MIT TMax/OneWire RG6 System

[LaserMark4]

Anyone had any experience or opinions with the MIT OneWire system, which is the silver-coated copper RG6 with TMax connections at both the power and source?

I have a local dealer here that's been in the business for 30+ years and seen it all, and absolutely swears by the stuff. From the specs, it is the highest throughput and shielding of anything I have found (VP of 83%, 52 pf/m, gas-injected PE). I'm fully re-wiring the dedicated HT and listening/sound/ recording room, and the cost is remarkably reasonable it appears.

From an installation standpoint, it seems really nice to have all the cables (audio, speaker, video, sat, etc) identically the same, as I have a lot of them to run with 5 BNC leads to the PT, bi-amping the fronts, sub-panels for mics, etc.

But, as I have discovered previously, once the walls go up, treated, and covered.....well, it's pretty much a "done deal" for good this time (or so my wife says- :>)

So I need to get it right this time around--

 

[jaxvon]

Few questions:

What guage is the wire? Is it a coaxial configuration? What are the coverage specs on the shielding?

And lastly...how much are you paying for this stuff? MIT doesn't exactly make inexpensive cable...

 

[LaserMark4]

MIT One Wire

I agree with cost. I'm cheap and definitely don't want to spend big $$ for expensive MIT type dedicated cables, which I don't think are worth it-- WAY overpriced. But this system is way cheaper than buying cables-- a sort of DIY solution on the surface, with the same specs of high end it seems to me.

The wire is standard RG6 size, and it's just normal looking coaxial cable. I'm not sure on the exact specs on the diamete of wire- I'll run that down.

Once the wire goes out from my equipment room to the wall plate (with an typical "F" female connector sticking out), the actual speaker wire is still the same RG6 cable made to length with two male "F" connector ends. The speaker wire connects to the wall, and then to the TMax connector at the speaker. To bi-wire or bi-amp the fronts, the two TMax connectors cost $80 per pair for both speakers. The center speaker will costs $40 for the connectors. The RG6 wire is $1.00 per foot. I've found gold plated "F" connectors and others for $.58 to $.89 a piece-- cheap. You can use either twisted or crimped on style wire connects. In fact, you then keep going by making all interconnects between components at the equipment stack, your sat/dish cables, the 5-cable video leads to my CRT, etc....all at a buck per foot and $.89 cents max for each end connector.

My ego may be crushed a bit when guys look at my micro-sized, 3/8 inch RG6 cables connecting my Martin Logans and say, "What is that sh*t". But this dealer swears it will deliver a better pipe to every device and component than the huge, $2,000 mega speaker cables. The key to me here is performance-- will this stuff deliver, right?

Finally, here's MIT's dope on the RG6 shielding:

The shielding is what protects the signal from outside interference such as EMI and RFI, while also providing a return for the negative signal back to the source.So, shield materials can have a large effect on performance.

Dual-shield vs. Quad-shield— It’s really not the number of shields, but how well they cover that really matters. Coverage, and resistance is everything when we consider shielding.The rule is at least 95% coverage copper braid (for low frequency protection) and at least 20° to 30° overlap on the foil shield (for high-frequency protection). Shielding is not cumulative,two braided shields that are 60% and 40% coverage will not give you 100% coverage,the combination can actually only end up to be about 80%, leaving 20% uncovered. Also,more is not necessarily better. Anything more than 100% shielding can be overkill just creating more capacitance, which reduces the bandwidth of the cable,and in turn system performance. Quite often, quad-shielded cables will tend to increase capacitance to such high levels,they will actually reduce the systems overall performance. So, in most cases, a well designed dualshielded cable will work best.This is why most manufacturers top level cables are dual-shielded.

Dielectric Material- The primary dielectric is the insulating material that separates the center conductor from the shield. The more air in the dielectric material, the lower the capacitance, and the higher the velocity of propagation (VP). Foamed or gas-injected dielectrics are more costly to manufacture, but are necessary for low capacitance and high velocity of propagation. VP is the speed that the signal travels through the wire and its value is expressed as a percentage of the speed of light. Low capacitance and high velocity of propagation are key for wide bandwidth high-quality video transmission.

The MIT OneWire cables (RG6 and RG59) are two of the very few coaxial cables available on the market today that are truly ready to handle the extreme bandwidth demands of modern High-Definition and Digital TV signals.These high performance double shielded (95-97% tinned-copper braid over 20-30° overlap aluminum foil) cables feature silver-clad and oxygen free copper (OFC) conductors and a gas-injected dielectric that provide very low capacitance, extremely wide bandwidth and a extremely high (83%) velocity of propagation.​

​

Make any sense you anyone else out there? Why hasn't there been more exposure on this if it's so good?

 

[jaxvon]

I'd strongly advise against using RG6 for your speaker wires. It sounds like high-quality coax for video and line-level audio (IE Interconnects), but NOT for speakers. Speakers demand a lot of power, ESPECIALLY speakers like Martin Logans. You need good, heavy guage cable for these, at least 12ga if not 10ga. You're going to experience too much resistive loss by running RG6 to your speakers.

The smallest guage wire you should be running to speakers (even bookshelves) is 16ga. The largest coax I've seen is 18ga, which is probably what MIT is using. Take the Belden 1694A. It's an 18ga Coaxial cable with a solid center conductor. It features a 95% coverage aluminum (edited, was tinned copper) braid shield and a 100% coverage foil shield. Velocity of Propagation is 82%. Capacitance is only 16.2pF/ft (very low). Dielectric material is Foamed PE.

Here's a link to the specs.

So, in terms of electrical specs (and build style), it's virtually identical to the MIT cable. It doesn't have a silver plated copper conductor, but that's just as well. The small amount of conductivity gained by using a plating of silver is negligible and completely inaudible. Besides, audio freqencies aren't high enough to exhibit much loss due to the skin effect (which is where signal tends to travel on the outside of a conductor as freqency increases). Silver is also not keen about being flexed, so while the copper bends just fine, the plating could start to come off.

Here's the real kicker: Belden 1694A (which is broadcast quality) is only $0.26 per foot, unterminated.

My recommendation for speaker cables would be to dump MIT and their high prices and go for some good, 2x10ga Belden cable (5T00UP) or 4x14 Canare Cable (4S11). The Canare cable can be used in 2 14ga pairs to make an effective guage of 11. Your dealer is probably paid by MIT to make sales, so that's why he's pushing the stuff. MIT is using real science in their description that you posted, but it still doesn't get around the fact that RG6 coax is just too small to use for speakers.

If you're running coax for your Satellite or cable (or as unbalanced interconnects), then I'd recommend getting something made by Blue Jeans Cable out of Belden 1505F, Belden 1694A, or Canare LV-77S. If you plan on running it in bulk and terminating yourself, then the best place I've found to buy from is Westlake Electronic.

I can't stress enough that you need to buy some speaker cables to hook up speakers. $2k speaker cables won't make a dB of difference (unless they have rediculously high capacitance or resistance), but using tiny RG6 will actually cause audible losses in volume.

 

[LaserMark4]

A Lot to Chew On

Great information and response, jaxvon. Definitely appreciate all the insight and perspective. I have had the same reaction to such a tiny ga wire....not to speak of the $$$ savings you have illustrated which is a further benefit.

Give me a little time to chew on this and take in all that you are saying, along with a bit more research. I'll check out Belden, Canare, and Blue Jeans-- sounds like this site likes all those you mentioned, and has some good experience and track record with each of them.

 

[jaxvon]

Good to hear! Canare and Belden are manufacturers of cable. Blue Jeans is just a reseller that offers both brands. If you want to terminate the speaker cables yourself, then I recommend that you purchase them from Westlake Electronic (link in earlier post) as they are much cheaper to buy in bulk from than Blue Jeans. If you want them to come pre-terminated, then I suggest that you have Blue Jeans do it. I'm feeling too lazy right now to post links, but if you want some good places to get terminations (just the connectors) for speaker cables, then I suggest checking out Parts Express or Cobalt Cable.

 

[mtrycrafts]

Great information and response, jaxvon. Definitely appreciate all the insight and perspective. I have had the same reaction to such a tiny ga wire....not to speak of the $$$ savings you have illustrated which is a further benefit.

Give me a little time to chew on this and take in all that you are saying, along with a bit more research. I'll check out Belden, Canare, and Blue Jeans-- sounds like this site likes all those you mentioned, and has some good experience and track record with each of them.

Don't use coax as speaker wires, period. That is not what they are designed for. Use 12ga or 14 ga of the lesser cost wires, $.30/ft range. It is not worth more for speaker wires.
Stay away from MIT cables, too expensive and full of marketing hype, bs and voodoo. Use regular RG6 type cables. That installer with 30 years is still after a living and is selling snake oil with the MITs.

 

[Richard Black]

"Anything more than 100% shielding can be overkill just creating more capacitance"

and

"VP is the speed that the signal travels through the wire and its value is expressed as a percentage of the speed of light. Low capacitance and high velocity of propagation are key for wide bandwidth high-quality video transmission."

and

"The MIT OneWire cables (RG6 and RG59) are two of the very few coaxial cables available on the market today that are truly ready to handle the extreme bandwidth demands of modern High-Definition and Digital TV signals."

Anything more than 100% screening is, er, effectively 100% screening. It has ABSOLUTELY NO effect on the capacitance unless you somehow, by sheer brute force, manage to squeeze the physical dimensions of the dielectric down while applying the extra screening. However, the addition screening will reduce the stray screen resistance, reducing (theoretically) some forms of interference susceptibility.

Neither low capacitance nor high VP is necessary for high quality video transmission. The capacitance should be 'just right', i.e. such that it makes for a cable with ideal matching characteristics for the system, normally 75ohm for video. That usually comes to 67pF/m, from memory. Any lower and transmission quality drops. But never mind that, you could in principle make a perfectly well matched system operating at an impedance of, say, 20 ohm, with cable of 250pF/m and a bandwidth to GHz. As for high VP, it's a complete red herring. Doesn't matter how long it takes signals to get through the cable as long as all frequencies take the same time.

Cables like RG6, RG59 etc. etc. have been on the market for many, many decades and are all perfectly capable of handling Digital TV. All RG-prefix types are generic and while quality may vary in minute particulars from one maker to the next, by and large they all perform much the same. That said, RG6 is normally a cable with copper-plated steel centre conductor, which makes it suitable for F connectors (where the centre 'pin' is just the cable centre conductor, stripped back), and as such it has particularly high DC resistance, around half an ohm on a 15ft run. That seems considerably to high for speaker cable duty, but it might end up sounding not entirely unpleasant.

 

[LaserMark4]

I think you guys have made a believer out of me-- RG6 is not the right direction for speakers when there are so many tired, proven, and tested methods out there for standard speaker wiring....and for a whole lot less $$.

Thanks for all the insight, and especially the "where and what to buy"-- this has helped immensely.

 

[jaxvon]

Check out the cable info section of this site. It's chock full of useful information that will help to explain and justify the position of myself and this site on cables.