There isn't much of a point in educating those people, considering that you can't even get a job at McDonalds with a felony conviction on your record. Absolutely no one wants to hire people who have a criminal record, so about the only thing the criminals have left is a life of crime. I find it amazing that the rate of recidivism is only 70% or so. Maybe we just aren't able to catch the other 30%.
Writing an article about the security hole that doesn't give much details would not count as exploiting it. Writing a working virus is certainly an exploit (and should be highly illegal). What you are saying is that breaking into someone's house is OK because someone else could have done it, too. It's not OK, even if you are simply letting the owner know that their lock is not that good.
The security problem is more a legal problem than a technological problem. A typical house lock is extremely easy to pick and is there mainly to keep honest people honest. What we really need is more active enforcement of the computer crime laws we already have. If we put a lot of script kiddies and exploit writers behind bars, we won't need to worry as much about security.
I almost never lock my door. The crime rate where I live is very low, and many people leave their doors unlocked. When you have to lock your door to avoid burglaries, you have a crime problem.
If jackasses like him weren't exploiting security holes, there wouldn't be a need to find them. It's rather sad that the current state of computing is analogous to having to put bars on bulletproof windows just to avoid having some asshat break in.
See that biggest speaker at the base of your huge speaker tower? That's pretty much doing the job of a subwoofer.
Wrong. The subwoofer is doing the job of those two speakers. Which means that instead of stereo sound, you get mono sound, for one. I've yet to see a subwoofer system that has good bass imaging. It's got bass, but you can almost always tell that it's coming from the subwoofer and not the speakers. In my experience, the assumption that bass is non-directional does not hold at all for frequencies above about 50Hz. Basically, a subwoofer will ruin any stereo imaging your system had.
Audio design is more of an art-form than an engineering craft.
It's a combination of both. If you don't follow engineering practices, you will never end up with a good speaker. Of course, a properly engineered speaker is not guaranteed to sound good.
I've also heard multi-thousand-dollar towers which sound like shit
Price does not equal quality. In general, any speakers you can buy at Circuit City are not going to sound that great.
I've heard "bookshelf + subwoofer" systems that sound absolutely fantastic when reproducing classical music.
That would be because most classical music does not have a lot of bass. If you listen to music that does, you will probably find it rather muddy.
Where are you getting this BS from? "Interference patterns" are good; they make the sound more natural. What do you think happens when sound waves bounce off of walls and stuff?
Subwoofers cause lots of problems. For one, you have to match crossover frequencies perfectly (and not have them set too high). For two, you have to match the speaker output so you get a flat response. Of course, if the crossover frequency is sufficiently low, you won't get any cost benefits from using a sub, because the other speakers will need to go fairly low (bass is directional down to about 70Hz).
Again, it's basically a cost compromise. If you can't afford to have two speakers with good bass response, you buy a subwoofer. In practice, this solution is notably inferior because the bass from the subwoofer is still somewhat directional and you ruin the imaging.
Actually, it's mostly a bad idea. Pipelining is great when it works, but there are many buggy servers out there which it totally breaks. This is perceived as a webpage that only partially loads. For instance, I've had trouble using some intranet apps (Peoplesoft crap) with Mozilla which worked fine with Firefox. It turned out that turning off pipelining in Mozilla fixed the problem. This is most likely why it is shut off in Firefox.
I'm not saying classical music doesn't have bass, I'm saying that a high-end sound system will not have a subwoofer. Subwoofers are a low-cost compromise between having large speakers with good bass and having small speakers with no bass. The bass a subwoofer produces is almost always muddy, boomy, and mismatched. It's OK if you are listening to hip-hop or movie explosions, it's not OK if you are listening to anything else.
Whatever. Good bass sounds good. Of course, if you are listening to classical music on a system that includes a subwoofer, you bought the wrong system. If the speaker has a flat response and lots of bass, it will sound good with any music. If it doesn't have bass, it will sound thin and puny. Of course, some types of music don't have much bass, but you still want it to be audible.
Here's a simple solution to that dilemma: DON'T TAILGATE. I'd be more concerned about the system doing something stupid, like braking on a sharp turn because it sees a tree or a car on the side of the road or something. That would really be dangerous.
For well-under $500 I certainly could put together a nice fanless mini-ATX PC.
Care to try? Make sure it is at least comparable to the G4 (i.e. Intel or AMD processor, none of that VIA crap). Also, be sure to include 256 megs of DDR RAM, a hard drive, a DVD/CD-RW drive, and a case that is roughly the same size as the Mini. I am pretty sure you won't even be able to build one for under $500, much less make it fanless or the same size as the Mac.
Whatever. You really don't learn enough in a BS program to do VLSI design. You can make it up with experience, but experience (i.e. making errors) is a very slow and expensive way to learn. Someone who managed to complete a PhD from a decent program is guaranteed to have quite a bit of knowledge and dedication -- unlike a BS, you can't just drink your way through a PhD.
It very much depends. The FCC definitely does monitoring, and they usually get pretty pissy about pirate stations. Even a low power station like this can easily be picked up with good equipment and a directional antenna. I'm sure the pirate radio station in your case has a few friends in the local FCC bureau.
Even 0.3W is a gross violation of FCC rules. If you build something more powerful, I can assure you that you will not stay out of trouble for very long.
While THD isn't the only spec to consider, it is a reasonable rule of thumb that low distortion is a good thing.
Nobody is arguing here. I'm not one of those who believes that 2nd harmonic distortion somehow improves music -- it doesn't. But given that tube amplifiers with 2% distortion don't sound distorted, the only conclusion that can legitimately be drawn is that THD should be under 3% or so.
The problem with THD measurements is that they do not represent in any way HOW a component affects the signal. It's like judging the quality of a compressed sound file by comparing bitrates. MP3 compression sounds a lot better than, for instance, downsampling the original to a lower sampling rate. Even though they both may have the same bitrate, one sounds a lot better than the other.
It's because natural sounds generally don't have the higher odd-order harmonics, and that's what our ears have evolved with.
Or perhaps it's because the speakers and/or the ears generate low-order harmonics and the brain filters them out?
This has all been studied comprehensively for the last 70 or so years, and is no mystery to anyone who has studied the psychoacoustic elements of audio engineering.
If it was studied comprehensively, we wouldn't be arguing about this stuff today. The thing is, we still don't know exactly how the human brain processes audio. Without this knowledge, we can only guess and use rules of thumb.
Wrong, this is precisely what you SHOULDN'T do when comparison testing, unless you have thoroughly matched the gain of the amplifiers under test to less than 0.5dB.
Why? The idea behind hi-fi is realism. If an amplifier makes a piano sound like a real piano, who cares what the volume is set to? When comparing equipment, you should interact with it and find out what it's capable of. If you just set the amplifiers to the same volume, you are probably missing the "sweet spot" on all of them.
I once "proved" an Aiwa 3-in-one was superior to a Krell to a recording studio owner
Maybe there just isn't much difference between them? The Krell might have the same circuit as the Aiwa boombox, with somewhat better parts. The distortion profiles are usually pretty similar for similar topologies, and some of the integrated chips have surprisingly good specifications.
*Its a particular quality of "bad" that some people like, but it isn't "high fidelity", especially after modern mastering.
I am quite familiar with Douglas Self's writings and do not think much of him. His essay on subjectivism is so full of serious errors that it's not even funny. He ignores the fact that hi-fi systems are intended for humans, not THD meters. He uses results from scientific papers as absolute facts, without appropriately qualifying them or even describing the experiment methodology. His philosophy is not scientific, it's simply stupid. He is like a blind man who tries to argue about picture quality of different TV sets.
It's a circuit board and a cable. The costs are negligible in either USB's or Firewire's manufacture; the cost was in the initial implementation in hardware and software.
It's pretty obvious you have never done any hardware design. USB supports 1.5Mbps; AFAIK, minimum speed on Firewire is 400Mbps. This means the cables, boards, connectors, and chips have to be about 10x the price. This means it's completely impossible to make $5 mice/keyboards/joysticks for Firewire (unless you want a $50 mouse with a 1/4 inch thick cord).
They designed USB to require an Intel processor to operate. That simply wasn't necessary, and it slowed the actual data rate a great deal.
Where are you getting this shit from? There is absolutely nothing in USB that requires an Intel processor (not to mention slowing down the data rate). There are USB ports on Macs, Playstation 2s, and lots of other things.
Yet a Celeron costs less than the old 486SX.
A 486SX costs a hell of a lot less than any Celeron if it's fabricated with a modern process. Intel could probably make 486s for less than $5 now if there was demand for them.
Remember, we had to wait a long time before USB2. We were putting up with pokey speeds on bloody everything.
IMO, the only peripheral where USB1.1 speed is way too slow is a hard drive or a DV camcorder. 12Mbps is plenty for a webcam, it's just that it's hard to make a good webcam for $20. It's more than enough for printers, most low-end scanners, network adapters, and so on.
Anyway, Firewire was never designed as a general-purpose peripheral bus. It was always intended strictly for high-speed stuff. Now granted, it may have become more popular if it was standard on PC motherboards. But you still can't blame Intel for it, since there were always at least 3 chipset manufacturers and several dozen motherboard manufacturers. The real reason Firewire wasn't integrated is that there wasn't much demand for it.
GPL is extremely UNfree, as it forces them to go down a road they normally don't want to go, against their will (open their source)
That would be UNfree as in beer. Nobody is twisting their arm. If they use GPLed code, they either agreed to abide by the GPL or are violating copyright. They actually get off pretty easy doing that, since there have never been any damages awarded. Try including an unlicensed copy of Windows with a product and see how much better off you will be.
You can brand them all as "evil" or "idiots" with in your cute little religion, but since it's due to them that most coders here on/. and elsewhere have a coding job (as opposed to coding hobby), doing so would be extremely infantile.
You are basically saying that stealing code is OK if it's GPL code, since you don't like the GPL. Now THAT is extremely infantile.
Where are you idiots coming from? There is nothing viral about the GPL. It's not any more viral than any other license: if you incorporate someone else's code into your program without respecting the license, you are violating their copyright and are liable for damages. The GPL isn't any different, except for a way to legally use someone else's code. Nobody can make you release your code against your wish.
Firewire does not require a CPU, ie a PC, to mediate file transfers.
This is irrelevant in most cases (unless you are transferring data between peripherals). The advantage of the USB approach is that the everything is considerably simpler and cheaper.
They did not exactly like Apple making a new standard.
How exactly does Intel (or Microsoft, for that matter) profit from USB being the standard? It was just that Firewire was considerably more expensive than USB to implement -- both on the host and on the peripheral side. To this day, the only popular Firewire peripherals I know of are DV camcorders.
As a result, to this day Firewire still hasn't hit the magic numbers to drop the cost down to parity with USB.
Maybe that's because the complex protocol makes everything expensive while offering few advantages?
Take two stereo's. One has 0.005% THD and the other has 0.1% THD. Do a side by side test, but have the 0.1% reciever set 3 DB louder. Guess which sounds better?
Just to clear up a popular misconception: THD has very little to do with the perceived quality of an amplifier. There are many different types of distortion, and humans are not equally sensitive to all of them. It's difficult to hear 1% THD if it's mostly 2nd and 3rd harmonic distortion, but 0.2% THD of mostly 7th harmonic will sound nasty. This probably has something to do with how the human ear operates.
Second, any amplifier should be evaluated at several volume settings. This prevents this type of issue.
Many car audio enthusiasts have amplifiers that require kilowatts of power. That means hundreds of amps. You need something about as thick as welding cable for running hundreds of amps. Look at some automotive jumper cables sometime. Even the cheap ones are about a 1/4 inch thick.
Well, actually, SPDIF requires 6MHz bandwidth. As far as the 75 ohm impedance: I didn't pull it out of my ass, it's specified by the relevant standard (IEC958), and it's not some kind of audiophile debate. Basically, it's the impedance of standard TV coax. Pick up any book about radio and read about impedances. Here's a link to a short description of SPDIF, in case you are curious: here.
As for your link: don't believe everything you read. The Audioholics article shows many gross misunderstandings. For instance, the reason direction is marked on some high-end cables is for optimal grounding, not because cable manufacturers don't know audio is AC. Also, they seem to have failed physics when they claim that a battery cannot do anything if the circuit is not complete. Ever hear of FETs?
Cable quality certainly makes a difference for just about any application, including audio. Even a "digital" protocol like USB imposes a number of requirements on the cable quality. Cable quality for sensitive analog signals is even more critical. If you have a few hundred thousand dollars' worth of test equipment, you can probably quantify the differences, calculate bit error rates, and so on. It's easier to just listen, though.
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I don't see this as bad at all. They're in prison for a reason. Why should the tax payers be footing the bill for this?
RTFA. The inmates paid for the system and the games (it was bought on profits from the prison commissary).
There isn't much of a point in educating those people, considering that you can't even get a job at McDonalds with a felony conviction on your record. Absolutely no one wants to hire people who have a criminal record, so about the only thing the criminals have left is a life of crime. I find it amazing that the rate of recidivism is only 70% or so. Maybe we just aren't able to catch the other 30%.
Writing an article about the security hole that doesn't give much details would not count as exploiting it. Writing a working virus is certainly an exploit (and should be highly illegal). What you are saying is that breaking into someone's house is OK because someone else could have done it, too. It's not OK, even if you are simply letting the owner know that their lock is not that good.
The security problem is more a legal problem than a technological problem. A typical house lock is extremely easy to pick and is there mainly to keep honest people honest. What we really need is more active enforcement of the computer crime laws we already have. If we put a lot of script kiddies and exploit writers behind bars, we won't need to worry as much about security.
I almost never lock my door. The crime rate where I live is very low, and many people leave their doors unlocked. When you have to lock your door to avoid burglaries, you have a crime problem.
If jackasses like him weren't exploiting security holes, there wouldn't be a need to find them. It's rather sad that the current state of computing is analogous to having to put bars on bulletproof windows just to avoid having some asshat break in.
See that biggest speaker at the base of your huge speaker tower? That's pretty much doing the job of a subwoofer.
Wrong. The subwoofer is doing the job of those two speakers. Which means that instead of stereo sound, you get mono sound, for one. I've yet to see a subwoofer system that has good bass imaging. It's got bass, but you can almost always tell that it's coming from the subwoofer and not the speakers. In my experience, the assumption that bass is non-directional does not hold at all for frequencies above about 50Hz. Basically, a subwoofer will ruin any stereo imaging your system had.
Audio design is more of an art-form than an engineering craft.
It's a combination of both. If you don't follow engineering practices, you will never end up with a good speaker. Of course, a properly engineered speaker is not guaranteed to sound good.
I've also heard multi-thousand-dollar towers which sound like shit
Price does not equal quality. In general, any speakers you can buy at Circuit City are not going to sound that great.
I've heard "bookshelf + subwoofer" systems that sound absolutely fantastic when reproducing classical music.
That would be because most classical music does not have a lot of bass. If you listen to music that does, you will probably find it rather muddy.
Where are you getting this BS from? "Interference patterns" are good; they make the sound more natural. What do you think happens when sound waves bounce off of walls and stuff?
Subwoofers cause lots of problems. For one, you have to match crossover frequencies perfectly (and not have them set too high). For two, you have to match the speaker output so you get a flat response. Of course, if the crossover frequency is sufficiently low, you won't get any cost benefits from using a sub, because the other speakers will need to go fairly low (bass is directional down to about 70Hz).
Again, it's basically a cost compromise. If you can't afford to have two speakers with good bass response, you buy a subwoofer. In practice, this solution is notably inferior because the bass from the subwoofer is still somewhat directional and you ruin the imaging.
Actually, it's mostly a bad idea. Pipelining is great when it works, but there are many buggy servers out there which it totally breaks. This is perceived as a webpage that only partially loads. For instance, I've had trouble using some intranet apps (Peoplesoft crap) with Mozilla which worked fine with Firefox. It turned out that turning off pipelining in Mozilla fixed the problem. This is most likely why it is shut off in Firefox.
I'm not saying classical music doesn't have bass, I'm saying that a high-end sound system will not have a subwoofer. Subwoofers are a low-cost compromise between having large speakers with good bass and having small speakers with no bass. The bass a subwoofer produces is almost always muddy, boomy, and mismatched. It's OK if you are listening to hip-hop or movie explosions, it's not OK if you are listening to anything else.
Whatever. Good bass sounds good. Of course, if you are listening to classical music on a system that includes a subwoofer, you bought the wrong system. If the speaker has a flat response and lots of bass, it will sound good with any music. If it doesn't have bass, it will sound thin and puny. Of course, some types of music don't have much bass, but you still want it to be audible.
Here's a simple solution to that dilemma: DON'T TAILGATE. I'd be more concerned about the system doing something stupid, like braking on a sharp turn because it sees a tree or a car on the side of the road or something. That would really be dangerous.
For well-under $500 I certainly could put together a nice fanless mini-ATX PC.
Care to try? Make sure it is at least comparable to the G4 (i.e. Intel or AMD processor, none of that VIA crap). Also, be sure to include 256 megs of DDR RAM, a hard drive, a DVD/CD-RW drive, and a case that is roughly the same size as the Mini. I am pretty sure you won't even be able to build one for under $500, much less make it fanless or the same size as the Mac.
Whatever. You really don't learn enough in a BS program to do VLSI design. You can make it up with experience, but experience (i.e. making errors) is a very slow and expensive way to learn. Someone who managed to complete a PhD from a decent program is guaranteed to have quite a bit of knowledge and dedication -- unlike a BS, you can't just drink your way through a PhD.
Don't refer to RFCs. This is not an IETF matter, it's a legal matter. RFCs have no bearing towards the legal standing of a crawler bot.
It very much depends. The FCC definitely does monitoring, and they usually get pretty pissy about pirate stations. Even a low power station like this can easily be picked up with good equipment and a directional antenna. I'm sure the pirate radio station in your case has a few friends in the local FCC bureau.
Actually, on ham bands, you cannot legally broadcast -- unless it's an emergency. You have to actually be talking to someone.
Even 0.3W is a gross violation of FCC rules. If you build something more powerful, I can assure you that you will not stay out of trouble for very long.
While THD isn't the only spec to consider, it is a reasonable rule of thumb that low distortion is a good thing.
Nobody is arguing here. I'm not one of those who believes that 2nd harmonic distortion somehow improves music -- it doesn't. But given that tube amplifiers with 2% distortion don't sound distorted, the only conclusion that can legitimately be drawn is that THD should be under 3% or so.
The problem with THD measurements is that they do not represent in any way HOW a component affects the signal. It's like judging the quality of a compressed sound file by comparing bitrates. MP3 compression sounds a lot better than, for instance, downsampling the original to a lower sampling rate. Even though they both may have the same bitrate, one sounds a lot better than the other.
It's because natural sounds generally don't have the higher odd-order harmonics, and that's what our ears have evolved with.
Or perhaps it's because the speakers and/or the ears generate low-order harmonics and the brain filters them out?
This has all been studied comprehensively for the last 70 or so years, and is no mystery to anyone who has studied the psychoacoustic elements of audio engineering.
If it was studied comprehensively, we wouldn't be arguing about this stuff today. The thing is, we still don't know exactly how the human brain processes audio. Without this knowledge, we can only guess and use rules of thumb.
Wrong, this is precisely what you SHOULDN'T do when comparison testing, unless you have thoroughly matched the gain of the amplifiers under test to less than 0.5dB.
Why? The idea behind hi-fi is realism. If an amplifier makes a piano sound like a real piano, who cares what the volume is set to? When comparing equipment, you should interact with it and find out what it's capable of. If you just set the amplifiers to the same volume, you are probably missing the "sweet spot" on all of them.
I once "proved" an Aiwa 3-in-one was superior to a Krell to a recording studio owner
Maybe there just isn't much difference between them? The Krell might have the same circuit as the Aiwa boombox, with somewhat better parts. The distortion profiles are usually pretty similar for similar topologies, and some of the integrated chips have surprisingly good specifications.
*Its a particular quality of "bad" that some people like, but it isn't "high fidelity", especially after modern mastering.
I am quite familiar with Douglas Self's writings and do not think much of him. His essay on subjectivism is so full of serious errors that it's not even funny.
He ignores the fact that hi-fi systems are intended for humans, not THD meters. He uses results from scientific papers as absolute facts, without appropriately qualifying them or even describing the experiment methodology. His philosophy is not scientific, it's simply stupid. He is like a blind man who tries to argue about picture quality of different TV sets.
It's a circuit board and a cable. The costs are negligible in either USB's or Firewire's manufacture; the cost was in the initial implementation in hardware and software.
It's pretty obvious you have never done any hardware design. USB supports 1.5Mbps; AFAIK, minimum speed on Firewire is 400Mbps. This means the cables, boards, connectors, and chips have to be about 10x the price. This means it's completely impossible to make $5 mice/keyboards/joysticks for Firewire (unless you want a $50 mouse with a 1/4 inch thick cord).
They designed USB to require an Intel processor to operate. That simply wasn't necessary, and it slowed the actual data rate a great deal.
Where are you getting this shit from? There is absolutely nothing in USB that requires an Intel processor (not to mention slowing down the data rate). There are USB ports on Macs, Playstation 2s, and lots of other things.
Yet a Celeron costs less than the old 486SX.
A 486SX costs a hell of a lot less than any Celeron if it's fabricated with a modern process. Intel could probably make 486s for less than $5 now if there was demand for them.
Remember, we had to wait a long time before USB2. We were putting up with pokey speeds on bloody everything.
IMO, the only peripheral where USB1.1 speed is way too slow is a hard drive or a DV camcorder. 12Mbps is plenty for a webcam, it's just that it's hard to make a good webcam for $20. It's more than enough for printers, most low-end scanners, network adapters, and so on.
Anyway, Firewire was never designed as a general-purpose peripheral bus. It was always intended strictly for high-speed stuff. Now granted, it may have become more popular if it was standard on PC motherboards. But you still can't blame Intel for it, since there were always at least 3 chipset manufacturers and several dozen motherboard manufacturers. The real reason Firewire wasn't integrated is that there wasn't much demand for it.
GPL is extremely UNfree, as it forces them to go down a road they normally don't want to go, against their will (open their source)
/. and elsewhere have a coding job (as opposed to coding hobby), doing so would be extremely infantile.
That would be UNfree as in beer. Nobody is twisting their arm. If they use GPLed code, they either agreed to abide by the GPL or are violating copyright. They actually get off pretty easy doing that, since there have never been any damages awarded. Try including an unlicensed copy of Windows with a product and see how much better off you will be.
You can brand them all as "evil" or "idiots" with in your cute little religion, but since it's due to them that most coders here on
You are basically saying that stealing code is OK if it's GPL code, since you don't like the GPL. Now THAT is extremely infantile.
Where are you idiots coming from? There is nothing viral about the GPL. It's not any more viral than any other license: if you incorporate someone else's code into your program without respecting the license, you are violating their copyright and are liable for damages. The GPL isn't any different, except for a way to legally use someone else's code. Nobody can make you release your code against your wish.
-USB is not. At least last I heard.
USB is royalty-free.
Firewire does not require a CPU, ie a PC, to mediate file transfers.
This is irrelevant in most cases (unless you are transferring data between peripherals). The advantage of the USB approach is that the everything is considerably simpler and cheaper.
They did not exactly like Apple making a new standard.
How exactly does Intel (or Microsoft, for that matter) profit from USB being the standard? It was just that Firewire was considerably more expensive than USB to implement -- both on the host and on the peripheral side. To this day, the only popular Firewire peripherals I know of are DV camcorders.
As a result, to this day Firewire still hasn't hit the magic numbers to drop the cost down to parity with USB.
Maybe that's because the complex protocol makes everything expensive while offering few advantages?
Take two stereo's. One has 0.005% THD and the other has 0.1% THD. Do a side by side test, but have the 0.1% reciever set 3 DB louder. Guess which sounds better?
Just to clear up a popular misconception: THD has very little to do with the perceived quality of an amplifier. There are many different types of distortion, and humans are not equally sensitive to all of them. It's difficult to hear 1% THD if it's mostly 2nd and 3rd harmonic distortion, but 0.2% THD of mostly 7th harmonic will sound nasty. This probably has something to do with how the human ear operates.
Second, any amplifier should be evaluated at several volume settings. This prevents this type of issue.
Many car audio enthusiasts have amplifiers that require kilowatts of power. That means hundreds of amps. You need something about as thick as welding cable for running hundreds of amps. Look at some automotive jumper cables sometime. Even the cheap ones are about a 1/4 inch thick.
Well, actually, SPDIF requires 6MHz bandwidth. As far as the 75 ohm impedance: I didn't pull it out of my ass, it's specified by the relevant standard (IEC958), and it's not some kind of audiophile debate. Basically, it's the impedance of standard TV coax. Pick up any book about radio and read about impedances. Here's a link to a short description of SPDIF, in case you are curious: here.
As for your link: don't believe everything you read. The Audioholics article shows many gross misunderstandings. For instance, the reason direction is marked on some high-end cables is for optimal grounding, not because cable manufacturers don't know audio is AC. Also, they seem to have failed physics when they claim that a battery cannot do anything if the circuit is not complete. Ever hear of FETs?
Cable quality certainly makes a difference for just about any application, including audio. Even a "digital" protocol like USB imposes a number of requirements on the cable quality. Cable quality for sensitive analog signals is even more critical. If you have a few hundred thousand dollars' worth of test equipment, you can probably quantify the differences, calculate bit error rates, and so on. It's easier to just listen, though.