Frequently asked questions

What is the primary purpose of audio cables in a high-quality system?

The primary purpose of audio cables is to reliably transfer the signal from one component to another without altering it. They should not be used as a way to 'tune' your system.

What factors should audiophiles focus on for tuning their system's sound, instead of cables?

You should focus on your room acoustics, your speakers, and the source material you're streaming or playing. These elements have a far greater impact on sound quality than cables.

Do cables matter at all for audio systems?

Yes, cables matter very much for proper signal transfer. Using the wrong kind of cable, especially in digital systems, can lead to erroneous measurements, signal loss, and other problems.

What is the specific impedance requirement for digital audio XLR cables?

Digital audio XLR cables need to be 110 Ohm impedance. This is different from analog XLR cables, and using the wrong type can cause significant issues in a digital environment.

What was the issue with the expensive speaker cables John Siau tested at a trade show?

These speaker cables were poorly designed; their frequency response would change depending on how they were laid out on the floor, effectively rolling off high frequencies.

Are special 'audiophile' USB cables necessary for high-quality audio?

No, a stock USB cable is generally all you need. There's nothing special about expensive USB cables; they just need to meet the USB specification for reliable data transfer.

Why does Benchmark Media Systems prefer Speakon connectors over traditional binding posts for high-power speaker connections?

Speakon connectors are preferred for their durability and reliability, especially in professional settings where systems are frequently deployed and taken down. Binding posts can be unreliable and tend to loosen up over time.

What is the main takeaway regarding cable selection for audio enthusiasts?

The main takeaway is to take a practical approach to cables. View them as a way to reliably get the signal from one point to another, rather than a tuning tool. This approach can save you money and frustration.

Transcript

Welcome to Benchmark.

Today, we're gonna talk about cables.

We're gonna talk about snake oil

and, you know, is there such a thing as snake oil cables,

or

are these claims

that that we hear,

about cables

changing the sound of our audio system? Are these are these true? Should we buy into that?

Should we buy the

$500

cables,

the $5,000

cables,

the $20,000

cables?

Are these gonna make a difference in the way our system sounds?

Well, I would contend that if the cable

makes

a change in the way your system sounds,

it's a sign that you've got a cable that's not transparent. You've got a cable that's in some way

changing

the audio.

And so cables have a very specific

purpose, and that is to get signal

as clean as possible

from point A to point B.

And

you should not be thinking of your cables as a way

to tune your system. Now let me give you an analogy. So let's suppose

that,

you're a designer of race cars.

Okay. And you've got an engine control unit, and that's communicating with the various sensors on the engine.

And, what kind of cables are you going to use to connect those? You're looking for

a highly reliable cable. You're looking for a cable that can withstand the,

the environment that,

that it's gonna be exposed to in in the race car. So

it's gotta be

resistant to high temperature. It's gotta be durable. It's gotta be resistant to abrasion. It's gotta be properly

dressed in the,

in the chassis.

But what I'm not going to do is I'm not going to select different cables

to try to tune my engine performance.

I'm gonna select the cable that gets the signal from point a to point b,

and then I'm going to adjust my engine control unit

to tune

my engine. So,

what I see a lot of times in audiophile circles is is this mentality

that we're going to tune

our audio system

using exotic cables.

And,

what I'd like you to think about is that really the purpose of the cables

is is not a tuning device, but the purpose of the cables is to be as transparent

as possible.

So,

if you're trying to

change your the way your system sounds, one of the first things you should do is think about

speaker placement,

listening

position placement.

Think about your room.

Think about the speakers themselves.

And then work your way down the chain

and and think about

various

parts of the chain,

the electronic chain, the

the amplifier,

the preamplifier,

your DDA converter,

and,

even,

your streaming device and,

what files you're you're streaming or what

CDs or other material, vinyl,

whatever you're playing,

all the way to your source device.

The very

smallest

incremental changes are actually gonna come from the cables themselves. Now, does this mean that cables

don't matter at all? No, they very much do

matter. If I use

the wrong type of cable on a digital signal, for example,

if I use

an RCA cable that's not a coaxial

cable, it's not a 75 ohm cable,

and I use that cable to hook up my SPIDIF digital coaxial

signal from,

maybe a CD player to an out outboard D to A converter.

If I use the wrong kind of cable,

I may find that at certain sample rates, that cable just plain doesn't work.

And that's because of

the cable reflections

down that cable and back

because the impedance doesn't match.

And so this is very important

in a digital cable

that in a digital audio system,

coaxial cables need to be 75 ohm coaxial cables. You don't wanna use 50 ohm

coax,

in in an audio system because the inputs and outputs are,

are terminated at 75 ohms.

I've got

coaxial cables

out on the bench

that are designed for RF testing.

And,

those cables are all set are all 50 ohm cables.

My RF test equipment

is

designed with

50

ohm output impedance and 50 ohm

terminating impedances.

And

if I put a 75 ohm cable

into

my RF gear out on the bench,

I'm gonna have all sorts of problems. I'm gonna have erroneous measurements. I'm gonna have signal loss.

I'm gonna have reflections.

And so it's important

in a digital environment

to use the proper

cable impedance.

Now,

one of the things that was done in the early days of digital audio is

somebody had the brilliant idea that it would be wonderful to be able to use

XLR cables for digital audio. So they said, well, gee, let's put digital audio on an XLR connector

and, we can use all of our existing

XLR cables and we can send digital audio

around the studio

with

our existing cables. Well, it turned out to be a really bad idea

because

none of those cables were the correct impedance.

And

so, we very quickly learned as an industry that

that those cables needed to be

matched impedance.

They needed to be 110

ohm

twisted pair using standard XLR

connectors,

but,

a very different wire inside. And so, if you go to our website, you'll see that we sell XLR cables for analog audio, and we sell a completely

different

kind of XLR cable for digital audio. And,

just to keep those

easy to identify,

we sell all of our digital

cables with a blue jacket on them. We can get them in any color we wanted to, but we we

ordered the cable with a with a blue jacket so that

the digital cables

are easy to identify and easy to separate from the analog cables that we're going to use

for line level signals and for microphone signals.

So there's an instance where the type of cable you use is is very, very important.

Now let me tell you a little story about a a trade show that we did.

We were

sharing a room with, several other vendors. There was a speaker vendor there. There were we had our electronics there,

and there was another vendor that was a cable vendor. So,

you know, okay. We're gonna

we'll split the, the cost of the,

of the trade showroom,

three ways and, you know, cable guy will bring his cables in, we'll bring our electronics in.

We really like the speakers and so we're very happy about that. So,

cable guy comes in and he's got he's got a pair of speaker cables that are

obviously made out of, welding cable.

So, maybe a thousand strands of copper,

very flexible,

capable of,

high currents,

very low resistance.

And, you know, on the surface, it seemed like, you know, this is this is

a great way to make a speaker cable.

Well,

it turns out that they were really very poor speaker cables.

They were good at low frequencies

because of the very thick copper.

But he had these cables laid out individually on the floor. So there was

one black cable and one red cable.

And,

I brought those into the lab after the show. He says, you know, hey, we'd love love to have you test these. And so, okay. I'll

I'll I'll I'll go ahead and test them. But, you know, we had a discussion at the show,

as to, you know, this isn't this really isn't the way,

you should be building speaker cables. You shouldn't have this large separation between the two conductors because that, creates a large inductance and the inductance

rolls off high frequencies.

So,

bringing these into the lab,

I could

separate the wires

and watch the high frequencies roll off

half a dB or so,

and bring them back together

and

watch the high frequencies improve.

And then, even worse, if I coiled up

one of the conductors and then coiled up the other conductor,

that would roll off the high frequencies

even more. And then, depending on how I overlap those coils and which way the coils were wound,

I could change the frequency response of these cables just by the way I I put them on the floor.

Now,

not only were these

ordinary

welding cable

with fancy

snakeskin jackets on them,

but they were also $20,000

And for $20,000

you got a cable

that didn't really work very well.

Where you put the cables

had a big

impact on how they actually sounded

and how you laid them on the floor

made a difference in in how they performed. So you could spend $20,000

or you could actually buy a $5 piece of zip cord and actually have something that was a better cable

than this,

this $20,000

solution. Now I'm not saying go out and buy a piece of zip cord because obviously we can do

better than a, a simple piece of zip cord. But the point is that that piece of zip cord would give you a more consistent

response

than what we got out of those $20,000

cables. So, you know, we said, we don't want to be

a part of this in, in future trade shows. We will not be,

showing with your cables. So if you're gonna charge $20,000

for

a cable that doesn't work, we don't wanna be a part of it. You know, obviously we get heat from time to time from, cable manufacturers

when we talk about,

you know, we use the word snake oil for some of these cables. Let me give you another example.

In the early days of the benchmark DAC one, we had one come in for service and, it's got this

really fancy

USB cable

stuck in the connector.

And, you know, it's carefully wrapped up in the box.

But the USB cable absolutely

will not

unplug

from the DAC. And this is, you know, the A style connector, the doghouse shaped

connector.

And

there's no way you could get that connector out. It was in there. It was you put it in, and it's never coming out. You know, we talked to the customer, and he says, oh, you know, I I spent a thousand dollars on that cable.

You know, anything you can do to,

to,

get that cable out,

and salvage the cable, you know, I'd really appreciate it. At that time,

the DAC one was $950

and the USB cable

was $1,000

So,

we got a $1,000 cable stuck in the back of this.

And so, we

took it into the shop and one of the technicians very carefully,

unsoldered the connector.

And,

we put a new connector on the board,

and

serviced it under warranty and put the unit back in the box along with the customer's cable

and, sent it back to him and said, well, you know, send the cable back to the manufacturer.

Obviously, there's a, a tolerance issue here. This cable's not

made to,

USB specifications.

You know, it goes into certain

USB connectors,

and locks itself right in there. There was nothing wrong from a performance standpoint with the cable that we ship,

with every deck one and every deck two and every deck three.

They're generic

USB cables,

but we know from testing

and know from running

jitter tests

and

running

all sorts of

different measurements,

that those cables,

work

flawlessly

even though

they're, you know, a $5

USB cable. You may have,

some USB inputs that are sensitive to jitter,

not on a benchmark product, but you may find products that do.

And and so certain cables and different,

cable lengths,

USB cables

possibly could make a difference. I've never actually seen

any,

solid measurements that that show that, but,

theoretically, that that might be possible. But suffice it to say that the $5 cable that we,

ship with our products,

USB cable,

there's nothing special about it. It's it just meets

USB,

standards as far as data transmission,

bandwidth, and and so forth. And that's just a

a stock USB cable, and that's all you need

on a

benchmark deck. You don't need to spend a thousand dollars on a cable that's gonna get stuck in the jack on the back of the unit.

Now we had another

deck one

come in,

that had a similar problem.

This one

had

an aftermarket

headphone cable

stuck firmly

in the

headphone jack on the front of the unit.

And again, there was no way you could pull this thing out. This is a quarter inch headphone jack. How in the world can a quarter inch headphone

jack get stuck into,

into the headphone jack? And

and beautiful cable,

you know, gold plated,

plug on the end, really beefy,

quarter inch plug. Beautiful piece of cable to look at. And, of course, it had been unplugged from the headphones so they could send it into us.

And

no way to get it out. So, again,

technician

unsolders the connector,

removes it from the board, put a new connector in,

service this under warranty, and and,

send the customer's cable with the connector still attached,

back to him along with this repaired

deck one. What the issue there was is,

they had taken a standard off the shelf quarter inch phone plug

and,

plated it with

very, very thick gold plating. You know, there had to be

some value at least in in all that gold that was on the,

on the connector, and it it looked

absolutely gorgeous.

But when you put a micrometer on it, you could see that it was well over

a quarter inch

and,

too large to actually go into

most

headphone jacks. There's a lot of snake oil out there. There's a lot of

expensive cables

that don't work. Now let's talk a little bit about

the connectors that are on your speaker cables.

One of the things that you wanna avoid

are the spring loaded

banana plugs.

We've done a number of measurements

in the lab.

Whenever we've tried to measure an AHP2

with spring loaded banana plugs,

the distortion

is just about double or triple

what we'd expect it to be. And it turns

out that there's more distortion

generated across

that spring loaded banana plug

than there is from the entire

AHP2 power amplifier.

A simple solution

is

to use a

locking banana plug. So, these plug in, and you turn the

knurled

screw and and they tighten up internally

with four individual

fingers, that makes a very

reliable,

very low impedance

connection.

The other thing that we found is that

spade lugs,

can be

very unreliable. If they're clean, if they're perfectly flat, and you tighten them down sufficiently

in the binding post,

they work wonderfully.

Problem is the minute you bump the cable,

they tend to loosen up. And so,

after

bumping them multiple times,

it's very common to find them

loosened up to the point where they're

producing more distortion

than the entire

AHP2 power amplifier.

So connectors

are extremely important.

Connectors

are,

to a large extent,

what determine

the reliability

of your cable.

So,

we always use

Neutrik

XLR connectors.

We use Neutrik

SPECON connectors,

and it's because these are proven

connectors that are that are used widely in sound reinforcement

applications

where where systems are being put up for one night, torn down, moved to another city, put up, taken down.

And so day after day, these systems are are deployed and and taken down, and these cables are unplugged and plugged in,

and they're stepped on and and all sorts

of, abuse.

They're designed to take that abuse and give you good reliable connections. In our own facility here, we use the Neutrik connectors and

canary

cables in all of our test stations. And so,

maybe twenty, thirty, 40 times a day, we're plugging in and unplugging,

testing the next piece of gear, plugging that in, unplugging,

testing the next piece of gear, plugging in, unplugging,

and about once every

five years we have to replace

those

cables.

They're that durable.

They can go through that many cycles.

But, eventually,

the the plating on the XLR

pins

and the XLR

sockets,

wear out.

And

and that's usually what

determines end of life for those.

Now the canary cable,

that that we're using on those

is surprisingly durable.

That's a that's a four conductor

star quad cable

with a braided shield

and

a number

of reinforcement

strands in there.

Turns out it's a super durable cable.

We don't find that those fail

at our test stations.

What what does eventually fail are the connectors themselves.

Now on the back of the AHP2

power amplifier,

you'll find that we have, Speakon connectors.

And, we have binding posts as well, so you can use the binding posts. But we actually recommend for for best performance that you actually use the, Speakon connectors.

And the reason for that is that those are

high current,

connectors.

They're they're very durable.

They

have a wiping action when you put them in and and lock them in place. They they stay locked in place.

And,

these are industrial connectors that are used in sound reinforcement

systems used for very high power,

speakers for line arrays and and so forth. So if you go to a concert,

every single speaker you see

in that line array is

is connected with the Speakon connectors.

So,

very proven reliability

and very low impedance

connections.

No measurable

distortion

across those,

those connections.

So,

that's what we recommend

using.

And and if it had been my choice, there would have been no binding posts on the back of the AHP two.

I had the sales department twisting my arm saying, no. No. No. We've got it. We've got to put binding posts on there. Everybody's got binding posts. So

so you can thank the sales department for,

the binding posts on the back of the AHP two, but

my personal preference would have been to leave those off there entirely.

But the whole

point of

benchmark cables is to give you

a reliable connection

that gets the signal,

from point a to point b with maximum

integrity,

so

without loss of quality.

And it doesn't take

a $5,000

cable or $10,000

cable or $20,000

cable to do that. It takes

well designed cable,

which is

readily available.

We use the Canari

star quad cable, for example.

Also, we use coaxial cable for

the coaxial

connections,

the SPIDIF coaxial connections.

There's all sorts of wonderful

75 ohm cable that's readily available that's,

that, you know, all of the specs are are available to us to look at.

And so we're selecting,

the best materials

and,

and giving you a cable that's

reasonably priced,

that reflects the actual

value of the of the cable and the connectors and the labor that it takes to put them together.

So I hope that helps avoid,

some of the pseudoscientific

claims about cables.

Take a practical approach to it.

Don't look

at a cable as a way to tune your system.

Look at a cable as a way to reliably

get a signal from point A to point B.

Again, remember,

I wouldn't use a cable

to tune a race car.

I use the cable

to get the signal from the sensor

to the engine control unit

and,

and then tune the engine control unit to, to tune my engine. So,

I hope that helps,

and, I hope that,

in the long run can save you some some money and some frustration

when you're trying to put together a great audio system.