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Science on Bi-wire - Page 3

post #61 of 105
Quote:
Originally Posted by Rutgar View Post

Actually, it's a change in current flow that causes the cone to move. With a constant current flow, the cone will be stationary.

...
post #62 of 105
Quote:
Originally Posted by Chu Gai View Post

Would you care to contrast that distortion with say the distortion inherent in a driver of your choosing?

That is an excellent question...
post #63 of 105
Quote:
Originally Posted by bizwiz41 View Post

I must admit that I am thoroughly confused now, hence my question: "what is the best method to connect my bi-wired speakers?

Just get speaker cable that is the right gage for the distance your speakers are from the amp and be done with it.

http://www.audioholics.com/education...er-cable-gauge

I've been at this hobby for over 30 years, and I've tried everything under the sun, bi-wire, bi-amp, you name it, and bi-wiring is a waste of time, money and wire.
You want an appreciable audible difference in your system? EQ & room treatment working in harmony, that's where the rubber meets the road.
I've ended up using a single run of 12/2 home depot in-wall speaker wire. I think it's a buck a yard.
post #64 of 105
Quote:
Originally Posted by kiwi2 View Post

Of course not. But as it is the current that turns the bird into a ball of flames... it is also the current that causes the speaker cone to move.

So why would current distortion be irrelevant... as it is responsible for cone movement and thus the sound we hear?

People always seem to dismiss bi-wiring because it doesn't separate signal voltage. But that is totally missing the point about what bi-wiring is about in the first place.

so bi-wiring requires shielded cables?

You do realize that the current moving forward toward the speaker is also moving back towards the amplifier and they generate an equal opposite magnetic field? Essentially and effectively these fields would cancel each out.
post #65 of 105
Quote:
Originally Posted by Bill Fitzmaurice View Post

Another link to useless information. Current drive cannot be used with moving coil loudspeakers because moving coil loudspeakers do not present a constant impedance load. Their impedance varies with frequency, so a constant current source would result in every frequency being at a different level. That's why amplifiers are constant voltage sources, so that levels don't vary with impedance load. Try using a speaker with a constant current signal and see what happens. But first you'll have to build a transconductance amplifier to deliver that constant current signal.http://www.avsforum.com/avs-vb/archi...t-1125574.html

Firstly, that link does have some useful information in regards to current drive amplifiers. Secondly, current drive can indeed be used with moving coil loudspeakers. In fact, it has been with a reasonable amount of success. One example:

http://www.6moons.com/audioreviews/f...irstwatt2.html
These designs are rarely used for a few reasons. A couple of main ones being the complexity of design and the fact that loudspeakers are designed for voltage source amplifiers. As a result, modifications to almost all speakers are required for current drive amplifiers.
post #66 of 105
Quote:
Originally Posted by txmxer View Post

You do realize that the current moving forward toward the speaker is also moving back towards the amplifier and they generate an equal opposite magnetic field? Essentially and effectively these fields would cancel each out.

This is categorically false. I understand bi-wiring is a hot topic and will probably never have a consensus. However, I don't understand why so much incorrect information has been posted in regards to electrical and magnetic theory. I assume it has been misinformation that has propagated through many sources. I don't mean to call you out or anything. I'm sorry if I come off that way. I am just interested in helping people understand. Pretty much any textbook on physics or electromagnetics covers the case of two parallel conductors carrying the same current (different directions) and the field do not cancel out at all. In fact, most of the fundamental theories relating electrical current flow and magnetism were discovered and studied using this exact scenario. Reference Ampere's and Orsted's work.
post #67 of 105
Quote:
Originally Posted by leger433 View Post

modifications to almost all speakers are required for current drive amplifiers.

Exactly. And the benefits of doing so are so slight that you don't see it proposed even in the DIY section, where members have the skills to do so, let alone the consumer sections. Not even the oddiophile segment, always eager to spend uber-bucks on anything and everything no matter how screwy, including bi-wiring, has jumped aboard that bandwagon.
post #68 of 105
Quote:
Originally Posted by leger433 View Post

This is categorically false. I understand bi-wiring is a hot topic and will probably never have a consensus. However, I don't understand why so much incorrect information has been posted in regards to electrical and magnetic theory. I assume it has been misinformation that has propagated through many sources. I don't mean to call you out or anything. I'm sorry if I come off that way. I am just interested in helping people understand. Pretty much any textbook on physics or electromagnetics covers the case of two parallel conductors carrying the same current (different directions) and the field do not cancel out at all. In fact, most of the fundamental theories relating electrical current flow and magnetism were discovered and studied using this exact scenario. Reference Ampere's and Orsted's work.

Right, my last post was a bit off as well. (deleted) Must still be too early in the morning for me or something.
post #69 of 105
Quote:
Originally Posted by Jon Lane View Post

That is an excellent question...

I'm allowed one per year.
post #70 of 105
Quote:
Originally Posted by leger433 View Post

This is categorically false. I understand bi-wiring is a hot topic and will probably never have a consensus. However, I don't understand why so much incorrect information has been posted in regards to electrical and magnetic theory. I assume it has been misinformation that has propagated through many sources. I don't mean to call you out or anything. I'm sorry if I come off that way. I am just interested in helping people understand. Pretty much any textbook on physics or electromagnetics covers the case of two parallel conductors carrying the same current (different directions) and the field do not cancel out at all. In fact, most of the fundamental theories relating electrical current flow and magnetism were discovered and studied using this exact scenario. Reference Ampere's and Orsted's work.

You are absolutely right. I was being lazy and not thinking it through. Although there are minimums and maximums. One could select a conductor arrangement to minimize the EMF between the two wires.
post #71 of 105
Quote:
Originally Posted by txmxer View Post

You are absolutely right. I was being lazy and not thinking it through. Although there are minimums and maximums. One could select a conductor arrangement to minimize the EMF between the two wires.

Twisted pair > twisted quad > you get the idea.
post #72 of 105
These questions usually bring a banged up and battered thread. This one is one of the better ones I've seen (I've only seen a few lol).

Here's something to chew on; Isn't every speaker sold with two sets of terminals already pseudo bi-wired to begin with?

What is bi-wired? Sending two sets of wire from the same source to the same speaker with two sets of terminals?

So, even with one set of wire going to either top or bottom terminals, if you have the jumpers in place (and I'm pretty sure all do), you're still dispersing power from the same source to two different sets of terminals.

So weather it's a second set of wire, or a pair of gold plated jumpers, we're pretty much just bi-wiring anyway.

Can you dig it?
post #73 of 105
Quote:
Originally Posted by Geoff4RFC View Post

These questions usually bring a banged up and battered thread. This one is one of the better ones I've seen (I've only seen a few lol).

Here's something to chew on; Isn't every speaker sold with two sets of terminals already pseudo bi-wired to begin with?

What is bi-wired? Sending two sets of wire from the same source to the same speaker with two sets of terminals?

So, even with one set of wire going to either top or bottom terminals, if you have the jumpers in place (and I'm pretty sure all do), you're still dispersing power from the same source to two different sets of terminals.

So weather it's a second set of wire, or a pair of gold plated jumpers, we're pretty much just bi-wiring anyway.

Can you dig it?

Very true.. But when entertaining the bi amping crowd, you cant bi amp the speakers with the jumpers hooked up.
post #74 of 105
Quote:
Originally Posted by Geoff4RFC View Post

So weather it's a second set of wire, or a pair of gold plated jumpers, we're pretty much just bi-wiring anyway.

No, because bi-wiring is keeping a separation of the LF and HF current all the way back to the amp terminals and avoids running them together on a single wire. Unless you are running two individual pair of wires all the way back to the amp terminals... you aren't bi-wiring.
post #75 of 105
Quote:
Originally Posted by rnrgagne View Post

You want an appreciable audible difference in your system? EQ & room treatment working in harmony, that's where the rubber meets the road. I've ended up using a single run of 12/2 home depot in-wall speaker wire. I think it's a buck a yard.

All very true. I've spent a lot of time finding optimal speaker and listening position placement and conduct measurements with a real time analyser and utilised 4 to 6" broadband room treatments. I also only use cheap 12 gauge speaker cable from the local electronic shop. This is why it's no big deal to run another couple of metres of cable each side for bi-wiring my front speakers. The extra cost of the cable for bi-wiring the fronts is insignificant compared to the extra wire needed for the surround speakers.

Hey, maybe multichannel audio is just a con from the cable manufacturers in order to sell more cable!
post #76 of 105
Quote:
Originally Posted by kiwi2 View Post

Hey, maybe multichannel audio is just a con from the cable manufacturers in order to sell more cable!

I thought everybody already knew that.
post #77 of 105
Quote:
Originally Posted by kiwi2 View Post

All very true. I've spent a lot of time finding optimal speaker and listening position placement and conduct measurements with a real time analyser and utilised 4 to 6" broadband room treatments. I also only use cheap 12 gauge speaker cable from the local electronic shop. This is why it's no big deal to run another couple of metres of cable each side for bi-wiring my front speakers. The extra cost of the cable for bi-wiring the fronts is insignificant compared to the extra wire needed for the surround speakers.

Hey, maybe multichannel audio is just a con from the cable manufacturers in order to sell more cable!

What analyzer did you use ?
Please post those measurements.
Especially the two that compare single wire to bi-wire with no other changes.
post #78 of 105
Quote:
Originally Posted by kiwi2 View Post

No, because bi-wiring is keeping a separation of the LF and HF current all the way back to the amp terminals and avoids running them together on a single wire. Unless you are running two individual pair of wires all the way back to the amp terminals... you aren't bi-wiring.

He meant that, when using the gold-plated plates, you are effectively biwiring the last two inches.
post #79 of 105
Quote:
Originally Posted by kiwi2 View Post

. The extra cost of the cable for bi-wiring the fronts is insignificant compared to the extra wire needed for the surround speakers.

Hey, maybe multichannel audio is just a con from the cable manufacturers in order to sell more cable!

My point was the outcome of bi-wiring is what's insignificant. It's never made one iota of difference in any system I've put together.

More speakers is the goal there. 11.2 are you kidding me?
post #80 of 105
Quote:
Originally Posted by Venomous View Post

Very true.. But when entertaining the bi amping crowd, you cant bi amp the speakers with the jumpers hooked up.

Well if it's a 3-way design you're tri-wiring inside the speaker.

There's not much electrical difference between a foot and 10 feet of wire, at least not in terms of transmitting an audio signal accurately, so really anything but a single driver speaker is being bi-wired, or more, anyways.

There's a delicious irony when someone hooks up a speaker with $100 a foot cryogenically treated, 102% copper and kryptonite shielded cable and the magically enhanced signal then has to travel through $5.00 binding posts and maybe $5 worth of wiring in the crossover's coils, and subsequent connections to the drivers.
post #81 of 105
Quote:
Originally Posted by kiwi2 View Post

No, because bi-wiring is keeping a separation of the LF and HF current all the way back to the amp terminals and avoids running them together on a single wire. Unless you are running two individual pair of wires all the way back to the amp terminals... you aren't bi-wiring.

You just keep digging yourself a deeper hole. Why don't you look at this website to see who you are trying to argue with. You're way out of your league.


http://www.billfitzmaurice.com/
post #82 of 105
Quote:
Originally Posted by rnrgagne View Post

Well if it's a 3-way design you're tri-wiring inside the speaker.

There's not much electrical difference between a foot and 10 feet of wire, at least not in terms of transmitting an audio signal accurately, so really anything but a single driver speaker is being bi-wired, or more, anyways.

There's a delicious irony when someone hooks up a speaker with $100 a foot cryogenically treated, 102% copper and kryptonite shielded cable and the magically enhanced signal then has to travel through $5.00 binding posts and maybe $5 worth of wiring in the crossover's coils, and subsequent connections to the drivers.

Yeah, it's all about the cables, binding posts don't matter here lol.

I will say the aventage and paradigm studio/signatures have nice binding posts however
post #83 of 105
Quote:
Originally Posted by rnrgagne View Post

Well if it's a 3-way design you're tri-wiring inside the speaker.

There's not much electrical difference between a foot and 10 feet of wire, at least not in terms of transmitting an audio signal accurately, so really anything but a single driver speaker is being bi-wired, or more, anyways.

There's a delicious irony when someone hooks up a speaker with $100 a foot cryogenically treated, 102% copper and kryptonite shielded cable and the magically enhanced signal then has to travel through $5.00 binding posts and maybe $5 worth of wiring in the crossover's coils, and subsequent connections to the drivers.

is that green kryptonite or red? I've heard that the green gives it a mellow flavor while the red provides crisper highs.
post #84 of 105
Quote:
Originally Posted by Bill Fitzmaurice View Post

The fact of the matter is that the very finest passive crossovers available are still far from perfect. From the standpoint of insertion loss alone active does work better, and you can't instantly dial up any slope, corner frequency or Q value you wish with a passive. That doesn't mean that you don't need a minimum skill set to successfully implement an active crossover, but it's not rocket science either. OTOH designing high quality passives is pretty close, so most speakers used by average listeners with average budgets don't have sophisticated crossovers. If one wants to significantly improve the sound of an average speaker, and has the knowledge of how to implement an active system, it can give much more bang for the buck than investing in a more expensive passive system.

Thanks for speaking truth Bill. My next speaker will be actively managed. If you are going to go high end then go high end. Passives will never have the flexibility of Actives.

You could get three DSP based amps for under $1K and have all your needs met. You will never beat that sort of flexibility with passives. Period. The other nice thing with actives is I never have to hear about the capacitor, resistor, or cable debate. They all are arguments for the speaker level analog side of things. Modern active setups are all in the digital domain.

You will never need a MIT 'Music Interface' because the driver will be such a benign load (or whatever excuse they want to use). That's the funny part: Lets spend $8K on cable when you could get a DEQX and amplification for less.
post #85 of 105
Quote:
Originally Posted by kiwi2 View Post

Err... no. Electricity works off demand. The HF side of the crossover blocks the LF side, so only the current for the HF driver will flow in the cable going to it and vice versa. This isn't about signal voltage.

If I read his post correctly Bill is talking about inductance.
post #86 of 105
Quote:
Originally Posted by txmxer View Post

Bi-amping still seems really silly, especially for those that buy expensive speakers.

You've got this whiz kid that designs and carefully selects the components that go into a speaker circuit to perform in a very exact way.

Then someone installs said speaker by disconnecting the crossover and bi-amping the speaker, completely defeating the designers efforts. .

You mean the designers efforts for a 10X8X8 room? Or his efforts for a 14X21X10 foot room? Or a large orthogonal room? Or his efforts with the speakers backed to a wall, away from the wall, one in a corner, one not?
post #87 of 105
Quote:
Originally Posted by kiwi2 View Post


No, because bi-wiring is keeping a separation of the LF and HF current all the way back to the amp terminals and avoids running them together on a single wire. Unless you are running two individual pair of wires all the way back to the amp terminals... you aren't bi-wiring.

What about the wire inside the amplifier connecting the output terminals to the final output stage of the amp circuit? Or even the output stage itself? Oh nos that HF and LF current is combined there....? Well I guess that negates the need to biwire. ? Call me crazy... im still sticking to a single wire pair living with less than optimal sound.
post #88 of 105
Quote:
Originally Posted by kiwi2 View Post

No, because bi-wiring is keeping a separation of the LF and HF current all the way back to the amp terminals and avoids running them together on a single wire. Unless you are running two individual pair of wires all the way back to the amp terminals... you aren't bi-wiring.

Well, at least two of the long standing members here knew what I was saying.

Let me ask you this; I have 4/12 in wall rated wire going from my amp to my center channel, the two positive and two negative wires are twisted together at the amp end and are connected to the pos and neg amp terminals, now here's where it gets tricky nicky what was only two wires at the amp end, now becomes four wires at the speaker end, two pos terminals, two neg terminals, four wire connections BUT, only two wires back at the amp.

Is this not a bi-wire connection because I don't have two separate runs?

Again, and in my first post I did use the term pseudo. When you have a speaker with two sets of terminals, you are going to have a "pseudo" bi-wire of some kind weather its one set of wire and two silver plated concrete plates or the stock jumpers.

One electrical source, plus four terminals equals a bi connection.
post #89 of 105
Quote:
Originally Posted by chashint View Post

What analyzer did you use ?
Please post those measurements.
Especially the two that compare single wire to bi-wire with no other changes.

I use TrueRTA level 4. I have only used it for in-room frequency response which is far too crude of a measurement to show any difference from bi-wiring.
post #90 of 105
Quote:
Originally Posted by Geoff4RFC View Post

Let me ask you this; I have 4/12 in wall rated wire going from my amp to my center channel, the two positive and two negative wires are twisted together at the amp end and are connected to the pos and neg amp terminals, now here's where it gets tricky nicky what was only two wires at the amp end, now becomes four wires at the speaker end, two pos terminals, two neg terminals, four wire connections BUT, only two wires back at the amp.

Is this not a bi-wire connection because I don't have two separate runs?

Providing the jumpers have been removed from the back of the speaker, yes, that is a bi-wire setup.


Quote:


Again, and in my first post I did use the term pseudo. When you have a speaker with two sets of terminals, you are going to have a "pseudo" bi-wire of some kind weather its one set of wire and two silver plated concrete plates or the stock jumpers.

One electrical source, plus four terminals equals a bi connection.

Your "pseudo" bi-wire isn't bi-wired. Thousands upon thousands of speakers come with two sets of posts and connecting jumpers. If someone just runs one set of wires to one side of the posts... then that is just a conventional single wire setup.
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