Sunday, February 17, 2008

Wired Up

So, as part of our ongoing efforts to prettify and organize the house, I've been rewiring the home theater; both for ease fo maintenance, and for cosmetics.

I redid my interconnects last week (with audio dynamics braided shield stuff; it's good, and it's cheap. You can get it from Costco) which only took about an hour; this week was a bit more work.

The task here is to re-wire the 5.1 speakers, conceal the wiring, and ceiling mount the surrounds. Not as big a job as building a dedicated theater room from scratch; but still a fair bit of work.

First, John and I built new speaker wires.

Here's where I piss some folks off.

Now, audiophiles think that magic speaker wire will somehow produce "more musical" sound etc... etc... , but really there's nothing special about it.

All speaker wire is, is copper wire, with maybe a gold plated or gold/brass alloy connector at the end of it. It's used over relatively short runs, and relatively low power, as cabling applications go.

It's all basic physics; so much so, that so long as you cut your cables to within 10 meters or so of the same length, and terminate them properly; that there will be no measurable difference either sonically, or electrically between any two reasonable quality cables.

Unless you live in a very high RFI (radio frequency interference) environment, shielding your speaker cables won't make a lick of difference; and the resistance of a reasonable gauge of stranded copper wire is so low as to be nearly immeasurable at any run less than 40 feet in length; and of no practical difference until you reach runs of about 200 feet.

14ga stranded copper wire has a resistance of 1 ohm every 400 feet, and a continuous current capacity of 32 amps at 14.4vdc for short runs (or 8 amps for long runs). Most people have runs of 50 ft. or less; and their amplifier is outputting a signal to the speakers of most likely 1 amp or less; and certainly less than 3 amps.

Alright, so what's the deal?

First, buy yourself a 100 foot spool of 14 gauge stranded copper wire:



Yes, it's even oxygen free, and it's $21 for 100 feet of the stuff (actually I paid $30 because I bought it locally).

Unless you are running more than 200 watts, more than 100 feet; anyone who tells you to go heavier than 14ga for home speakers is either listening to bad advice, or trying to sell you something.

For most folks, with an amplifier under 100 watts per channel (the average a/v receiver outputs 70-90 watts rms per channel, with 2 channels driven; and less with all 5,6,or 7 driven), and a load of well under 10 amps total across all of their speakers (probably under 5), really you only need 16ga; but the cost difference is negligible, so why not. Besides, the connectors fit 14ga better.

But... But... what about Monster Cable?

Uhhh yeah.... no. They charge $100 for a 100 foot role of 18ga; and it's EXACTLY THE SAME WIRE as you buy from monoprice for $8. Their 14ga (they dont actually label it as 14ga, but that's what it is) it $125 a roll, vs $21.

Worse, if you buy assembled pairs from them... watchout.

Seriously, you would not believe how much they charge for speaker cable. It's actually offensive to me.

My setup has two 40ft runs for the surrounds, two 8 foot runs for the mains, an a 6 foot run for the center. Monster charges approximately $2.00 a foot, plus $20 per cable.

To buy the equivalent in pre-assembled cables from Monster?

$304...

I don't think so bubba.

The only difference between what monster is selling you, and what you can make yourself, is the cable ends... which Monster also sells you, if you're fixated on the name.

Actually, their cable ends are one thing they do very well; and if you can get a decent price on them, I don't mind buying them.

These:



Run $20 for two pair (enough to make one cable), which is a bit much, but they are very good connectors (presuming you like banana plugs of course; they make other varieties).

These ones:



are just $12 for two pair, which I think is a reasonable price given their quality, and in fact that's what I used for my cables (and what Monster uses on their pre-made cables as well).

You can get slightly cheaper crimp on connectors (they used to be dirt cheap at radioshack, but the whole audiophile scam industry has brought the price up all 'round), but I prefer these ones. You can also use solder on connections; but with these, if somehow corrosion does occur (the main problem with non-soldered connections), I can just unscrew it, snip off a half inch, strip it, and screw it in again.

So, for a total of $80, I've got the same thing as $300 worth of Monster cable... and hell, they even says "monster cable" right on them.

This is how many pro audio installers make a fair portion of their profit. They sell you commodity copper wire with fancy cable ends that took them 2 minutes per cable to strip and assemble, at 4 times the bulk cost of the cables and connectors for outrageous "custom premium speaker interconnect" charges (Sorry for saying this speakertweaker, I know you're a good guy and not a cheat, but most of those in your profession are not as honest).

Of course then I had to figure out how to run the stuff.

My house was built in 1953. I have plaster and lath interior walls with blown cellulose, and a plaster over blueboard ceiling in my living room (the original lath ceiling was replaced between water damage and an air conditioning retrofit in the early 80s).

I've been running the cabling in between the baseboard and carpet; but the 14ga is a bit to big for that, and I'd still have to deal with the run up the wall for the ceiling mounts.

As I said, the construction of the house conducive to running in wall wiring, without doing some serious work; and I really didn't feel like doing that.

Instead, I grabbed some of this stuff from wiremold:



That's the Wiremold Cordmate II system. It's self stick, interlocking conduit; with lengths available up to 10 feet (special order only unfortunately). It's commonly available in 30", 48", and 60" lengths, and a variety of connectors, corner pieces etc...

The Cordmate II is about the smallest, and lowest profile conduit you can get, that can actually take two pair of 14ga cables. They make smaller round section conduit (for antennae wires mostly), and conduits that are both wider, and taller (and even corner, crown molding, and baseboard conduits); but I don't need that much space for my home theater cabling (I do for my office with LAN wiring though).

I picked up a couple of the kits at the local Home Despot; because the way it's priced in every retail outlet I've checked, it's actually cheaper to buy one of the kits, than it is to buy the equivalent length of the conduit.

The kit comes with three 48" sections, and a variety of angles and connectors. The connectors are pretty discreet; and up against the corner of the ceiling and wall, they (and the conduit itself for that matter) are really pretty unobtrusive.

So I ran up the corner behind my equipment, then along the edge of the ceiling to the back wall, and along the back wall itself, breaking out with a tjoint and a flat corner joint at the end of the conduit run, to run the cables to these:




Omnimount 20
wall and ceiling speaker mounts.

I've been meaning to ceiling mount the surrounds for months now, and the mounts have been sitting around for a while waiting for me to run the conduit, and mount them up.

My surrounds have been siting on a shelf right behind our seating position, which put the right surround less than a foot from my right ear... less than ideal. Putting it up on the celiing let me move it out to the sides, and now the sound stage is far more diffuse, and imagin more accurate (thank you audessey).

Really guys, it's that easy. I can't understand these folks that spend more on their cabling and isntallation than they did on th gear.

So go, do it yourself; at least then you'll know how to fix it if it breaks.