In digital systems termination problems frequently arise with cables much more than an "inch or two"... terminating scsi cabling leaps to mind. So you might want to phrase your explanation explicitly as greater than or equal to 1/4 of a wavelength.
You need to worry about impedance and termination when your transmission line (cable) get to be too long. If you have a one-inch SCSI cable, you can probably get away with no termination at all.
In audio impedance mismatch might occur relative to two outputs (and their sinks), which could possibly affect an amp. As far as impedance mismatch between source and sink causing reflection in a cable then the relevant numbers would be 20KHz and 344m/s (speed of sound; since the electrical waveform mirrors the waveform in air, one simply being the other run through a transducer). This gives a wavelength of 17.2mm. One quarter of that would be 4.3mm... about 1/6th of an inch.
Well, if the signal ends on a tape recorder, the tape probably moves at 1 inch-per-second. What if the destination is a hard drive spinning at 7600 RPM? The actual linear speed depends on where the head is positioned.
Sorry for being a smart-ass, but what the signal does at the other end really does not matter. You have a signal travelling down a wire -- hence it is an electrical signal and you use the speed of electrical signals for determining wavelength. It depends on the cable, but a good rule of thumb is in the 0.7 to 0.8 times the speed of light.
The reason is that a loud speaker is a reactive load, when the amp drives the speaker, the speaker drives it back or tries too. The amp combats this by having a low output impedance and negative feedback. The problem is that the speaker wire and the speaker are not part of the feedback loop. An analogy might be to imagine that you have lost the remote control for your tv. Being lazy you get a long cane from the garden shed and tape a pencil eraser to the end and use this to sit in your chair and prod at the buttons on the telly with your cane. Dont knock this, I've seen it done. Clearly the longer, thiner and more springy the cane the more difficult this will be to do. You will keep overshooting and over correcting and the end will bounce up and down. not an exact analogy as you can see the end of the cane, but close.
Loud speakers often have an impedance of about 8 ohms so a 1 ohm resistance in the cable and connectors is getting on for significant.
What you say about the inductance true. This effect will be clearly noticable at higher frequencies as your speaker cable runs start to approach a mile or two. The speed of light is 186,000 miles per second. Assume that the speed of an electrical signal is 0.8*c, or 148,000 miles/s. Let's also assume that you want your signal to be accurate up to 30,000 Hz (just to be extra safe). That means that one wavelength is 4.96 miles. As long as your cable is a couple hundred feet or so, the cable might as well not be there, as the resulting back-EMF from the inductance of the speaker is almost perfectly in phase with the driver.
You are absolutely correct about resistance. Fatter cables = less resistive loss in copper. After a point, though, you reach dimishing returns. For a 20 watt power level, is it worth it to drop your losses from 0.1 to 0.05 watts? There are two approaches here:
1) Engineer way: determine desires power level, speaker resistance, cable length & cross section, and select based on calculations.
2) Common-sense way: buy the thickest thing that is reasonable priced and call it good enough (easiest, and good enough)
As for twisted, twisting a cable improves its performance at higher frequencies. I don't know if this is significant in the audio spectrum.
What you are talking about is most likely the skin effect and, unless you are running 100 W and using gigantic cables, the "skin" still extends to the center of the cable for audio frequencies. Forget about it.
Ever seen an old penny? Some of them even turn green. Corrosion is bad. Gold does not corrode like copper. Even tin can get dull and tarnished over time. Nuff said.
Randi missed his target - cause Monster cable is the same trick - just a lower price point.
My twin-lead is working just fine - and with the same frequency response as the monster cable at 20Khz.
True, but up to a point.
There IS a difference in the quality of cable. Really, it is just the "quality of construction" type stuff. Cheap connectors will eventually start to corrode, and maybe even corrode itself to the device so that you break something when you unplug it (been there, done that). Getting a good quality of construction is important: nice strong strain relief, quality crimping/soldering, gold plating is sure nice to have to prevent corrosion. Also, for speaker wire, bigger is always better. This helps reduce I^2/R losses. Monster does seem to provide pretty good quality. However, with that being said, unless you find an absolute steal of a bargain, Monster is overpriced for what you get.
I am not an audiophile, but I am an engineer. Here is my shopping list:
Line-level cables (RCA cables): Nice thick jacket. You want your cables strong. Sometimes you get a rat's nest of wires and you need to pull on a cable. Get one strong enough to survive a good tugging. Gold-plated connectors are very nice to have. Make sure that the connectors look like quality stuff.
Super-video (mini-DIN) cables: This, to me, is harder to tell because they all look the same. Gold plating is nice to have.
Speaker Cable: This may be raw cable with cut-n-soldered ends, or it may have a special pin on the end. The main thing for speaker cable is that it is thick (more important for high power levels & huge amps). This cuts resistive losses. As always, if it has a pin on the end, get gold-plated. For raw cable, if you get corrosion, you can just chop an inch and re-solder.
Anybody who tells you to worry about impedance matching or termination on a stereo system is full of bull. When I design digital systems, I have to worry about this sort of stuff when the lengh of the transmission line get to be about 1/4 the wavelength of the highest frequency that I care about. In digital systems, this number is typically about an inch or two. For audio, I would not worry as long as my cables are shorter than 1/4 mile or so.;)
What you say is true, but consider the "family geek" effect.
Brand Z starts to ship decent linux drivers, or at least offers up datasheets.
Geek "Y" decides that he loves this company, and recommends them to all of his friends and family, who trust him because he is the family geek. Suddenly, company "B's" sales increase even with non-geeks.
You are absolutely right. 2D acceleration is very nice to have. But, here is another hint: 2D acceleration is not rocket science either. I design digital hardware (but not aimed at general consumers). I could come up with some pretty nice 2D acceleration all on my own. You have basic things like block fills and block copies, and that goes a long way towards speeding things up.
At least this way he can take the "It's actually my intellectual property" defense to the US Copyright Office if he gets thrown into court.
Until the studio pulls out the contract with his signature that states that the studio owns the IP.
That is the way that it (AFAIK) usually works. The artist gives the rights to the studio, they publish it and give the artist some money back. If the artist retained the IP, they could sell it themselves and bypass the studio. Studios don't like that.
I am looking forward to the day when all RAM has ECC and all filesystems have checksums.
Not gonna happen. The problem is that ECC memory costs more, simply because there is 12.5% more memory. Most people are going to go for as cheap as possible.
But, ECC is available. If it is important to you, pay for it.
Huh? I do not understand this at all. What does "high quality" mean in terms of 2D?
Does it mean that the 2D acceleration is awesome? With current bus speeds, you could take out all acceleration, and probably not even notice a difference on a 2D desktop (including XP).
Does it mean that the image quality is awesome? If so, that relates strictly to the DAC installed (one single part), and is rendered obsolete by using a digital DVI interface.
From the article's description, it sounds like it isn't "sliding" magnetic data in a metaphorical sense, but actually physically sliding magnets around.
TFA is far from clear on this point. If it IS mechanical, I would have serious doubts about its reliability. If there are no moving parts, then he has just re-invented Bubble Memory
Of course I haven't RTFA, but don't they connect the tanks on these things? That seems pretty obvious, and something they've been doing with airplane fuel tanks probably since they built the first plane with more than one tank.
No, you didn't RTFA, and it shows.
Apparently, they DO connect them together. However, being space, the tanks do not automatically equalize the liquid fuel, even though they are connected. This scheme involves using data about the temperature of the tank to guestimate how much fuel is in each tank, and using selective heating to distribute the fuel around.
The Eee, on the other hand, has the potential to be a winner. If they can deliver them really cheap (which has yet to be seen), then it's the ultimate satellite PC for a home network.
The Eee is looking to be something of a train wreck in the happening. Of course, it is not released yet, so nothing is certain untill the first customers get one in their hands, but things are not looking as bright as they once were according to the rumors flying around.
Asus initially stated that a unit with 512 MB RAM and 2GB Flash (hard drive replacement) was going to be around $200, with better specs for more money. This was only about three months ago.
Now, $230 is supposed to get you 256MB / 2GB. If you actually want the 512MB / 4Gb that they initially promised, that will cost you $400 (only about a 100% increase in price in three months). Nothing is finalized yet, but these are the advance numbers being quoted by Asus dealers.
Take a game that's already made it's money back, and probably sells all of 2 copies a month, but hey, let's make some more money from it! Always with the string attached. Dang money-grubbing companies. *sigh* I tell ya, as far as I can recall, there hasn't been a game released without strings since Guitar Hero.
Activision gave away the original Zork trilogy as a way to help promote one of their graphical Zork adventures about a decade ago.
Sierra used to do this very occasionally. They gave away "Betrayal at Krondor" (a surprisingly good game for the time) in order to promote the sequal "Betrayal at Antara."
It does not happen often (or often enough), but it does happen.
Are there any that I missed?
PS: If I owned a game company, I would stick to a fixed schedule: Retail sales for the first five years. After that, stick it into a "best of" anthology. After ten years, freeware.
I have a Dell Latitude D810 and when I'm playing Warcraft if I don't limit the CPU speed to 1.6Ghz or lower the CPU temp climbs to 190F (according to gnome's CPU temp monitor). I think this is a combination of the heat produced by the CPU and the ATI GPU, cause it doesn't get so hot when I'm not doing 3D graphics.
That doesn't matter, dude. The CPU is made of sand. Sand won't burn no matter how hot it gets. In fact, some people use sand to put out fires. This problem is related to the batteries.
On the other hand, I wonder how much heat from the CPU makes it to the batteries. The heat sink is usually fairly close to the battery comparment, with the exhause air port usually begin in the back (where most batteries are).
Please note: this software simply creates a directory that is hidden from the Windows API for its fingerprint authentication. It's not actually a rootkit
Please note the defenition of "rootkit," ripped from the beginning of the rootkit wikipedia article:
A rootkit is a set of software tools intended to conceal running processes, files or system data from the operating system.
If it looks like a duck, quacks like a duck, yada yada yada.
They were in the 8th dimension, and they developed their own oscillation overthruster, which they used to escape.
On a more serious note, the tags for this article seem rather negative about Roland Piquepaille. Can anybody explain this? Is he an accomplice of Hans Reiser or something?
For what it's worth, I thought that your post was somewhat on the insightful (or at least interesting) side. Whoever modded you as flamebait is a himself an idiot.
Anyways, the average user of Firefox is a lot less likely to "punch the monkey." That does not mean that they spend less money. They just spend less money on herbal viagra.
Yes, there IS something else. You have a team of people making processors for everybody. The current cutting-edge processor designs will, with some minor modifications, eventually cover everything from the top-of-the-line processor to (in a year or two), the basic budget box (with some cache chopped out and the multiplier locked). The one-time cost can be spread out over hundreds of thousands or millions of units.
With music, on the other hand, is much more limited (with maybe the exception of a few super-stars). I have some bands that I like, and I buy their music). You, on the other hand, probably will not like the same bands. For many artists, selling 20,000 albums is a big deal. If the artist makes $1 and album, they are still in poverty if they make one album a year. This is assuming a solo album. If it is a band, the money is split among the band members.
Do they really need to spend thousands of dollars analyzing data to determine there's more crime around check-cashing stores on paydays?
Yes, they do. It sounds obvious, but WHOSE payday do you use. Some people get paid every Friday. Others get paid on the 1st and 15th. I get paid on the 6th and 21st. My last job paid me every other Friday. Social Security recipients get paid once a month (not sure of date). Which payday do you choose?
In a world without copyrights, an artist makes and album and sells it for $15. You buy one copy, make a thousand copies and sell it for $5. You make a bundle even though you did no work, and the artist goes broke and never makes another album. Same story for books and movies. Capitolism means benefitting from your labor.
Copyright is SUPPOSED to be a balance. It encourages people to make creative works by guaranteeing them a period of monopoly. But, after the copyright term expires, the work enters the public domain where it benefits all. The idea is fine. The problem is that the "limited period" has almost turned into perpetual copyrights, which is bad for the public.
The cost of the music is not JUST the cost of distribution.
The guys making the music do not really do it as a hobby. They expect to be paid. Yes, you can get a microwave now for $30 when it used to cost $300. But that does not mean that a musician would be happy to make 1/10 of what he would have been paid 20 years ago.
I am also fully aware that major labels only pay their artists a mere pittance, and most artists make the money on tour. I wish it were otherwise, and perhaps it is with indie labels.
But the fact still remains that, in order to make an album, you have to pay employees to run the recording studio, you have to pay for the studio itself, you have to hire artists to make the cover art, etc.
Look at is this way: the manufacturing cost of a CD or DVD (with case) is less probably less than a dollar, yet people consider paying $30 for a videogame to be a bargain, and usually don't start bitching until the games hit $50 or more.
So, I have absolutely no problem paying a dollar per track for music that I like. The only things that I would change are the amount that the artists are paid, and to eliminate DRM forever.
We had the same sort of thing when DVD-R and DVD+R we duking it out. Now, we just buy a $35 burner that can handle both and use the cheapest media that we can find. Life goes on.
In fact, I probably don't want my scheduler to be fair at all - I want it to run the stuff I want fast, and the other stuff it can run slow. That's not very fair.
Slashdot Mirror
Sorry for being a smart-ass, but what the signal does at the other end really does not matter. You have a signal travelling down a wire -- hence it is an electrical signal and you use the speed of electrical signals for determining wavelength. It depends on the cable, but a good rule of thumb is in the 0.7 to 0.8 times the speed of light.
You are absolutely correct about resistance. Fatter cables = less resistive loss in copper. After a point, though, you reach dimishing returns. For a 20 watt power level, is it worth it to drop your losses from 0.1 to 0.05 watts? There are two approaches here:
1) Engineer way: determine desires power level, speaker resistance, cable length & cross section, and select based on calculations.
2) Common-sense way: buy the thickest thing that is reasonable priced and call it good enough (easiest, and good enough)
What you are talking about is most likely the skin effect and, unless you are running 100 W and using gigantic cables, the "skin" still extends to the center of the cable for audio frequencies. Forget about it.
Ever seen an old penny? Some of them even turn green. Corrosion is bad. Gold does not corrode like copper. Even tin can get dull and tarnished over time. Nuff said.
True, but up to a point.
There IS a difference in the quality of cable. Really, it is just the "quality of construction" type stuff. Cheap connectors will eventually start to corrode, and maybe even corrode itself to the device so that you break something when you unplug it (been there, done that). Getting a good quality of construction is important: nice strong strain relief, quality crimping/soldering, gold plating is sure nice to have to prevent corrosion. Also, for speaker wire, bigger is always better. This helps reduce I^2/R losses. Monster does seem to provide pretty good quality. However, with that being said, unless you find an absolute steal of a bargain, Monster is overpriced for what you get.
I am not an audiophile, but I am an engineer. Here is my shopping list:
Line-level cables (RCA cables): Nice thick jacket. You want your cables strong. Sometimes you get a rat's nest of wires and you need to pull on a cable. Get one strong enough to survive a good tugging. Gold-plated connectors are very nice to have. Make sure that the connectors look like quality stuff.
Super-video (mini-DIN) cables: This, to me, is harder to tell because they all look the same. Gold plating is nice to have.
Speaker Cable: This may be raw cable with cut-n-soldered ends, or it may have a special pin on the end. The main thing for speaker cable is that it is thick (more important for high power levels & huge amps). This cuts resistive losses. As always, if it has a pin on the end, get gold-plated. For raw cable, if you get corrosion, you can just chop an inch and re-solder.
Anybody who tells you to worry about impedance matching or termination on a stereo system is full of bull. When I design digital systems, I have to worry about this sort of stuff when the lengh of the transmission line get to be about 1/4 the wavelength of the highest frequency that I care about. In digital systems, this number is typically about an inch or two. For audio, I would not worry as long as my cables are shorter than 1/4 mile or so.
What you say is true, but consider the "family geek" effect.
Brand Z starts to ship decent linux drivers, or at least offers up datasheets.
Geek "Y" decides that he loves this company, and recommends them to all of his friends and family, who trust him because he is the family geek. Suddenly, company "B's" sales increase even with non-geeks.
You are absolutely right. 2D acceleration is very nice to have. But, here is another hint: 2D acceleration is not rocket science either. I design digital hardware (but not aimed at general consumers). I could come up with some pretty nice 2D acceleration all on my own. You have basic things like block fills and block copies, and that goes a long way towards speeding things up.
That is the way that it (AFAIK) usually works. The artist gives the rights to the studio, they publish it and give the artist some money back. If the artist retained the IP, they could sell it themselves and bypass the studio. Studios don't like that.
But, ECC is available. If it is important to you, pay for it.
Does it mean that the 2D acceleration is awesome? With current bus speeds, you could take out all acceleration, and probably not even notice a difference on a 2D desktop (including XP).
Does it mean that the image quality is awesome? If so, that relates strictly to the DAC installed (one single part), and is rendered obsolete by using a digital DVI interface.
No, you didn't RTFA, and it shows.
Apparently, they DO connect them together. However, being space, the tanks do not automatically equalize the liquid fuel, even though they are connected. This scheme involves using data about the temperature of the tank to guestimate how much fuel is in each tank, and using selective heating to distribute the fuel around.
The Eee is looking to be something of a train wreck in the happening. Of course, it is not released yet, so nothing is certain untill the first customers get one in their hands, but things are not looking as bright as they once were according to the rumors flying around.
Asus initially stated that a unit with 512 MB RAM and 2GB Flash (hard drive replacement) was going to be around $200, with better specs for more money. This was only about three months ago.
Now, $230 is supposed to get you 256MB / 2GB. If you actually want the 512MB / 4Gb that they initially promised, that will cost you $400 (only about a 100% increase in price in three months). Nothing is finalized yet, but these are the advance numbers being quoted by Asus dealers.
Activision gave away the original Zork trilogy as a way to help promote one of their graphical Zork adventures about a decade ago.
Sierra used to do this very occasionally. They gave away "Betrayal at Krondor" (a surprisingly good game for the time) in order to promote the sequal "Betrayal at Antara."
It does not happen often (or often enough), but it does happen.
Are there any that I missed?
PS: If I owned a game company, I would stick to a fixed schedule: Retail sales for the first five years. After that, stick it into a "best of" anthology. After ten years, freeware.
I always thought that "Hoary Hedgehog" had a nice ring to it. I wonder why they didn't use that. That name wasn't taken, was it?
That doesn't matter, dude. The CPU is made of sand. Sand won't burn no matter how hot it gets. In fact, some people use sand to put out fires. This problem is related to the batteries.
On the other hand, I wonder how much heat from the CPU makes it to the batteries. The heat sink is usually fairly close to the battery comparment, with the exhause air port usually begin in the back (where most batteries are).
Please note the defenition of "rootkit," ripped from the beginning of the rootkit wikipedia article:
If it looks like a duck, quacks like a duck, yada yada yada.
No no no.
They were in the 8th dimension, and they developed their own oscillation overthruster, which they used to escape.
On a more serious note, the tags for this article seem rather negative about Roland Piquepaille. Can anybody explain this? Is he an accomplice of Hans Reiser or something?
For what it's worth, I thought that your post was somewhat on the insightful (or at least interesting) side. Whoever modded you as flamebait is a himself an idiot.
Anyways, the average user of Firefox is a lot less likely to "punch the monkey." That does not mean that they spend less money. They just spend less money on herbal viagra.
Yes, there IS something else. You have a team of people making processors for everybody. The current cutting-edge processor designs will, with some minor modifications, eventually cover everything from the top-of-the-line processor to (in a year or two), the basic budget box (with some cache chopped out and the multiplier locked). The one-time cost can be spread out over hundreds of thousands or millions of units.
With music, on the other hand, is much more limited (with maybe the exception of a few super-stars). I have some bands that I like, and I buy their music). You, on the other hand, probably will not like the same bands. For many artists, selling 20,000 albums is a big deal. If the artist makes $1 and album, they are still in poverty if they make one album a year. This is assuming a solo album. If it is a band, the money is split among the band members.
No. Copyright MAKES capitolism.
In a world without copyrights, an artist makes and album and sells it for $15. You buy one copy, make a thousand copies and sell it for $5. You make a bundle even though you did no work, and the artist goes broke and never makes another album. Same story for books and movies. Capitolism means benefitting from your labor.
Copyright is SUPPOSED to be a balance. It encourages people to make creative works by guaranteeing them a period of monopoly. But, after the copyright term expires, the work enters the public domain where it benefits all. The idea is fine. The problem is that the "limited period" has almost turned into perpetual copyrights, which is bad for the public.
The cost of the music is not JUST the cost of distribution.
The guys making the music do not really do it as a hobby. They expect to be paid. Yes, you can get a microwave now for $30 when it used to cost $300. But that does not mean that a musician would be happy to make 1/10 of what he would have been paid 20 years ago.
I am also fully aware that major labels only pay their artists a mere pittance, and most artists make the money on tour. I wish it were otherwise, and perhaps it is with indie labels.
But the fact still remains that, in order to make an album, you have to pay employees to run the recording studio, you have to pay for the studio itself, you have to hire artists to make the cover art, etc.
Look at is this way: the manufacturing cost of a CD or DVD (with case) is less probably less than a dollar, yet people consider paying $30 for a videogame to be a bargain, and usually don't start bitching until the games hit $50 or more.
So, I have absolutely no problem paying a dollar per track for music that I like. The only things that I would change are the amount that the artists are paid, and to eliminate DRM forever.
We had the same sort of thing when DVD-R and DVD+R we duking it out. Now, we just buy a $35 burner that can handle both and use the cheapest media that we can find. Life goes on.
Me too confused.