No one actually knows how to lculate what speaker cable they need


It goes back to cable manufaturars, mostly provide no relevant data! to sales and the users. None will answer this!
Whay do you think that you own now the optimal cable to your setup?
I think I've figured it out. 


128x128b4icu
Mr. ppc67
This thread is about speaker cables. I would prefer not to open her a discusion on electrical wiring in the walls. Please fell free to open your own thread. Thanks.
b4icu,

You misunderstood my (fully hypothetical) question and cut it in pieces that lost the original meaning in the process.

"How thin is that last connecting piece on the 0 AWG wire allowed to be" I'd answered that already before! It should be as thick as possible, or as thick as the banana plug can get.

The question was, in fact,...

How thin is that last connecting piece on the 0 AWG wire allowed to be before it can be considered a fuse?

Not that I expect anyone to have an answer, or speaker cable to become a fuse, but there is a conceptual similarity in things I mentioned (fuses and thin wire attached to the thick wire).

"If you think of an 8-10 gauge wire as a fuse, you are wrong! The 0 AWG is the fuse in that system…"
You got me on this one. I could have sworn that every fuse I have ever encountered had a filament inside that was thinner than the wires it was placed between. I stand corrected although puzzled by this development in electrical engineering. I will blame the dogma they taught me in elementary school and my lack of keeping up with reality. I am too scared to find out why thicker wire would, in a fuse, burn sooner than the thin one. In my, admittedly mislead, mind I thought the thicker one conducts better and, sort of, more. Not to make it a wall wire thread, although it deserves comparison, but I cannot but think that we should have been putting thinner and thinner wires in the wall if we wanted carefree conduction.

Which might have been the point of all those manufacturers selling hair-thin speaker cables.

Whatever it is, I am puzzled.
b4icu,

"Those observations were both for the reporter and his spouse that confirmed his impression of grate sound improvement. It’s on this the thread, you can find it and read it."
I read it. In fact I think I read about 95 % of this thread and I hope it will not count against me on judgment day.

Still, my point was only that logic would tell me that thicker wire, as you suggest in all of your responses, conducts better and would measure/calculate better. On the other hand, some would say that measured differences at realistic cable lengths are so small that they could be considered negligible. The only way to determine what happens sonically would be to listen. Which is exactly what you reported in your response above. That would make calculations/measurements marginally useful for anyone interested in sound and not technical lamentations.

Now, why thinness of the wire is such a huge factor while it is not a factor when attached between the thick one and a banana plug is a little confusing. I do not expect that answer. Not from you, not from anyone. I feel that answer may have less to do with electrical properties and more with other characteristics of human nature.

Mr. glupson

1.       "How thin is that last connecting piece on the 0 AWG wire allowed to be before it can be considered a fuse?"

The 0 AWG is not for the current. It is for low resistance to match the relative low resistance of the amp. (DF). Some short and not so thin (I always repeated to use as thick as possible) wires at the end, won't change the cables resistance by much. Even a 12-14 AWG is no fuse. Most speaker cables on the market today are about that thick.

 

2.       My two cents on fuse in Audio:

I don't think that on the amp – speaker's path, a fuse is a good idea. I would rather prefer some sought of electronic protection in the amp. This whole thread is about minimizing the resistance of that loop, so a fuse will not do well to that.

That fuse you are talking about, what is its purpose? To protect the amp from short circuit or to protect the speakers from a faulty amp.?

Most damage to speakers is caused by using a low power amp. that might go over derived (volume) to get it play louder. When that happens the amp. might go into clipping (saturation). That’s a situation when it runs from positive to negative saturation, causing a very steep transient (dv/dt) that has a nature of high frequency and high energy. The speaker's cross over passes it to the tweeter, that in no way can handle it and its very thin wire coil, fries. A fuse in series with the speaker wire won't protect your tweeters from that.

Most of my systems since I'm in this hobby, never had a fuse on the audio path. On the mains supply: yes.


b4icu,

I was not talking about real fuse or about placing one anywhere. It was a hypothetical question "how thin does the connecting wire have to be before it is called a fuse?". It may not be 12-14 AWG, but at what AWG would it be? Now, when I think about it, that is the question that could probably be answered with a  calculation. Not by me, but by some reasonably experienced electrical engineer.

"This whole thread is about minimizing the resistance of that loop, so a fuse will not do well to that."
and

"Some short and not so thin (I always repeated to use as thick as possible) wires at the end, won't change the cables resistance by much."
I fully understand what you mean by both statements, but also do notice that you decide to downplay/ignore ("won't change by much") increased resistance on one part while considering the resistance of the other significant. At the same time, both of those resistances cannot be that huge and that is what your "opponents" claim.

Mr. glupson

How does it work in engineering:

Most times when values are minor regarding the other major circuit values, they tend to be ignored. Otherwise, it may complicate a lot the calculations. When it must be meticulously engineered (NASA, military, medical life saving etc’) no short cuts are allowed.

If you would like to dig into it, the path between the amplifier’s power supply back to ground, through the speaker cables and the speaker components, could be represented by a series of resistors (in the speaker there are also non resistive elements, as capacitors and coils). R=R1+R2+R3…+Rn. https://www.electronics-tutorials.ws/resistor/res_3.html

That would also apply to the cable part as a standalone.

Each piece in that puzzler equals to some R:

· The banana plug contact area with the binding post’s,

· The banana plug itself,

· The short cable between that plug and the 0 AWG cable,

· The two connections: between the banana and the short cable,

· The short cable with the 0 AWG, to be applied in both ends (added twice).

On top, the R should be doubled, as we have two cables per channel: the red and the black.

For some you might need to do a measurement as it might be impossible to calculate.

For some reason, you are now digging into the most minor details of a 0 AWG cable, at a time before this thread, all were good so with a 12-14 AWG cables!


Post removed 
I’ve been following this thread since the beginning and have been sitting on the sidelines questioning myself if I should participate or not. I am not a EE nor do I play one on TV but I like many here have been in this hobby most of my life. I’ve learned a lot over the years, and much has been pure snake oil and some tweaks that appeared to be off the wall have me further pursuing this hobby I have spent some forty years playing with.

I’ve learned a lot of things just can’t be measured or be proven by any equipment, logic or math but my ears tell me otherwise. Maybe I’m the fool with a decent enough income to play along... I don’t know and really I don’t care. I know what I like and that’s all that matters to me.

I’m sure I’ve missed a few post and honestly I’m not going to spend the time to read through all this again but I do believe it’s only fair to hear for oneself if there’s an improvement to ones system regarding the OP’s claim. My short research on the cable most often suggested does not seem to be expensive so why not see or hear. I really don’t care about whether or not there really is or is not a secret formula, but maybe it’s just a gut instinct the OP persues. From what I’ve read no one can really argue b4icu doesn’t have some smarts or maybe just spends a ton of time researching things on the internet and post the links back to us;,my guess he has a background in math and EE above mine so I’m smart enough not to get in a pissing contest.

OK... enough jibber jabber from me. I want to participate and I give my word to b4icu I will buy and build these cables and give you my honest opinion of them on my system and I will compare them to the two cable brands that anyone here can go to my profile to see what I have and my associated equipment. My gear is decent and although not as costly as many here I do have a good ear and I am a musician so I know what to listen for or knows what many instruments sound like on stage.

Before I throw out my amp, speakers and length of I do have a question that maybe has already been asked, but as I stated I’m not going to go back and read through all these post so please forgive me if it’s been mentioned several times. I am curious with such a large cable running the + and - parralel to each other not being twisted around each other is there any concern of these becoming an antenae basically picking up nearby radio stations - RF/EMI? I would think it’s possible. I know as a kid back in the 80s I had a speaker cable that was not twisted or braided that did just that.

I have a Pass Labs X250 amp not a .5 or .8 and I believe the DF is 250. My speakers are Aerial Acoustics 7B’s and my speaker cables are 8ft long per side. I biwire at the speakers only with wire jumpers, so my cables are not configured for biwire. As mentioned above I will build the cables, which I’ve built many cables over the years so I will be careful and not blow anything up. As mentioned earlier I was thinking why use a block or make a pigtail to connect to spades or bananas but just cut back the strands 6” or so from the end before termination... why have anything to degrade the signal?

I look forward to your response on size of cable to proceed and it has to be a 8ft pair please so my comparison between my two other cable brands is fair. I will likely try the experiment cables with the stock speaker biwire metal straps and the two other brands of jumpers I have. In closing I am curious if you have any concerns with RF/EMI and if you do not I would appreciate your response why. Again if the subject of RF/EMI has already been discused I do apologize.

Mr. adg101

Welcome to the thread. Good luck with the cables DIY. Regarding your speaker cable requirements (DF is 250. My speakers are Aerial Acoustics 7B’s and my speaker cables are 8ft long per side) you need a 2 AWG. A 0 AWG will be also fine.

What is the thickness of the cables you are currently using?

Bi-wire as you use it (short jumpers and one cable) is the best. Keep it this way.

EMI RFI

No speaker cables need any EMI/RFI treatment. The Amp's output impedance is so low, that it is like a short circuit to GND, from EMI/RFI aspect. The twisted pair however, may cause some capacitance and inductance while two separates won't. (I explained it down this thread already). There will be no noise issues with the speaker cables I offer (for you to DIY).

 


Post removed 
Damping factor
https://en.wikipedia.org/wiki/Damping_factor

In an audio system, the damping factor gives the ratio of the rated impedance of the loudspeaker to the source impedance. Only the resistive part of the loudspeaker impedance is used. The amplifier output impedance is also assumed to be totally resistive.

For the rest of that link, it is a mistake! This thread is the why. Those who tried it, are the proof.

Mr. batenet

The Inter-M R-500 phone in the US http://www.inter-m.net/_upload/product/2/R-150PLUS_dw_ae.pdf is not responding (not connected). I'll try the S. Korean when time will be proper.

I'm still waiting to your answer about the 10 amp's configuration.

I'm a bit baffled from this £275 amp, with 500W/Ch. In 8 ohms bridged, designed in S. Korea and made in China. The 10 sets of DIY 0 AWG may cost you close to the price of the amplifiers!

 


Mr, b4icu

Thank you for your effort you put down in research of Damping factor.
Have a simple explanation about so many amplifiers,my set up is a combination of hometheater and 2-channel for music,11 channels + 2 subwoofers with amplifiers including buttkickers with own amplification,2 channel with 2 bridged Inter-M 500 to upper registers and one 500 amplifier for left and right woofers with active crossover.Believe me this korean amplifier is a fantastic amplifier for very small money,but only the 500 model sounds good.So my expensive and powerhungry class-a amplifiers have to do service in surround channels,and for serious listening in two channel my Korea design "made in Kina" . 

Mr. batenet

Sorry, S. Korea is also not responding. None of the e-mails came back with an answer, and both lines (US and S .Korea) are not responding. The date on the data sheet is 2005 (11 years ago). They might change the phone numbers or no more in business. It is a dead end.

Some links say that the DF is high but no figures are provided. I would assume it is 500 and go with a 0 AWG for 8 ft. long.


Mr. mitch2

How is your DIY cables in progress are doing?

Any difficulties with the cable's ending? Please be kind to share.

When you are done and you share, please be kindly reminded to add the data as I asked for, to get all facts together. Thanks.

Post removed 

Posts:

There are two things that posts contain: a subject and a way to say it.

No subject was ignored…but

When the posts are insulting or repeatedly harassing, there is no room for that in this thread.

So far, I proved my case and no one really challenged it, in a technical or logical way. Unfortunately, says like this that has no particular sense, except undermine my thread, as a general statement, with nothing real behind it, are common and they are not supported by anything.

For you Mr. kosst_amojan, you are on a mission to go against me and my thread, over and over again. I haven’t seen from you any grate idea or even a slight technical insight. I would categorize you as a delegate from the industry that has an agenda to avoid the message from spreading, for very obvious reasons.


" So far, I proved my case and no one really challenged it, in a technical or logical way."

In your 214 posts and thousands of words you have 2 people that have bothered to experiment with your methods. It would be interesting to see, if in 6 months, they are still using the welding cable in their systems. Mitch2 has revealed the "secret formula", so, is there really any reason this thread should exsist anymore? What has been proven?

12-01-2018 11:58am
Do not waste your money on expensive cables. Me and my friends have spend thousands on expensive cables to our speakers and this gentleman ‘b4icu’ calculated the correct cable gauges for the amplifiers we used which is Goldmund and Passlabd. We bought 4 AWG copper wires from Amazon as recommended by him with spade and banana connectors and DIY the cables. For $200 between the 3 of us, we have 3 set of speakers cables. We are very happy with the sounding from this DIY cables to our speakers. If we have know b4icu earlier, we could have save thousand of $$$, but nothing to be ashamed for the mistakes we made, thank you b4icu. God Bless for your sharing 
When you say that you could have saved thousands of dollars one assumes you must have thrown your old cables in the trash. Most people break even when they sell their used cables, if not make money on the deal. Remember, don’t throw them in the trash next time.
Post removed 

Thank you Mr. khiak

To rest my case, all who listened to me on this thread and followed, ended up happy and with way better sound than they started with (whatever was the old cable).

Could you please be kind to share some of your impressions on the sound with your new DIY cables vs. the old once (what were they?). Thanks.

I was surprised how strong the cable industry was represented here by some very annoying posts, or by others who bought their urban myths and tried to spread them. Both are so wrong! As they try to keep you in the dark and sale their cables (bad for you and too expensive).

Where is your dignity?

For my thread, it was silent for quite a while. I thought that no one will join the DIY any more. Mr. khiak proved me wrong (I'm happy he did). There is still a guy called mitch2 who said he is doing a DIY attempts but I think he was not really doing it.


Update of the excel table of the DIY cables:
https://imgur.com/a/utMuqzK
Mr. khiak, could you please be kind to add the missing data? Thanks.

I'm happy for all those who followed and ended up with a better cable, way better sound and little investment.
I am standing behind my word, that the calculated cable is the best you can have for your equipment. All others would do only a partial job and provide a partial sound quality of your equipment full potential.

b4icu,
we are thinking of changing from 4 AWG to 2 AWG to squeeze a little bit more from the amps. What is your opinion?
We are looking for better connectors from Furutech. Most connectors max wire 6 mm only 😰
" we are thinking of changing from 4 AWG to 2 AWG to squeeze a little bit more from the amps."

- But wait, isn’t the "correct" cable size based in the magic formula that includes the speaker specs. & the amps DF? If you go to a different size, would that not violate the prime directive?
- Who is the we? Do they have the same amp & speakers that you have?

"What is your opinion?"

- How can an opinion matter? Remember the formula tells all ...
Mr. khiak
For your equipment, going from #4 to #2 won't do much of improvment.
As per the AWG table: https://www.powerstream.com/Wire_Size.htm
The chnge in resistance is not that much from  #4 to #2.
For the banana plugs, I recommend on this:
https://www.ebay.com/itm/8x-Nakamichi-24k-Gold-Plated-Audio-BFA-Banana-Speaker-Plug-Screw-Cable-Wire...
and a short #8 to connect between the #4 and the banana plug.

Please be kindly reminded for my requests. Thanks. 

Do NOT use Nakamichi bananas. The advertising on these are false, they are not gold plated copper, they are brass, no copper to be seen. See link below, I cut one open. Use the higher end Furutech or Cardas bananas. Also, it would not surprise me the 4ga. or 0ga. wire you are using are not pure copper, at low prices battery or welding cables might be an alloy.
https://photos.app.goo.gl/yHvsgifGyJVwy5Nh9
Post removed 
" Brass is used in all connectors."
- Not true, check out quality connectors from VH Audio, Cardas, WBT and others. I removed the Nakamichi bananas 2 days after I installed them and replaced them with  Furez TSTSB40NP . 

Don't use Nakamichi termination products, there are much better available. For example:

https://www.amazon.com/Viborg-4XPure-Copper-Conductor-Speaker/dp/B01LC1QI88?SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-d-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B01LC1QI88

BTW: b4icu, do you really see the need to resort to profanity to get your point across?
This debate regarding brass and pure metals for connectors is probably best written off as just another high end vs mid fi misunderstanding.

I really don't care what banana plugs you will use with your DIY projects. Even thou I can explain why it is the best possible banana plug for your DIY cable.

Please look at this: "This debate regarding brass and pure metals for connectors is probably best written off as just another high end vs mid fi misunderstanding".

Well, all guys (Mr. conradnash, Mr. keppertup, Mr. khiak and also Mr. Willson from BC) who made a DIY cable, with products cost under $60 (what is referred as: mid fi misunderstanding), ended up with a way better sound than with the cables called: another high end…

Are the definitions of Hi end and mid fi, were reversed? Is a high end is what some swindler calls an inferior product Hi end, and a first class sounding product (best possible), is now called mid fi? 

Let's face it, it is not what those cable dealers or manufacturer's call a product, but it is about what that product sounds like, in comparison with all others in its class.

I have the best sounding cable, they call it mid fi, they have a bad sounding cable but it is Hi end, just because they call it like that. What do you charge for that say, as the cable doesn't worth a penny (from sound perspective).


The cables that were replaced by the dudes you mentioned were not (rpt not) high end cables, or they did not (rpt not) have pure metal connectors. Just because you say they were doesn’t make it true. For example we already know the cables the guy in UK was using were not (rpt not) high end cables. Those Blue things.
Who is "We"?  (For example we already know the cables the guy in UK)
What is your hi end brand or model? A link would be nice.

It’s the editorial “we.” We’ve already discussed the UK and his Blue cables, the ones that did not fair too well in at least one review. It was about two months ago on this thread. Of course, many posts have mysteriously disappeared since then. But I have a photographic memory, thank goodness. 
I seem to remember in one of your 220 posts, on this subject, your criticism of the cable companies not providing details on wire design & construction. Well, here you go:

http://www.iconoclastcable.com/story/speaker.pdf

Looking forward to your white paper.
Let me examine one statement made before by b4icu:

The DF is actually the way the Amp. is getting control over the speaker's coil. A coil, especially a moving one in a magnetic field, generates an electric current that is equal to the one made it move, but in the opposite direction. It is called the "Lentz" law.
Speaker cables are in a way two resistors (Rc) that connect the power Amp. to the speaker. Why two? becuse the cables go to the speaker (red) and goes back (black) to the amplifier.
As so, the speaker's impedace has no significance in this electrical circuit.
 Of course it has big significance.  Speaker's resistive impedance (equal to about 2/3 of nominal impedance) is in the circuit.  The whole idea of damping comes from the fact that voltage created on the speaker terminals (known as the "Back EMF"), by the motion of the coil in magnetic field, produces current (flowing thru speaker) that causes opposite membrane motion effectively stopping the membrane.  This current flows from one speaker's terminal thru speaker wire, amplifier's output, another speaker wire, another terminal and the coil.  Changing resistance in the circuit from 0.1ohm to 0.001ohm means change in total circuit resistance from about 6.1ohm to 6.001ohm (for 8 ohm speaker) resulting in very small change in the "braking" current.  

I don't know why do they make very thick cables.  Perhaps to reduce inductance (straight wire inductance is slightly lower for thicker wires), but this would not make sense since the same can be achieved by better twisting of thinner wires (that reduces inductance and increases capacitance).    One possible reason can be skin effect, that starts at gauge 18 (20kHz, copper).  I'm not sure if it is audible, but remember Audioquest FAQ.  Stranding wires even with isolated strands won't help since wires are still in magnetic field of each other.  Placing wires in helical twist on hollow tube serves two purposes.  It subjects strands mostly to magnetic fields of neighboring wires only and provides twist.  This twist not only reduces wire inductance but also provides immunity to external electric and magnetic fields.  Since each of perhaps 20 or so strands has decent gauge (for the ease of working with) it makes overall gauge much lower.  That's how my Acoustic Zen Satori is constructed.

One observation  - amplifier's output has very low impedance for low frequencies only.   High frequency electrical noise induced in the cable is injected into the output of the amp and amplified by the amp because of negative feedback.

As for cable directionality - yes, AC charge flows forth and back but energy to speaker is delivered one direction only, on the outside of the cable where other factors (including insulation) might play role.  Again, I don't know if direction is audible or not - but it is much more complicated than it seems.

Mr. khiak

You have been ignoring my two requests:

a.     To share your impression about the sound with your new DIY cable.

b.     Fill in the data missing on the excel table.

Please do.

Your approach regarding the equation of the amp-speaker circuit, with the speaker cables in between is wrong! If you would isolate (as you did) the DF from the circuit, and use optimal cables (0.0000 Ohms), it still not the 8 or 6 ohms of the speaker impedance, vs. the DF resistance value.

DF is provided by the standard, in an 8 ohms load (no matter what is your speaker's actual impedance!) and at 1 KHz. Some brands would extend that data into higher Fr.

However 1 KHz is not a low frequency at all.

Directionality: What directionality in AC where the wave is symmetrical both ways?

Skin effect: When you look at the AWG table, you see that the data provided is regarding the top Fr. That a cable can still pass it's full power. A 4-0 gauge cable is way thicker than an audio system needs to pass through its full power. At the playing power (even at peak) the 4-0 gauge cables still pass more than sufficient at 20kHz.  


I’m the UK guy. Geoff’s right, the cable I replaced with the custom 0AWG cables aren’t “high end” (van damme blue). I read the review of them, and it’s not great. I’ve also given my reasons for choosing them.

My personal dilemma with this whole thing was whether I think speaker cables matter at all. If they don’t, then what cable I choose doesn’t matter so the van dame blue or the 0AWG should be the same. If they do then it’s a gamble as to whether they’re an upgrade or not. Lots of variables. The 0AWG sounded better, but that could have been for lots of reasons: oxidation, the cable, or just the matter of re-seating them.

Anyway, to test, ive bought myself a length of kimber 12TC cable. Hopefully we can agree that cable is closer to “high end” and that my “mid-high end” system, as I’m guessing some would call it
would reveal the differences? I would hope so.


Mr. Dill

Big misunderstanding.

1.       You link an article not a spec on a wire.

2.       Why do you need me to read a long (endless) document that has nothing, but absolutely nothing to this thread? After 220 posts you still do not understand a thing!

3.       Even if you would bring one spec., it is nothing in that big pile of others who has no data at all.

4.       For the sake of this thread, try to post things on subject and not off subject. Thanks.


Mr. conradnash

Good luck with the kimber 12TC cable. Let us know what your verdict is.

Even with a mid end system, before you lay down your equipment, it needs a proper room and some excellent sources (recordings). Are you sure you have that as a start?


I’ve EQd the room <1000Hz to within +-3db down to about 8Hz. My mic isn’t accurate above that. I’m waiting on my calibrated mic which I’ll get in March.

im using all digital sources ranging from Spotify through flac from HDTracks up to Sacd (Telarc, plus others) and DSD 512. My dac is only good until 24/192, but I have an alternative dac that supports full DSD as well, it’s just not in my main system (it’s only 2 channel). 

So, all things being equal, my system is high-end (RME HDSP, Classé ct-5300, B&W 802N) The cable is high end? The room is ok? The sources are ok? I should hear a difference, right?
" Even with a mid end system, before you lay down your equipment, it needs a proper room and some excellent sources (recordings). Are you sure you have that as a start? "

Ah, are we now back peddling at bit?
Not sure I go along with the presumption that Kimber 12TC are “high end cables.” I guess we need to define what high end cables means.  Kimber does have good name recognition going for him, however. I’ll give him that. By the way sales of fake Kimber 12TC cables appears to be rather brisk on eBay. Maybe I’m missing something.

On another subject I’m not sure why people assume that a given set of components have a certain predictable level of sound quality or that photos of a system reveal anything about how it sounds. There are way too many variables to be able to make such judgements.
Kimber 12TC Electrical Specifications:

(Cp) parallel capacitance: 494 pF / meter - (Ls) series inductance: 0.09 uH / meter - (Rdc) dc loop resistance: 0.005 Ohm / meter.

geoff is correct, here is an ad for fake Kimber 12TC

https://www.ebay.com/itm/1pair-FOR-Kimber-12TC-8N-OCC-Main-Speaker-cable-Rhodium-plated-Y-plug-1-5M-...

https://www.kimber.com/counterfeits
Neither of those responses really answer my question, other than: we don’t know how it’ll sound.

quite the punt then at $1000 from here: https://www.russandrews.com/kimber-12tc-speaker-cable-biwire-kimber-bananas-31909999101/
I’m not trying to be cryptic or trap anyone. An important factor in any good experiment design is to determine what success looks like.

I’ve done everything I think I can: dedicated power circuits, decent components, good sources, good speakers, room analysis, there’s really not much more I can do. I’m trying to put myself in the best position to determine if I can hear a difference between speaker cables. If I can, great, if I can’t, then they’re going back. They might go back anyway if they don’t make enough of a difference. And no, I don’t know what “enough” is for me to feel like I’m getting good value.

anyway. I’ll report back when I’ve tried them out.
Folks, everyone is talking resistance but there are two other factors that come into play.   One is the inductance and capacitance of the cable, the other is the skin effect.   For audio work, skin effect becomes a non issue when the wire is 16 g copper or thicker, and I doubt anyone reading this is using 20 or 18 g wire.  The other is capacitance and inductance and these are tied together.  If you are using dynamic loudspeakers, that is a speaker whose motor is a magnet with a voice coil and cone, then one needs very low inductance cable with the result of it being higher capacitance.  The reason is inductance becomes a significant factor when the load impedance is low and most speakers have impedance dips below 8 Ohms and peaks above 8 Ohms.   This causes an attenuation of signal if the cable is not low inductance.   Plain zip cord is fairly inductive and thicker zip cord, that is the stuff with larger gauge copper, becomes even more inductive while the resistance drops.   This is the reason speaker cables sound different.   If you have a non dynamic speaker, that is a pure resistance load, i.e. Magnapan, ribbons, etc. or an electrostatic, then the parameters change.   Resistive speakers require low resistance and a moderate inductance cable while electrostatic speakers are a special case but can more or less live with higher inductance cables.  There are other losses as well, but these variables are secondary to the above.
Regarding the question why no manufacturer will calculate the cable needed is a lot depends on the output impedance and phase margin of the amplifier.   One just can't hang high capacitance on the output of an amp, it might cause it to oscillate. At the very least, it won't like the load; worst case is the amplifier dies a violent death.  No cable manufacturer is going to take that risk, rather it is left up to the user to sort all this out.
Plain zip cord is fairly inductive and thicker zip cord, that is the stuff with larger gauge copper, becomes even more inductive while the resistance drops.

Inductance of straight wire is lower for thicker wires.  For instance gauge 16 wire has inductance of 0.33uH/ft  while gauge 10 wire inductance is 0.29uH/ft

Mr. spatialking

You are a late comer to this thread. The issue was brought up earlier.

1.       The DF and the speaker 8 Ohms values are ref. as resistive only (https://en.wikipedia.org/wiki/Damping_factor):

In an audio system, the damping factor gives the ratio of the rated impedance of the loudspeaker to the source impedance. Only the resistive part of the loudspeaker impedance is used. The amplifier output impedance is also assumed to be totally resistive.

2.       This is not the reason speaker cables sound different!

There are as many attempts to explain, justify, point at factors without really checking it or study the matter. Impedance (as it is a complex "resistance" that includes an inductive (coil) and capacitive values, is none relevant when a speaker's cable (a good one) is way under 0.002 Ohms. For a cable, no matter how bad it is made (as a copper wire alone shall have no inductive or capacitance at all!) the values of those inductive (coil) and capacitive values are so low, that referred to the resistance value they have no effect.

Those values, with resistors of kilo Ohms do. This is a ratio of 1:1,000,000! Between 0.002 Ohms and 2k Ohms.