Make Your Own Home Audio Cables

Introduction

Are you an audiophile who is frustrated by the high cost of loudspeaker cables and interconnects? If your introduction to hi-fi dates back to the 1960s and '70s, then you remember the days when "zip cord" (18 gauge lamp wire) and thin coaxial, often configured in a spiral for neatness and fitted with molded RCA plugs, were the norm. Furthermore, if they accounted for 1% of your system's cost, you were probably spending too much. It wasn't until Bob Fulton introduced "Fulton Brown" and "Fulton Gold"" audio cables in the late 1970s, that anyone give these a second thought.

Today, when the audio mantra is "Everything makes a difference," one typically budgets 10% of one's audio dollar for these ancillary items. Speaker cables, often made from a variety of exotic metals, have been known to cost up to $40,000 per pair and interconnects can be proportionately pricey. Luckily, there is an antidote to this madness. Read on and learn!

But first, a quick note. Although this page has been online in one form or another since 1997, it was only in late 2005/early 2006 that I was able to put together a dedicated room with an audio system that was sensitive enough to distinguish even the slightest modification. With this long awaited tool at my disposal, I've set out to re-examine the subject, try some new ideas, and revisit some old ones. Consequently, there will be many more updates throughout the first half of 2006 than in all the years previous and you are encouraged to check back every few weeks for the latest ones.
 

 
Interconnects terminated with WBT-0110Ag NextGen Locking RCA Plugs

Cable Types

To set the basics straight, audio cables fall into two general categories, interconnects and speaker cables. The former connect your source (turntable, CD player, tape deck, and so on) to your receiver or amplifier and the latter connect the amplifier to the loudspeakers.

Interconnects that are terminated with RCA plugs are called "unbalanced" and those that use 3-pin DIN or XLR connectors are referred to as "balanced."

Commercial speaker cables usually have a spade, banana plug or, in less expensive designs, a heavy pin at one or both ends. However, in special cases, they can also be fabricated in the aforementioned "balanced" configuration and terminated with 3-pin XLRs. The argument in favor of balanced is that they are more immune to noise, especially in long runs (typically over 20 feet), than "unbalanced" or regular cables. Thus, they are typically found in professional audio applications, such as from a microphone to a sound board. The advantage for home audio really just exists if the components they connect are designed with balanced circuits in the first place. If not (and 99.9% are not), save your money and stay with unbalanced.

To build state of the art (well, state of the DIY art) audio cables, you only need two basic parts -- an appropriate length of fine silver wire (not sterling) and a spool of Teflon^® PTFE Spaghetti Tubing to use as an insulating jacket. Because of they way they typically interface with home audio components, interconnects will always need a connector, either RCA or XLR. On the other hand, bare speaker cables don't actually require terminals and can just be inserted into the center hole of a 5-way binding post. Alternatively, the ends can be formed into a "J" shape and hooked around the posts or they can simply pushed into those cheesy spring-loaded clamps that grab the wire on cheaper units.

Wire Gauge

Allen Wright, author of The SuperCables CookBook, is a vocal advocate of using the thinnest wire possible, such as 30 AWG (or smaller) for interconnects and a thin ribbon of silver foil, 25 mm wide x 0.05 mm thick, for speaker cables. Do the math and you'll find that the latter actually translates into a cross section equivalent to 16 gauge, as well, albeit with a much larger surface area than round wire.

On the other hand, Martin DeWulf, editor of the Bound For Sound Report, published an article in January, 2004, which extolled the virtues of 6 AWG copper speaker wire made from a cable type commonly found in the electrical departments of home supply stores. In the 1980s, Enid Lumley, then a columnist for The Absolute Sound magazine, also shared this view (she called them "welder's cables").

I recently tried these for myself and found them to be surprisingly good, especially since the price was only 30¢ per foot. While 6 gauge silver wire should do copper one better, keep in mind that DeWulf and Lumley were referring to multi-stranded copper that adds up to 6 gauge. Solid silver in 6 gauge is more like a rod than a wire. If you're so inclined, you could try bundling nine 12 gauge silver wires to approximate 6 AWG. Whether it's copper or silver, if you do take the 6 gauge route, don't bother with spades or other connectors. One of the five ways a five-way binding post works is the hole in the center. Just insert the bare bundle and tighten. FYI, since the conductive properties of silver are somewhat higher than that of copper, an 8 AWG silver conductor will closely approximate the properties of 6 AWG copper. In practical terms, that means you can reduce those nine 12 gauge silver wires to six.

As usual, there are cases to be made on both sides. Gizmo's final experiments suggested that thinner was better and you can read the whole story in his article entitled "Less Is More."

Update, February, 2006: In February, 2006, I tried to make a set of 8 gauge silver cables using multiples of both 13 and 16 AWG, but found that the mechanics were not as easy as they seemed. The bottom line is stay with a single strand of wire, regardless of gauge. In my own system, 16 gauge solid silver wire out performed all heavier gauges, including the 6 gauge home supply store's copper wire and the very expensive Kimber 8AG, a 9 gauge equivalent, multi-conductor silver cable.

Update, April, 2006: Until recently, the verdict regarding which gauge to use was out in my personal system. For years, I typically used 16 gauge for speaker cables and 20 gauge for interconnects, but I recently did a lengthy comparison between 16 and 20 gauge single-strand, silver speaker wires. To my surprise, the 20 gauge exhibited a slight increase in detail and a perceptibly tighter bass. Whether this trend would carry through to 24 gauge or smaller has yet to be determined, but apparently, less really is more and I now recommend 20 gauge wire for everything.

Material Sources

You can purchase "fine silver round wire" from Hoover & Strong, a leading supplier of 99.9% pure silver milled stock to jewelers and industry. Our metalworking friends say that when it comes to jewelry grade metals, their quality is the best. Keep in mind that much of the gold and silver you may purchase has been recycled from previous use and is not necessarily "virgin" or newly mined. Poor refining of ore or scrap can leave a large proportion of impurities, so buy from a reputable source.

Regardless of form, sales of precious metals, including silver, are based on weight multiplied by today's spot market price, plus a percentage to cover the refiner's overhead and profit. On a given day, this is generally double the spot price. For example, if today's price of silver is USD $10 an ounce, H&S will it sell for about $20 an ounce. So, if you have a run of 10 feet (3 meters) between your amp and your speakers, multiply by four (there's a positive and a negative wire running to each speaker, times two speakers) to get a total of 40 feet (13 meters). If one ounce of fine silver bullion yields 7.25 feet (about 2.2 meters) of 16 gauge round wire, divide by 7.25 and you'll need to buy approximately 5.52 ounces of silver in wire form. At $20 an ounce, this comes to $110.40, plus shipping. There's a nominal handling charge for orders under $100. Remember, the price of silver changes from day to day depending on the world market, so please don't quote my math back to H&S -- this is only an example!

Update, March, 2008: It was recently brought to my attention that as of January, 2008, Hoover & Strong stopped selling directly to the public and now only sells to other businesses. Basically, they don't want to be bothered with small orders. However, if you own a business (any business) and can prove it, they will be happy make you a customer. Otherwise, you'll need to go online elsewhere or make your purchase through your local jeweler or jewelery fabricator. Also, since I first wrote this article, the spot market price of silver has doubled to about $20 an ounce. Don't be surprised when you get the bill!

Purity

Commercial grade silver is typically 99.9% pure. The balance (0.1%) consists of various other trace metals that exist naturally in silver ore, are blended in with the scrap, or are too expensive to refine out. To get 99.99% purity, you'll pay a hefty premium and to obtain 99.999% purity, you'll probably have to refine it yourself or be a government agency where cost is no object.

Commercial audio cable makers have made a fetish about metals purity that just doesn't make sense in the real world. After all, look at the path that your audio signal travels through. The leads on resistors, the foil used to form capacitors, the traces on circuit boards, and the formulation of solder all add up to a myriad of metals -- aluminum, copper, gold, nickel and so on. Don't believe the hype! Sorry, folks, but spending more to achieve a level of purity that's higher than 99.9% is a complete waste of money and the stuff that advertising is made of.
 
Temper

"Temper" refers to the degree of hardness of the metal and is determined by the amount of heating and reheating used in the refining and finishing process. For years, I had always purchased "regular" temper silver wire. However, with the recent completion of the new listening room, I was now in a position to do some serious investigation into the subject. In March, 2006, I ordered some "extra soft" temper wire from Hoover & Strong to try as loudspeaker cables. The difference between regular and extra soft was not subtle and the improvement was obvious from the very first note! All of a sudden, the sound stage doubled in size, transparency increased by a similar magnitude, and details that were previously hidden, emerged from the darkness. When you make your purchase, be sure to specify "extra soft temper, pure silver, round wire."
 
For comparison, I borrowed a pair of Kimber pure silver 8AG loudspeaker cables -- retail price: $600 per foot pair or $5,000 for the five foot pair that I had on hand. Sorry, Ray, but my 16 gauge, DIY, extra soft temper cables clearly outperformed the 8AG, as well as everything else in the house. The sound stage was larger, the imaging more three dimensional, and there was greater transparency, along with reduced hardness and glare. What's not to like?

Update, April, 2006: As mentioned above, I now recommend 20 gauge wire, rather than 16 AWG. However, my amplifiers are 20 watt single ended triodes (tubed amps) and their distance to the loudspeaker terminals is only 30 inches (762 mm). It is possible that a higher wattage solid state amp positioned several (or many) feet away, could still benefit from 16 AWG (or higher) cables.
 

When it arrives, the silver wire is bare. Avoid handling it with your fingers -- the acidic oils on your skin can quickly degrade the metal. Ideally, you should wear a pair of nylon, polyester or cotton gloves, such as lint-free film handlers' gloves available from a professional photo supply store. An alternative are the thin latex gloves that people in the medical arts favor, typically found at your local pharmacy. Industrial supplier McMaster-Carr sells Nylon tricot "inspection gloves" (their catalogue # 5443T22) at 12 pairs for $8.85.
 

PTFE Spaghetti Tubing, Standard Wall Thickness, (which is the technical name of the Teflon insulating jacket) can also be purchased from McMaster-Carr. A 100-foot (33 meter) roll of 16 AWG tubing costs about $18.00, 20 AWG tubing costs $14.00 for 100 feet, and 24 AWG costs $8.00 for 100 feet. As of this update (April, 2008), it's on page 793 and the catalogue numbers for 16, 20, and 24 AWG tubing are 5335K16, 5335K13, 5335K12, respectively. To locate it in their online data base, do a keyword search using those catalgue numbers.

Update: April, 2008: Some experimenters prefer thin-wall PTFE tubing, which can be sourced from Small Parts, Inc. Prices per 100 feet are much higher, however.

Update, March, 2008: Over the past year or so, I've received an number of inquiries about the use of cotton piping, instead of Teflon. Some DIYers claim that cotton sounds better than Teflon. Personally, I haven't tried it (cotton tubing is not as easy to find as you might think), so I really can't comment. Certainly, for interconnects or speaker cables, there's no harm in experimenting. However, I would caution you against using cotton tubing over wires that carry high voltage. If you are thinking about rewiring your electronics internally with fine silver wire, stay with Teflon! As far as electricity is concerned, cotton is a very poor insulator and a short circuit inside an amplified could start a fire.

Update, April, 2008: We recently had occasion to fabricate interconnects that were up to 18 feet (6.5 meters) long and discovered the limits of using same gauge tubing as the wire. Using medium temper wire, I've been able to insert polished silver wire into the same gauge tubing in lengths of up to 7 or 8 feet. However, the extra soft temper kinks much more easily and has greater difficulty overcoming the natural curl of the coiled tubing. After a while, it simply becomes impossible to continue inserting past a certain distance.
 
To simplify matters, I now recommend using larger guage tubing when longer lengths are more likely to kink or become too resistant to easily insert. This chart will help to guide you:
 

Form Factor

To begin, regardless of their form or gauge, it's important to make sure both left and right cable runs are equal in length, even if your electronics are closer to one speaker than the other. This keeps the audio circuit symmetrical and prevents phase shift -- the arrival of the signal at each speaker (and ear) at different times.

As with which gauge to use, how to arrange the wires is also the subject of differing opinions. The major issue revolves around how to avoid RFI (Radio Frequency Interference) and EMI (Electro-Magnetic Interference). Wire will not only conduct a signal that's fed directly into it, but it can also act as an antenna. In a worst case scenario, it can pick-up RFI, mainly in the form of AM and short wave radio broadcasts. By contrast, EMI is usually a hum or buzz that's caused by a nearby electrical field, such as a power supply's unshielded transformer or an AC power line, even one hidden in a wall or under the floor.

These phenomena are completely local and somewhat unpredictable. By way of example, for almost 15 years, I lived in a very rural part of New York State where the neighbors were principally dairy farms. Yet, every evening, if I put my ear close to the loudspeakers, I could distinctly hear a far-off radio station. In addition, for two of those years, every night from 8 PM through 1 AM, there was a distinct buzz, probably caused by a poorly grounded mercury vapor lamp attached to a barn located a couple of miles away. It was apparently travelling down the single high voltage line that serviced every house on the road. Today, my listening room is in an office building (strange, but true!) located in the heart of a mid-sized city. There's a college radio station sitting on a hill five blocks away, a taxi stand across the street that communicates with its fleet via short-wave, and who knows what else. Yet, despite all this, I've never heard anything at this location, other than music, coming from my stereo. I mention this, because it's the urban environment, not the rural, that's notorious for RFI, but neighborhood conditions are the real determinant.

Free Air

Under ideal circumstances, hot and neutral wires that are completely separated work perfectly well. You can arrange them an inch or more apart and impress your friends by calling it an "air dielectric." Nelson Pass, well-known amplifier designer and frequent contributor to Audio Xpress magazine, suggests that 6 inches is the ideal, but in my experience the exact distance isn't critical -- each conductor can dangle freely without ill-effect.

If you're truly obsessive and demand precise separation, you can purchase dowel stock at the hardware store or lumber yard. Cut the dowel to appropriate lengths, make a notch at each end, and insert the (+) cable in one side and the (-) in the other. For a variation on this technique, you can even drill holes through the dowels about a half inch or so from each end, thread the cables through before terminating the second end, and use Mortite insulating putty or modelling clay to secure the wires. Odd looking, but it works!

Update, April, 2006: Based on recent trials, "free air" cables, as described above, still work well between amplifiers and loudspeakers. However, I no longer recommend this for interconnects and think that speaker cables, too, can benefit from a gentle twist. Read on below and continue down to Update 5, as well.

Parallel Runs

Lately (April, 2006), I've been making interconnects in which the hot and neutral lines are actually as close as possible, not separated, as above. They are not twisted or braided, but run side by side in close parallel proximity. In my system, at least, separating them induces a hum that disappears when run together. One can hypothesize that the parallel run turns the interconnect into a small value capacitor which, in effect, makes it act like a line filter, as well. In any event, so far there's been nothing detrimental to the sound.

Twisting

There are those who feel that loose wires, even run in parallel, are still antennas and an invitation to RFI, especially when used as interconnects to pass low level signals. They advocate braiding or twisting the conductors, as well optionally adding some sort of shield or drain.

The next advance beyond parallel runs is simply a gentle twist of the conductors at a rate of 3 or 4 twists per foot, which This works for both interconnects and speaker cables. This could be considered the first (and simplest) defence against EMI, but may also add a bit more capacitance.

Adding A Drain Wire

The next step up is to add a third wire called a "drain." Generally speaking, this is commonly done with interconnects and rarely with speaker cables where the signal is so strong that the effect of the drain is negligible. In theory, the third wire drains away any stray magnetism caused by EMI and acts as a simple shield against RFI. Depending on your dexterity, you can still run the wires in parallel, give them a gentle twist, or braid them, as Kimber Kable does. For an illustration of 3-wire braiding, visit this page from the Wikipedia.

Ideally, the drain wire should be identical in composition to the principal conductors, but you can also economize by using common solid bus wire (18-24 gauge), available from most electronic stores. It may even make sense to leave the drain wire bare, since uninsulated wire is more likely to perform the function it's designed to do.

Regardless of how you arrange the wires, the drain will only function if it's grounded by soldering it at one end to the neutral. For more details, skip down one paragraph and read about "Grounding The Shield."

Shielding with Copper Braid

Finally, if Wolf Man Jack is still in the house, your only solution is full shielding with expandable copper braid. Unfortunately, this is also the messiest and most expensive. Because foil or braided copper shield also has a tendancy to kill the high frequencies, finding and covering the source with either MU metal (available from Michael Percy Audio) or ERS cloth is often more effective and easier to do.

However, if this isn't practical, you can still shield the interconnects without high frequency loss by first wrapping them with a thin sheet of foam or the type of bubble-pack that's used for cushioning delicate objects -- it's the one that's made with miniature bubbles. Secure the foam or bubble=pack every few inches with your favorite tape (it does not have to be tight), expand the copper braid, and gently slip the whole affair into the braiding. Granted, this looks more like a garden hose than an interconnect, but what you have is basically what those commercial garden hose-like cables really are -- lots of insulation around very little wire.

Grounding the Shield

Whether you choose to use a simple drain wire or go all the way with copper braid, neither will work unless attached to the ground at one end. If you only use a drain wire, it can simply be soldered to one of the ground connections at the plug. For the braid, however, you may have to take the intermediate step of winding some thin (18 to 24 gauge) bus wire around one end of the braid and soldering that to the ground.

The reason you don't want to solder both ends is that it creates a parallel circuit, commonly known as a ground loop. Instead of curing the problem, this will actually make it worse!

Either way, mark the end where the drain wire or braid is soldered to the plug. That's the end that the arrow on commercially packaged wires points to. While the common belief is that the signal should always exit from this end (i.e., point toward the loudspeaker), I recommend pointing the arrow toward the preamplifier, instead. This mimics a star or central ground scheme, using the preamplifier as the center of the star. Why? Because, ideally, the audio signal is grounded to earth at the point of lowest inductance, which is usually at the phono input on the preamplifier. However, feel free to experiment. Orient all of the interconnects one way, then the other, then in the star ground pattern. Which ever way sounds best is the one to use.

In the end, just use the form that works best for your situation and try not to get too neurotic about it. Don't lose sleep because you can't locate dowels made from Mpingo wood, either. Relax! Enjoy the music!

Update 5: My conclusion (and new recommendation) is that the best scheme is parallel conductors with a gentle twist (three or four twists per foot), including a drain wire for interconnects, but not for speaker cables. I'm not sure if the configuration has anything to do with it or whether the additional stiffness allows the wires to be routed farther away from AC input inputs and cables, but there seems to be a slightly better bass response with the wires arranged this way. On the other hand, I suspect this is only audible if you have a very sensitive system.

Assembling The Cables

Enough theory -- let's make some cables! To begin, simply cut the silver wire to the desired lengths. As a test, you may want to use some cheap copper wire first in order to verify the correct run between your components. Avoid sharp turns, which stress the outer skin of the metal. Next, carefully insert the bare wire into the Teflon tubing. To make insertion easier, you may need to file the ends of the wire first to eliminate any burr from cutting. Also, make sure the Teflon tubing is 1½ - 2 inches (2 - 3 cm) shorter than the finished length, so that some bare wire is exposed at each end.
 
While you'll have little trouble feeding 4 to 6 feet of wire into the Teflon tubing, if you polish the wire with steel wool, there's almost no limit to the footage you can easily insert. This is even recommended this for short runs. Many DIYers, as well as manufacturers, say that polished wires sound better, but this is a level of minutiae that I have not been able to verify. On the other hand, it only takes a few minutes, does not add to the cost, and will make assembly much easier.

Hold the wire with one hand and, to avoid kinking it, polish it with the other hand, always drawing the steel wool over the wire in one direction, away from the anchor point. Alternatively, you can hold one end in a table-mounted metal vise (a large clamp, vise grip, or similar device will work, too) and carefully draw the wire out toward you with one hand while using the steel wool to burnish it with the other, as you back away. Although Allen Wright recommends using silver polishing paste, this can get rather messy.
 

I use 0000 gauge steel wool and find that it does a perfect job. Just polish a few inches at a time by burnishing it with 3 or 4 strokes of the steel wool, being careful not to kink the wire. Making kinks are very easy to do, especially with 20 AWG and smaller. For ease in working, you'll need to be set up in a room that's long enough to allow you to keep uncoiling the wire to the finished length, since keeping it taut as you walk backwards makes the operation easier.
 

To insert the wire, either clip off the blemished end that was clamped or start inserting from the opposite end where you finished. Still wearing gloves, hold the tubing in one hand while inserting 1 or 2 inches at a time with the other hand. The wire is very easy to kink and kinks make smooth insertion difficult. There's a pretty short learning curve to both steps, but if you don't rush either of them, you should have no problems.
 

To terminate the speaker cables, either solder a good quality spade or pin (corresponding to the terminal on your amp or speaker) or just use the bare wire itself (As Wright says, "The best connector is no connector."). To do this, take a pair of needle-nose pliers and bend the end into a loop to use around the binding posts or just insert the straight ends into the post's center hole. Silver is soft, so tighten gently for a firm fit. For proper orientation, mark the ends of each cable with red (for positive) and black or white (for negative) tape or heat shrink tubing. If you prefer to use them, Michael Percy Audio offers a wide selection of spades (as well as silver solder) at reasonable prices, though my personal choice is the very expensive WBT-0660Ag or WBT-0680Ag Silver Signature Spade. At $2.50 each, an economical alternative is the Alpha-Core Silver Spade. Ignore the kit. Just give them a call, buy the spades in bulk, and use lead-free WBT solder to attach them to your wires. The main reason to use spades instead of bare wire is durability. As mentioned, silver is relatively soft and if over tightened, the bare wire can deform or even break inside the binding post.
 

To terminate the interconnects, you'll need a good quality RCA plug. Cardas makes a very nice silver plated version (Model SLVR) which retails for about $14.00 per pair. Again, I prefer the WBT-0110Ag NextGen Locking RCA Plug which makes a much tighter fit, especially with it's matching socket. But at $98.00 per pair, they are very pricey and, for some, this calls into question the point of DIY economy. A new kid on the block is Eichmann Bullet Plug, also available in solid silver. A set of four retails for about $85.00, but because of their plastic bodies, some users find them more difficult to install without causing damage.
 
When you solder the wires, the hot signal (+) is on the center pin and the neutral (-) is on the outer ring. Because some plugs are sold without channel markings, the convention for color coding is red for right and black or white for left.
 

Oxidation

In addition, Dr. Arthur Loesch, well known audio designer and Professor of Atmospheric Dynamics at the State University of New York, maintains that fears of silver oxide contaminating the sound are completely unfounded. As he puts it, "Silver oxide is still silver and it all sounds the same."

My personal experience is that after more than 10 years of service, there is no evidence of silver oxidation within the Teflon jacket, although it does appear on the exposed ends. Silver will oxidize, but the oxide of silver is conductive, so oxidized silver will still make a good signal path. Don't confuse this effect with copper oxide, which is definitely a bad conductor.

Multiple Runs

At one time, it was popular to double the run of your wire in both directions (the so-called "shot gun" configuration). My recent personal tests suggest that the improvement is marginal, if at all. However, if your speakers are constructed with dedicated binding posts for each driver, you may reap some sonic benefits by using separate cables that have a common termination at the amplifier end (referred to as "bi-wiring"). The idea is that separate grounds for each driver create a more efficient signal path.

There's also a hypothesis that different audio frequencies travel best over different gauge wires and that wherever possible you should use a combination or bundle of different gauges for each driver: one length of 16 gauge for the woofer, two lengths of 20 gauge for the midrange, and two lengths of 24 gauge for the tweeter. Again, my recent experiments suggest that using 20 gauge wire throughout the audio system is all you really need.
 

Enjoy The Music!

Voilà! You've now fabricated $5,000 cables for about $200 and never have to upgrade again...
At least not until you can afford to terminate those babies with Silver NextGen's.
 
 

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