rcaudio, I bought some of the flat monster cable for an under carpet run in my bedroom. It was much thicker than I expected after it was installed. I put it under the carpet and pad and then re-ran it between the two. I could still feel it if I walked over the spot where it was (which was right by the door. . . ). Maybe a better quality pad/carpet would eliminate the problem. I decided to bite the bullet and run in-wall wiring and get rid of the flat cable all together. For me, it was definitely the way to go.

If you are in a house where you can run in wall wire, I would suggest it from my own personal preference. Unless the area where you run the flat cable will be seldom if ever trod upon, in which case it would probably work wonders and be the easiest.

Just trying to help out and save a few bucks (and hours) if your situation was anything like mine.

S.

This is what Mr. Dunlavy wrote about his own interconnects;
With respect to interconnect cables, the best-quality ( but modestly priced) ones sold by Radio Shack are among the very best we have measured and used. You can spend a lot more and, believe it or not, get a lot less with respect to such important attributes as capacitance, shielding, mechanically induced noise (piezo-electric properties), etc. Sure, we have designed and sell interconnect cables that are without peer, with respect to important electrical properties, but they are no better, audibly, than the Rat-Shack types within most systems.
Found this here;
http://home.austin.rr.com/tnulla/dunlavy9.htm

Gotta point this out:



Sorry, but - if a deaf person guessed they would be expected to score 50% in this test. Like guessing heads or tails without looking. A significant figure HIGHER than 50% indicates a difference is heard. And just as more trial runs will bring your score closer to 50% on coin flipping, so to here.

Just so my bias is known, I think the high end cable stuff is mostly snake oil. In a low impedence high (relatively speaking) current circuit like the power amp to speaker connection, assuming sane cable lengths, I've never seen (on an instrument) or heard any difference not attributable to the power of suggestion.

The locking rca gizmos outlaw sells are nifty though I doubt there is an audible improvement.

For audio interconnects I'm on the fence - I can imagine that in this case sheilding etc. COULD do something for you, but I doubt it would amount to much.

For video I start to believe cables would be of value, but most video cables are rg59 anyway.

For digital - it's a joke, right? Nobody really thinks a better one or zero matters, do they? Please say it isn't so!

Charlie

There is a chance that a digital cable could be so bad as to actually drop bits. I doubt any commercially available cables are *that* bad, though, unless you're running a cable with totally off the wall characteristics.

I wonder if you could use the old 10base2 cables for SP/DIF audio... If I remember right, those were 50 ohm coax, which should be close enough for short distances... Hmm...

I have always had an interest in electronics, and have long been a tinkerer. I was an EE major for a while (though I wound up in the IT profession), and I believe I have a pretty good grasp of at least the fundamentals of electronic circuits.

There's a basic fact: no wire is perfect. Any wire will have some resistance, capacitance, etc. that becomes a part of the circuit. And those effects will be different from one type of wire to the next... the materials, the construction, the geometry, all make a difference. So it's not a stretch to say that one wire can have better characteristics than another for a given application.

But are those differences audible? You bet! I've observed it myself. But that does not mean that you have to spend huge bucks to get good-sounding cables. In fact, I'm sure that there IS a lot of snake-oil in the audio cable industry.

Being a DIY-er, I constructed my speaker cables out of CAT5 network cable, using a design based on this design . These cables are vastly better than the Monster cables I was using before. And I spent quite a bit more for the Monsters.

Of course, you could say that my opinion is biased because I made them myself. But I took those cables to try them on my friend's very expensive, very high-end audio system that has comperably high-end speaker cables. My audiophile friend and I did A/B comparisons, and found that while the super-expensive cables were better, my CAT5 ones were nearly as good.

As far as (line-level) interconnects, I havn't done much experimenting yet. But the DIY articles on the TNT audio have some generally sane discussion on interconnects.

With my background in both computers and electronics, I have always been very skepical that a digital audio connection can be affected by the cable. After all, "bits is bits", right? How can one CD transport sound different than another, when all it has to do is read the numbers off the CD and spit them out the digital connection? I've done a bunch of reading, and some experimenting, on the matter.

Yes, it's jitter that is the culprit. With digital systems, you'll have a "clock", which is basically a signal that goes "on off on off on off..." regularly at a specific frequency. A "clock source" is a circuit that generates a clock. Like everything else, no clock source is perfect. Ideally, the interval of time between one "on" and the next should be the exactly the same, but it practice, it varies. That variation is jitter.

Ok, but what is jitter's effect on audio? Take a typical playback chain where you have a CD transport with a digital connection to a receiver. The CD transport reads the data off the CD and applies a little processing to convert the raw data into the standard digital PCM stream. That data stream goes out the jack in the standard S/PDIF format, which combines clock and data into one signal. The signal clock is derived from the master clock source in the transport, so any jitter in the master clock will also appear in the output signal. So now the signal is passing through your optical cable or coaxial cable. This cable, being imperfect, is smearing the transitions (where the signal goes from "off" to "on" and vice-versa). It's a small amount of smear: not enough to obscure the data, but it does increase the random variation in time between one bit and the next (i.e., more jitter). The signal now enters the receiver's digital input. A circut called a "PLL" tracks the incoming signal, and attepts to sychronize with it. This is necessary to be able to extract the data bits. The PLL, when locked on to the incoming signal, generates a clock based on that incoming signal, and the clock is carried forward into the Digital-to-Analog Converter (DAC) along with the data. It is at THIS point that the jitter (which was present in the clock source in the transport, and which was made worse by everything in between) has its degrading effect on the resulting audio. Because the samples are supposed to be "evenly spaced", but they aren't, so the resulting analog waveform has a different shape than it should.

One might ask, "Why can't you generate a new clock for the DAC, and throw away the jittery clock that came from the digital input?" The answer is, you can. I know of several products that do just that. But in the early days of CD transports and DACs, such a fix might have been difficult to implement, and anyway the designers probably weren't aware of the negative effects of jitter.

All of the previous discussion pertains to CD audio only. When it comes to Dolby Digital or DTS bitstreams, jitter should have no impact on sound quality (which means that the quality of the digital interconnect makes no difference). This is because the digital data is processed by a computer in the surround receiver, which then creates new digital audio streams to feed the DACs.

I have done some A/B tests, where I compared Dolby Digital over: A) an el-cheapo ($6) TOSlink cable, and B) a high-quality coax. I could hear no difference between the two when playing Dolby Digital or DTS. My DVD player and receiver each have both optical and coax connections, so I was able to flip back and forth instantly with the remote.

I have also compared an el-cheapo CD player with an optical out (using my $6 optical cable) with a good CD player using the high-quality coax. In that comparison, I could hear a difference, though it was subtle.

As a EE and a module/ASIC designer for the last 15 years in the telecom industry I'm quite familiar with "jitter"; jitter generation, jitter tolerance and jitter transfer. We could have a long dialog on jitter in the network but let's concentrate on IEC60958, the AES3 and S/PDIF data format rather than the Bell Core specs.

You blame the oscillator for the jitter generation in your equipment, a quick look at Digikey found that even the $1.00 oscillators are spec'ed at 50 ppm and jitter at 100 Hz was way down there with some at 100 dB down. The IEC60958 is a rather lax 1000 ppm requirement but mentions 50 ppm for precision applications. I don't think you can find a 1000 ppm crystal oscillator, none are that bad.

I checked the Cirrus Logic data sheets for their S/PDIF transmitter and receiver. The jitter generation of the transmitter is spec'ed at 1 nS. The receiver employs a PLL in it's clock recovery circuit. The 950 will most likely use these parts or equivalent devices.

The IEC60958 spec call for 75 ohm cables with S/PDIF and 110 ohm balanced cables for AES3. I would recommend that you adhere to that spec. The frequency is 3 to 6 MHz. Any video cable should work fine. A composite video cable has roughly the same requirements. Few of us will have AES3 equipment but any DS1 cable should work fine.

Here is a site I ran across and it does talk about the jitter problems in the interface. My argument is with the expensive cables which are not required. When a standards body puts together a formal standard, IEC60958, they specify the minimum requirement and design it in such a way that it works as intended. Please take a look at where the important jitter occurs, during sampling. The interface jitter is the result of slew rate limiting for noise concerns and will be removed by the clock recovery circuit.
http://www.epanorama.net/links/audio digital.html#spdif

If your CD player was dropping bits you would have pops and dropouts not a subtle degradation in sound, Similar to DSS in a storm.

I'm glad you're a DIY. I myself have designed and built a few things, power amps, pre-amp/active crossovers and of course interconnect and speaker cable. I also have built all my speakers but I used George Short's crossover expertise on these. I also bought the Model 750, I can't really compete with Outlaw's pricing. By the time you buy all the parts I would have spent the better part of a grand, and the amps themselves are already built. My sub amp is mine, all 450 watts.
Those CAT5 cables are extremely capacitive. Did you use them with an Outlaw product? They can easily cause some amps to become unstable. I can see them "coloring the sound"; they are not what you might call electrically neutral. That is just as bad as zip cable's inductance causing roll off at the upper reaches, just different. The TNT audio site kinda sucked, no info there. Here is some real DIY info. Build a Pass amp.
http://www.diyaudio.com/
More audio myths;
http://www.sound.au.com/

I'm glad you're happy. As others have pointed out, there is no assurance that comparing a hand or custom made wire with odd characteristics to a reasonable speaker wire will result in no audible difference.

I had an experience where I convinced myself a tweak was improving the sound when, as I later discovered, it wasn't changing anything. A great lesson in human perception.

Since that day, if you can't show me signifcant difference in an double blind test (ABX is great) or on an instrument it doesn't exist IMO.

As always, YMMV, and have fun.

Wanna try a nifty experiment? Hang the probes of an o-scope off the amp (channel a) and speaker (channel b) ends of some 12 gauge zip cord and play music. Set the channels to subtract.

Charlie

Wow! What a great thread, although it has taken me many hours to read all the posts and the attendant links.

I would like to give my two cents worth, only from a slightly different perspective. I have been involved with high-end car audio for many years and only ventured into home audio and home theatre relatively recently. Home and car audio are definitely linked in the way we all pursuit the "Holy Grail," but car audio has its own set of obstacles and challenges – especially when it comes to interconnect cables.

What has yet to be mentioned in any detail is the real, measurable advances that have been made over the years in general cable technology. It has only been a few years since "twisted pair" cables were first marketed for car audio, and they have made a huge impact as far as noise reduction and signal-to-noise ratio goes. Interconnect noise from RF and EMI can be a big problem in car audio. Not only in noisy older cars with lousy grounding, but also in newer cars with their myriad of computers and electrical components. I have experienced first hand how twisted pair interconnects (sometimes incorrectly referred to as "balanced") have had a major impact on the war against noise. I have also seen how the shielding of a cable can affect the noise floor of an audio system. I would also like to mention that some car audio cables are "directional" – not because of any audio properties, but because the shielding is connected to a "drain" wire at the source. By grounding only one end of the cable's shield, EMI and RF noise is more efficiently routed to ground. This, too, has had tangible results in car audio systems. I have yet to see any "directional" home audio cables that incorporate a shield drain wire (or any kind of lifted shield plane), so I am very skeptical. (To be fair, most home audio gear has a single ground plane for power and signal, whereby some car audio gear uses differential circuitry with separate power and signal grounds. This sometimes benefits from an interconnect with a separate ground shield.) I would never install, or recommend installing, anything but twisted pair interconnects with some sort of shielding in a car. Since I have seen how well this technology works in the mobile environment, these are also the only types of cables I would use in my home audio system.

Based on my experience installing and listening to many car audio systems, I would never buy a coaxial audio interconnect again. I have read that coaxial cable may be better for video and digital signals, but twisted pair interconnects are definitely the way to go for analog audio cables. I don't think the type of end connector, or "termination," has much to do with sound quality (within reason), but it does have a lot to do with the use and longevity of the whole cable assembly. An installation shop I used to work for made all their own interconnect cables with twisted pair Carol cable and cheap nickel-plated ends. The key to achieving excellent results was the good quality twisted pair wire and decent all-metal RCA ends. Twisted pair interconnects are pretty much the norm in car audio now, but I still see a few "high-end" home audio interconnects that use a coaxial design. Radio Shack cables may be as sonically good as more expensive cables, but unless they are a twisted pair design I would stay away! Also avoid plastic RCA ends as they tend to not be as robust as all-metal barrels. The RCA ends with a Teflon insulator (usually white in color) between the center tip and ground seem to be better built and stronger than the ends with cheaper circuit-board material (usually brown or tan in color) around the center tip. All it takes is an RCA connector falling apart on you when you pull it out to wish you spent the extra $5 on interconnects.

I have also been reading a lot about the newer Ohno casting technique that seems quite credible. Perhaps it's because these castings have cool pictures to demonstrate their superiority to lesser extrusions, but who wouldn't want fewer squiggly microscopic lines in their copper? I do believe that there is a measurable difference between oxygen free copper (OFC) and less-pure grades, so it's reasonable to believe that Ohno castings are even more superior (assuming the same grade of OFC is used) for use as an electrical conductor. There's also a lot of buzz about silver – solid silver core, silver coated copper, etc – but I haven't seen any test results comparing copper and silver. I guess I'll have to wait until there are some cool microscopic pictures of silver conductors with even less squiggly lines before I'm convinced.

Keep up the debate, and thanks to all for the honest opinions and great links.

- Jeromy

Let's put it this way......its not the cables that make the system great its the overall collective effort of your equipment. If you have a $500.00 cable attached to a $200.00 system I betcha you won't hear the difference. Put $5000.00 cable on a $20,000 equipment you'll hear it. The difference sometimes is subtle so the question is are you willing to pay the big bucks for it......
I have tried doing AB's on different cables and I do hear the difference. One easy way to do an AB is not by sound but by sight. Get an elcheapo video cable and get one of a higher grade. If your player has 2 same video outs connect them both. Play a movie pause it at one scene switch it back (video 1, video 2) then see if notice any difference. Just did that to my friends TV last night and he did notice the difference.
Cables do make a difference but it has to be a collective effort between your system and your cables.

tooRew2btrue,

Enjoyed your post, had to point one thing out though:



This is actually done to prevent 'ground loops', where a difference in ground potential causes a current to flow in the shield. The single connection is plenty to drain the shield without completing a circuit.

It is rumored that some 'directional' home audio cables are actually constructed this way, thus the arrow to indicate which end goes to the ground plane.

I suspect some sales pinhed didn't understand and came up with 'directional' cables.

Twisted pairs are nice, but they really need to connect to balanced inputs to get the full benefit. Due to the differing impedence to ground the induced voltage will not be equal on non-balanced signals.

Anyone know why higher end (or all) audio gear hasn't switched to balanced signal IO?


Charlie