[reed.hannebaum]

I personally use 12 AWG. In the past I have bought from Parts Express; BUT, the last roll of wire I received from them was of thinner gauge even though it was marked as 12 AWG. I compared their new wire with some wire left over wire from a previous purchase and it was definitely thinner. I made a complaint about it but nothing ever happened.

So as a word of advice, compare wire before buying a large quantity; and I don't mean the insulating jacket. Buy small quantities from various sources and look at the actual wire size. Now it may not make a great diffeence if you buy 12 AWG and the wire size is actually 14 AWG, but you should get what you pay for.

 

[reed.hannebaum]

I believe that a wire is rated by the total cross sectional area of all it's strands. If one wire of the same gauge uses 10 strands and another uses 20 strands, the one with 20 strands will result in a smaller overall diameter. The smaller individual strands pack together tighter and there is less wasted space between strands. This could account for the reason two wires were rated the same but different diameter.

This is certainly true. In addition, wrapping geometry, and how tightly the strands are wrapped can make a difference. Though significant, these factors will have only a small to moderate effect on the overall wire diameter. In all cases, a stranded wire should be of greater diameter than an equivalent guage solid wire due to the inherent air gaps.

The kind of diameter difference I am talking about is illustrated in the picture below (curtsey Roger Russell):

Unscrupulous wire manufacturers can make a wire look to be of a heavy gauge when in fact it is only the insulation that is heavy, not the actual wire.

 

[reed.hannebaum]

Reed, I've looked at the pics you fwd. and I have a quick question. I cut back the insulation like your pics showed and then twist the wire strands together. I then fold the twisted strands over about midpoint on the bare wire. I do this because I believe that by getting a larger diameter wire into my speaker terminal, It makes for a better contact point between my wire and the terminal. I do not know if this is correct reasoning or not and am just wondering if you or anyone else would have an opinion about this practice I am doing. I realize that buying larger wire may be the answer, unfortunately, I am in the "Job" hunting mode right now and not willing to put out more money for wire at this time.

Thanks for any assistance.
Bob.

Bob, I wish you well on your job hunting.
Your practice of doubling over the bare wire is not a bad idea. In order to maximize the amplifier's control over the speaker voice coil, you want to minimize the impedance between the amplifier and the speaker. This effectively increases the damping ratio which is a good thing to do. Everything interconnection (amp binding post to speaker wire, speaker wire to speaker binding post, etc) between your amplifier and speaker is a point of resistance which you want to minimize. Increasing the contact surface area of the interconnection will help minimize that resistance.

 

[reed.hannebaum]

I think a few things are getting mixed up here. I suspect he is thinking of Damping Factor, which is the ability of the amp to damp back EMF from the drivers. This is generally better in amps with lower output impedance. It is like braking a motor with a short.

I think he was also talking about reducing impedance in the wires, not in the load. You can affect frequency response with capacitance and inductance in the wires, and resistance causes losses overall. The Kimber wires, for instance (IIRC), have low inductance but higher capacitance than most, leading to a bit of a high frequency roll-off. A twisted pair like you would have in Cat5 ethernet cable would reduce the inductance as well. Most of this has so little effect at the distances and frequencies that we are talking about that it makes a small difference at best.

I agree, room treatments, or even just moving the listening position or speaker location a small amount will make far more difference in most cases.

Yes, Damping Factor is the correct term. However, the Damping Factor is a ratio of the speaker resistance to the source resistance. You are also correct in assuming I was talking about lowering the impedance in the wires and in particular the impendance in the interconnections between the amp and the speaker. I agree, that at the audio frequency range these things don't have a great impact, especially with amplifiers having bipolar outputs where the output impedance is very low as compared to Mosfet or transformer outputs.