pauln

Top notch!

And I thought this thread was going to be about the need for frequency response 23KHz and above... for amplifiers!

"Move along citizen, there's nothing to see here."

I have been very suspicious of what has been going on in the oil business for a while now. What has had me bothered about it is the justification of price and supply concerns on the one hand, and a public policy encouraging over consumption on the other. Even "following the money" to find clues to whom receive the spoils seems counterintuitive in so far as the present path and impacts leads to "killing the golden goose". The only line of thinking that seems to make sense is to wonder if there is a piece of the puzzle that has been closely held by those "in the know". Ask yourself under what circumstances would the present course make sense for the producers? What situation would drive them and their proxies in government to encourage such over consumption in the face of supply constraints and at the risk of a consumer rebellion resulting in the potential collapse of the industry? Why no movement to build refineries in the last 30 years? Why tax breaks for the purchase of Hummers? How can those who make decisions be so cavalier and fearless in the face of current perceived reality? Under what scenario does this path makes sense? Scenario A: It makes sense if there has been a discovery in the energy industry that will make oil based energy obsolete - some kind of new technology that will run our cars and truck, fusion that works, zero point energy, something unknown. This discovery is being held in secret until the current folks running this business have squeezed out all the profit they can from the exiting situation. Sort of a use or lose it approach - sell and consume now full tilt before the secret is out. Scenario B: It makes sense if secret knowledge about the supply of oil has changed on the increase side. This would be like discovering that the Earth's mantle is comprised mostly of oil (Bondi's and Gold's theory). This would mean a virtually infinite supply of oil drillable from any place on Earth by pushing a pipe through the Mohorovic Discontinuity. This would be millions of times more oil than the oceans have water. There are other possible scenarios to explain the current actions in this way - they all either find a larger supply of oil held in secret, or an alternative energy source discovery held in secret; in either case the idea is to soak the consuming world until the new thing is disclosed. I guess my point is that the public policy and the private producers are both acting as if there is no problem... maybe that is the true answer, the problem has been solved, so now it's just a matter of unloading the current stock of oil at the highest possible price before the secret gets out that there is no future energy source problem.

Probably none. The single most influence on mileage is how one drives (with proper tire pressure). If you can stand to accelerate very gently (15 seconds 0-25mph and 30 seconds 0-50mph), drive in town at 25mph and on the highway at 50mph, make your turns without hitting the brakes, and coast up to all the stop signs and red lights, shift to neutral at the red light, turn off the car where you know the wait is more than a minute or so... well I tried this on my last tank and got 8mpg more than usual (and I usually drive pretty easy). It is really hard to do at first as old habits are hard to break - takes concentration and attention to your speed, awareness of the distance to the next stop, remembering to avoid the brake, and learning to ignoring all the lead foot drivers around you. I got better at it as I tried this and I think I can get 2 more mpg improvement by keeping the RPMs below 2K even while accelerating. In my car (Mazda 6 with 4 cylinders) a steady 25mph is about 1250 RPMs, 50mph is about 2K RPMs. The engine loves high revs and really shines past about 3500, and the suspension is just made for handling tight curves with hard power, etc. But I'm looking forward to pressing into a little higher mileage. Even if it takes a little planning and more time on the road to get places, I am shooting for 30mpg city, 40 highway. I got interested in trying this after reading about some folks getting very high mpg with regular cars using some extreme exotic techniques of light driving - they get between 80-120 mpg, but no one can really drive using their techniques in the real world. the_hypermilers

"Ever noticed how much better your car performs in the rain (or seems to)." Reasons why: 1] The water drops all over the body of the car act as a low pass filter and absorb a lot of the higher frequency familiar car body noise, so it sounds smoother. Plus the noise of rain falling on the car masks lots of noises. 2] The water in the wheel wells and under the tires makes noise that is different from the more familiar dry sound. The tread/road noise sounds a little smoother. 3] On wet surfaces one is more inclined to drive slower and more carefully, no fast starts, hard turns, or hard braking. Less noise from those things, and the subjective performamce of cars seems to feel stronger at lower speeds (more torque? better suspension behavior?) 4] Supposedly the near 100% humidity in the air while driving in the rain naturally adds some moisure to the intake mixture (normal mix if air to gasoline is about 10,000 to 1). The additional water is said to cause the combustion in the cylinder to happen slower so one enjoys a smoother better power transfer. On this last point, there is a device that operates exactly like a water pipe that some folks have put in their cars. One of the vaccum lines on the intake is connected to the output of the water pipe (just a plactic bottle with two straws, one in the water, one above the water) so as to force the air to bubble through the water first. This is supposed to humidify the air before it gets into the engine.

1998 article about oil predicts today pretty well - 80 million barrels per day peak, the Saudi purchases of US skyscrapers, and the emergence of goofy ideas for what to put in the fuel tank. 1998

Feeling twice as dirty as earlier in the day, I run a bath, but find that it feels twice as hot as I expected. This makes me mad, and in a few minutes I'm twice as mad as I was before. Is it twice as inconvenient to wait for it to cool or draw the bath again? Now I am resolved to apply twice as much attention when preparing my next bath. Will I smell twice as good when I'm done?

Is this anything other than the very operational definition of "twice as loud"? Let us have two speakers... one comes on at x dB, it's loud. Second one comes on at x dB. With both speakers on you have x+3 dB. So, now it is twice as loud, 3 dB louder. Any different subjective notion of what is twice is loud; +6 dB, +10 dB or whatever is simply not the right answer. It may be true that the average person makes this error consistently, and it may be true that people in general make close to the same degree of error. For psychoacoustical research that is interesting, but to answer the question of what is really twice as loud, looks like it is 3 db.

"I shave my dry face with a big hunting knife." Real men hammer their beards, then bite it off from the inside and spit it into the sink.

What in the world has happened to our cars? Look at this site which ranks the EPA MPG of high mpg cars from 1984!!! Unbelivable! Of the 249 cars considered high mpg (equal to or better than 40mpg highway): 202 cars in the 40-49mpg range 37 cars in the 50-59mpg range 10 cars in the 60-69mpg range Some of these are trucks and station wagons.

Look at www.lpnow.com http://www.lpnow.com/'>New sealed unplayed in and out of print records from long ago. Majority look to be in the $7-$10 range. I've done business with them.

Yeah, I shopped the Boxcar Wille cover... you can tell by the pixels.[*-)] The other one is a real record. The model that became a singer is Vicki Ford - photo model for car shows, pinups, and bikinis from the 60's. Quite a few people own this album (I don't) becaue it completes their collections of work by some the the excellent and well known musicians featured on it.

I've taken the liberty of adding a censor sash on behalf of preserving this young lady's modesty... the song titels tittals , darn... T I T L E S are intriguing as well.

Ah yes, the classics...

"Complex audio waveforms are absolutely caused by frequencies different from the fundamental being added to that fundamental frequency. ... A single, individual frequency can exist only as a sine wave, and a complex waveform can only be made up of sine waves of various frequencies and amplitudes." That is all I am trying to point out - the sine wave is not king of the waves nor is it the primary most basic element from which all other waves are composed - but by selecting the sine as the "measuring" tool your results will yield a specific collection of frequencies, amplitudes, and phases. Those are also not basic or primary. When all you have is a hammer, everything starts looking like a nail. As long as one fixates on the idea that sine waves are the only "real" building block of complex waves my points will be lost. One watches complex waves go into Fourier and sine waves come out - this is ONLY because the sine wave is chosen by the operator as the shape of the component into which the complex wave is decomposed. The sine is chosen because the math is easier, NOT because it is a special primary waveform. There is no such special primary waveform. One may perform the same operation choosing another arbitrary waveform as the shape of the component into which the complex wave is decomposed. Different choices of component wave shape will result in different values of the frequency, amplitude, and phase - this is why it is misleading to think that there are additional frequencies existing independent of a measuring process. Each shape wave used as the choice of component will yield different frequencies of these components, and no choice of component wave shape is prior, superior, more fundamental, or more "real" than any other. The sine is chosen to make the math easy. The selection of the sine determines the frequencies that yield; other waves yield other frequencies. When you write "A single, individual frequency can exist only as a sine wave", that is not strictly true.. First of all, it is critical to see how there are no frequencies prior to selecting the component wave shape one will use to decompose the complex wave. The specific frequencies only "appear" by virtue of the shape selected to perform the decomposition. Chosing another shape will yield different frequencies. When you write that " complex waveform can only be made up of sine waves of various frequencies and amplitudes", this is clearly not true. A complex wave may be made up of any arbitrary shape of periodic wave of various freqs and amplitudes (and phases). It totally depends on the operator's choice for the component wave shape when making the measurement or calculation.

I understand all of that.The idea I am arguing is that when you start with a sample waveform and decide to break it down into its components, breaking it down into component sine waves is only one of the ways to do the breakdown. You can also break it down into other kinds of waves, although the amplitudes, frequencies, and phases of those waves will be different. The Fourier decomposition does not require that the component waves are sine waves. A sample waveform is not "naturally" composed of sine waves - it can be broken down using Fourier to be composed of any kind of wave. The implication of this is that a particular sample wave may be reconstructed from component waves of any type, not just sine waves; although again the amplitudes, frequencies, and phases of those component waves will be different, depending on the type of component wave selected to build up the sample wave. This means when one asks what kind of wave "really" is the building block that is used to combine them in superposition to result in the sample complex wave, the answer is "you have your choice to use any wave as the component - most use sine waves because that is usually easiest, but in reality, it can be whatever you chose". This is why it is misleading to believe that the element is "generating" the additional frequencies in distortion. Those particular frquencies only hold when the signal is analized from the standpoint of decomposing the complex wave into those specific components by selecting a particular shape of component wave. In 'reality' those particular frquencies are an artifact of the shape of the component wave selected (usually the sine wave) with which the Fourier decomposition was performed. Chosing to decompose the complex wave into sawtooth waves will work just as well, but the resulting frequencies of the components will be different. There are no intrinsic component frequencies in a wave until one chooses the type of wave shape one will use to decompose the complex wave. Only then you get a set of amplitudes, freqs, and phases. For electrical/audio/acoustic applications the selection is almost always the sine wave. But that is not required. Any wave shape may be selected and consistent and correct values for amplitude, freq, and phase will come out of the Fouier transform. It is like asking what is a factor for 60? There are an infinite number of them, but if all you need is 2x30, which is easy, the others don't get used only because they are more difficult but no less correct. But it would be misleading to always see 2x30 and eventually assume that is the "most real" or only factor.

"Already demonstrated that if the fundamental is removed the harmonics are still present." I don't see how that disproves what the Navy teaches at all. Of course removing the fundamental (the undeformed aspect of the waveform) from a signal will leave behind the deformed part of the waveform. That no more reveals the true origen of these frequencies than arguing that thier presence must be attributed to having been generated in the element in the first place. When you suppress a component waveform from a complex waveform you must choose the one to suppress. If you are familiar with this kind of analysis of superposition you may know that the process works no matter what the type of wave is used as the member of the superposition - the classical and standard waveform used is the sine wave, and it is common to see statements that imply that complex waves are built up from sine waves of various amplitude and phase; but Fourier analysis works perfectly well if one selects square waves, sawtooth waves, tuba waves, or any continuous periodic waveform as the basic wave from which to derive all other waveforms using superposition. Sine waves are used because their math is simple, not because they are the actual ultimate reality truth of the form of the component waves that make up a complex wave. The Navy would probably reply that the harmonic distortion remaining after suppressing the fundamental will be considered to have not been actually produced in the element, but that rather the effect on the output signal is the same as if these harmonics had been introduced. What I mean is that logically the supression of the fundamental to see the remaining distortion does not act as a proper test of the idea that the distortion frequencies are not generated in the element but that the effect on the signal is as if they were... I think the issue may be that just because a distorted waveform may be conceptually thought as superposition of additional frequencies of a particular form of wave (sine wave) to a fundamental does not necessarily imply that those particular types of waveform were generated by the addition of those sine frequencies to a fundamental. Ultimately, the selection of the type of waveform used to decompose a complex wave is arbitrary - any continous repeating waveform can be used to perform the analysis. This is what underlies the concept of Complementarity in physical measurements. There is no a priori absolute correct waveform to use as the building block for decomposing complex waves. Each one measures a different attribute. This also addresses the assertion that "Music is of course made up of nothing but sine waves." That is conceptually true if you select sine waves to perform the decomposition. If one selects any arbitrary continuous periodic wave to do the analysis ("X" wave) one may just as well claim that all music is made of nothing but X waves. I think the writers of the Navy manual knew this but did not go into it because is was just an electronics training book, not a discussion of modern physics and old math.

Do you have a boot disk? If so, try that; and if you don't have a backup of your files, do that right away. You could copy them to a network location. Sometimes the BIOS gets whacked and needs to be reset to default. Pulling out the battery for a day or two will force a reset of the BIOS. Do you have the "repair" and "restore" utilities on disk/CD? Both repair and restore can fix some problems without losing your files. Put the Utility CD in and start up the computer. If the repair and restore utilities fail you may have to reinstall the OS. One option is to reinstall without formating the drive. There are some tools that will allow you to recover your files before a hard option reinstall that wipes all data - you'll need help from the manufacturer\technical support to do that... Good luck.

The idea that the second, third etc harmonic distortions are not actually produced in the element, but that rather the effect on the output signal is the same as if these harmonics had been introduced is not my idea. It comes from the US Navy electronics training course NAVPERS 10087-A, 1955. I'm sure that the observation that up to 10% second harmonic distortion is difficult to discern comes from tests of listening to normal musical program material, not lone test tone sine waves which never appear in music. To me that seems like comparing two very close shades of paint stroked on a blank white canvas. Once the painting is completed and viewed, you really can't tell which one was actually used...

I wish that there was another word to use for the addition of frequencies to the original waveform other than harmonic "distortion". The majority of people think of distortion as a buzzy fuzzy sound. Harmonic distortion occurs when the waveform is altered by the operational element in the signal stage - stylus/cartridge (mechanical), gain stages (electrical), speakers (mechanical). The thing many mistakenly believe is that the harmonic distortion comes from adding the additional frequency components, but in reality what happens is the waveform is slightly deformed as if these frequency components were added. It's not really intuitive, but this is not a distinction without a difference. It's not that additional frequencies are generated by the element but that the deformation characteristic of the element is the same as if these additional frequencies were added. The shape of the deformation of third harmonic distortion on the upper and lower parts of the waveform are symmetric. Intuitively, many would guess this is the least offensive type of distortion because of the preservation of waveform symmetry. On the other hand, the second harmonic distortion is very offensive looking on the scope because it effects the upper and lower parts of the waveform assymmetrically. It makes the upper part more flatly rounded, but makes the lower part more pointy and extend further down. Intuitively - at first look most would see that and expect a severe impact on the sound. Yet, second harmonic distortion only adds a whole multiple of 2x to the frequency - an additional perfect octave above component, which all natural sounds already have. The octave is the most consonant interval to the ear. The second harmonic can be up to 10% before it becomes noticable to even an experienced critical music listener. Third harmonic distortion (3x fundamental freq) adds a fifth in the second octave above the funtamental, but its pitch departs from the tempered scale by +2 cents (very slightly sharp off key). The degree to which this error in pitch is disagreeable to the ear depends on the music and the melodic and harmonic aspects of music composition outside of the deliberate call for a fifth interval based harmony in the particular chord of the progression or phrase.

Micro Cars! Wow! Just wow! Be sure you spend a moment looking at all of them!

There was a news story recently about the unsucessful search for a South American priest how had tied ballons to a lawn chair and disappeared into the sky, presumably landed in the Atlantic.

There are those that think the elephant has only been trained to paint and that he does not know what he is really doing... the addition of the flower seems to support that. There are those that say the sign languaging apes and the texting dolphins are also just acting out of carefully constructed behavior modification training. The thing I noticed right off was that the elephant pauses for what seems like a moment of reflection before his first stroke of the brush - longer than before any of the other stokes of the painting. I suppose they taught him that, too? What's going on in the mind of the elephant? How young a child could be taught the same thing? What would that child's idea be of what was going on? At what point does a behavior become complex enough that it is attributed to the actor and not the trainer?

My theory is that people who hear sound as music don't tend to use tone controls, those that hear music as sound, do. Just a theory...