in fact quite like a real cello.
I wonder then what happens if a natural-sounding system is presented with an unnatural input. If input and subsequent transform combine by multiplication, then Bjork could be properly rendered by a natural-sounding system.
The attraction of such an argument, or something similar and better informed by science, is that it holds the prospect of uniting the subjectivists and objectivists. A good system must be both accurate and natural. Everybody's right.
My guess is that engineering now easily achieves the one, but it takes years of design evolution to get the other.
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Further, considering that the transient response of a system is a property of the system, whereas the steady state response is a property of the input, it may be true that:
"The transient response of an audio system should be either natural, or zero."
In other words, more or less, it shouldn't sound bad if you kick it. Er...did we know that already?
"The transient response of an audio system should be either natural, or zero."
In other words, more or less, it shouldn't sound bad if you kick it. Er...did we know that already?
https://en.wikipedia.org/wiki/Shepard_tone
http://www.youtube.com/watch?v=BzNzgsAE4F0
And the near obvious Music = ( 1 + rt/ 5 ) /2
http://www.youtube.com/watch?v=pOwMDO0-zBw
http://www.youtube.com/watch?v=BzNzgsAE4F0
And the near obvious Music = ( 1 + rt/ 5 ) /2
http://www.youtube.com/watch?v=pOwMDO0-zBw
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Nige, while I agree it's common sense to avoid crossovers in the region where our hearing is at its best and most perceptive, on the other hand we need to be actutely aware of our drivers' capabilities. Finding a quality driver capable of covering the 500 Hz-7 kHz range will NOT be easy at all.
And it quickly stops being cheap and simple.
I think 5 kHz is the ideal mid-to-tweeter crossover point. By comparison, the legendary JBL 100 "Century" did it at 1.5 and 6 kHz and still sounded wonderful. I would never cut my bass at 1.5 kHz, but there you go, living proof that it can be done without (too much) adverse effect. Mine cuts the bass off at 800 Hz, and the mid at 3.5 kHz, yet is as clear as a mountain stream.
I would suggest that much more important than the cutoff points is what you do or not do with the crossover. You need to compensate for its funnies, as Chord, Rogers, Spendor and others used to do, to obtain a relatively easy load to drive.
Just my 2 cents' worth.
All I remember is the famous amp used what valve guys refuse to call a long tail pair made of pentode in trode out . Now I know about pre distortion I recon it might have virtues . At the time it was said easy pentode drive and nice triode distortion in the mix . I think that is a half truth . That valve a bit like the 7199 .
Richard Hay of Nytech was one of his crew , he died recently . Nytech were well thought of . He showed me Radford TriStar 90 speakers . Really good speakers .
Radfords latter amps claimed to be zero distortion . I hated one so much I nearly gave it away . Having looked at the circuit it is so near to what I pen myself as to make me want to re-tests it . Ironically Magneplanar would be OK as far as I can see . The load is fairly constant being the point . I truly don't think me disliking zero distrotion has anything to do with it . I have listened to others that are equally low and liked them .
Richard Hay of Nytech was one of his crew , he died recently . Nytech were well thought of . He showed me Radford TriStar 90 speakers . Really good speakers .
Radfords latter amps claimed to be zero distortion . I hated one so much I nearly gave it away . Having looked at the circuit it is so near to what I pen myself as to make me want to re-tests it . Ironically Magneplanar would be OK as far as I can see . The load is fairly constant being the point . I truly don't think me disliking zero distrotion has anything to do with it . I have listened to others that are equally low and liked them .
Dvv thanks for that . 600 Hz and 7kHz look favourite . Will save a ton of money . The 600 Hz to 7 K will be with virtually zero damping factor . The 50 Hz to 600 Hz might be highly damped . The 7K is like an electrostatic load so might be SE valve . The speaker sold work well with no super tweeter . Like FM it will chop the last 5 kHz if no tweeter .
The 600 Hz to 7 K driven at up to 40 V rms at low current . LME49811( 10 ) via FET if bias range OK . About 38 db gain so Cdom might be made smaller . 26 dB gain = the maximum feedback . PSU will be +/- 80 V . The idea is to get a large reduction in crossover distortion and HF distortion due to high voltage low current 1.3 A max . Like using a reduction transformer . The gamble is no damping = no problems if 600 Hz .
The 600 Hz to 7 K driven at up to 40 V rms at low current . LME49811( 10 ) via FET if bias range OK . About 38 db gain so Cdom might be made smaller . 26 dB gain = the maximum feedback . PSU will be +/- 80 V . The idea is to get a large reduction in crossover distortion and HF distortion due to high voltage low current 1.3 A max . Like using a reduction transformer . The gamble is no damping = no problems if 600 Hz .
A "good" system may be so at the macro level, that is, in the world of conventional measurements, but mostly is not so at the micro level. Testing virtually never takes into account what happens to low level signals in the presence of high level input, and, interference effects.
Unfortunately, the human hearing system is more adept, hence the quandry ...
Unfortunately, that demonstrates the lack of depth of experimentation done by yourself - yes, masking exists, and it's easy to find examples where the primary source of sound generates such a level of acoustic 'noise' that anything uncorrelated would be masked. I've already looked at the infamous Sousa band test, and it's obvious that the level of reverb is so intense that any background differences would be undiscernable - I posted my take on this ages ago ...
Unfortunately, recorded music has more styles than just those with intense echo, hence the need for better performance of the replay system.
I design and build or craft solutions to the problems that prevent realistic replay of recordings - I find that level of effort sufficient to do the job with already existing equipment, there is no particular pleasure in merely repeating what's been done by others 1000's of times. The experiments are done continuously as part of the prcoess of refining playback quality - the oscilloscope is of almost zero value because only the extremely expensive ones would possibly be capable of the resolution necessary to get useful results.
The responses to Pano's interconnect test indicate that the majority of audio people can't hear, or are not interested in hearing, the differences in quality due to system weaknesses - so it appears that there is little point in attempting to improve the general quality of playback systems -- it's a bit of a lost cause, it seems ...
Unfortunately, recorded music has more styles than just those with intense echo, hence the need for better performance of the replay system.
I design and build or craft solutions to the problems that prevent realistic replay of recordings - I find that level of effort sufficient to do the job with already existing equipment, there is no particular pleasure in merely repeating what's been done by others 1000's of times. The experiments are done continuously as part of the prcoess of refining playback quality - the oscilloscope is of almost zero value because only the extremely expensive ones would possibly be capable of the resolution necessary to get useful results.
The responses to Pano's interconnect test indicate that the majority of audio people can't hear, or are not interested in hearing, the differences in quality due to system weaknesses - so it appears that there is little point in attempting to improve the general quality of playback systems -- it's a bit of a lost cause, it seems ...
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