The addition of the resistor-capacitor "Zobel" termination network completely eliminates the anomalies. His testing of "DIY Cross Connected Coax Cable", which is exactly what my cables are, found a huge phase anomaly at 10 Mhz and other cable reflections at 100 MHz. I then used the Belden speaker cables described above for the tweeters, and my old 12 AWG Monster Cable for the woofers.Īfter reading Rod Elliot's article on cable impedance I decided to add a 100 nF ceramic capacitor in series with a 50 ohm resistor across each speaker terminal to properly terminate the cable and dampen the high frequency phase anomalies caused by cable reflections. I modified the AR.com's crossovers so that the woofer and tweeter circuits were independent, and did not share grounds, and hooked each circuit up to its own set of speaker input terminals. Thus, the more delicate tweeter signal is separated in its own cable and is not damaged as it would be if the woofer and tweeter signal were traveling in the same cable. The theory behind bi-wiring is that by branching off from the amplifier and using separate cables for the runs to the woofer and tweeter circuits in the speaker crossovers, the inductance and capacitance that is generated by the relatively higher currents in the woofer signal do not affect the lower-powered tweeter signal. Because I built my new AR.com speakers with two sets of speaker terminals so I could experiment with bi-amping (which didn't work out so well), I decided to try bi-wiring instead. For connectors, I used Radio Shack gold-plated banana plugs.Īfter living with the above setup for a year or so, I decided to make a change. The wires are crossed in such a way that the conductor of one and the shield of the other carries the (+) signal, and the shield of the first and the conductor of the other carries the (-) signal. The speaker cables use two pieces of coaxial cable for each lead. At least, I use the Belden cable for the tweeters anyway see the "Bi-Wiring" section, below. Now I use speaker cables made from the Belden coaxial cable discussed above in the "Interconnects" section. Also, it generates high levels of capacitance from all those wires that is not good for the amplifier. Then, I tried braiding CAT5 network wire (described, among many other places, here), and that may have sounded better (hard to tell), but the braided wire is bulky, ugly, and unwieldy. That seemed to make an improvement, especially in the bass. My first experiment with improving my speaker cables, many years ago, was to buy 12 AWG "Monster Cable" (still "zip" wire, just very expensive zip wire). The Radio Shack plugs are the cheapest gold-plated plugs I could find (about $3.00 each). I don't think the gold makes any difference in the sound, but they won't corrode over time, and I think corroded connections can make a difference in the sound. I followed Jon Risch's detailed instructions for building the interconnects and speaker cables (also here).įor the interconnect connectors I used Radio Shack gold-plated RCA plugs. The cable is coaxial, low capacitance, has both a foil and a braided shield, has Teflon insulation, and a Kevlar jacket (see the specifications at the bottom of the page). As it turns out, this kind of cable is ideal for making very high-quality interconnects and speaker cables. I was fortunate to have come into the possession of a small amount of leftover Belden plenum network cable that was used to set up a network in an office where I worked years ago. God forbid they should short-out and blow the amplifier. It sounded a little brighter than the cheap-o cables, but the wires were very delicate and difficult to manage in the rat's nest behind the equipment. I didn't know any better.įor interconnects, I tried braiding thin (30 AWG) magnet wire (described, for example, here). I used to use standard 18 AWG "zip" wire for speaker connections, and the thin cheap-o interconnects that come with commercial low- to mid-fi equipment. I have experimented with various kinds of speaker cables and interconnects over the years.
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