testing 'sound audio facts'...

[esldude]

Hi Jud,

 

DSP is not ideal, of course. Only next development spiral turn.

 

Tomorrow appear new analog computers. And we will work with analog/digital signal again.

 

What is analog signal? It is digital signal with infinite sample rate and bit depth precision.

 

Can you provide an example of one of the infinite signals?

[audiventory]

Can you provide an example of one of the infinite signals?

 

Y=A*sin(w*t), where

 

Y - signal,

A - amplitude,

w - angular velocity

t - time (-infinity, +infinity)

[gmgraves]

"9) Absolutely true. I don't know where this started, but from an electrical standpoint bi-wiring is merely doubling-up on the wire size. The signal is the same at either end. Doesn't matter whether you split the lows and highs at the amp end of the cables or at the speaker end of the cable. With your speakers bi-wired, take an ohm-meter and with the amp OFF, check continuity between the + terminal of the tweeter connection and the + terminal of the woofer connection. You will get continuity. Now remove both bi-wire connections from the speaker and re-attach the shorting straps between the woofer and the tweeter and check continuity again. You will still get continuity. All Bi-wiring does is make the shorting straps longer!"

 

You just haven't the right setup. Sometimes you don't here a difference, and sometimes the difference can be as big as a component upgrade.

 

 

In places where "it made a difference" try replacing the "bi-wire" arrangement with a single run of bigger wire. I'll bet that you will hear the "same" difference.

[wwaldmanfan]

In places where "it made a difference" try replacing the "bi-wire" arrangement with a single run of bigger wire. I'll bet that you will hear the "same" difference.

 

Here we go, with another controversial subject. B&W recommends biwiring their speakers. I've tried it both ways, and I think I hear an improvement with the biwire arrangement. If I think it sounds better, then I will continue to do it. I use Furez 4-conductor 12AWG cable; The cost difference is only pennies per foot.

Here is one opinion on the subject. YMMV.

 

What effect does Bi-wiring have? : Empirical Audio

[gmgraves]

This is a curious one here and makes little sense. Plenty of good amps can handle 4 ohm speakers. Plus calling a speaker 8 ohm or 4 ohm is a gross over-simplication of what load a speaker will present to the amplifier. My speakers are over 20 ohms in the low end and not a full ohm in the treble and highly reactive. What load is it?

 

 

I wondered about this one as well. It doesn't make much sense to me. As in your rather extreme example, above (20 Ohms on the bottom end and less than 1 Ohm on the top) specified speaker impedances generally are only that impedance at some certain frequency chosen by the manufacturer and represents an average (although only speakers like electrostatic designs tend to vary as much as your example). The only speakers that I know about where the impedance is pretty constant all across the audio spectrum are Magnepans and that's because their impedance and their DC resistance are the same due to their isodynamic nature. Most modern Solid State amps don't really care, as long as they have enough power to handle the range of load. Right now, I'm powering a pair of Maggie Point-Sevens (4 Ohms) with a Perla Audio "Signature 50". This amp puts out 50 WPC into 8 Ohms, and 100 WPC into 4. So it's putting out 100 WPC into the Maggies, and everything is fine. 50 Watts, though, wouldn't be enough. That's about the only type of instance where I'd say that speaker impedance would make any real difference in a modern setup.

[gmgraves]

Here we go, with another controversial subject. B&W recommends biwiring their speakers. I've tried it both ways, and I think I hear an improvement with the biwire arrangement. If I think it sounds better, then I will continue to do it. I use Furez 4-conductor 12AWG cable; The cost difference is only pennies per foot.

Here is one opinion on the subject. YMMV.

 

What effect does Bi-wiring have? : Empirical Audio

 

 

Don't misunderstand me, please. I'm not suggesting that you abandon bi-wiring, if that's what makes you happy and you believe that there's a difference - well, there probably is. I'm merely suggesting an experiment to see whether the difference you hear is the result of the two parallel runs of wire, or that the parallel runs constitute a bigger gauge of wire, by doubling-up the diameter with the two runs. From an electrical standpoint, the math would indicate that the perceived improvement in sound would be the result of the latter rather than the former.

 

By the way, in the article you reference: "This arrangement forces the woofer currents and the tweeter currents to run in separate cables." Sorry, bi-wiring does nothing of the kind. The cable has no way of knowing what currents it is carrying. Fact is, both cables are carrying exactly the same currents from exactly the same source. The crossover; I.E. the capacitor in line with the tweeter, and the inductor in series with the woofer filter out the unwanted frequencies from exactly the same signal, just like they do when the two sets of contacts are shorted together at the speaker terminals.

 

But do try the experiment I suggested sometime. I'd love to know your thoughts afterward.

 

Cheers

[wwaldmanfan]

Don't misunderstand me, please. I'm not suggesting that you abandon bi-wiring, if that's what makes you happy and you believe that there's a difference - well, there probably is. I'm merely suggesting an experiment to see whether the difference you hear is the result of the two parallel runs of wire, or that the parallel runs constitute a bigger gauge of wire, by doubling-up the diameter with the two runs. From an electrical standpoint, the math would indicate that the perceived improvement in sound would be the result of the latter rather than the former.

 

By the way, in the article you reference: "This arrangement forces the woofer currents and the tweeter currents to run in separate cables." Sorry, bi-wiring does nothing of the kind. The cable has no way of knowing what currents it is carrying. Fact is, both cables are carrying exactly the same currents from exactly the same source. The crossover; I.E. the capacitor in line with the tweeter, and the inductor in series with the woofer filter out the unwanted frequencies from exactly the same signal, just like they do when the two sets of contacts are shorted together at the speaker terminals.

 

But do try the experiment I suggested sometime. I'd love to know your thoughts afterward.

 

There is scientific logic in your comments. However, I have tried ganging up the 4-conductor cables that I am using--effectively creating a 9AWG paired cable, plus bridging the speaker's woofer and tweeter terminals with the same, and I still think I hear a bit more detail with the biwire arrangement. Of course, this is only my subjective impression.

 

Here's what B&W has to say about it:

 

"Most B&W speakers are provided with two pairs of speaker terminals; this allows you to either bi-wire or biamplify

them. The aim of both these techniques is not to simply get the customer to spend more on cables and

electronics (although no manufacturer objects to this spin off) but to improve the resolution of the speakers.

A multi-way speaker contains a crossover network that not only divides the incoming signal into different

frequency ranges, appropriate to the working range of each drive unit, but also equalises each driver’s

response to be flat (raw driver responses are usually anything but flat).

There are two different basic types of crossover – series and parallel. Series crossovers have each filter section

wired in series between the positive and negative input terminals. It is impossible to treat each filter section

individually – each interacts with the others – and such crossovers are not suitable for bi-wiring or bi-amping.

But by far the most common type is parallel. Here, each driver has its own filter wired between it and the

input terminals. If there is only one pair of input terminals, the inputs to all the filters are connected in parallel

to that one pair of terminals. If, however, you have more than one pair of terminals, you can completely

separate the inputs to each filter. Why on earth would you want to do such a thing?

In the case of bi-wiring, the answer lies in the cable connecting the speaker to the amplifier and the fact that

the amplifier is a voltage source but the speaker is a current driven device (force on voice coil = magnet flux

density x length of conductor in the magnet gap x current).

Firstly, all cables are a compromise. Some types of construction work better at low frequencies and others at

higher frequencies. Providing separate inputs to the speaker allows you to use different cable types, each

optimised for the frequency range of use.

Secondly, consider that the cable has an impedance that causes a voltage drop along its length. Now consider

the current flowing along the cable. Assume for the argument that the amplifier delivers a perfect voltage

waveform to the cable and the cable itself adds no distortion. However, each driver has a non-linear

impedance (for example, the inductance of the voice coil alters depending on its position in the magnet gap)

that causes the current to be non-linear. This non-linear current through the impedance of the cable causes the

voltage drop along the cable to be non-linear and thus the voltage across the speaker terminals is also nonlinear,

even though it is linear at the amplifier end.

If we were just concerned with one driver, things would not be too bad. But that non-linear voltage at the

speaker terminals may contain harmonics within the frequency range of one of the other drivers and that

driver will reproduce them, albeit at low level. If, however, you separate the inputs to each driver filter, each

driver’s distortion is kept to itself and the total system distortion goes down. We are talking small changes

here, but the resolution of some modern drivers is now so good that small improvements like this are readily

detectable by keen listeners.

Many people ask us whether the load on the amplifier is different if you bi-wire. It is not. As far as the

amplifier is concerned, it matters not one jot whether you parallel the inputs to the filter sections at the speaker

end or the amplifier end of the speaker cable."

[Kal Rubinson]

Here we go, with another controversial subject. B&W recommends biwiring their speakers.

Some years back when I got a pair of B&W speakers in for review, they were accompanied by a V.P of their parent company. When I raised an eyebrow about the dual terminals for biwiring, he agreed that they didn't do anything but that they are installed because their dealers have requested them. Guess why?

 

Disclaimer: I will not identify the guy (he is long gone) and say that none of the current personnel have said such.

[semente]

If cables were to provide the largest profit margins, it would make sense to have bi-wiring capabilities in loudspeakers.

[Jud]

Vandersteen, which is not in the cable business, has always recommended biwiring. I'm sure that deep down it has some nefarious motivation.

[One and a half]

Pass SR 2 speaker manual extract:

 

"The SR-2 speaker cabinets each have bi-wire input connectors and it is strongly suggested that the customer bi-wire or bi-amp the speakers with wire of their choice.

Speaker wire is a very personal preference; please discuss cable options with your dealer if you do not already own cables that you favor. Pass Laboratories has included a set of jumper cables to allow temporary operation of the speakers with a single run of speaker cable; we strongly suggest dual runs of cable. "

 

Works for me.

 

Hooray, another cable thread discussion starting!

[CR250]

No need to bet, I've already tried. Not only that, but many other combinations as well. But like I said before, the difference you here depends on the equipment. Most of my speakers are Vandersteen, and biwiring makes the biggest difference with them over any other brand. Just to give an example, I took the Tara 2's ($3800 for a single run) off my Wilson's (Wilson is at the other end of the spectrum. They don't believe in biwiring and offer no connection for it), and put them on a pair if Vandersteen model 2's. I compared them to 2 runs of AQ Type 6 ($400 for both pairs) and found that AQ beat the Tara's in every possible way. I don't know about you, but I would much rather spend $400 on speaker cables, than $3800.

[One and a half]

 

By the way, in the article you reference: "This arrangement forces the woofer currents and the tweeter currents to run in separate cables." Sorry, bi-wiring does nothing of the kind. The cable has no way of knowing what currents it is carrying. Fact is, both cables are carrying exactly the same currents from exactly the same source. The crossover; I.E. the capacitor in line with the tweeter, and the inductor in series with the woofer filter out the unwanted frequencies from exactly the same signal, just like they do when the two sets of contacts are shorted together at the speaker terminals.

 

The woofer and tweeter are on separate circuits in bi-wiring speakers. The current drawn by each driver will be different since I = E/2PifL, the L and f will be different for the woofer as for the tweeter. I don't understand how the cables can draw the same current for both drivers when the impedance is different, let alone the vastly different back emf when the driver returns to its neutral state?

 

Bass energy has the most clout in music, so in proportion the majority of current is drawn by the woofer.

[CR250]

"Some years back when I got a pair of B&W speakers in for review, they were accompanied by a V.P of their parent company. When I raised an eyebrow about the dual terminals for biwiring, he agreed that they didn't do anything but that they are installed because their dealers have requested them. Guess why?"

 

If I had to guess, I would say that aside from bi-wiring, 2 sets of binding posts are needed for bi-amping.

[audiventory]

Some years back when I got a pair of B&W speakers in for review, they were accompanied by a V.P of their parent company. When I raised an eyebrow about the dual terminals for biwiring, he agreed that they didn't do anything but that they are installed because their dealers have requested them. Guess why?

 

Besides bi-wiring can be used bi-amping via dual terminals.

 

For long cables (7 ... 20 meters) bi-wiring can be useful.

 

Bi-amping + good crossover + EQ can give significantly more.

[Sal1950]

In places where "it made a difference" try replacing the "bi-wire" arrangement with a single run of bigger wire. I'll bet that you will hear the "same" difference.

 

+1

[NeroMetalliko]

Hello,

I don't want to add unnecessary snake oil arguments to the ever disputed cables/connection topic (about the bi-wiring in this case).

 

However, over the years I have made a lot of experiments alone in the humble darkness of my little room, playing with different cables and/or topologies, just in order to discover if and/or how much a different arrangement it could make an audible difference (for me).

 

The final conclusion I found is that, based strictly on my listening personal tests, the best approach for me is to avoid to split the signal path as much as possible. This means that I always preferred solutions in which all the audio signal flows for the maximum possible length in the same physical channel/configuration, being split only at the extreme end of their path (usually the loudspeaker connectors). There are some points I can bring to support my (limited and partial) experimental findings but at the moment I will avoid to do it, trying to keep this post short.

 

So, what I noticed is that the more the signal get manipulated/divided earlier, the more the final results is less coherent/pleasant to my ears (after the final "re-joining" in the air).

 

This concept has several aspects and applications obviously, but focusing only on the single/bi wiring topic, I found that I always slightly preferred the single wire connection to the bi-wiring one.

 

The funny thing is that I have even found another little improvement to the single wire connection, adopting what I have called a "single wire X-connection" (Uh? ). This is possible only for loudspeaker that are provided of bi-wiring connection options, and it is very simple, just look at the picture attached below:

 

So it is very simple (just switch one input of the single wire connection, leaving the bridges there) and it has no cost.

 

Please note that it could easily be that the potential difference is negligible or non existent at all (or existent only in my mind...), but this is what I have finally adopted for my loudspeakers connections after a lot of tests, and never looked back since then.

 

I suggest you to give it a try and maybe let me know if you found something better/worst adopting it, or nothing at all...

 

I will be happy to discuss the more general concept above (regarding my preferred approach of a maximally uniform signal path) if someone likes it.

 

Have a nice listening time,

ciao.

 

Andrea

[Kal Rubinson]

Besides bi-wiring can be used bi-amping via dual terminals.

True. They can be.

 

For long cables (7 ... 20 meters) bi-wiring can be useful.

Why? All that is accomplishing is a doubling of the cable and that is equivalent to using a heavier, more appropriate cable for the longer run.

 

Bi-amping + good crossover + EQ can give significantly more.

Sure but that is beyond the capability of most people who want to bi-wire.

[audiventory]

Why? All that is accomplishing is a doubling of the cable and that is equivalent to using a heavier, more appropriate cable for the longer run.

 

Yes. Possibly use bigger square for 1 wire pair instead bi-wiring. Here no difference.

 

Sure but that is beyond the capability of most people who want to bi-wire.

 

Bi-amping and good crossover is not cheap decision. But all even mid budget active studio monitors have 2 amps: 1 per driver.

 

From manufacturer point of view easier achieve more flat characteristics in several narrower bands than single wide.

 

Also monitors have specially tuned amplifiers to certain drivers. It also give more opportunities for better characteristics.

 

Me seems, impossibly done this work via hearing tests only.

[NeroMetalliko]

Yes. Possibly use bigger square for 1 wire pair instead bi-wiring. Here no difference.

 

From a conceptual point of view there is still a little difference: the circuit topology is not exactly the same ("star" vs "bus" we can say to simplify the things) with the collateral effect that the signal loop is slightly different for each driver connected by their own branch.

 

So in abstract terms there is a subtle difference, if (or how much) this will produce audible benefit or detriment it is another story obviously...

 

As indicated in my post above my personal preference is to avoid differences in the signal path/topology as much as possible, but it is difficult to generalize the things...

 

Ciao,

Andrea

[audiventory]

I suppose, for given resistance and so low frequency range 0 ... 20 kHz no difference.

[Allan F]

The funny thing is that I have even found another little improvement to the single wire connection, adopting what I have called a "single wire X-connection". This is possible only for loudspeaker that are provided of bi-wiring connection options, and it is very simple, just look at the picture attached below:

 

[ATTACH=CONFIG]22881[/ATTACH]

FWIW, I have also found this "X-connection" arrangement to be superior to the conventional method of installing jumper cables, i.e. one main speaker cable connected to the upper binding post and the other to the lower binding post, instead of both connected to the lower ones.

[Speedskater]

The woofer and tweeter are on separate circuits in bi-wiring speakers. The current drawn by each driver will be different since I = E/2PifL, the L and f will be different for the woofer as for the tweeter. I don't understand how the cables can draw the same current for both drivers when the impedance is different, let alone the vastly different back emf when the driver returns to its neutral state?

Bass energy has the most clout in music, so in proportion the majority of current is drawn by the woofer.

Let's simplify this and say that the current on each speaker cable depends on the impedance of it's load (crossover to driver) at the frequency in question.

 

ps. that's only one of several formulas.

[Sal1950]

ps. that's only one of several formulas.

 

Also if you can see your speaker cables getting red in a darkened room, they may be too thin. WOOT

[rodrigaj]

This has always worked well for me:

The designer of these speakers, Peter Thomas, began to offer separate terminals as a response to market forces. I have tried different arrangements, including the silver shorting bars that came with the speakers and I could not hear any differences. I also tried the "X" arrangement noted in another response.

 

For those wishing to try this, leaving a short tip of insulation on the end makes insertion easy.