Well, actually, octane rating reflects a gasoline's retardation of flame spread (propagation). A higher octane gas will reduce engine knock, which is caused by the ignition detonation occuring to fast/too soon, and attempting to drive the piston downward before it passes TDC.

The only reason high-performance engines benefit from high-octane fuel is because it allows for a higher compression ratio. The lowest octane that eliminates knock is adequate; anything higher is wasted. I guess the analogy is not too far off after all.

Larry
www.fineelectricco.com

Gee Whiz?

Impedance, Inductance and capacitance have a dramatic and direct effect on any type or kind of power or operational amplifiers function, and is a major point in the development of just about all components that use any form of amp. The small wires contained inside your amp do not pose any real threat to performance as they are only a couple inches long and further are well shielded by the components chassis.

Further, oxidation happens faster and more often on the crappy cables! The rest is obvious and moot.

I don’t know what your friend’s background really is, but I would venture a guess he works for Bose.

I have to add my fuel to the fire.

The cables do make a difference. As frequency changes, impedance changes, voltage changes, etc.... All the pieces of the pie are interconnected. Change one, and they all are effected. Some cables can add resistance at higher frequencies, and have high capacitance. All cables add some resistance. That is a fact. But the question is how much resistance and where? In some systems, you will be hard pressed to hear the difference between the cheap gimme cables, and the more expensive ones. In other systems it is easy discernable. We choose to err to the side of caution and always spec decent cables. $10-40 per cable for audio, $20-80 per cable for video(depending on length). Some clients choose more expensive cables, and we sell them. I have seen systems where changing out a low-grade S-Video cable made the picture better. Better to be safe than sorry.

On the fuel side.... Why is it that for a given length and quality(lets take 2 metre, analog audio, gamma geometry (or whatever your brand calls braided cable) that the same cable for a car costs 1/3-1/2 the price of the home audio version? Is it noise reduction? Cars are by far a noisier environment. Is it reliability? When was the last time your house made a sudden stop? Or, crossed a railroad track at 20 MPH? Car cables are engineered to have a better "grip". Is it the OFC content? Cars are exposed to a lot more moisture than a home(when was the last time you put your muddy feet on a piece of carpet on top of all your AV cables?. Is it the UL listing? The interconnect aren't run in the walls, and the home versions aren't rated for in-wall anyway. Is it the voltage? The gage is the same, the strand count is the same. The sources in cars are typically 1-5 volts on the pre-outs, similiar to home. So what is the difference in the home version that makes it twice as expensive?

Most expensive 6 foot car cable from Crutchfield:
[Link: crutchfield.com]

Most expensive 6 foot home cable from Crutchfield:
[Link: crutchfield.com]

6.6 foot car cable twisted pair, directional:
[Link: crutchfield.com]

6.6 foot home cable twisted pair, NOT directional:
[Link: crutchfield.com]



My theory: Cable manufacturers understand homeowners have deeper pockets.


Jason

This message was edited by PHSJason on 11/17/03 23:44.

RTI, it's not that you don't know what you're talking about, it's just that you don't know ENOUGH about what you're talking about. The formula for distributed inductance in cable is 2PiFL and for capacitance it's 1/2PiFC. You're L and C are on the order of 10 to the -12, that's a lot of zeroes. Your F as I'm sure you are aware is on the order of 10 to the +3. Unless your ear can distinguish differences of 10 to the -9 (here's a hint: you can't) you will not hear a difference. Enjoy your job at Best Buy.

The water pipe analogy is a good one that alot of people get wrong. It works when you are talking straight conductors but when you start talking coax and high frequencies things change due to the inductive capacitive properties. For the water pipe analogy if you run water at 70 psi through 100 feet of 12" inch pipe you will have more preasure at the sprinkler head then if you ran it through a 1" pipe. This is due to the fact that water flowing in 1" pipe is going to have a higher ratio of contact to the pipe surface which causes friction and turbulance which over a 100' pipe will result in a lower preasure at the sprinkler head, lower preasure=lower flow. Relate this to audio electronics substitute preasure for power which is wattage. This is similar to the scenario you mentioned with the smaller wire in the equipment. For short runs it will not have a big effect but run it over 100' of 22awg and you will not have much power left at your speaker lower wattage=less sound. There will be different effect over the frequency range of the audio. The bass will sound better with bigger cable but at high frequencies you will start to notice the effects of the capacitive and inductive properties of the cable.

Sorry Pro-ton but you are making up physics. The water pipe analogy is really only good for DC electricity and the better analogy is not a 12" pipe vs a 1" pipe but maybe 120' vs a 10' pipe. Does that make any difference at your theoretical sprinkler head? The answer, as if you didn't alredy guess, is no, not very much. Just look at how much power is delivered from Hoover Dam via 1" wire to Los Angeles. We're talkin' megawatts, baby.

Annie
Making up physics?!? I think not! It may not be a true equal comparison but the physics are correct. And I do beleve I eluded to the fact that it really only applies to DC. Maybe you should read it again. Or you can wait for some one else to add to this thread and take a shot at them. Ok go out to the garage and try this for an analogy, put a 28awg wire accross your car battery and see what happens then drop a 3/4" wrench accross it and see what happens. Either way the current/power will be dissipated as heat it is a question of where will that happen. Power/wattage is equal to current squared times voltage. In the Hoover Dam scenario they use high voltage low current. I don't know exactly the voltage etc. In a home stereo high current and low voltage is used to produce the crisp clean HiFi audio we all love. I am actually one of the sceptics of high dollar cables. I can't beleve the money some people spend on it. For my customers I use good but not outragously expensive cable. I am also very sceptical of the monster power strips. Sure they may take out some noise but I would bet none of that would make it into your audio or video.

WHOAAA.....hold on to your lug nuts!!!

Hey,

This is SOOO much more than I anticipated, but I love it! I thought I knew alot about this topic, but my knowledge in this area is apparently just starting to scratch the surface.

Maybe I could start another thread on this, but I'm curious, some of you have SO much knowledge of physics, and protons, and general stuff, I'm curious what everyone has done PRIOR to A/V, or your backgrounds.

It never ceases to amaze me the true DEPTH of knowledge and education we have in this industry, and just how bright some of us (you) are!

So....what do you do when you're not playing with A/V toys?

avdude

This message was edited by avdude on 11/18/03 23:33.

avdude
My past experience was most helpful in this thread. I started in electronics in the Navy the first two and a half years going to school 8-12 hours a day the next three and a half years I spent working on everything from crypto eqpt to shipboard cable systemsn and going to more school. After that I worked for a test equipment manufacturer, for a total of 7 years, as a technician then as a component engineer while taking engineering classes. Before starting my business I worked for 4 years in my brothers business as a (beleve it or not) certified sprinkler system designer. I missed the electronics so I am back.

Annie, you obviously haven't actually heard a high end system, and thus haven't experienced the difference interconnects and cables can make.

I'd probably know a lot more about this subject if I had any customers who even remotely qualify as audiophiles. Heck, *I* don't even qualify. Whether the sound quality is a 9.8 or a 9.9 doesn't matter as long as ease of use is a 10. I've installed systems with everything from Monster Interlink Jr. to Tara Labs, and never got a more wood from one or the other.

But it IS a part of our job to know the difference, whether we implement it or not. This thread has been helpful to me in that respect. Thank you.

- Doug

This message was edited by deb1919 on 11/19/03 07:46.

OK, Pro-ton. I put the 24awg across the battery and it melted. I put the wrench across the battery and it got real hot. Now, what exactly was that supposed to prove? I agree that enough current in one direction will cause metal migration to occur. A dead short across a car battery is not a very good analogy for a high end speaker system. I did re-read your original post and you are correct, you did alude to the fact that the water pipe is a DC system. I just wanted to clarify for other readers because the water pipe analogy is widely misused. It really applies more to FREQUENCY capacity than CURRENT capacity. Don't get me wrong though, I'm not saying that Monster or other expensive cables aren't better, I'm just saying they are unnecessary for our application. Anybody who tells me they can absolutely hear the difference will have the privelege of buying them from me at $100 a pop. Sirround, you are also correct in that I have not had the opportunity to do a true double blind test. I would love to try it. I'm a little skeptical however because I've heard that while expensive cables really can't improve performance they can be made to sound "DIFFERENT". Much like turning up the blue gun on the TVs you want to unload in your showroom or Bose putting in a tube to distort the bass. Joe consumer will actually notice a difference and believe one is better than the other when, in fact, it may be the other way around.

I have read the different opinions on this subject, and now for my experience (or 2 cents).
The cables you get in the box work, are they good? Not really. First, if you are doing any kind of system that has to be put into a rack or cabinet, chances are they may not be the right size. Second, it is rare to find shielded cables that come with equipment. With all the other cables and power cords going behind the equipment, you should have shielded cables - your systems may not need them all the time but it doesn't hurt to be cautious. Third, how many trips back for sevice do you want to make? The cheapy cables typically have cheap ends and are not reliable connections, the client moves the DVD to clean under it and the audio connections fall off. He isn't going to want to pay you for a sevice call to re connect cables that in his mind shouldn't have fallen off.
Next, the debate about how much of a difference better cables make for sound and picture.
The picture side is easy, you can see the difference.
Cheap cables can cause the picture to look grainy, a halo effect and many other issues. This is something easy to test in your showrooms or at home. Even S-video cables are not all the same. The better the display the easier it is to pick out the difference. Keep in mind the picture is only as good as the source. There are lots of places to find out about good test material, even this site should have a thread somewhere about this.
The audio side is not so easy. In most basic systems good interconnects "can" help. Things to listen for would be better base response and the "sound stage" should open up a little more. Not all systems will sound different, you may aready be getting all that it can do. As you move up to higher end gear and high end speakers the effects can actually be dramatic. Anyone that has had to chance to play with equipment like Wilson/JM Labs/MBL/Martin Logan/Mark Levinson/Boulder/Theta and the many other exotic brands will know first hand about the wow factor of using expensive cables and speaker wire.
Keep in mind, and most that know will agree, it's all relative to the capabilities of the equipment.
It's also a sale, if you are trying to offer your client a system that is easy to use and reliable then cables that are good and the right length (or custom made)add to the value of his system and your bottm line.

Annie
The battery analogy was more of a joke but it sorta had a point. My guess is the 28 gauge wire would melt and with the wrench the battery would melt. But I am not about to try it. The point is where do you want your power to be used? By the wire or the speaker? The rest of what you said in your last post I totally agree with. I am also not totally sold that speaker wire that has more strands is better then less. It seems to me a 14 gauge solid wire would have less effect on high frequencies then a multi stranded wire. Of course it is not practical to pull solid wire through walls etc.

Heres my two pence;

I do not work for and am not an agent for QED but this report is excellent

[Link: qed.co.uk]

Most of my customers want a cable that "looks" like it does the buisness.They just want hifi jewellery.

cheap cables are often very poorly constucted so are most free in the box cables it makes sense to upgrade to sensible well constructed reasonably priced cables.

one dealer (Russ Andrews) suggests you spend 80% of your budget on cables!(guess what they sell) My opinion is that is just silly.
I would definately have a £400 DVD player with a £100 cable rather than a £100 DVD player with a £400 lead.

Gilbert Briggs was the original engineer at Wharfedale speakers and his phrase "the more you open the window the more muck blows in" is quite true .Better equipment does reveal more and a cables effect can be heard and seen .But on cheap equipment it cant make a silk purse out of a pigs ear.Thats what most customers want and the cable companys suggest they do.

The Optical cable as mentioned on other posts in my opinion is the biggest cable con. We have become used to thicker is better but optical fibres have to be narrow enough to keep the angles below the critical angle for total internal reflections to occur.so most of the thickness on expensive optical cables is just plastic covering.I have NEVER heard ANY difference in ANY optical cable ever.

bob