Speaker wire questions (1 Viewer)

[Jared_C]

I want to know what is the best gauge wire to use with bookshelf and tower speakers. I have wharfedale, so they're biwireable, should i run smaller wire to the high frequncy and larger gauge to the low frequency speaker? What gauges do you reccomend, 100watts/speaker. Does brand matter?

 

[Bob McElfresh]

Hi Jared.
The real physics involved cause a roll-off of the higher frequency sounds for a LONG run. This is why many speaker sites recommend the following gauge depending upon run length:
1-10 ft: 16 ga
11-20 ft: 14 ga
21+ ft: 12 ga
Since it's a high-frequency roll-off we are trying to solve this means:
thicker wire to the tweeters
thiner wire to the midrange/woofers.

Does brand matter?

This is the question that causes more wars than any other around here.
In truth, for a 'sensitive' enough system, a different brand of speaker wire will affect the sound.
My favorite way of describing this is to think about drinking beer/wine from different glasses. Think drinking from paper/stryofoam/glass. The liquid always tastes the same, but there is a change in the experience.
You WILL get salesmen trying to sell you $500 speaker wires to hook up your $100 speakers. This is like putting 150 mph speed-rated tires on a Yugo.
My advice is to START with some good, oxygen free speaker wire like the "Sound King" brand from www.partsexpress.com. Get used to the sound, then later audition some more expensive copper and decide if the sound change is worth the $$$.
And always remember the 10% rule: Budget 10% of the speaker price for the wires. If a wire costs more than this, you are likely over-buying. (This works for electronics as well).
Hope this helps.

 

[Jared_C]

thanks bob for the detailed explanation. do you think it is worth spending the extra $$ to biwire my wharfedale 8.3 bookshelf's which will be furthest from the receiver and require larger gauge wire? i am using a sony str-de845 receiver (100x5), doldy, dts, etc.

 

[Tim Morton]

Thicker wires to the tweeters? I would offer up the opposite thinking. Woofers are bigger so they get thicker wires Well I am serious about what i say, but am rushing off sometplac, so the argument will have to be taken up by another. But suffice it to say that power consumption is greater with the larger drivers so it would make sense, at least to me that you wold not want to starve them. 12gauge seems to be be the disired wire if you are running straight monster style twisted cable, Once you get into esoteric wiring it ain't so simple.

 

[Jared_C]

Ok, i found a 100ft role of biwire cable in 14gauge at partexpress for about $30. I am assuming four wires of 14gauge to any of my speakers at 20 feet or less should be ample. anyone care to comment? thanks

 

[Mike Matheson]

Jared,

Just for fun (and in the joy of experimentation) I'd jump on that biwire cable you found. Then when it arrives, first hook everything up using a single run, listen for several days, then hook up the second or biwire run. Listen for several days. Now go back to the single run--and see if you notice a difference.

I'd love to hear the result of your test.

The cable you've found isn't all that expensive, so why not get it, be done with cable shopping, experiment a little hooking things up, and enjoy the music?

 

[Chu Gai]

a rather simple way of determining if biwiring results in any audible differences as opposed to the the same run not biwired can be found at the bottom of the following thread. at the very least, using two runs of 14 gauge gives you an equivalent 11 gauge wire.

 

[Jared_C]

thanks for the responses. i think i will give mikes idea a try, biwire and and single run. Too bad the wire is out of stock until the 24th at partsexpress

 

[brucek]

Bob says,

thicker wire to the tweeters - thinner wire to the midrange/woofers

I'm afraid I'll have to respectfully proffer an alternate opinion. Tim Morton has it correct in his post.
To fully appreciate the reason that this quote is somewhat incorrect requires an understanding of wire DCR (DC resistance), reactance (AC frequency dependant resistance) and system damping.
The impedance of a speaker wire (or any wire for that matter) is the sum of the DCR (frequency independant resistance) plus the reactance (frequency dependent resistance, made up of inductive reactance and capacitance reactance).
Since a speaker connection is a low impedance interface with average loads of 4 to 8 ohms and amplifier output impedances of (an almost ideal voltage source) near-short, we can easily ignore capacitance, whereas inductance adds a reactance (frequency dependent resistance) that increases with frequency and can have a marked roll-off effect at upper audio frequencies. This reactance, (that by the way is fairly independent of wire size), increases with length, since it's an attribute that's additive per foot. A typical inductance of most zip is about 0.20 microhenries/foot and can create a roll-off of higher frequencies if the cable is of sufficient length. As I said though, the wire size has little to do with the inductance and remember the reactance only becomes important at higher audio frequencies and longer lengths, so the watch word is to keep your cables short as possible, combined with a cable that exhibits as low an inductance as possible, specifically with respect to tweeters.
The DCR though, is directly affected by wire size. This is the frequency 'independent' resistance a wire exhibits, that increases as the wire gets smaller and is additive as the wire gets longer. So, independant of frequency, as the impedance increases because of length or decreased size, we will experience a loss in the cable (in the form of heat). Low frequency drivers do have a special problem with their connecting cabling, which comes under the heading of damping.
Damping generally effects the "tightness" of bass frequencies. The higher the number the better.
It's the amplifiers ability to control or damp the speakers voice coil oscillations. When a signal is sent to a speaker and then stopped, the speaker cone continues to move, and creates or presents a back voltage to the amplifier. If the output impedance of the amplifier combined with the impedance of the interconnecting speaker wires is very low (read a short) then this oscillation is damped and the bass sounds very tight. The higher this combined impedance, the more the speakers' voice coil will continue to move and effect the sound.
Damping factor is a ratio of the load impedance (generally considered a flat 8 ohms) to the output impedance of the amplifier. Very nice, but generally in practice though, you have to take into consideration the impedance of the wire connecting the two devices and the fact that speakers with passive crossovers are an extremely non-linear device. Again, the short answer is that the higher the number the better.
The long answer is that in most solid state amplifiers the output impedance is fairly constant (read linear) and very, very low over the entire audio spectrum and as such can almost be ignored in the formula because the system impedance is overwhelmed by the non-linearity of the speakers crossover plus the interconnecting wire resistance (DCR). This is the reason to ignore small differences in amplifier specs of damping. It's usually insignificant in relation to the effect of the speaker wire. I'll show you why shorter or heavier gauge speaker wires are better.
Look at the formula for damping using a figure of 300 for damping. This yields about a 0.026 ohms amplifier output impedance:
(speaker impedance) / (amplifier output impedance)
= 8.0 / (0.026 ohms)
= 300 : this is a very acceptable amplifier damping factor.
Now add in a typical connecting wire of 12 feet of 12 gauge zip cord.
12 gauge at 12 feet yields about 0.039 ohms of pure resistance. Capacitive reactance can be ignored as insignificant, as can inductive reactance at the lower frequencies and this short length. I calculate at 100 Hz that inductance would only add about .0015 ohms to 12 feet, so I'll ignore it here.
(speaker impedance) / [(amplifier output impedance) + (wire impedance)]
= 8.0 / (0.026 + 0.039)
= 123
Anyway, you can see how the system damping factor dropped quite significantly from 300 to 123 even when using very heavy gauge wire. It shows the importance with respect to LF drivers of using a low gauge (thick wire) connection and the importance of using thicker short speaker wires to raise the system damping factor.
The conclusion would be to get heavy gauge speaker cable with as low an inductance per foot and keep it as short as possible. This would be the best for both LF and HF drivers........
Jared, as far as bi-wiring is concerned, there is simply no scientific support (other than anecdotal evidence) for using bi-wiring. I'm afraid as far as bi-wiring is concerned (if you already are using it), you'd probably be better off using bi-wire cables with your speaker straps reinstalled. At least then you'd take advantage of the lower gauge realized by combining two cables to each speaker. It would certainly help the LF drivers damping path to ground through the amplifier output.
Follow the advice to get heavy gauge speaker cable with as low an inductance per foot and keep it as short as possible.
brucek

 

[Jared_C]

thanks for the great reply brucek. I plan on using this cable for my ht click here , 4 14gauge wires to each speaker, probably biwired, can't hurt. any closing comments?

 

[Jared_C]

I am about to go out and buy some speaker wire today, i have very limited funds so should i spend the extra $$ to get 100ft of 12 gauge or stick with my intentions of getting 100ft of 14gauge($26) for about $10 cheaper. I will be running 100wx5 to wharfedale diamond speakers, rated 100w rms. I believe 14gauge will be ample, the main speakers will be about 10ft apart, the center 5ft from receiver, and the rears 20ft at most. What do you guys suggest? please reply asap, thanks

 

[AustinKW]

Jared,

14 will be fine but you'll always be wondering - "What if I had bought the 12"? Bottom line - get the 12 and enjoy your system - $10 is cheap for a lifetime of no regrets.

Austin