How to select a good Speaker Cable


Speaker cables do have a significant role in how our system sounds. Different cables sound different. 

So which one is the right one for you?

The Speaker Cable is an extension of the Amp. and not an addition to the speaker's load. It shall have a certain resistance (low) not to spoil the Amp's DF figure. As so, it can be calculated and there is a formula to do it.

The higher the Amp's DF, the lower the Speaker Cable's resistance shall be. As today SS power Amp's get DFs of 400 and above (Digital Amps go by thousands) the cable of 10 ft (3m) long, gets as thick as 0 AWG.

I can see your eyebrows elevates, when that thick cable is to be deal with. Most Speaker Cable makers skip it because of that. So most cables on the market (regardless of the look or price) are of 14-12 AWG. Way less that supposed to be.

Worst! no Speaker Cable maker, dealer or seller knows the answer, of what is the correct cable for your system. 

So most of us ended up, with a cables too thin for the task.

A conducted test, on this site, about a year ago as well as with some closer friends, shows a significant improvement with a calculated size cable over their previous cable. The results were all positive and preferred the calculated cable.

So, instead of asking: which of two brands, or two prices or two colors of Speaker Cable do I need, you should ask how thick of a Speaker Cable do I need.

I'll be happy to provide you the calculation, for who request it. All you need to provide is:

1). Length (Ft. or meter)

2). The Amp's DF figure.

Thanks


128x128b4icu
Sorry Mr. djones51
There are many articles on the web, claiming other. None is saint.
At the time your link has no test data, no evidence of people who tried it and reported of the difference in sound - I do.
Pleas try not to send me read long and none relevant articles.

The truth about low DF (20) is that it is mostly common in Tube amplifiers, Amps with output Transformer (like McIntosh). or old (70’s) SS amps. Yes, when the DF is that low, the speaker cable has no significance. But when it goes above 200, as most SS power amps do, it matters a lot. Exchanging a poor #14 or #12 cable with the right cable makes a significant difference.

Sorry Mr. b4icu but try again. Large guage cables have inductance problems. Normal sized cables between 10awg and 16awg are sufficient in most all cases. DF isn't that big a deal. Quit shilling nonsense.

https://benchmarkmedia.com/blogs/application_notes/audio-myth-damping-factor-isnt-much-of-a-factor

1). 12 Ft. length

2). damping factor of 3 (Three)


Been using single runs of 26 gauge solid core copper for 15+ years (various 8 and 16 ohm speakers have no crossover).


DeKay


Mr. djones51

I’d kindly asked not to refer me to web articles. There are so many out there, with different ideas. So what?
None are yours. It is your choice which one to addaped, and which one do reject. So it is for myself.

This idea here is mine. So as the articles won’t keep up the discussion, let’s leave it out from the beginning. Thanks.

For the inductance, if you read what DF is, and how it is calculated,
than you may see, it is ignoring the inductance and capacitance and use pure resistance values. Even though, if you look into a power amp’s schematic, you will find a few from both on the output stage!

The DF value, as so, is a pure number (just as dB) as it is the ratio between a constant 8 ohms (resistance, not impedance) and the internal Ro (output resistance) of the Amp. as so, the value (lets say 400) is a pure number. no values.
A thick cable comes assingles and not pairs, molded in a flat or round synthetic compound. You can drop the inductance. A #4 or #0 cables resistance is so low, that if there is any inductance, it is negligible.

On top of all said, did you ever gave it a try?
Because for those who did, it made a huge difference.
If you didn’t, why won’t you try it and then come back to the discussion.
That would make more sense.
Mr. dekay

What Amp has a DF of 3?
I assume it’s a tube amp. None of this discussion is applicable in that case. For a DF of 3, a phone line cable may do.
DF of 3 equals to Ro = 8/3 = 2.67 Ohms.
For a SS Amp’s DF as high as 200 (PASS Labs), Ro = 8/200 = 0.04 Ohms.
For a DF as high as 700 (Luxman), Ro = 8/700 = 0.01 Ohms.
For the last two, the cable’s resistance (in series and need to calculated twice (for the + and -)) is significant.
For 2.67 Ohms - Not much.

Bottlehead Paramour(s) 2A3 DH SET amps without C4S.

I used Bell wire once (22 gauge) when I moved the amps to a friends to try them with Klipsch Chorus II's, and it seemed to be fine.

DeKay

Battery cables ride again!!  Woohoo!

I wonder if somebody makes hawsers out of copper...

Amp with DF of 200 , 8/200 = .04 Ohm
 1 ft, 0 awg copper cable has resistance of .0000983 Ohm/ft
Total drive resistance. .04 +.0000983 = .0400983 0hm/ft

1 ft ,10 awg copper cable resistance = .000998 Ohm/ft
Total drive resistance .04 + .00099= .040998 Ohm/ft

Difference between 10 awg and 0 awg is .040998 - .0400983 = .0008997 Ohm/ft
For 10 feet of cable + - ( .0008997 * 20 = .017 Ohms)

.017 Ohms = insignificant
Mr. djones51

The AWG STD : https://www.powerstream.com/Wire_Size.htm
Shows a ratio of 1:10 between a
#10 wire: 0.9989 Ohms / 1000 ft. and a
#0 wire: 0.0983 Ohms / 1000 ft. resistance.

There is an additional decimal zero there!

It makes no matter of how long is a cable, the ratio remains the same.
For a 10ft cable, that has two wires: a + and a -, ( = 20ft in total),
For a #10 it is 0.9989/1000*2*10 = 0.020 Ohms.
For a # 0 it is 0.0983/1000*2*10 = 0.002 Ohms.
Same ratio as with 1ft. or 1000 ft or any in between.
10 times lower resistance is significant for a DF of 700:
Ro = 8/700 = 0.011 Ohms.
Take a #10 cable of 10 ft long: 0.020 + 0.011 (DF) and you get a new DF of only 258! You Just lost 442 or 63%.
Just by using a thin cable, you gave up 63% of your investment, as far it regards to the DF quality. about the same in sonic quality too.
Those who tried, rather than argue, reported so.
Not all DF call for the same #AWG. For a DF of 200, #4 will do.



Mr. twoleftears
Not all amps and length call for a #0. It may go less, but also more!

Your link to Amazon is a good start. Some did it in 2018 and here is what they had reported:

1).

Pass Lab 250.5 with Magnepan III's.

I replaced DIY 5 foot 16 AWG silver ladder line.  Have previously used a variety of commercial Helix design, solid flat wire and braided multi-stranded wires insulated and in multiple sleeves.  Alll 12 AWG, 5 to 8 foot length.  Costs ranged from $400 to $2,000.

I purchased 25 feet of 0 AWG form a supplier on eBay for $45 ($12 shipping) and four brass (supposedly gold plated) battery connectors ($7.49).

I constructed four five foot cables in just over one hour.  Battery connectors were converted to spades with a cold chisel and wire cutters, cable was cut with a hacksaw and insulation stripped with the hacksaw.  Spades were connected to Pass Labs 250.5 terminals (PL does not supply banana plug receptacles).  I attached banana plugs to a two inch piece of silver plated 8 AWG wire.  I hollowed out a holle in 0 AWG wire with a punch and did not remove insulation.  I then inserted the stripped 8 AWG wire in hole and secured the assembly with a hose clamp around the insulation at the cable’s end.

The cables were attached to my thirty year old modified MG IIIa’s.  

The results are stunning.  The amount of undistorted energy filling the room, is jaw dropping.  I keep turning up the volume to levels that previously irritated my ears, and experience no irritation.  In the modified lyrics of B.B. King, “The shrill is gone.”  My wife is hearing new detail in cuts she has listened to many times before.

In my case, b4icu57, you were absolutely correct, thank you (except for the part of you doubting ribbon speakers would be improved with installation of your design).  I can’t wait to try the cables in one of my other systems that employs cone speakers.

I am sure every case is different.  Nevertheless, I encourage other hobbyist to test your theories.

Thank you for your generosity and patience.
All good wishes 

2).

My cables arrived today. They're beasts!

As suspected the forks won't sit in binding posts without an adaptor. I'm currently using banana plugs. Here's an image of the before and after cables: https://imgur.com/a/De0LmuG (credit card for scale).

I hooked them up and there's a definite improvement. The sound is more transparent. I need to listen more but I'm happy with this investment. I'm going to replace the bananas with some bolt on ones: https://uk.farnell.com/staubli/22-1053/banana-plug-50a-4mm-screw-m4/dp/1085560, that'll give me a better connection. The current plugs are on tight, but it'll be nice to get a stronger hold. The stiffness of the cables means that there's actually very little weight on the binding posts as the cables stand up straight from the floor.

Thank you b4icu. As you said to me, where else can I get that level of upgrade for that money.

Amp: Classe CT-5300
Speakers: B&W 802 Nautilus
Previous Cable: 4mm / 12 awg, 2.5 m

Cost is £25 for the 5 meters

New cable: 0 awg, 2.5 m (I was recommended at 4 awg but was told 0 would be fine)

Impressions:

More detailed, more transparent. Like another layer has been peeled back from what was, in my opinion, an already transparent system.

Either way, b4icu said he’d recommend a cable that would give me an improvement. I tried it, it did. I don’t see the problem.

And now he’s two for two.

3).

Mr. Wilson, who exchanged a Transparent Audio Laboratory 14 AWG 12 feet long cable, that costs about $250, with a 0 AWG 2.5m long cable:

Amp: Emotiva 250W/Ch.

Speakers: Vienna Acoustics Beethoven.

 

"My initial impressions: It’s like having new speakers. The sound is pure and clean. Minute details are suddenly apparent. The range is amazing. Highs, mid-tones and a new bass that I didn’t know my speakers were capable of. I wonder now what I need the new … subwoofer for!

It feels that for all these years my speakers were being chocked and suddenly they can breathe and have their full voice.  

To say I’m happy about my new speaker cables is an understatement. I’m thrilled. Thank you for building these superbly engineered cables to unleash the full potential of my home sound system".

 4).

It improved the sound quality of my speakers (B&W 802N). Sounds are clearer and less congested. Continued listening and swapping back and forth reveals the same result. Others have said the same, including my wife.

For the £150 or so it cost me I would heartily recommend it.
I upgraded from Van Dam blue speaker cable.

5).

Below is SAM’s DIY cables sound impression.

My room is quite big so I have an issue of insufficient bass.  I recently added a pair of Rel 212se to pair with my Wilson Alexia driven by Passlabs 350.8 and I thought that it has made my day.  I have top to bottom and the music flowed v nicely with the Kharma Grand Ref speaker cables. The 1st impression upon installation of the DIY cables was wow 😮 it sounded very musical.  While the music sounded sweet with Kharma, the DIY cables sounded more realistic.  Soundstage was equally wide and the overall music has more drive.  Bass notes were drier and has better separation / weight.  As lack of good bass was my issue, I was pleasantly surprised.  The high extension seems to have lessened and sounded less sparkle, but sufficient and overall adequate.  The mid's and vocals seems to have taken to be more backward staging.  Therefore the presence of the mid's is where it is weak in.  Overall, this set up sings and I feel that the flow of music is more realistic and enjoyable and the Kharma is now in the box.

6).

Below is JOHN’s DIY cables sound impression.

I have been chasing for a better hifi system all the time. I have gone through numerous changes of preamps, amps, turntables/cartridges, phone amps, CD transports, DAC, interconnect cables and speaker cables over the many years in this hobby.

My present amps are Pass Labs 160.8 mono blocks (damping factor 200) driving Magico Q5 speakers with Ansuz Speakz C2 speaker cables. My 1st impression after installing the DIY 4AWG 2 meters length cables was the system sounded very pleasant and musical. Bass response was enhance and tighter and I noticed more excursion on the woofers motion.   The soundstage was equally wide but with more body presentation. The high is a notch less which is good as it is less edgy especially on vocal. I am very happy with the new DIY cables that I decided to retired the Ansuz in the box.

7).

Below is my DIY cables sound impression.

My interest in hifi date back to late 60s with Dual system. Bought JBL4315 speakers and Harman Kardon Citation 16 pre and power in 1970. I still have the Harman Kardon power amp in mint condition. Like John, I have gone through numerous changes in both equipments and cables in my hifi system over the years, trying to chase after that dream system.

Now I am using 4 Telos 600 mono blocks bi-amp to the Kharma Exquisite Ref 1 E Signature speakers with 2 pairs of Kharma Enigma Signature Loudspeaker cables for the last 10 years. My 1st impression of the DIY cables which cost less than USD100 was overwhelming. It sounded musical and not bright to the point of edginess especially on female vocal when I play loud to around 90dB region. Soundstage is wide with overall presentation very dynamic and full. Lost a wee notch on the sustain on the treble resulting in quicker decay of the high notes or less sparkle. However with the diamond tweeters of the Kharma, the extension of high is still more than adequate.

The best takeaway for me on the DIY cable is no edginess of vocal (hurting my ears) when I play loud. Like my friends, I retired the Kharma cables in the box which I have been using the last 10 years. I may try to parallel the Kharma with the DIY cables after spending some extended time with the DIY cables.

All our high-end cables are 2 metres in length with no spec on the gauge or size of

the cables.


SAM’s Kharma retail price USD 8,000 for 2M pair.
JOHN’s Ansuz Speakz C2 retail price USD 8,400 for 2M pair.
KHIAK ‘s Kharma retail price USD 17,000 for 2M pair.


So, instead of asking: which of two brands, or two prices or two colors of Speaker Cable do I need, you should ask how thick of a Speaker Cable do I need.

This is right out of Stereo Review circa 1970. Awful long time to still be fanning the flames for Julian Hirsch. Or are you just being thorough and decided to start your speaker cable research with articles from 50 years ago?

My guess is this is sincere, and genuinely oblivious of just how out of date this is: Half. A. Century.

You’re not adding the amp resistance.
DF 700 = 8/700= .0114 Ohm
0awg resistance = .000098 ft
10 awg resistance = .00099 ft
Total drive resistance 0 awg = .0114 +.000098 =.011498 ft
Total drive resistance 10 awg = .0114+ .00099= .01239 ft
Difference = 10 awg .01239 - 0 awg .011498 = .000892 ft

The difference between using 10 awg and 0 awg over a 10ft speaker wire
10*2 * .000892 = .017 Ohm
Learn how to figure what you’re supposed to be doing you’re not adding the amp resistance to the speaker wire resistance so your numbers are skewed. The DIFFERENCE is only a .017 Ohm for a 10ft speaker wire in other words INSIGNIFICANT.

Most cable resistance is fairly low enough that DF may not be that importance.  

The problem comes in when the impedance of the speaker load increases toward 20KHz that damping factor could be a problem especially with tube amp.  If so, the sound could sound harsh on the treble.  

A speaker with high impedance at high frequency can use a Zobel network to flatten out the impedance so that it may work well with tubes which are more sensitive to speaker load vs. solid states.
Just got the Cardas Clear Cygnus. I just love them. I hear a sonic difference. And it isn't a psychosomatic thing. 
Post removed 
I just use 0000 AWG welding cable. $40/ft at my local welding supply store.

NEXT.
Mr. djones51

I stand behind my calculations. 
Rather than do a comparison of the difference (R #10 awg - R #0 awg), 
Do R #10 awg / R #0 awg.
The ratio is 1:10
your DF 700 Ro is not correct: 8/700 = 0.0114 or 0.011 ohms, rounded.
It is significant.
Just read the sharing of those who tried it (if you have the time and the patient to read the thread of 2018:)
https://forum.audiogon.com/discussions/no-one-actually-knows-how-to-lculate-what-speaker-cable-they-need
It's all there. People, that rather argue the numbers gave it a fair try.
The results are interesting: They claim that it makes a difference and a BIG one! 
Mr. fuzztone

Which model of tara labs did you purchase? How much did you paid for it?

The Omega (#4 awg) or the The Grand Master Evolution ( $000 awg) ?
Your favorite brand is thinking that the thicker the better. So this is a good start.

They do not link the need of such thickness with length or DF, but it well related to the price.
My recent check (about 4 years ago) suggested a price of $32,000.- for the Omega, at my local dealer.
I made my friend a pair of #4 awg (PASS LAB 250.8) for material cost:
Less than US $75.-
Up’s that’s a bit cheaper than the Omega...Yes, it came without a fancy box, nor fishnet sleeve (-:. 
I really don't think it makes a difference when he cleans the dust over the cables, once a while.

Now I’m into assemble a #0 awg, so he asked me to have it for a demo.
The material BOM is about to arrive till Aug. 5th. 
Even though the calculation shows that #4 awg is enough, I would be happy to see if a #0 awg improve the already good sound he has (B&W 802D).


Mr. andy2

Tube Amp. have a low DF (less than 20) so the cables are insignificant in that case. Not at 20kHz nore any other Fr.
Above there is a guy who has an Amp. with a DF of 3 !!!

It is very significant when using a fine SS Amp. with higher DF's (above 200, up to 700 or 1000, before getting into D class with DF's of 2000 and above).
^^^ If an amp has low DF (high output impedance), it will drive the high frequency more if a speaker has a rising impedance toward 20KHz which will result in harsh treble.  

But if an amp has high DF (low output impedance), then the difference is less at low freq. vs. high freq.
I’d kindly asked not to refer me to web articles. There are so many out there, with different ideas. So what?
None are yours. It is your choice which one to addaped, and which one do reject. So it is for myself.
Wait a second:  I'm not sure what you're saying.  Are you claiming that because something is published online that it can be immediately discounted regardless of the source?  Are you saying that footnoted claims are dismissible because they rely on others' research?  Are you saying that the only valid opinion is one you have derived yourself, and that prior work by others can be dismissed simply because someone else did the research?  I really don't get what your point is, other than that no claim can be true if it can be backed up, which is just sad.
No I am going to argue numbers because you're trying to sell cables using irrelevant numbers. What's relevant is the DIFFERENCE  between one guage and the other using the amplifier resistance plus the wire resistance not the percentage of change in one wire over another without taking the DF into account. To be even more precise you should know the speakers impedance swing as well. 
Mr. hilde45

Not yet.
All the cables thing was absolutely free.
I provided the calculation, some advice and all the rest was done (DIY) by those who had the will to pioneer the idea.
As you can see, some sharing of their comments is attached...

If someone would ask for a cable, I might do it. Never did it for sale or money.

However, I did developed some methods, to include one to use the same product, for #0 awg, 2x #0 awg and 4x #0 awg.
I made one #4 awg and one #0 awg for friends, for the cost of materials and shipping. (one is local (Israel) so no shipping, one was in Vancouver BC, Canada).
Now I'm building a #0 awg (10ft. / 3m long) for domestic demo.
Mr. djones51

As you can see above, I’m not selling anything. I’m offering an idea for free. Mostly for a DIY project that cost below $100.- In this hobby it’s a small and insignificant amount that no other investment of $100 would do so much improvement to your sound quality.

For the calculations, sorry but you are wrong. It looks that you are determined to go against me, no matter what!

The speaker’s impedance is non relevant in this case. The Speaker Cables (even though they called so) are an extension of the Amp. and not of the load (speakers), when analyzed.

It can be a
Magi 1.6 or III, with 4 ohms and 86dB/w/m SPL efficiency (hard to drive) or a
Klipsch Forte-II with 8 ohms and 99dB/w/m SPL efficiency.
The same apply for both. It was checked and tested.
The same don't apply for both. Why bother with DF? Speakers don't have a flat 4 or 8 Ohms they can fall to 1 Ohm and jump to 30 Ohms. A 4 awg cable in home audio is not necessary and when figured with amplifer and speaker resistance is a fraction of resistance of the whole. Now perhaps if your speaker run is 50ft to subwoofers it might have an audible effect but normal 8 to 12 foot runs I'm not going to bother with a battery cable. 
I used to be in the camp that wire is wire, I have learned through my own experience that this could not be farther from the truth. Speaker wire can have a large impact on SQ IMHO and I view speaker wire not so much as an extension of your amplifier, but more of an interface between Amp and Speaker. I have also learned that one not need to invest a major outlay of $ to get excellent results. Unless someone asks, I'm not going to bore readers of this with my long journey that resulted in my final "interface" with my speakers. The short answer is I ended up Bi-Wiring my speakers. My Speakers are two-way, each with a 15' run of #10 awg Belden 1313A going to the low frequency driver, and Audioquest Type 4 (#15.5awg) going to the high frequency driver. The results were excellent with this configuration and my total outlay ended up around $220 for two fifteen foot runs. I have read about many high-end Audiophile speaker cables, but there is no way I can justify spending over 5K on speaker wire, I just do not understand what I would be missing, I don't believe much! Thanks!  
Mr. grm

May I contribute my 2 cents to your happiness?

1. What Amp. do you use (more as what is it’s DF)?
2. Bi wire is a way to connect two relatively thinner wires instead of one thicker. On Spice (SW) analysis, the results of connecting one cable of #7 awg ( 0.4982 ohms / 1000 ft.) is equal to connecting two #10 awg, of the same length ( 0.9989 ohms / 1000 ft.).
The problem is, that it’s hard to find ready made #7 awg cables, but more common to find #10, #12 or #14 awg cables.
3). 15’ is a bit long for a speaker cable. As longer it gets, so is the resistance increase. So #10 awg with that length might be no so good of a cable.

Please pay attention, that I do not say a thing about prices.
A simple DIY project and cables + accessories, cost less than $100 can work for you. That’s way less than $220 or $5k!
I never thought that cable prices should be high.
Mr.  djones51
It's getting a bit annoying...
If you are not going to bather with my idea, why do you keep nudging on endless errores issues?

Most Amp's on the market will not deal with a load as low as 1 ohm and will shut down. For most 8 ohms rated speakers, the impedance is between 3 ohms and 30 ohms.
Running 50' of speaker cable is not recommended.
Buy a long XLR cable and place the Amp. as close as possible to the speaker.
Most speaker cables out in the market, used by sound owner is about 10ft, give and take 2ft.
The best would be to use two monoblocks as close as possible to the speakers (even put them back to back and use very short jumpers. The distance between the power Amp's and the Pre. can use XLR balanced cables of extended length if required.
It is essential to lower the cable resistance and one good way doing so is shorten it. The other is getting it thick.
It's your choice which suits you.





If you think Richard Vandersteen knows anything about speakers he always says use the shortest speaker cable possible and longer component cables for the best sound. Not the other way around. When running all your calculations don’t disregard length, it can be more important that gauge.
Mr. sgreg1

Thanks. I do take length into my calculation. Length and DF.
The outcome is the thickness (# awg).
The thing is, that the Amp's DF and required cable length are a given.
The thickness is the outcome.

None balanced cables (interconnect cables) over 3ft. are a bad idea.
Try to avoid it.


"Yes. But it was 2 years ago. It's time to undust it again..."
Some skeletons are better left in the closet.
Mr. glupson

Says who?
The one that have an interest? Someone who is Making Speaker Cables, a Dealer, a Salesman?
They would benefit from that (If: " skeletons are better left in the closet").

You say: The Audio hobbyist should be treated as mushrooms:
Kept in the dark and feed with crap...

I say: let’s light Speaker Cables issue up, get some sense in it, and enjoy from a way better sound.
All have the right to know the truth and enjoy from it.

As for the skeletons:
Mom say: Johny, you can play with grandma, but when you are done, return her skeletons to the  closet
:-)
b4icu,

What I really meant is that your previous, virtually identical, thread was long enough and, in the end, not useful enough to deserve repeating.

Most of the people who visited did learn that cable has to be too thick to be conveniently connected, has to be short, and that despite all the calculations you provide, it is always like that. Maybe you should dust that thread off by yourself and check what it came down to. An arm-thick cable and some, quite bizzare, methods how to connect it to equipment without damage.
Sorry, there were quite a few who made a cable and posted very positive replies. A #0 awg, is more like your thumb rather your arm. A #4 awg is way less.
Is that is your excuse? I hope you don't want to hear such a say: "its  too thick to be conveniently connected", from your doctor before a surgery.
It is unaccepted. If so many pioneers could easily overcome that problem, all can. Bizzare? a thin cable, good for all, cost an arm and a leg, is  Bizzare!
Some methods were offered, practiced and successfully implemented.
If that is your requirement, just say so. 
Hello OP,

You asked for the specifications of my Amplifier, it's a Krell Vanguard driving a pair of Sonus Faber speakers rated at 8ohms.

The output impedance of the Amp is 0.075 Ohms 20hz - 20Khz.
The Damping Factor is 106 20hz - 20khz @  8ohms.

Thanks!
I need the required cable length too. The speakers data (Load) is not required.
Thanks.
DF of 106 is relatively low...
Hi,

I am using 15' of cable to each speaker. Right channel 15' and left channel 15'. As I mentioned, I am Bi-Wiring my speakers. Each speaker has a run of Belden 10awg 1313A speaker cable for the low frequency driver and Audioquest 15.5awg for the high frequency driver, again all of them are 15' in length.

Thank you!
Thanks
https://www.powerstream.com/Wire_Size.htm

For 15’ (4.57m ~ 5m), and for a DF 100 (106): a #4 awg cable is recommended.
The Bi wire of #10 awg (equals to 2x #10 awg in parallel) is:
1 ohms per 1000 ft, each so it equals* to 0.5 ohms for both.
But a #4 awg (as required has a resistance of 0.25 ohms!) So now you have only half of the recommended conductivity.

*:
Bi wire never did the Job. It’s a good trick to make double the money over speaker cables :-)
but not good for anything. They invented a BS theory for it, most fall in.

An analysis with Spice simulation SW shows (used by all analog design engineers),
that the single 0.5 ohms (per 1000 ft) does a better job than two of 1 ohm in bi wiring.
Thats, because most of the current goes to the low Fr. (woofer) and only
a small portion to the High. So now, with the Bi wire, only 50% left for the low, while most of the current flows there. A single wire of 0.5 ohms would hold better that current, than a 1 ohms cable.
I would say, if you go for a #4 awg, drop the bi wire.
So I'd like to know, how much of this makes a difference in how things SOUND?