A hard look at the effect of cables

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...

Knownothing,

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.

Dave,

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)

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.

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.

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.

and

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.

and

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}

and

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!

if multiamplification is such an obvious advantage, why don't I hear more ..... Just wondering.

Knownothing,

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!

Waffle35,

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.