A hard look at the effect of cables

Hey guys
A fellow EE audionut directed me to these articles and I thought some of you might be very interested to read them too. Two arguably qualified engineers went through the pains to take high quality measurements of the effect of cables and their interation with a complex electrical load, such as a full range loudspeaker, and with a complex signal, such as music. The link below is to the final installment but be sure to also read parts 4 and 5 very carefully. Part 5's Figures 6.8 and 6.9 are really amazing. I had never seen such measurements and they definitely seem to correlate with what we hear. The cables lengths are longer than normal but I think the point is well made. Hope you enjoy this read as much as I did.


Blame the cables.

It is the cables fault.

Everyone knows that the amplifier and cable and complex speaker load interact. However, blaming cables is a "cop out" to me. It is all too obvious that the distortion products (due to complex interaction) will be different at each end of the cable; after all one is shorted by an active amplifier - a virtual SHORT and highly dependent on the amp circuits whilst the other end is connected to the complex but higher impedance load of the speaker and its moving diaphragm(s).

The more complex the load and the less stable or capable the amplifier then the more chance of problems. In problematic combinations, slight differences in cables will certainly accentuate or attenuate certain forms of audible distortion (there is always distortion but not all forms are large enough to be audible when playing music). IMD distortion being a particular problem, as it is quite audible compared to other forms and IMD is often a product of complex interactions between amplifer and a complex load with mechanical moving parts.

This throws in to question the "standalone" or "isolated" design of many amplifiers and speakers....that they should be so badly designed in isolation. In the extreme, the speaker designer my ignore how they are to be driven and the amp designer may make the ridiculous assumption of optimization to drive an 8 Ohm resistor accurately: in this case, the two being so badly designed, as to be overly sensitive to a mere piece of wire between them. Add to this the consumer, who randomly selects to match certain items totally ignorant of how the poor amplifier is being mistreated or abused with a terrible load from a ported speaker with enormous LF bass extension!!

=> The design fault is with the speakers and amplifiers and the selected combination of the two, IMHO. The lack of a holistic view towards design and equipment selection.

Tweaking by changing cables to improve sound clearly implies that there are distortion products in the amplifier/speaker/cable complex interaction that are audible....and this is bad. Is the cable tweaking a solution? No it is a band aid, IMHO!

Yet most people incorrectly BLAME the CABLES as the cause of the problem when cables cause a significant change. And yet cables are a PASSIVE element and the LEAST complex element of the system by SEVERAL ORDERS OF MAGNITUDE.

The root PROBLEM is bad Amplifier and/or Speaker design or in rare cases a very odd choice of cable or combination of all three!

These differences can be made small through proper design and selection. And the far superior design of active speakers allow these kind of surprises to be designed out of the system - through thorough testing and design of amp and load to ensure stability, precise phase characteristics and much lower intermodulation distortion. An active speaker with a separate mid range amp only working from 380Hz to 3.5 Khz has to contend with a mere decade of frequencies and no nasty crossover)...so a much much easier job for this amp.....so no IMD distortion leaks between this frequency range and that from bass or treble (especially that nasty hard to drive bass frequencies where much amplifier instability issues occur)....so that this amp can be designed to be much more stable and low distortion over a greater SPL range and variety of music...it has such an EASY job compared to what most amps are asked to do!

Active Speakers have some serious advantages and this series of articles clearly demonstrate this by highlighting the deficiencies in conventional approaches to equipment design and selection. Actives have disadvantages too - less chance to tinker around and tailor the sound. However, active speakers do eliminate the speaker cable/amp/load matching problem mentioned here (the "effect of cables"); actives mean a lot less to worry about, which is good unless you like worrying about unknown untested complex interactions from your personal equipment choices...
Shadorne, I'm not used to seeing you respond with so many paragraphs littered with all-caps. I'm also surprised that this little cable item has led you to call for a moratorium on passive loudspeakers with an eye toward examining the possibility of an all active speaker world:]

Unfortunately, most if not all of the most highly regarded speakers in existence are passive.

Cables, themselves, do cause significant differences in sound regardless of how unsuccessful engineers are at properly understanding those differences.
I gather from the article several points. Correct me if I am wrong.

1. Amps, speakers and cables all interact and therefore the amps and speakers will change the characteristics of the cables. Cables will potentially sound different in different systems.
2. The longer the cable, the more it picks up interference, especially RFI.
3. The configuration of the cable, coax or parallel, will show measurable change in the level of interference measured.

If I am summarizing several of the many points correctly, then I propose that:

1. Reviews of cables are meaningless because they are not using the equipment that you will be using.
2. If you have long runs, you may need shielding to prevent the pickup of RFI, and maybe EMI.
3. Metal content, physical configuration, dialectric and length will all contribute to measurable differences in cables, and may give them different sounds. Therefore all cables can potentially act as tone controls, some more than others.

Did I understand the article? Did anyone else come to the same conclusions?

Sorry for the caps - too much coffee this morning I guess,

As for moratorium on passive speakers....no I don't believe that. I agree that that the vast majority of the best speakers are passive.

I believe that for a well designed amp and for well designed speakers ( that are a suitable match) then the cables should have minimal effect (barely audible). I know many audiophiles vehemently disagree with this concept. I suspect the links in this thread to respected researchers who have discovered distortion when an amp and speaker complex load are coupled by a cable is intended to prove what many believe; speaker cables are a significant issue in home hi-fi and they dramatically affect the sound.

So my suggestion to those "cable worried people" would be to simply investigate Active Speakers - because this largely eliminates the problems with cable choice and matching amp to speaker load by leaving these critical choices to the designer with their skills and lab test equipment. I also gave justifications for why active designs will reduce this problem significantly . The most compelling argument, for those non technical minded, is to realize that the cable is almost eliminated altogether (it becomes at least 10 times shorter...an order of magnitude less important)
This article unfortunately reminds me of attempting to make good speaker cables using my Nakamichi AV10 as test amp. What finally sounded only OK on AV10 was poor on everything else. The weird loads with normal speakers is why I was so taken (and purchased) some TBI speakers as they are closer to resistive load than inductive. I have not seem many threads from people with successfull experience from 2 inch long speaker cable mono amp hook-up. How can we normal folks use this info ?
Nothing is truly passive. Even what we call passive is reactive.

I still find it hard to fathom how a speaker cable can be so important, considering the inductors, capacitors and windings in the drivers of the speakers. It's almost comical after the mile of wire in an output transformer. Yet, I've heard amazing changes, at least once.

It should be noted that IC's are completely different and capacitance/inductance play a bigger role.

I'm disappointed that this thread isn't more controversial and misunderstood.
hi shadorne. there are two cable interfaces that you may be overlooking, namely the source to preamp and the preamp to amp. what about transport to dac. and what about line cords ?

ihave personally observed affects of line cords with respect to the above mentioned interfaces.

by the way, i am not aware of any panel that is fully active. some provide an amp to a woofer driver, but then the owner must furnish the amp for the panel.
Bring back the stereo console and have everything hard wired and stop all this craziness!
hi shadorne. there are two cable interfaces that you may be overlooking, namely the source to preamp and the preamp to amp. what about transport to dac

Since these are just signal cables (almost no power or current), they have a specifically designed buffer circuit at the input of each component in a chain (rather than a nasty complex load of a speaker). These cables are far less of an issue than speaker cables. The components can be designed to preserve signal integrity across interconnects to a much higher degree.

So 20 feet of shielded XLR with good components at each end is therefore much better than the equivalent in speaker cable connected to a nasty complex load.
Ngjockey makes some great points.

I don't believe the article was meant to blame cables but rather highlight the complex interaction of the system due to the cable's connection - and that the cables themselves also contribute to the overall effect to varying degree.

I don't feel I have any answers but I do know that I have experienced significant changes (relatively speaking) with different interconnects and power cords, as well as speaker cables. And not only that but in some cases, I've had significantly larger changes with different interconencts and power cords than I have had with different speaker cables. Not sure why but I have witnessed it with my own ears, which I trust.

But this would make sense too in the context of what Ngjockey brings up: how can a simple cable have such an impact when you are talking about inserting it in a system with huge capacitance and inductance all over the place?

It is amazing and humbling for me to witness the complexity of our universe. The more I try to learn and figure out, the dumber I realize I am.

"It is amazing and humbling for me to witness the complexity of our universe. The more I try to learn and figure out, the dumber I realize I am."

Arthur, if only we all were as humble.
I don't believe the article was meant to blame cables but rather highlight the complex interaction of the system due to the cable's connection - and that the cables themselves also contribute to the overall effect to varying degree.

Arthur, now I fully agree. However, the title of the thread was "a hard look at the effect of cables", which implies that the cables themselves are the primary cause of observed differences. I am just presenting the alternate viewpoint that one should look at the system holistically.

The authors (Philip Newell and Keith Holland) in your original link state

It does not take too much imagination to realise how a 20 or 30 amp low frequency current can modulate high frequency signals passing along the same cable at levels of 40 dB below.


the generally prevailing opinion is that multi-amplified systems sound 'cleaner' than equivalent systems using single, full-range amplifiers. And of course, with multiamplification, multi-cabling is an automatic result.


There is no doubt that it is asking a lot of any amplifier, or loudspeaker cable, to faithfully pass up to 11 octaves of musical signal with a dynamic range of 90 dB or more. Considering the fact that no loudspeaker driver can do this, it seems perfectly reasonable to split the frequency bands ahead of the amplifiers and drive each frequency range independently. {Note: This describes an Active Speaker}


It has been the experience of the authors that as the frequency bands become narrower, the need for specially selected cables reduces considerably. {my point above, earlier in this thread}

=> I interpret the authors as saying that you can, if you like, regard cables as the root problem (presumably band-aid or color your sound by finding a cable that has the least problems in combo with your gear) or, alternatively, you can turn to Active Speakers if you simply want to avoid a whole bunch of issues that they describe (drawback: this requires accepting a manufacturer's design rather than your own recipe for sound, a kind of straight jacket).

BTW: Great that you pointed this article out. It is the most compelling argument for taking a serious look at Active Speakers that I have seen in a long while. Of course, for those who are not interested in tackling the root cause, then it can be construed as a good reason to try another more expensive speaker cable...perhaps it will sound better ....perhaps it won't...at least the cable tweaking provides hours of entertainment!
Not being an EE I don't know if I really grasped the article, but I wonder if this research and argument supports the use of magnet wire (Speltz, et al.): no dialectric, short wires from mono amps close to the speakers, wires separated from each other in space? Also, he tested coax type speaker wire. Who makes coax style speaker wires? I see lots of ICs with this configuration, but don't recall SCs. Thanks again for the info. It is lots of fun to explore deeper into the science of music reproduction.
From my very novice perspective, the way I look at this series of articles is that:

1) speaker and amp matching for peak performance is difficult at best, and in the home audio world where design standards are loose, a hit or miss affair

2) speaker cables have a significant impact on the interaction and combined performance of these components, and

3) one way to reduce this effect is to use the shortest pieces of wire possible with reasonable resistance, capacitance and impedance characteristics in a configuration that effectively rejects EMF/RFI.

The fact the authors report on significant and distinct distortion signatures of different length runs of different wire types should indicate to most that wires make a measurable difference in both extreme and real life situations, confirming what most audiophiles have discovered at some point on their own. This information has me questioning my own 10 meter runs of speaker cable, but understanding why the switch from standard side by side stranded cord to a more complex configuration made a noticeable (but expensive) difference in sound quality.

It is doubtful to me that any of us will usher in a new era of active speakers as the dominant format as a result of this and other findings. I do think this information is as much about the relationship between amp and speaker design as it is about cables. In some ways this just further confirms what most audiophiles have already experienced, that it takes a long time and a lot of equipment swapping to find a match made in heaven, and happily or unhappily, cables can contribute (greatly) to that quest.
Wouldn't multiamplification come with many attendant challenges, including more (but shorter) wires, signal loss and coloring by two or three amplifiers instead of one, signal level matching across several separate frequency bands complicated by perhaps using different types of specialized amplifiers for each range, etc? Essentially some of the challenges one deals with now for subwoofers, and the jury is still out on the hi fi benefits of using a sub.

Don't know enough to understand how crossing over occurs in an active versus passive system - how similar or different is this process with amplification occurring before or after signal separation? Or is this really a non issue?

One could imagine the complexity driving costs quite high for this type of equipment. I realize that these products are already available - but seems like a manufacturers delight as they capture two markets with one product.
"Bring back the stereo console and have everything hard wired and stop all this craziness!".
Actually I think it's going in opposite direction. Wire has acquired such magical properties in recent years that soon we will be able to eliminate speakers, amps, sources, etc. and the magical cables will make music all by themselves.
"Wire has acquired such magical properties in recent years that soon we will be able to eliminate speakers, amps, sources, etc. and the magical cables will make music all by themselves."


I guess this is why Spectral had MIT design some cables for them. At least MIT demonstrates an appreciation of some of the basic interface problems when they provide for impedance matching? Not magic, just solid engineering features.
Knownothing, not to criticize but the jury is "definitely" 'not' out on the hi fi benefits of using a sub, and hasn't been for a very, very long time. JBL was making dedicated subs(350 & 460 in the early '80's if memory serves) that dramatically improved the mid & upper range clarity and dynamics for high quality full range speakers as well as enriching the bass response & quality. The level of quality available today is jaw dropping as is the ease of set up provided by the sophisticated units from Revel for example.
Arthur, thanks for providing the great post and link. If only more Audiogoners could only follow your example in brevity, clarity, usefullness and supporting documentation.
my personal experience points to the source as having a significant affect upon the performance of a stereo system.

thus, the signal from a cd player passes through 2 interconnects and a preamp before it reaches the amplifier.
it is this link that has a greater audible impact than that of speaker cable, amp and speaker.

the signal fed to the amplifier is critical, for obvious reasons.
Psacanli, It's OK to criticize, but I don't have to agree. My limited experience is that subwoofers are not embraced by the all members of the audiophile community. Can they enhance bass response and overall system performance? YES. Are they easy to match with your system and room and set up to create coherent and musical reproduction? NO. Just my opinion, but I know it is shared by at least a few other dinosaurs.

PS - I own a subwoofer in my HT set up, and it enhances reproduction of both soundtracks and music. But it isn't perfect and I am not pining to add one to my modest hi fi-only set up, even though bass response is far from Full Spectrum. Maybe I should check out the Revel model you mentioned...

FWIW, your strategy as regards a sub woofer seems quite sensible. I believe it is better without one unless you can get something of high enough quality to not do more harm than good to your bass and lower midrange. Producing good ultra LF with accuracy seems exponentially expensive compared to an equivalent quality mid range and treble, IMHO.
Shadrone, interestingly I recently brought a relatively cheap sub into the listening room. I have two independent sets of electronic's available to drive my speakers. With one set the sub's inclusion really flesh out depth, tightness, and imaging - a pretty good, even if with relatively inexpensive components, 'audiophile' listening experience.

However with the other set of components, in which the amp is fuller, deeper, and rounder on its own, it sounds more of 'one voice' with the system, draws less attention to the audiophile essentials, and allows a far more relaxed and enjoyable listen to musical content. Interesting......

BTW it took me about 18 hours of effort to match the sub with the mains using an SPL meter, test records, and some very critical listening. Not a walk in the park and I can imagine why folks get frustrated in trying to combine a sub with any speakers, let alone full range speakers, in a problematic room. :-)
Knownothing, I agree with you. Being near 60 and having been keenly into reproduced misic for ~45 yrs(picked it up from my dearly departed Dad w his Grundig console & the Limelighters & such) I guess I'm a little overappreciative of the tech marvels of today. (I'm even awed/thrilled a bit that my cellphone will update my computer records, do email & cerf the net. ATB.
HA! No worries, the sub does add a quite a lot to any recording by Missy Elliott. Badonkdonkdonk.
Psacanli, btw,
I guess this is why Spectral had MIT design some cables for them.
Reportedly, no. The spectral amps are wide-bandwidth devices (up to ~1MHz), so the wire must protect against picking up hi freq noise. Other amps are bandwidth limited so the matter is moot. Cheers
agree with Pscanli--newer subs are much easier to set up -- revel b15a for example has its own internal EQ--does take some time but not bad for the benefits if you have never heard what a good sub can do!! you would be amazed how much more dynamic a system can be with one .
I am just curious, if multiamplification is such an obvious advantage, why don't I hear more on this site about Meridian speakers? Specific execution by that brand, or not as great in general practice as in theory? Or is it marketing psychology - being hard for folks to drop the big bucks on two speakers and some wire instead of boxes and boxes of gear from different manufacturers, each with their own individually smaller price tags, but adding up in the end to the same or greater cost? Or, if everybody owned Meridian products, what would there be to talk about on the gear side of the hobby when the manufacturer has done nearly ALL of the fooling around for us? Just wondering.
Hi Greg, beyond 1MHz; I think that's the next 'new' thing we'll be learning.
High bandwidth good.
Ps: Actually there are a few manufacturers who offer wide-bandwidth amplification devices. Amazongly, there has been little marketing bull about this, so as you imply "however much the marketing bull* there's always room left for more".
Watch out for the next big thing in audio: GHz reproduction!
if multiamplification is such an obvious advantage, why don't I hear more ..... Just wondering.


I think you have nearly answered your own question...a lot of it is established marketing psychology whilst some of it is historical in origin. The High-end audio industry is more akin to the fashion clothing market than pure engineering. Industrial design is an important aspect of most products and may often determine their success - after all these things sit in people's homes.

There is also a "value network" established between individual component makers that can be "matched" by the consumer/dealer to create unique combinations. You are obviously unlikely to hear an amp manufacturer or a passive speaker maker endorse Active designs, as this is promoting a competitor's product...and currently there are far far more individual component makers than there are "Meridians".

The reality is that individuality is also extremely important to high end customers and the existing approach allows for mix and match for clients, just like women's clothing: women dread the thought of turning up to a ball wearing the same gown! Funnily enough, men are comfortable in these situations wearing identical tuxedos....not so, however, for audio!!! The value network is similar to Apple iPod success...the accessories market is a big part of why it is attractive to sell iPods...people keep coming back for incremental purchases.

Active designs have had somewhat greater success in professional circles where transparency and how a mix/master translates is more important, but it has been far from a cakewalk; studios also like to differentiate from each other - a kind of gear arms race - my gear is better than yours - it can't be better if it is the same - so most often "custom" designs are made, even with active speakers. However, in this market there is a greater need for engineered accuracy to help remove a little of the guess work when an audio engineer works in one studio or another (often with a new combination of gear). Although an alternative, still popular, is for studios to simply stock or rent dozens of various reputed speakers (all diffeent sounding) simply to allow clients to hook up what they are already familiar with for near field monitoring.

As for the "obvious advantages" of Active Speakers...yes, purely from an engineering perspective, the advantages are indeed quite obvious.....but most people regard integrated multi-amped active speaker designs as too narrow a "straight jacket", restricting the freedom to mix and match for sound, which is the main reason many people pursue this hobby - it is one of collecting, experiencing and trading...and dare I say it fashion too!
Is it really that difficult for a cable to carry a full range signal? I don't know much, but this is the first I"ve heard of this.

Also, I've heard substantial, significant changes with new cables (speaker and interconnect, but not power cables so much) with what I think is pretty high end gear that is well matched (check my system). Cable changes have almost always made a bigger impact on the sound in my system than changes in digital front end gear.

Power cords haven't though, and that, I still don't understand why. I keep seeing and hearing how this PC sounds like this, or that, and I can't hear any difference. I've still gone ahead and tried different highly rated cords, and am keeping them, but they just haven't panned out the way speaker or interconnect cables have.

Guess I have a wacked pair of ears...
LMAO. Shadorne, you're quite right. Integrated multi-amp matched componentry with minimal cable is theoretically better. Are you really John Meyer! You missed a big part in that a lot of the fun in audiophile is finding those "magical" pairings. Why else would some of us spend all this time trying to match "NOS" tubes and get excited over Hammond transformers.
hi Psacanli, nope, haven't tried those, but i've tried many that are well regarded. I"d think I'd hear something. Could be that my gear isn't sensitive, tho that doesn't seem likely as I've never heard any real difference between power cords.
If the Meridian approach was a smashing commercial success, I guess it would be more popular among manufacturers. Market forces, whatever they may be, seem to dictate otherwise. I got a kick out of your analogy with the fashion industry - perhaps I have more in common with my wife than I thought...
Is it really that difficult for a cable to carry a full range signal? I don't know much, but this is the first I"ve heard of this.
Of course not. The problem (if problem there is) is in the way that wire carries a wide-band signal; i.e. there may be attenuations & small phase anomalies in parts of the bandwidth...

But then, you can get similar anomalies just by using a single channel to amplify from dc to daylight AND expect a pair of passive boxes (speakers) to produce sound, accordingly from dc to daylight -- all of this in totally linear fashion. A tall order.
Just think about it! :)

You missed a big part in that a lot of the fun in audiophile is finding those "magical" pairings.

I agree - "freedom to mix and match for sound is the main reason many people pursue this hobby"

An Active Speaker is like a "straight jacket" to those looking to tailor sound to their own tastes.
you can get similar anomalies just by using a single channel to amplify from dc to daylight AND expect a pair of passive boxes (speakers) to produce sound, accordingly from dc to daylight -- all of this in totally linear fashion. A tall order.

A tall order! Exactly. It is not so much what the cables are being asked to do! It is really what the poor amplifier and complex transducer system has to handle - it all comes together at the amplifier that is often being asked to handle a dogs breakfast of signals/impedances.

A full range speaker with four (and often more) drivers and three crossovers and a supertweeter is being asked to produce reasonably flat response from 20 HZ to say 35 Khz. All the complex reactance interacts. All the diaphragms are moving all the time and their movement and inertia induces electrical energy back into the shared circuit with all the other drivers. The bass woofer requires several AMPS to produce bass signals and yet the tweeter and supertweeter respond audibly to the tiniest miniscule signals.

Now couple this all together with some wires and all to the same browbeaten amplifier, typically a power amplifier with an on paper flat response from 20 Hz to 100 Khz (into a resistor 8 Ohm load of course!!!!).

This system now has a lot going on and Power Amplifiers are not supernatural machines that can respond to anything and everything without the slightest signal interaction. Delivering a huge bass signal of several amps at 40Hz to 80Hz without causing audible intermodulation distortion of a small tweeter signal of a few milli-amps (thousandths of an amp) is a tall order! Worse - the reactance of the system is complex....the load swings from low impedance to high impedance depending on what frequencies the amp is asked for. Worse - the drivers have inertia and are moving....these are making the complex load not just frequency variable but time variable too - depending on the drivers movement and position. Worse - as you get further into a track the drivers voice coil heats up and this changes the way it interacts with the passive crossover as well as changing its fundamental response due to its rising resistance. Worse - over half the amplifier power is dissipated as heat in the crossovers alone (it never reaches the speaker drivers).

The idea that a high tech speaker cable or bi-wiring might help solve some of these issues is kind of on the right track but it is largely wishful thinking, as the problem is really the overall complexity of the total interacting system. It is incorrect to simply extol a cable for any perceived improvement it makes...there are surely more problems going on if such a small change makes a dramatic difference - a mis matched amp and speaker for example! In some cases a particular type cable may improve the stability of a system in others it may not...all will depend on the particular gear combination and how or what kind of detrimental distortion is being produced through the complex interaction.
Dennis--very interesting that you have not noticed any differences in pwr cords --you have a great system that should be quite revealing--I have been amazed at the differences in pwr cords --just changed from mit ac-1 on my amps to bpt L10 pwr cords with much improvement-the mit's and my previous old marigo's were prob little change -have also noticed changes when an L10 was added to my furman ref15it--nothing short of spectacular --waiting on a more expensive pwr cord for my cdp to see whether it will make a diff --I also have oyaide outlets and thought they tightened up the bass--rich --any ? email me
Hi-Pscanli--was using the shotgun--obv not as good as the magnum or oracle or even the ac-2 with amps-and of course not as expensive either--I am sure the upper models are much better--I have just spent a bundle on a new cord for my cdp and hoping it will be much better-waiting on delivery ---the bpt L10 is a steal for the cost--and made a diff in my system--of course every system is different --rich ?email me