HydrogenAudio

CD-R and Audio Hardware => Audio Hardware => Topic started by: mkop on 2003-10-11 04:12:46

Title: Why does the gauge of speaker wire matter?
Post by: mkop on 2003-10-11 04:12:46
I've read some things discussing speaker wiring such as speaker reviews and their is always something like "the included cables are ok but you'll probably want to go and get something thicker." My question is why do I want some huge python of a cable? And what principles are used to decide what size is big enough?
Title: Why does the gauge of speaker wire matter?
Post by: boojum on 2003-10-11 04:29:13
If you are driving speakers which require much power you might require larger diameter speaker wire.  Think of pushing water through a pipe as an analogy.  For more force of water larger pipes would make moving more water easier.

I am sure someone who is not a LibArts major can supply a better technical explanation.  Mine is how I think of the answer to your question.  And, BTW, the heaviest guage zip cord is OK.  Monster cable makes you feel good though.  B)
Title: Why does the gauge of speaker wire matter?
Post by: TwoJ on 2003-10-11 04:38:43
I think I have never seen such bending of physical laws then the marketers of "special" wire manufactures!
The actual determination of the thickness (gauge) of the wire just goes back to good ol Ohms law, V=IR, if you know the voltage & resistance of the speakers then you get the amount of current that will flow through the speakers. This current then can be carried by a conductor of a suitable gauge, the higher the current the thicker the cable, this is more relevant for power appliences such as the power cord for a A/C unit or a cloths dryer or range has to have thicker wire is that if you tried hooking it up with a 18 guage wire or smaller the amount of current would heat the wire so much that it would melt.

If you believe that a speaker will need the same thickness as a 1500W A/C or heater than the marketers have another convert. They talk about oxygen free copper and getting a "cleaner" signal to the speaker but the truth is that you could make the wire out of silver (very good conductor - better than any copper) and you would not be able to tell the difference between that and a regular power cord that you rip off a lamp. If you can ABX a test like that I'm pretty sure Monstercable would love to enter you in a few tests.

I believe the actual determination of wire load is that the nominal current load must be 50% or less of maximum current load, where maximum current load is determined by some electrical laws about surface area, length, and electron permiability for the particular metal (how easily electrons pass through a particular conductor) of the wire.

The short answer is don't fall for the slick marketing - your ears would have to be 1000X more sensitive to hear the difference!
Title: Why does the gauge of speaker wire matter?
Post by: ScorLibran on 2003-10-11 06:12:21
[reaching back 15 years to my electrical engineering classes at Auburn]

IIRC, electrons only travel on the surface of a wire, hence to move more electrons you need more surface area of wire.

Braided cable works better than solid because many smaller wires bound together have a lot more surface area than a single cable of the same thickness.

The more current/voltage you need to get to the target, the more "wire surface area" you need, hence the need for heavier gauge braided cabling.  So boojum's analogy of water through a pipe is a good one, except instead of "in the wire", electricity moves on the surface of a wire.

This concept (or my description of it) might be wrong because my major was not EE (it was actually aerospace engineering) and I don't consider myself an expert on matters of electricity.  [Spent more time with Bernouli's Principle than with Ohm's Law.    ]  But I'm pretty sure this concept is the right one.
Title: Why does the gauge of speaker wire matter?
Post by: TwoJ on 2003-10-11 06:37:03
Right concept but wrong application, sorry ScorLibran

The travelling on the surface is correct for HF (High Frequency) transmissions, it is known as skin depth (the depth that the signal is carried within the the conductor and is inversely proprtional to the square of the frquency (if I recall correctly), ie the higher the frequency the smaller the skin depth and hense the power is carried on the surface of the conductor and the EM field surrounding the conductor.

Unfortunatly (or fortunatly) the human audio freq. 20Hz-20kHz are not considered HFs and therefore the signal will be carried within the conductor for the most part. If the 50 or 60Hz mains power could be carried on the surface you wouldn't need such large guage wire for power transmission.

It was a few years ago that I came across a test done in one of the electronic mags (yes i'm an EE) between "beastiecables" and regular electrical wire that you get at the hardware store. The verdict was that you could see a small difference with an oscilloscope but that was it, no one was able to actually tell the difference because the difference is not perciable to the human ear.
Title: Why does the gauge of speaker wire matter?
Post by: ScorLibran on 2003-10-11 06:43:00
Quote
Right concept but wrong application, sorry ScorLibran

The travelling on the surface is correct for HF (High Frequency) transmissions, it is known as skin depth (the depth that the signal is carried within the the conductor and is inversely proprtional to the square of the frquency (if I recall correctly), ie the higher the frequency the smaller the skin depth and hense the power is carried on the surface of the conductor and the EM field surrounding the conductor.

Unfortunatly (or fortunatly) the human audio freq. 20Hz-20kHz are not considered HFs and therefore the signal will be carried within the conductor for the most part. If the 50 or 60Hz mains power could be carried on the surface you wouldn't need such large guage wire for power transmission.

Heh...proof that two classes do not an electrical engineer make!  (In fact, ~sixty classes did not an aerospace engineer make either.  My career's in IT.    )

Thanks for the clarification, TwoJ.
Title: Why does the gauge of speaker wire matter?
Post by: AgentMil on 2003-10-11 08:02:01
Quote
Quote
Right concept but wrong application, sorry ScorLibran

The travelling on the surface is correct for HF (High Frequency) transmissions, it is known as skin depth (the depth that the signal is carried within the the conductor and is inversely proprtional to the square of the frquency (if I recall correctly), ie the higher the frequency the smaller the skin depth and hense the power is carried on the surface of the conductor and the EM field surrounding the conductor.

Unfortunatly (or fortunatly) the human audio freq. 20Hz-20kHz are not considered HFs and therefore the signal will be carried within the conductor for the most part. If the 50 or 60Hz mains power could be carried on the surface you wouldn't need such large guage wire for power transmission.

Heh...proof that two classes do not an electrical engineer make!  (In fact, ~sixty classes did not an aerospace engineer make either.  My career's in IT.    )

Thanks for the clarification, TwoJ.

RoFL... look at me I studied to get into Computer and Electrical Engineering but ended up doing Finance... and now I ended up doing Sales... but I am only young so I am gunning to get a nice role as an analyst. Fingers crossed.

EDIT
I got out of engineering cause I was stuck with a bunch of pompous idiots (students included). All they did was talk about engineering!! Sigh went to Finance and met some real people who talked not only Finance but real life itself. Not saying engineering ppl are all pompous idiots... the one in my stream were. I might go back to uni to study something again.

Regards

AgentMil
Title: Why does the gauge of speaker wire matter?
Post by: _Shorty on 2003-10-11 08:24:28
the longer the cable of X gauge is, the higher its resistance gets. Using a larger gauge reduces that effect. I seem to recall being pointed by someone here to a comparison of different gauges of wire all 30 feet in length. I believe there was quite a difference below 16 gauge, but after 16 gauge there was no noticable difference. The biggest culprit for the differences was simply the fact that the smaller gauge wire added enough resistance to alter the end result, IIRC. So for runs up to 30 feet or so, 16 gauge bulk cord is more than fine. For significantly longer runs than that I guess you may want to jump up to a larger wire to try keeping the wire's resistance down. Yes, I'm too lazy to search for the thread right now, hehe. Just got back from watching The School Of Rock, pretty funny.
Title: Why does the gauge of speaker wire matter?
Post by: JeanLuc on 2003-10-11 10:29:02
There are three major parameters that influence electric conductivity (and thus the sound) of a given speaker cable.

1.
The specific ohm resistance (resistivity with the greek designation Rho, SI Unit is Ohm·mm2/m is a material constant which will be multiplied with length and divided by diameter and result in an non-frequency-dependent Ohm Value.

At 20°C, the Rho value for copper is: 0,0178 Ohm·mm²/m

This pure ohm resistance will neither cause phase shift of the electrical signal nor will it cause a loss in a relevant frequency band. If this resistance becomes bigger, you just lose volume (just like a potentiometer). Only in case of very high currents (some speakers' impedance undershoots 1 Ohm in the low end which will demand high currents from your amplifier), the cable will heat up and thus change its specific resistance and sound. This can happen, but most likely it won't.

2.

A cable always states a capacitance (C, measured in the SI unit Farad) which states a complex (frequency-dependent) Resistance RC (RC hyperbolically follows C/f which means that in the low-end, RC gets higher) ... your target should be to avoid a cable with a high capacity (funny thing is that thicker cables show even higher capacities).

Capacitance causes a positive phase-shift BTW.

3.

Inductivity (I, measured in Henry) is the third major resistance which mostly occurs when winding up cable to some sort of coil ... this resistance is complex as well and affects the high frequencies (RI follows I·f) - a cable with higher inductivity might dampen high frequencies.

Inductivity causes phase shift as well, in a reversed direction to capacitance.

If you take a look at a frequency crossover network, you will find resistors, capacitors and coils put together to split up frequency bands according to the used chassis in the loudspeaker.

As you can see, your cable doesn't need to be thick as long as you do not cover long distances or loading the cable with extreme currents - thick cable will show higher capacitance which might influence bass response in a negative way.

Marketing allows a lot of so-called "wonder cables" to be established in the high-end (or high-price) segment - but I think that no one will be able to reliably ABX some high-end Monster cable against standard copper cable of the same diameter (changes in simple loudness due to variation of diameter might be detectable, though).

What you might be able to ABX against speaker cable is perhaps some thin wire, used for door bells or telephones ....
Title: Why does the gauge of speaker wire matter?
Post by: boojum on 2003-10-11 11:18:09
Reading the posts of my learned engineering colleagues remiinds me why I should stay away from discussions of speaker cable.  At the end-up no one can put forth a really clear explanation of how speaker cable works, which might be why some folks buy two six foot cables for US$15,000 and think they did a smart thiing.  Me, I'm sticking with the heaviest lamp cord.   
Title: Why does the gauge of speaker wire matter?
Post by: fewtch on 2003-10-11 12:56:07
Baah... I think I want to try $15,000 speaker cables with my lamp, maybe with such expensive cables the light will be "bright" and "heavenly" ... 
Title: Why does the gauge of speaker wire matter?
Post by: Pio2001 on 2003-10-11 13:53:30
Speaker cable blind tests :

Placebo at work : http://www.nytimes.com/library/tech/99/12/...les/23down.html (http://www.nytimes.com/library/tech/99/12/circuits/articles/23down.html)
ABX tests (negative) : http://www.pcavtech.com/ABX/abx_wire.htm (http://www.pcavtech.com/ABX/abx_wire.htm)

Skin effect evaluation :
http://www.hydrogenaudio.org/forums/index....50&#entry135877 (http://www.hydrogenaudio.org/forums/index.php?showtopic=12941&st=50&#entry135877)

Frequency response of speaker cables, theory :

Gauge : a 2.5 mm2 cable (big lamp cord) should stand 3000 W IIRC. If you don't pump up more than 3000W from your ampli (this might cut off your electric supply anyway) it's OK.

The resistance of the cable interacts with the impedance of the speaker.
Say that the speaker impedance varies between 4 and 8 Ohm according to the frequency, the ampli output is 0.08 Ohm, and the cable 10 meters and 0.75 mm2 (cheap speaker cable).
Resistance of the two wires of the cable (20 meters) :
0.0178/0.75*20=0.47 Ohm.
Voltage difference at 4 and 8 Ohm :
At 4 Ohm :
V4=E*4/(4+0.08+0.47)=0.936 E
V8=E*8/(8+0.08+0.47)=0.879 E

With V4 volage on the speaker at 4 Ohm, V8 at 8 Ohm, E being the Thevenin Voltage of the ampli.

The attenuation is
20log(0.936/0.879)=0.54 dB

Ths might or might not be audible according to the width of the frequency range affected.

If we suppose that the speaker impedance can fall to 1 Ohm at a given frequency, as suggested by -, then we get 3 dB of loss at this frequency, that should be audible. But I wonder under which condition an 8 Ohm speaker can fall to 1 Ohm.

Since these data are near the threshold of audibility, and thicker cable not much expensive, it's better to stay on the safe side and use a thicker cable.

Frequency response of speaker cables, measurments :
http://www.hydrogenaudio.org/forums/index....50&#entry135916 (http://www.hydrogenaudio.org/forums/index.php?showtopic=12941&st=50&#entry135916)
Title: Why does the gauge of speaker wire matter?
Post by: AgentMil on 2003-10-11 14:06:42
Quote
Baah... I think I want to try $15,000 speaker cables with my lamp, maybe with such expensive cables the light will be "bright" and "heavenly" ... 

Gimme some of that... I want my room to bask in that "heavenly" light!! LoL
Title: Why does the gauge of speaker wire matter?
Post by: TwoJ on 2003-10-11 16:03:37
What I think most "real" audiophiles will tell you is that you are better spending more $$$ on good quality speakers (where there is a difference between $50 and $500 speakers) then on python cables.

Of course I highly recommend that you buy that $15,000 cable for the lamp because the clarity & brightness will illuminate your stereo in such a blinding light that it will seem the clouds in the sky have parted and a heavenly halo will be shining down on your stereo (an analogy). Don't use with a halogen since the transformer will mitigate the halo effect!

@AgentMil - While I agree that too many engineers are consumed by the technical details (could have something to do with why they chose engineering) some of us still have other interests and are hopefully not too pompous. I actually just switched back to EE from being a logger and while some EE are pretty full of hot air, they are still a bit easier to work with then drunk chainsaw toting drug-addicts. Moral - every profession has their pompous idiots (I know - except lawyers of course.)
Title: Why does the gauge of speaker wire matter?
Post by: JeanLuc on 2003-10-11 17:05:16
Quote
But I wonder under which condition an 8 Ohm speaker can fall to 1 Ohm.

Older Infinity (Kappa 9 Model IIRC) fell down to some 0,5 Ohms at 30 Hz - this Loudspeaker was known to fry Amps according to ohm's law one after another ...
Title: Why does the gauge of speaker wire matter?
Post by: _Shorty on 2003-10-11 18:30:27
http://www.hydrogenaudio.org/forums/index.php?showtopic=3119 (http://www.hydrogenaudio.org/forums/index.php?showtopic=3119) is the one I was thinking of, the article from the cables.zip file. But it's no longer there and I can't seem to find my copy at the moment. Pretty sure I saved it, but possibly I renamed it, heh. Where is it?!?! hehe

found it, I'd extracted it to .\cables\ somewhere and deleted the zip, heh. http://www3.telus.net/~phuncky/cables.zip (http://www3.telus.net/~phuncky/cables.zip)
Title: Why does the gauge of speaker wire matter?
Post by: sshd on 2003-10-12 00:05:20
There sure is some interesting information about electronics and cables above. I am ignorant in this field and there is much of the above I do not understand. However, I noted an interesting thing - everyone is obsessed with the cable alone and completely ignoring the enviroment. I think this is wrong, based on this previous experience:

Back in 1997 I bought an external DAC and wanted to connect it to my 1993 CD player. Both CD player and DAC had coax and optical connectors. I really wanted to do it optically - seemed the coolest way. A digtial signal is a digital signal - there should not be any difference whether connecting via optically or electronically. When I purchased the optical cable, the guy at the shop told me there was and recommended me a very expensive coaxial cable. I ignored him and purchased the optical one.  When I went home I compared the connectors using a cheap signal cable for the coax connection - it was considerable better than the optical. The explanation for this came a few years later: The 1993 technology for optical circuts was not good enough to transmit a digital audio signal. So while the optical cable was in perfect condition, the problem was in the enviroment.

I am not going to claim anything, as I have no real knowledge. But I am going to bring two things from the enviroment. Perhaps someone would like to comment on those?

1. Zip/cobber wire corrodes. I moved my speakers two years ago. They had only been standing in their previous position for 1½ year. When I unplugged the speaker cables the ends were visible corroded - even though they were firmly connected to speaker and amp all the time. I assume the corrosion will become a problem at some point. I also assume it becomes a problem slowly - that is slow degradation of sound quality.

Furthermore the length of the cable is discussed, but not how the "cable path". I know that things happen when you wind up excess cable in a circle/coil. I also cannot help wondering what happens if a 240V power cable is running along of across or twisted around a few places? What about the antenna cable for the TV and sattelite disc? I am using cheap solid core twisted pair network cable myself for my speakers. It was recommend by a friend and I am quite satisfied. However, I know this cable can be damaged by bending it sharply.
Title: Why does the gauge of speaker wire matter?
Post by: adamjk on 2003-10-12 01:14:51
Pio2001,
I'm rather observer, but you're the best
Title: Why does the gauge of speaker wire matter?
Post by: NeoRenegade on 2003-10-12 06:03:35
Quote
[reaching back 15 years to my electrical engineering classes at Auburn]Braided cable works better than solid because many smaller wires bound together have a lot more surface area than a single cable of the same thickness.

Braided cable is used much more often than solid cable for the simple reason that it's more flexible.
A pertinent and strong example is, if headphone cables were solid, those of us who use portable MP3 or CD players would probably be buying new headphones every month or so, because the wires would keep breaking.

At least, this is what I was taught three years ago in my Electrical Technology course.
Title: Why does the gauge of speaker wire matter?
Post by: TwoJ on 2003-10-12 06:16:03
Quote
However, I noted an interesting thing - everyone is obsessed with the cable alone and completely ignoring the enviroment. I think this is wrong, based on this previous experience:

The topic was started on wires not enviroment, and I don't believe people have been obsessed with cables (no one is saying "buy mostercables or you might as well not listen to music")

Quote
A digtial signal is a digital signal
- Although it should be the case - I can tell you that in practice it is not always that way. Prime example was my last MB which was getting random data errors from the VIA chipset - because of what i guess was interference the digital data was getting corrupted.
There are quite a few reasons I can think of why your optical transmission sounded worse than the coax but I doubt it has to do with the actual transmission of data. I remember some early designs would actually have a DAC from the CD player and then a ADC to the optical out - and conversly on the reciever another DAC. So the signal goes through 2 stages of unnecessary quantization which doesn't help in keeping the origianal signal. There was also promblems with optical out of different manufacturers that would overdrive the sensors which caused considerable errors in transmission and reception. But I'd say the problem was with one or both units and not the "enviroment" in that case.

1) corrorosion is a problem, there is another niche market that deals with terminators that reduce the amount of corrosion that the ends will experience, also for certain countries like Japan, where there is a high humidity in the air, they will plate the conductors with metals such as gold which are more resistant to corrosion. But a normal interior should not have a problem for at least a few years and yet if you do notice that the wires are getting corroded then just snip off enough wire to get back to non-corroded copper.

2) the cable path should be intelligently laid out; Don't run it near mains line which could affect a 50/60Hz hum into the speakers, the cables lying in a coil is not that big an issue but it is more important that you keep the legnth of the wire to  the speakers from the amp as short as necessary- an said before the longer the cable the more resistance and hense the signal is degraded more. As for the cable from the TV or satellite these use the stardard coax cable which by designis suppose to eliminate EM radiation outside of the cable so they should not affect your speaker cable
Title: Why does the gauge of speaker wire matter?
Post by: lucpes on 2003-10-30 13:43:09
Quote
Say that the speaker impedance varies between 4 and 8 Ohm according to the frequency, the ampli output is 0.08 Ohm, and the cable 10 meters and 0.75 mm2 (cheap speaker cable).

Here's something more beefy - impedance varies between 1 and 10 Ohm:

impedance curve: http://www.rageaudio.com.au/kappa9.jpg (http://www.rageaudio.com.au/kappa9.jpg)

speaker specs: http://oellerer.net/infinity_classics/Kapp...y_kappa_9a.html (http://oellerer.net/infinity_classics/Kappa_9A/body_kappa_9a.html)

Could you redo the calculations for these? A quickie would be more than 3dB reduction (both in low frequencies & highs).
Title: Why does the gauge of speaker wire matter?
Post by: Dex4now on 2003-10-30 14:07:04
Quote
Baah... I think I want to try $15,000 speaker cables with my lamp, maybe with such expensive cables the light will be "bright" and "heavenly" ... 

What an absolutely killer idea for a parody webpage.   

I'm going to start on working on this right now! 

Dex
Title: Why does the gauge of speaker wire matter?
Post by: lucpes on 2003-10-30 14:27:49
Nice  I always wondered why the lights in my house look a bit muffled

Back to the original topic, I'm in the 'As thick as it gets' & 'Size does matter' phase, for use with these (http://www.gd.ro/images/room.jpg)
Title: Why does the gauge of speaker wire matter?
Post by: fewtch on 2003-10-30 15:09:19
Quote
Nice  I always wondered why the lights in my house look a bit muffled

Back to the original topic, I'm in the 'As thick as it gets' & 'Size does matter' phase, for use with these (http://www.gd.ro/images/room.jpg)

Are those planar speakers?
Title: Why does the gauge of speaker wire matter?
Post by: lucpes on 2003-10-30 15:46:20
No, conventional drivers but dipole (open baffle) & require a hell lot of power to drive. More pics (unfortunately uncared for sets) here: http://oellerer.net/infinity_classics/RS_I...body_rs_ii.html (http://oellerer.net/infinity_classics/RS_II/body_rs_ii.html)

PS. I like them better than the HD600 for listening (ok, the Senns are a tad bit better in microdetail & dynamics but 'everything's in your head' instead of a conventional, wide front sound field)
Title: Why does the gauge of speaker wire matter?
Post by: Pio2001 on 2003-10-30 19:07:21
Quote
impedance curve: http://www.rageaudio.com.au/kapa9.jpg (http://www.rageaudio.com.au/kapa9.jpg)

File not found !

It is very important to know how much octaves the impedance falls to 1 Ohm for.
Title: Why does the gauge of speaker wire matter?
Post by: lucpes on 2003-10-30 20:50:00
Quote
Quote
impedance curve: http://www.rageaudio.com.au/kapa9.jpg (http://www.rageaudio.com.au/kapa9.jpg)

File not found !

It is very important to know how much octaves the impedance falls to 1 Ohm for.

http://www.rageaudio.com.au/kappa9.jpg (http://www.rageaudio.com.au/kappa9.jpg)

Oops! fixed in the original post too... and the impedance range is more like 0.8 to 8.something ohms
Title: Why does the gauge of speaker wire matter?
Post by: Pio2001 on 2003-10-30 23:01:11
Before starting, how do we know that this is the amplitude diagram and not the phase diagram ?
Title: Why does the gauge of speaker wire matter?
Post by: lucpes on 2003-10-31 13:00:56
ABX result of 2xCAT5 cables per polarity (4x8 wires/speaker) versus thicker 'lamp' cord (sorry didn't measure any gauge/diameter) (both 3m long)

playback: 'inherited' MPC (Dire Straits - My Parties) -> FB2k (24bit/dither/ASIO) @-12dB/replaygained -> M-Audio Delta 410 directly to poweramp (193W sinus power in 4Ohm)-> cables in question-> Infinity Reference standard II speakers (don't have impedance curve but I guess it varies from a near-short to 8-9Ohms).

Recorded at one speaker binding posts using 20Kohm & 1Kohm resistors to adapt the signal to line-in levels for Delta 410 (http://www.hut.fi/Misc/Electronics/circuit...er_to_line.html (http://www.hut.fi/Misc/Electronics/circuits/speaker_to_line.html)). Needed to make sure that the speakers are sucking the amp dry *- attenuation was a bit too much for the line in (the sound is a bit grainy) - noise level was around ~60-70dB in Sound Forge 6, signal levels around -20dB, 24bit 88khZ. Removed DC offset, normalized to ~93%, resampled to 44.1 using Anti-Alias filter/4, noise shaped & dithered down to 16bit.

* that's at normal-to-medium loud listening levels

-------------------------------------
WinABX v0.4 test report
10/31/2003 14:49:30

A file: E:\30sec_2x2_cat5.wav
B file: E:\30sec_big_cable.wav

14:49:48    1/1  p=50.0%
14:49:57    2/2  p=25.0%
14:50:03    3/3  p=12.5%
14:50:16    4/4  p=6.2%
14:50:56    5/5  p=3.1%
14:51:03    6/6  p=1.6%
14:51:16    7/7  p=0.8%
14:51:26    8/8  p=0.4%
14:51:46  test finished

Should I upload the files in case someone is interested? The difference is more than OBVIOUS!

edit: files uploaded http://www.hydrogenaudio.org/forums/index....showtopic=14732 (http://www.hydrogenaudio.org/forums/index.php?showtopic=14732)

edit2: corrected resistor values; added link to speaker to line-level adaptor
Title: Why does the gauge of speaker wire matter?
Post by: lucpes on 2003-10-31 14:30:57
Quote
Before starting, how do we know that this is the amplitude diagram and not the phase diagram ?

That is an older version of the LMS (loudspeaker measurement system) software. When you clicked on the phase button (right of impedance) it would display the phase graph. The proggie didn't excel in usability, but that is the impedance graph in the link.
Title: Why does the gauge of speaker wire matter?
Post by: Continuum on 2003-10-31 17:32:25
Quote
Should I upload the files in case someone is interested? The difference is more than OBVIOUS!

edit: files uploaded http://www.hydrogenaudio.org/forums/index....showtopic=14732 (http://www.hydrogenaudio.org/forums/index.php?showtopic=14732)

The samples are misaligned by ~1049 samples. I hope this didn't influence your test.
Title: Why does the gauge of speaker wire matter?
Post by: Pio2001 on 2003-10-31 19:08:27
Thank you very much for sharing your results, Lucpes.

@Continuum, no, the difference is clearly audible, and measurable :

(http://3141592.pio2001.online.fr/pictures/infinitycabledifference.png)

+2 dB above 10 kHz !
I've superimposed the two spectrums, and fit the levels for medium frequencies. In color, the differences between the cables, red=CAT5 louder, blue=Lamp cord louder.

What the hell is the gauge if this Cat5 cable ?
I'd like to know how the resistors were used, do you mean one time 30 kOhm and one time 10 kOhm in serial, so as to get 40 kOhm ?


Edit : picture link
Title: Why does the gauge of speaker wire matter?
Post by: lucpes on 2003-10-31 19:42:27
The offset did not influence the test:

ABC HR config file
---------------
TestName = Cables Listening Test
Original = 30sec_big_cable.wav
Sample1  = 30sec_2x2_cat5.wav
Sample2 = 30sec_big_cable.wav

Offset1    =  0
Offset2    =  1049

test results
----------------
ABC/HR Version 0.9b, 30 August 2002
Testname: Cables Listening Test

1L = 30sec_2x2_cat5.wav
2R = 30sec_big_cable.wav

---------------------------------------
General Comments:

---------------------------------------
ABX Results:
Original vs 30sec_2x2_cat5.wav
    8 out of 8, pval = 0.004

Speaker-to-line in converter:
http://www.hut.fi/Misc/Electronics/circuit...er_to_line.html (http://www.hut.fi/Misc/Electronics/circuits/speaker_to_line.html)

Sorry, I used 20kohm & 1kohm resistors (was not sure as I built that some 3 months ago to RMAA the modifications I did to the amp - no measurable anomalies (would need better soundcard) except for added crosstalk around -90dB) when using a 5W 100 ohm resistor as load (no speakers).

CAT5 (standard UTP Network cable): used 4 lenghts (with the outer jacket) of 4-twisted pair per speaker: so would be an equivalent to 24 gauge*16wires for one polarity... dunno how much that gets to...

However, there is no point in getting worried about cables if you don't have such a pathological case as mine: 4ohm nominal impedance, 86dB/W/m sensitivity & serious impedance swings so lots of current @constant voltage needed (no 2-way bookshelf speaker would exhibit such behaviour).

The infinity Kappa 9 I mentioned earlier is not my speaker, however it was the only impedance graph I could find for such a case. I guess my RSII's are somehow similar.
Title: Why does the gauge of speaker wire matter?
Post by: ff123 on 2003-10-31 20:11:58
Quote
The offset did not influence the test:

ABC HR config file
---------------
TestName = Cables Listening Test
Original = 30sec_big_cable.wav
Sample1  = 30sec_2x2_cat5.wav
Sample2 = 30sec_big_cable.wav

Offset1     =  0
Offset2     =  1049

If the offset was 1049 samples, then the value you used is incorrect (offsets in abchr are defined in milliseconds).  It should be more like:

1000 * 1049/44100 = 24

Also, this assumes that Sample2 is the one which starts later.

Probably the easiest thing to do would be to use Schnofler's abchr-java to automatically determine the offset.

ff123
Title: Why does the gauge of speaker wire matter?
Post by: Continuum on 2003-10-31 20:33:11
I didn't think that you were hearing the offset. It was just something I noticed when I created the difference-wave.
Title: Why does the gauge of speaker wire matter?
Post by: lucpes on 2003-10-31 20:37:37
Quote
I didn't think that you were hearing the offset. It was just something I noticed when I created the difference-wave.


Well, I'm not that handy with Sound Forge & don't have any Java package installed...

Lamp cord similar to one used here: this page (bottom right one) 12 gauge: http://home.earthlink.net/~rogerr7/wire.htm#alllowcost (http://home.earthlink.net/~rogerr7/wire.htm#alllowcost)

CAT5e more details: 4x8 twisted pair 24 awg per speaker. All white plus coloured ring wires are connected together for the (+) connection to the tweeter and all coloured wires as (-) connection.
Title: Why does the gauge of speaker wire matter?
Post by: Pio2001 on 2003-10-31 21:50:53
So it is quite a big gauge after all.
24 AWG is 0.20 mm2
16x0.2=3.2 mm2, that is around 12 AWG.

This is surprising... Maybe recording the signal at the ampli plugs and comparing the 4 results (the two cables, speaker-side, and the two cables, ampli-side) could give more info. If the two ampli-side recordings are similar, the speaker-side recording that is the closest should be the best.

By the way, I find the idea of an attenuator for speaker - line connection strange. The author assumes that the output of an ampli is 3 to 20 Volts. This is true when the ampli is completely overdriven, and the speakers maybe broken.
Actually, I plugged directly the speaker output of my ampli into the line input for my recordings, and I had to set the volume so that I was worried about the neighbours, because it was late, so as to reach a proper line in level.
Your attenuator was 20:1, thus without it, you'd have got a signal 26 dB louder. You say that it was -20 dB, thus it would have clipped by 6 dB.

I recall again for everyone else : this experiment is DANGEROUS for your amplifier : a short circuit, a loose contact, a jack plugged off... and your ampli is fried !
Title: Why does the gauge of speaker wire matter?
Post by: _Shorty on 2003-11-01 00:54:06
unless it has protection for those situations, many amps have over-current protection so they don't get cooked if they're accidentally short-circuited. Would hate to find out the hard way though if I were unsure if it had that kind of protection.
Title: Why does the gauge of speaker wire matter?
Post by: saratoga on 2003-11-01 03:49:31
Quote
- Although it should be the case - I can tell you that in practice it is not always that way. Prime example was my last MB which was getting random data errors from the VIA chipset - because of what i guess was interference the digital data was getting corrupted.


Just an aside:  If your board doesn't work, its broken.  No amount of interfernce you're going to get outside of a labratory (let alone your home) is going to effect your motherboard.
Title: Why does the gauge of speaker wire matter?
Post by: KikeG on 2003-11-01 18:31:43
High freq. attenuation of CAT5 cable is quite probably due to high capacitance of this cable, together with low impedance of load at high frequencies. This can cause a high-frequency rolloff. For this reason, CAT5 cable would not be good for tough loads such as this.
Title: Why does the gauge of speaker wire matter?
Post by: lucpes on 2003-11-01 21:04:04
Quote
So it is quite a big gauge after all.
24 AWG is 0.20 mm2
16x0.2=3.2 mm2, that is around 12 AWG.

This is surprising... Maybe recording the signal at the ampli plugs and comparing the 4 results (the two cables, speaker-side, and the two cables, ampli-side) could give more info. If the two ampli-side recordings are similar, the speaker-side recording that is the closest should be the best.

By the way, I find the idea of an attenuator for speaker - line connection strange. The author assumes that the output of an ampli is 3 to 20 Volts. This is true when the ampli is completely overdriven, and the speakers maybe broken.
Actually, I plugged directly the speaker output of my ampli into the line input for my recordings, and I had to set the volume so that I was worried about the neighbours, because it was late, so as to reach a proper line in level.
Your attenuator was 20:1, thus without it, you'd have got a signal 26 dB louder. You say that it was -20 dB, thus it would have clipped by 6 dB.

I recall again for everyone else : this experiment is DANGEROUS for your amplifier : a short circuit, a loose contact, a jack plugged off... and your ampli is fried !

As KikeG said, the attenuation might be due to the high capacitance/low impedance (which would act as an RC filter? ) - twisted pairs for all length - (+that would add a meter or two to the effective length of the cable...).

About the attenuator - my speakers have <<90/W/m efficiency and the Gemini might be in the 95dB range (http://www.bamberglab.com/s3.htm (http://www.bamberglab.com/s3.htm)

See a SPL calculator here: http://www.doctorproaudio.com/doctor/calcu...uladores_en.htm (http://www.doctorproaudio.com/doctor/calculadores_en.htm)

For 111dB SPL / 95dB/1W/1m speaker sensitivity a rough calculation would yield 25W. For 86 dB/1W/1m & the same perceived loudness one would need around 200W. Go figure that I want a beefier amplifier just after doing that

So i'd need lots more amplifier power/voltage/amperage/whatever for same SPL (also taking in account the supposedly impedance swings which would need lots of current). The lowish sensitivity & impedance troubles is due to 2*10" woofers, 3*5" mid drivers and two tweeters to be driven through what is seems to be a major network of capacitors, transformer-type coils, shunt LC filters and long lengths of wire. However, the sound is pure bliss (okay, I'm going to the dark side here...)

Crossover here: http://oellerer.net/infinity_classics/RS_I...nical_sheet.pdf (http://oellerer.net/infinity_classics/RS_II/RS_II_technical_sheet.pdf)

I'll try to redo the test with amp side recordings next weekend. Ugh... I'd also use my smaller 3-way bookshelf speakers to provide data on 'speaker load/cables/amplifier matching'. Until then I'll keep kicking myself in the nuts for staying three months with CAT5 cable... as the difference while listening is humongous (at least that's what I'm hearing on the other side of the speaker).

edit: Added link to SPL calculator
edit: added 'low impedance needs lots of current' claim.
Title: Why does the gauge of speaker wire matter?
Post by: sshd on 2003-11-01 23:43:49
What type of cat5 cable was used in this test?

I know of two types (probably noy described very good):

A: Solid core type -- used for installations.
B: Soft type -- used in network cables with plugs.
Title: Why does the gauge of speaker wire matter?
Post by: lucpes on 2003-11-02 00:24:11
El cheapo CAT5 solid core type used in the test.

Solid core is used for PC-PC or PC-switch direct connections.

Stranded or soft is used for patch-pannel connections.

I won't bother to use stranded, nor teflon insulated CAT5 (which some claim should sound better theoretically due to not having dielectric losses), no Belden-gaga whatever type to repeat the test.

edit: typos
Title: Why does the gauge of speaker wire matter?
Post by: sshd on 2003-11-03 23:24:16
Quote
Until then I'll keep kicking myself in the nuts for staying three months with CAT5 cable... as the difference while listening is humongous (at least that's what I'm hearing on the other side of the speaker).

It seems you have decided that big lamp cord sounds better that cat5 cable. Has this been established as a fact?

Some questions:

1. Pio2001 made an interesting graph comparing the signals to eachother. The signals are different, but which one is more transparrent? I believe the samples should be compared to the original instead of eachother.

2. The recording is made behind the speaker. Is this relevant to how the speaker sounds?

3. Does the signal cable from speaker terminal to line-in affect the sound?

4. A lossy codec + DSP operations was used to provide the source.  I should prefer a lossless codec without any replaygain/DSP operations done as the source for such an experiment (just to be sure we are testing the right thing).
Title: Why does the gauge of speaker wire matter?
Post by: Pio2001 on 2003-11-03 23:37:12
Quote
3. Does the signal cable from speaker terminal to line-in affect the sound?

Not under the assumption that only resistance (Gauge) matters, because the line in impedance is huge (47,000 Ohm). However, it can add very much capacity.
Title: Why does the gauge of speaker wire matter?
Post by: lucpes on 2003-11-17 14:05:21
Quote
It seems you have decided that big lamp cord sounds better that cat5 cable. Has this been established as a fact?

Some questions:

1. Pio2001 made an interesting graph comparing the signals to eachother. The signals are different, but which one is more transparrent? I believe the samples should be compared to the original instead of eachother.

2. The recording is made behind the speaker. Is this relevant to how the speaker sounds?

3. Does the signal cable from speaker terminal to line-in affect the sound?

4. A lossy codec + DSP operations was used to provide the source.  I should prefer a lossless codec without any replaygain/DSP operations done as the source for such an experiment (just to be sure we are testing the right thing).

No, CAT5 sounds worse in my particular case. With speakers which do not draw lots of current (eg. bookshelf or small 3-way) it may even sound better or there would be no measurable or audible difference.

1. The CAT5 sounds muffled & no dynamics. The lamp cord brought the sound close to my Sennheiser HD600.

2. Yes, it's what actually gets into the speaker as a signal.

3. I don't think so (10kOhms+ line in) versus 4 Ohms for speaker.

4. It's enough to test with a lossy codec. It would make a bigger difference with a full-bandwith (uncompressed lossless) encoding.

I won't do another test, as my amp got fried somewhere in the middle of the process... 3/6 output transistors gone (literally blew up), one driver transistor gone, two diode rectifiers, one trannie from the feedback circuit, two resistors that controlled the bias current and now I'm to emitter resistors which went gaga. Hope I pull it through somehow...

DO NOT CHANGE CABLES/DO ANY OPERATIONS ON YOUR AMP IF IT IS WORKING & TRIPPLE CHECK EVERYTHING BEFORE STARTING IT.

edit: it works 'ok' now but the side that blew gets too hot... back to the hacking table.
Title: Why does the gauge of speaker wire matter?
Post by: Pio2001 on 2003-11-17 22:36:04
Sorry to hear about this.
Either there was a short circuit somewhere, which is likely with thin coaxial cables, especially with one end stripped out for the speaker connection, or with the plugging-unplugging (center of the cinch accidentally in contact with any grounded metallic part), or even the line input muting (can be internally muted by short-circuiting it)... Either the capacity of the coaxial cable added to the speaker cable drove the output stage of the "audiophile-kind-sound-is-more-important-that-security" amplifier into positive feedback.

If all is repaired and one side is abnormally hot, there might still be partially burned transistors : try to play some pure sound at a loud level (but don't blow your speakers, it would be very annoying ! ), and watch for the hot channel to sound clipped.
Title: Why does the gauge of speaker wire matter?
Post by: lucpes on 2003-11-18 12:59:31
Phew, I fixed it... turned out that the potentiometer that controlled the bias current was a little oxidized too due to high current that passed through when a diode blew, cleaned it, adjusted quiescent current as per the other channel setting & everything is OK now.

Cost: 15 euros + 8 hours of 'debugging'

Now to use banana plugs on the cables instead of bare coax wires for line input purposes... but some other time...

Horror pic here (http://www.gd.ro/images/amp.jpg) (23cm diameter for the transformer can in the middle; you can see on the right board two white resistors that replaced the old ones which caught fire)