A Practical Realist

I (Brian Florian) came up with that term a couple of years ago as a means of summing up my view of home theater equipment.  Not that my take on things is so complicated, but it needs a little explaining.

I have no aversion to high prices, even though I myself am in no position to own the most expensive pieces of AV gear.  I respect the laws of diminishing returns, acknowledging that as performance continues to increase marginally, price increases exponentially.  To Meridian, one of the most expensive names in the business, I give my particular approval.  They're genuinely innovative and at the head of the audio industry, and if you want the cutting edge in available technology, they're one of the best.

What I do have a problem with, and take the gravest of exception to, is the myriad of voodoo, smoke and mirror marketing which strives to justify the existence of so many high priced AV products.

Therefore, I seek out high performance which is truly such, and not that which simply costs more.  I believe true high end performance is achievable without taking out a loan.  I want what is practical, and what is real.

And Then There is Cable

Believe what you want, spend what you like, but for me and mine, we'll steer clear of exotic AV cable.

I'm about to put together a speaker cable that just plain works and costs about a dollar a foot.  If you can believe such a thing will perform, this review is for you.

Recently I became enamored with M&K speakers (to the point of buying one of their subwoofers for myself).  What really had me hooked is their no-nonsense, total lack of BS.  They make speakers which reproduce the signal with a ruler flat response, not just in frequency but in the time domain as well (i.e., transient response), and they make sure it does that at all output levels.

The Pro Market, especially those in post production, love M&K speakers and subs.  But take a look at the back of any M&K speaker.  There is one set of binding posts.  M&K does not believe in bi-wiring, the benefits of which were dubious to me anyway. If you break it down into simple electronic theory, the only "benefit" possible with bi-wiring is theoretically more output at the crossover region (between the posts) if you've got long runs of high resistance cable, but I don't think that could be considered a benefit.  As for passive bi-amplification, the benefits, with some amplifiers, can be substantial, although only due to shortcomings of those amplifiers. Passive bi-amping can do little to increase the total voltage applied to the speaker, though it will relieve each individual amp of some current draw.  (Note: active bi-amping, as found inside of active speakers and better movie theaters, is a completely different and wonderful thing as outlined in our article on the subject).

Bearing all this in mind, I started to ponder the question, "What would M&K, bosses of no BS, use for speaker cable?" They do "strongly recommend" (their exact phrase) that their customers use the heaviest gauge of speaker cable they can, noting that M&K's binding posts will accept a 4 gauge wire!  They also warn about cost not necessarily equating to performance when it comes to cable. Of course, that applies to any product, in the A/V world and elsewhere.

Well, that at least gives us something to go on.

Fellow Secrets Editor Colin Miller and I exchanged e-mails on the topic of cable characteristics and figured out what was desirable for a speaker cable and how we could cheaply . . . I mean, simply achieve it.  Colin, feel free to jump in . . . .

Cable Electrical Factors and How They Affect the Sound - Colin Miller

When talking about cable characteristics, we can boil it down to the sacred trinity of L/C/R: Inductance (L in henries), Capacitance (C in farads), and Resistance (R in ohms). Resistance is a DC component, and is called resistive impedance. Inductance and capacitance are AC components, and are called reactive impedance.

Resistance is easy to wrap your hands around: The smaller the conductor, the more resistance it's going to offer. Find a really, really thin straw and a really, really fat one. Then go out and get your favorite, double thick chocolate milkshake and see which straw you want to spend a hour pulling the milkshake through. That's the intuitive part. The rest of it requires an understanding of Ohm's law (Voltage = Current X Resistance, or E=IR), and how that interacts with series and parallel circuits when those circuits are reactive, meaning that the impedance changes with frequency due to frequency dependent energy storage and counter electromotive force, commonly called back EMF.

If you're already familiar with the typical loudspeaker impedance curve and the above principles, you're already on board. If not, a quick summary will have to suffice.

The signal from a power amplifier is proportional to voltage. Even though we're delivering power, the voltage is what we want to control, hence the "voltage source" designation. If the correct voltage is applied at the loudspeaker terminals, the appropriate power (watts, which is voltage x current) will be drawn by the loudspeaker as a function of its own impedance and the applied voltage.

Cable resistance is a series component. You can think of that as "directly in the way." When the signal has to move through cable resistance, the resistance drops a portion of the voltage. Intuitively, we worry about a power loss. Unless you're running, a single pair of Cat-5 or 24 AWG wire you picked up at the thrift store, power loss is inconsequential.

What's of more concern is frequency response, and indirectly, damping and transient response. The frequency response issue arises with resistance, which in itself is not frequency dependent, but the impedance of the loudspeaker almost always is. The voltage drop caused by the resistance will be directly proportional to its share of the entire series circuit. That means, in short, wire resistance will cause less voltage drop at frequencies where the loudspeaker impedance is greatest.

For example, a loudspeaker's typical impedance peak is at the woofer's low-end resonance, often in the range of 20 ohms -30 ohms, say at 40 Hz. Say, then, for the sake of illustration, that the loudspeaker drops to 2 ohms above and below that point. It's an extreme scenario, but not impossible, particularly in the "tweak" market that considers a difficult load some kind of unsaid status.

If we insert a substantial resistive component in series with the loudspeaker, via cable or some misguided "current source" circus trick resistor, what you'll get is higher output at the impedance peak at 40 Hz, and less output above and below, making the bass sound boomy. This applies to all frequencies, but the typical impedance of most loudspeakers makes this range the most common concern.

Inductance is also a series impedance factor with cables, but the inductive portion of the impedance of a cable changes with frequency. The higher the frequency, the greater the series impedance contributed by the inductance. The same rule of series circuits applies, in that the voltage drop is in proportion it its share of the series impedance, but because its impedance rises with frequency, the inductance attenuates higher frequencies more. This is why inductors are used to keep high frequencies away from the woofer in crossover networks.

This is potentially significant with loudspeakers, especially electrostatic panels that have an impedance that drops with frequency at the highest range, because of the low impedance value of a loudspeaker make any series component of the cable more significant.

With low voltage interconnects, like audio cables between your CD player and receiver, the series resistance and inductance of a cable have very little effect, to the point of being forgettable, as the input impedances typically range from tens of thousands of ohms on up, where the effect of a few ohms in series is inconsequential. You want a very low impedance ground path for noise reasons to reduce ground loop problems, if you've got a ground at all, but that's an entirely different topic.

Capacitance is a parallel impedance factor in a cable. The impedance of a capacitor falls as frequency rises. If you took a tiny capacitor and put it in parallel with your loudspeaker terminals, it would reduce the bass. That is why they are used with tweeters in crossover networks. If it were a big enough capacitor, your amplifier would have a hissy fit, drive tons of current through it at high frequencies (as it'd look like a short), and smoke or blow a fuse. Except for long runs of exotic cables with lots of individually insulated conductors connected to inherently unstable amplifiers, there's not enough capacitance in a hundred feet of speaker cable to make any competent amplifier raise an eyebrow.

Capacitance is of interest on low voltage signal transmission between typical CD players and receivers, because of the typically high output impedance associated with such components, usually in the 1 kOhm range. If there's enough capacitance dropping the impedance of the total load that the output sees at high frequencies, the impedance of the output circuit itself will drop the voltage, causing less output at high frequencies. So, for interconnects, you want low capacitance. But with speaker cables, where the output impedance is usually lower than the contact resistance of the terminations, this issue isn’t one. For speaker cables, you want low inductance.

Addressing our speaker wires of discussion, 14 gauge cable pairs have less inductance than a 10 gauge cable pair because their cable centers are closer together due to the smaller diameter of each conductor, but we want the low resistance of the 12 gauge or 10 gauge pair. If we double up on 14 gauge wire, the impedance halves on all counts. Not only do we get the same amount of cable as an 11 gauge cross section (give or take a hair) and thus the low resistance component, but we also further halve the inductance as compared to a single run of 14 gauge wire (which already was less than a single 11 gauge run).

Those familiar with capacitors in parallel will note that the capacitance will then double, in which case we've gone from an amount that we wouldn't even remotely consider caring about, to twice that, which in our context is exactly the same.

Again then, when it comes to choosing between keeping inductance or capacitance down in speaker cables, low inductance is our priority, and low resistance is a given.

Keep in mind that the idea of doubling up on 14 gauge conductors for speakers only works when you bind two conductors together at each end. If you keep them separate on the loudspeaker side, as would be done when you bi-wire a speaker, the benefits described are forfeit, as you only have one cable in series with any given crossover section at a time! In other words, you’ve got the same resistance and inductance in series with a given driver section, but are still using twice the wire, AND have twice the capacitance of a single run. Sound like a good deal? Want to buy the Brooklyn bridge?

So for each ideal speaker cable, we need four 14 gauge wires (two for the + and two for the -) of decent pedigree and a single pair of terminators at each end.

Brian, build us a cable why don't you?

In-Wall Cable . . . Outside the Wall

In-wall speaker cable is commonly available in a four 14 gauge configuration, twisted together in a nice tidy jacket, perfect for our purpose.  For this project I turned to Ultralink.  I've had good experience with Ultralink's budget priced interconnects in the past and felt confident that they could pull off a basic 14 gauge wire without error.

Shortly after my solicitation for review sample, a box showed up with 30 feet of Ultralink CL414 cable, enough to make three pairs of 10 foot speaker cables for my front three channels.

The CL414 is a straight up copper speaker wire.  No nonsense, just what we want.  The conductor is quoted as 99.9999% oxygen free copper (OFC).  This is also called 6N copper (as in 6 nines - 99.9999% OFC).   6N copper costs more than pure silver - even in the huge quantities that Ultralink buys to make their cables, and many of us feel it (6N copper) is the best choice as an audio conductor.  Relatively speaking, in the CL414 we've got a lot of 6N copper for a fraction of the cost of most brand name speaker cable.  Four differently colored 14 gauge wires are twisted inside a PVC jacket.  You might say, "PVC is not a great dielectric".  True, it will have more capacitance than, say, Teflon or foamed polyethylene.  So, don't use it for an audio interconnect.  This is a loudspeaker application though, so we don't really care.

The jacket is key here.  The idea of doubling up on 14 gauge wire could be done with "normal" speaker wire, but that would look a little messy.  The In-Wall stuff gives us what we're after in a neat jacket which in the case of Ultralink is nice and flexible, and flexible is always welcome in my overwired world.  If you end up liking this wire, you'll probably want to use it with your surrounds too and, it's already UL/CSA approved for in-wall use.  The flexible jacket is a boon when passing the cable through tight spaces, and being so called "virgin" PVC, its actually quite slick, again good for feeding it through tight spaces.

Terminate This!

Making sure a cable has a good connection at either end is in all practicality as important as the cable itself, maybe even more so.  If you've got the guts to refute the snickering of hi-fi snobs, and both your amplifier and speakers have robust binding posts, you could just stick the bare wire in them and come on to that fastening nut with all your might.  Maybe put a drop or two of Caig's Pro Gold on the wire just to stave off oxidation.

In my position as a reviewer, I appreciate the cable end that makes it easy to swap gear, i.e., having the proverbial banana.  Ultralink has a whole range of bananas to choose from, but I'll highlight the UL0534 for a couple reasons.  It's very affordable and putting it on the end of a cable takes virtually no skill.  The wire is held in place by two offset micro screws on the barrel.  A crimp and solder type banana (of course Ultralink happens to have one) would make the "best" connection between wire and terminator, but that requires a pretty hefty soldering iron and some skill.  Plus, with the screws, if you want to try a different wire, or you need a longer piece down the road, you can reuse your investment in these ends.

The bananas have pure 24K gold plated directly to the conductor, without the nickel substrate that many others use.  A nickel substrate makes the gold a bit "golder" and shinier but  introduces a layer of differing resistance from a material that, like iron and cobalt, is ferrous and therefore magnetic (and the word "magnetic" is one we don't ever want to see in a cable).

I was pleasantly surprised by how snug these bananas were when I plugged them into the amp and speakers.  To look at them you would not think so, but they hold on pretty tight.

Presto: Speaker Cable

There is nothing to constructing these cables other than paying strict attention to the fact that this is not a bi-wire cable!  Do not be tempted to get an extra set of bananas at the speaker end just to make use of the bi-wire posts on your speaker.  As Colin already told us, that would ruin what we are trying to do here.  If you can't help yourself, at least leave the shorting straps on the speaker in place.  You'll then have the "cool" look of bi-wire with the benefits of our little design.

You will need a small screw driver so that you can fasten the wire tightly.  I actually warped my el-cheapo screw driver when putting these together. Want to get snazzy?  Get a little heat-shrink tubing to tidy up the pairs at each end. Slip the heat shrink stuff on before you attach the terminations.

If you expect a religious experience with any cable, you'll probably talk yourself into having one here, and I sincerely hope you enjoy it.  No, the soundstage did not open up for me, veils of detail were not revealed, the midrange did not bloom with extra life, the bottom end did not suddenly become more robust and defined.  Frankly, I jolly well hoped none of that poetic drivel would happen! If it had, that would mean the cable I've been using for the past three years sucks big time.  Instead what I found was no objection whatsoever.  My speakers sounded as clean as I have ever heard them, and the power amplifiers of my receiver seemed unimpeded, able to hit reference level without any distress or aberrations in the sound.

Conclusions

This cable does what a speaker cable needs to do:  It just plain works.  There is nothing "remarkable" about the sound (that's a good thing), and the bananas make a solid connection.  While much of the brand name cable market seems content to create an exorbitant expense for us by supplying a mix and match game of cables which are more "filter" than anything else, we feel that an unremarkable cable (in terms of sound) is what we should be after, and Ultralink seems to share that view.  They do make a bevy of more expensive cable.  Such things as Teflon dielectric, silver coatings, and other features do appeal to many consumers. If you can hear a difference with those features, be my guest.

If on the other hand the back-to-basics approach appeals to you, this semi DYI cable performs, looks cool, is easy to assemble (no assembly at all if you forgo the terminators), and costs less than a buck a foot, yet is still sophisticated.  In fact, unless they've read this review, I'll bet anyone who tries this cable will think it is a multi-hundred dollar "premium esoteric".

Post-Script

On a somewhat related and interesting note, I recently asked the Cinesphere what they use for speaker wire.  Cinesphere is the world's first permanent IMAX® facility, and IMAX® represents the finest available in terms of commercial motion picture and multi-channel sound.  Their wire of choice:  Four 10 gauge stranded wires, twisted together, for each run.  In other words, the exact same configuration as our cable, only "upsized" for the their long runs (which at Cinesphere are about 100 feet).

- Brian Florian & Colin Miller -

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