Another "Wiring" Demonstration

[DrWho]

Characteristic impedance CAN happen at audio frequencies, but it is

very easy to get around (just use the right guage wire for the length

of the run). It's not magic, you just plug into the equations and

anything above and beyond is a waste.

[D-MAN]

The typical pedantic approach is certainly not an approproiate choice for what is essentially a physiological/psychological issue. You cannot measure the perception of what is commonly called the "soundstage" or "stereo effect" with any electronic test equipment of any type.

Either you accept the existance of a so-called soundstage or not.

Since it cannot be measured, should it be ignored? Pedantism would dictate that it be considered non-existant and we therefore should only listen to monophonic sound systems.

I am always interested in gear or tweaks or speakers that increase the quality of the soundstage or further enhance the perceptual experience presented by the "stereo effect". Things like "clarity", "depth", "size", and "location".

DM

[sfogg]

"The typical pedantic approach is certainly not an

approproiate choice for what is essentially a

physiological/psychological issue."

And the even more pedantic approach is to avoid any and all sorts of verification of said effects through listening.

Next time you have someone over do the exact same thing with the listen

as you did for this guy. Except don't actually make any changes in the

wiring... just make it look like you did. Give them the same 'did you

hear that' expression on your face and fairly likely the listener will

go on to explain how much better it sounds now.

Until you realize how powerful the power of suggestion really is you

simply aren't going to understand how easy it is to be fooled by it.

"You cannot measure the perception of what is commonly called the

"soundstage" or "stereo effect" with any electronic test equipment of

any type."

Of course you can measure what contributes to those things. It is

primarily a combination of amplitude and phase correlation between two

speakers.

You have never played with any real time 3D mixing equipment have you?

If you had you would know you can move tracks around in the aparent

position in the soundstage both in depth and across the soundstage.

Devices like that couldn't be built if people weren't able to correlate

the imaging of a 'soundstaging' to what electrically causes it in the

signal passing to the speakers. Yet devices like that are built and

some of them are very effective at what they do.

Shawn

[DrWho]

But if there are changes in any one of those variables, then you should

also be able to see the difference on a scope (which has way better

resolution than our ears). And if you can see it on the scope, then you

can go about creating a model to predict the changes.

Psychology has a ton to do with our perceptions...it can even create an

audible difference that doesn't exist. You would have never tried the

other cable if you didn't believe it would make a difference - and thus

you are in a subconcious mental state where you want to hear the

difference. Likewise, I subconciously don't think it would ever make a

difference and therefore I'm not going to hear a difference. []

That's why double blind ABX comparisons are such a great tool...in

fact, they would be even more effective if the listener didn't even

know what was being compared! Now that'd make for some interesting

studies...can the person even identify the change being made let alone

consistently identify different kinds of changes.

[D-MAN]

Ok, I'll do the "fake-out" thing next time to see if it has an effect.

A cautionary note - this seems to be a test of what I would regard as so subtle of a change that it can be easily mistaken - it ain't subtle with real wires. Like I said before, its unmistakable.

But I'll do the fake-out test first for verification.

DM

[sfogg]

"I'll do the "fake-out" thing next time to see if it has an effect."

Do it with enough people and you will certainly see it. Even has a name.... Placebo Effect.

" it ain't subtle with real wires. Like I said before, its unmistakable."

Except that every time someone makes that claim and then goes on to

take a listening test using only their ears (not their eyes,

biases..etc..etc) they mistake it.

Shawn

[efzauner]

JJKIZAK.

The choice of 600 ohms, or 50 ohms, or 75 ohms has to do with compromise between cost of cabling, power capacity, characteristic impedance, loss, technology available etc. Lets just say that their are historical and technical reasons for the different impedances found in various gear, and yes, if you are transmitting signals over distances that are a good portion of a wavelength or more you do need to use cables of the same characteristic imepedance as the source/load in order to transfer power and not have reflections. Sending audio over many miles of landlines does indeed call for proper impedance matching and correct characteristic impedance of cable. But not for short distances. While microphones source/loads may be 600ohms, the characteristic impedance of a hundred feed of microphone cable is not important. Sure the overall capacitance/inductance is important, but not Zo for such short runs.

Even at microwave frequencies, you do make sure that cabling is 50 ohms, but a sort wire bond on a 10GHz chip is considered a lumped inductance and a capacitance, not a distributed transmission line

Yes, adding a pad to inputs of equipment will improve the VSWR, it will also protect it from overloads, and if it is measuring equipment, reducing reflections will also reduce missmatch uncertainty and improve measurement accuracy. It reduces the amplitude of the signal and the noise by the same amount. It also adds its own KTB noise, and since it reduces the signal going to the next stage, a 20db pad will also reduce the overal Signal to Noise ratio by the same 20dB.

[JJkizak]

efzauner:

Thanks. My initial intention was to apply those VHF/UHF techniques to the audio problems that the peoples on this forum so often become submerged in as a possible explanation of the amp/wires/crossovers/speakers enigma. It would be interesting to see some top shelf test equipment monitoring 5 distinct sweeps of impedance performance of the tweeter, squawker, woofer, crossover and amp all at the same time on an oscilliscope, if in fact that it could be done. Possibly a nice active, expensive computer controlled crossover would be the result.

JJK

[DrWho]

There's a professor on campus doing just that....and the tests are

quite elaborate (involving "shock mounting" to prevent traffic

vibrations outside from altering the results). The goal is to create a

huge database and then try to predict good sounding equipment

combinations and I suppose bad sounding combinations too.

It isn't too hard to design a perfect amplifier built around a specific

speaker, but the problem is it quickly gets very expensive. (same thing

goes for preamp stages as well....and the testing being done even goes

into studio equipment all the way down to effects units and

microphones). The goal of good engineering isn't so much building the

perfect product, but rather finding creative and inexpensive ways of

achieving the same/similar results.

I need to get in on this testing...I have a feeling there would be a lot to learn in the process.

[mark1101]

D-Man,

I assume you are using one of Al's networks. I have Dean's. We can take the names out of this because the issues are the same with both. I have a similar issue to yours, but with the tweeter.

The networks are adjustable only to a point. The autoformer tap choices are really only 2 (maybe), and those are approximations due to the differences in the networks themselves. The rest are completely out of the useable range, and not relevant.

Further, if you increase the level of the Squawker it drops the level of the woofer. This makes finding a happy home a touch more difficult (I have LaScalas, Khorns I don't know). The last thing you ever want to do is decrease the bass in a LaScala to increase the level of the squawker.

So, my comment about this (which I made in another thread), is that there needs to be a new autoformer design that makes all the taps useful. This would solve the issue in your post. There should be no need to mess with wires. I understand the current autoformer designs covers different networks and these designs were purposeful.

We are just experiencing the beginning of the network craze in my opinion. More tunable designs will be coming. I still think what's available is great, but everything is a tradeoff of some sort.

The number 1 improvement of these new networks would be better adjustablity for both the squawker and tweeter. I just chalk it up to first generation, and a darn good one at that.

[]

[D-MAN]

Got some silver wire - hooked it up between the crossovers and midrange drivers and - two words: Holy ****!

DM

[BEC]

Got some coat hangers - hooked 'em up between the crossovers and midrange drivers - two words: No difference.

Bob Crites

[DrWho]

lol Bob! even took a picture []

Now what we need to do is sneak into Dana' s house and install your

coat hangers without him knowing and then see if he notices the

difference the next time he turns on the system []

[BEC]

They work good. Listening to them right now. Measure about 0.125 ohms per coat hanger. Makes that about 0.25 ohms for the pair. A bit high for long runs or high power. Fine for the squawker or tweeter though.

Bob Crites

[DizRotus]

But what if we used Clayton Moore's silver coat hangers?

[BEC]

Send them down. I'll give them a listen.

Bob

[ZAKO]

Bob ...You hav,nt heard anything yet....Try barbed razer wire...cutting through all that silver muk. With razer edge sharpness. Dont use ceramic lifters. I use dead cats to lift wires off the floors...(change every couple of days).

[D-MAN]

You poor, DEAF Bas***ds! - Coat hangers? Not only deaf but CRAZY to boot![]

Seriously, I went from having too "hot" midrange; at certain frequencies, shrill, irritating, exagerated sibilance, "shouty" - the typical complaints concerning horns - to Holy ****! just with changing out a pair of wires about 15 inches long! Better imaging, striking presence and "realism", deeper soundstage, better bass definition, smoothness without "shoutiness". Frankly, I was thinking of going to an active crossover to tame the system, but the change of wires definitely makes the passive ESN's keepers. Better than EQ'ing the response, that's for sure! Total retail cost: $70 for both speakers. I know most of you spend that much (or should IMO) on a crossover capacitor or two...

If you choose not to believe that, fine. Nevertheless, regardless of your opinion, it's quite true.

DM

[DrWho]

Seriously, if you're that convinced go take the million dollar challenge...and then you can spend $5k for that 6" wire run []

[BEC]

D-MAN,

I am not going to call you crazy or deaf. I will say that you already have the equalizer you mentioned not wanting to use but it is between your ears. Bad thing about that equalizer is that you have no conscious control over its settings and it adjusts everything you hear to be what you expect to hear.

This is why we have (and should use) test equipment. There is nothing about wire that we can't test to much more precision than we can hear. That would also apply to caps and inductors.

Bob Crites