What's wrong

[liberalz]

Here is my system & how it is been hooked up.

AVR: Yamaha RXV 740
DVD Player: Yamaha 550
Mains: Mordaunt-Short 908 (Floor stand, 3 way) - bi-wired using A/B
Centre: Mordaunt-Short 905 - bi-wired
Rear: Boston Accoustic - diffuse
Sub: Boston Accoustic - 12", down firing
All speakers are set to small

My problem right now is, there is a buzzing noise comming from all speakers even when no feed from the source is presented. Now the noise is not intrusive but when I switch of the reciever i can feel that it is switched off, something like a florecent lights. (i'm not sure whether i explained my self well). and for me to localize the noise i need to press my ear against the driver to picked it up (am i being fussy here).

So yesterday i tried to pin point the problem by examining the connection, the only pontential problem i could think of is since I did not have a "proper" subwoofer connection cord, i used a normall RCA cord (black & red) and used the red connection only, and the black end was just hanging.

So I replaced the RCA with a coxial cord, not much difference in the buzzing noise.

But what i found was the base got really tight, and i couldn't localize the base from the sweet spot. I had to run to the subwoofer & touch the driver to make sure that it is working. I need more listning before I could say the base is good. In my first immpression i did not feel i lost any base.

I also wouldn't mind some general thoughts on my system, the weakest link etc.

By the way thanks Clint DeBoer for setting me up in the forum.

[majorloser]

Sounds like you've got a ground loop problem. :(
Usually comes from satelite or cable receivers (damn cable guy).

Read this: http://www.audioholics.com/techtips/setup/avhardware/groundloopcableTV.php

[liberalz]

Is there a way to eliminate it:mad: . What about coxial cord being used as sub connection?

[jcPanny]

All subs cables are coaxial so that cable should be fine. A coax composite video cable will work just as well as a "sub" cable.

Check out the Ground loop FAQ. Having the sub or other devices on a different circuit and the cable box are common sources of the ground buzz.

[mtrycrafts]

Mains: Mordaunt-Short 908 (Floor stand, 3 way) - bi-wired using A/B
.


I don't think you want to bi-wire this way, if you are using the receiver's A and B terminals.

[liberalz]

I don't think you want to bi-wire this way, if you are using the receiver's A and B terminals.

what would be your suggestion. I read in What HiFi site that A/B connection is fine. I don't mind another point of view.

Cheers.

[mtrycrafts]

what would be your suggestion. I read in What HiFi site that A/B connection is fine. I don't mind another point of view.

Cheers.


If you insist on bi-wiring, use the same post A. But, there is no real benefit to bi-wiring to begin with.

[liberalz]

If you insist on bi-wiring, use the same post A. But, there is no real benefit to bi-wiring to begin with.

Is this b'cause of impedance.

Well my listening area (room) is not that large, and in fact i did notice some improvement in the mid range (a good punch :) ), and some clarity in the high range. Especially these improvements were noticebale when listening to some rock music.

i understand the controversy surronding bi-wire, i did not spend a penny to buy additional wire :)

Maybe the difference I saw could be due to me using post A & B and the impedance is cut to half due to parrallel connection of these posts in Yamaha.:rolleyes:

[mtrycrafts]

Is this b'cause of impedance.
Well my listening area (room) is not that large, and in fact i did notice some improvement in the mid range (a good punch :) ), and some clarity in the high range. Especially these improvements were noticebale when listening to some rock music.
i understand the controversy surronding bi-wire, i did not spend a penny to buy additional wire :)
Maybe the difference I saw could be due to me using post A & B and the impedance is cut to half due to parrallel connection of these posts in Yamaha.:rolleyes:


Yes, impedance is one of the issues, main issue.
Spending extra for the wire is not the concern. Knowing the truths is.

Without doing a careful comparison, controlled, level matched, we won't know why your perception is what it is.

[Seth=L]

when you have your surround sound going is both A and B on? I would certainly think that it either wouldn't allow it, or would force the B to shut off, and depending on how they are bi-wired it would shut off either your tweeter and midrange or the woofer (woofers).

The thing with receivers is when you bi-amp on most receivers, it won't make any difference. The output stage, transistors, are designed to handle sizable loads, and the power would be limited most by the Power supply or the capacitors, and not the transistors. So Bi-amping on most receivers won't make any difference.

When you look at a receiver's power ratings it is usually only rated for just one channel.

[MDS]

Bi-wiring is absolutely pointless.

Think about what bi-wiring is doing:
You are feeding the exact same full range signal over two different wires. The xover in the tweeters will reject the midrange and bass it cannot handle and the xover in the woofer will reject the higher frequencies it cannot handle - exactly the same thing as if you only used one wire.

On a receiver, the A and B terminals are wired in parallel. So not only do you get no benefit whatsoever from bi-wiring but you get the additional disbenefit of presenting the receiver with a lower impedance load than it can handle reliably.

I'm suprised mtrycrafts didn't call it 'buy-wire' because that is exactly what it requires - buying more wire for no purpose at all.

[mtrycrafts]

I'm suprised mtrycrafts didn't call it 'buy-wire' because that is exactly what it requires - buying more wire for no purpose at all.


That is step two:D
Don't want that as step one, for this post. Maybe next poster:D

[sivadselim]

All arguments regarding the benefits of bi-wiring aside, it's perfectly fine to bi-wire using the A and B terminals. It just makes it easier to wire.

"B" just represents extra binding posts on the same amp channels; they're not completely separate amp channels. In doing what he's doing he is simply bi-wiring, not bi-amping. He's still using 2 amps (R & L), not 4.

And there is no difference in impedance (or anything else) from simply bi-wiring off a single set of posts versus using both; it's identical. It's just convenient to do it this way if you have the extra set of binding posts.

[Seth=L]

All arguments regarding the benefits of bi-wiring aside, it's perfectly fine to bi-wire using the A and B terminals. It just makes it easier to wire.

"B" just represents extra binding posts on the same amp channels; they're not completely separate amp channels. In doing what he's doing he is simply bi-wiring, not bi-amping. He's still using 2 amps (R & L), not 4.

And there is no difference in impedance (or anything else) from simply bi-wiring off a single set of posts versus using both; it's identical. It's just convenient to do it this way if you have the extra set of binding posts.
How is it easier that way. In theory it should take about half the time and frustration to connect only 2 sets of cables vs. 4. Binding posts on receivers can be a real pain in the @ss, so I want to spend the least amount of time jacking with the binding posts on a receiver. Speakers are easy, because the terminals are easy to get to, and if it doesn't come with bridge straps you can just make you own from wire. And lastly, it is a waste of wire.

[sivadselim]

Bi-wiring is absolutely pointless.

Think about what bi-wiring is doing:
You are feeding the exact same full range signal over two different wires. The xover in the tweeters will reject the midrange and bass it cannot handle and the xover in the woofer will reject the higher frequencies it cannot handle - exactly the same thing as if you only used one wire.

On a receiver, the A and B terminals are wired in parallel. So not only do you get no benefit whatsoever from bi-wiring but you get the additional disbenefit of presenting the receiver with a lower impedance load than it can handle reliably.

I'm suprised mtrycrafts didn't call it 'buy-wire' because that is exactly what it requires - buying more wire for no purpose at all.
I don't really want to get into whether or not bi-wiring is beneficial.

But if you're going to argue against something, you should at least understand the other side's argument.

You're post doesn't really address the the purported reason for bi-wiring at all. Of course the same full-range signal is fed down both sets of wire.

And as far as the impedance is concerned, bi-wiring does not "present the receiver with a lower impedance load than it can handle reliably".

And no, I am not currently bi-wiring.

[sivadselim]

How is it easier that way. In theory it should take about half the time and frustration to connect only 2 sets of cables vs. 4. Binding posts on receivers can be a real pain in the @ss, so I want to spend the least amount of time jacking with the binding posts on a receiver. Speakers are easy, because the terminals are easy to get to, and if it doesn't come with bridge straps you can just make you own from wire. And lastly, it is a waste of wire.
Because you just connnect 4 sets of wires and your done. No twisting the ends together and trying to shove that fat wad into a binding post or a banana plug.

But, mainly, it makes it really easy to add the second wire set if you were already previously single-wiring.

I guess if you were setting up a bi-wire run, fresh out of the gate, it might not be necessarily simpler. So I see your point.

[Seth=L]

I don't really want to get into whether or not bi-wiring is beneficial.

But if you're going to argue against something, you should at least understand the other side's argument.

You're post doesn't really address the the purported reason for bi-wiring at all.

And as far as the impedance is concerned, bi-wiring does not "present the receiver with a lower impedance load than it can handle reliably".
I said nothing about impedance.

The issue was the humming noise, which I am aware no one has really addressed that issue full swing yet, then again what you posted also does not address the problem.

What made no sense about the post was you said it was easier to bi-wire, and it isn't easier. As far as offering advantages the only effective bi-anything is Bi-amplification. Since you can't bi-amp with a receiver such as his, then there is no reason to do that.

The biggest problem with bi-wiring using the A and B terminals is this. When you attempt to activate the surround sound on the OP's receiver it will do one of two things, it will not allow him to use surround sound or it will shut the B speakers off, meaning that one of the terminal on the speakers will be getting no juice. So that means either the tweeters or the woofers will not even be on when he is using surround sound.

Do you see the delima?

[Seth=L]

Because you just connnect 4 sets of wires and your done. No twisting the ends together and trying to shove that fat wad into a binding post or a banana plug.

But, mainly, it makes it really easy to add the second wire set if you were already previously single-wiring.

I guess if you were setting up a bi-wire run, fresh out of the gate, it might not be necessarily simpler. So I see your point.
OK, say that in theory that bi-wiring actually offers advantages, that still doesn't account for using the A and B terminals causing problems when using surround sound.

[sivadselim]

I said nothing about impedance.
I was speaking to those that did. Not you.
What made no sense about the post was you said it was easier to bi-wire, and it isn't easier.
No, I said that the extra set of posts makes it easier to biwire, especially if you are already single-wiring to begin with.
The biggest problem with bi-wiring using the A and B terminals is this. When you attempt to activate the surround sound on the OP's receiver it will do one of two things, it will not allow him to use surround sound or it will shut the B speakers off, meaning that one of the terminal on the speakers will be getting no juice. So that means either the tweeters or the woofers will not even be on when he is using surround sound.

No, that's not how his (or most) A/B connections work. As I, and others in the thread, said "B" is just an extra set of parallel binding posts on the same 2 (L&R) amps. "B" is not a separate set of amps from the "A" amps.

The OP's hum has nothing to do with his bi-wire set up and would be there even if he single-wired.

BTW, if he connected 2 pairs (4 total) of identical speakers to A and B, then he WOULD be presenting twice the impedance to the reciever. But bi-wiring that way with a single pair will not present any different impedance than if he bi-wired off the "A" posts only. It's the same thing.

[sivadselim]

OK, say that in theory that bi-wiring actually offers advantages, that still doesn't account for using the A and B terminals causing problems when using surround sound.
No it doesn't, as I explained in my previous post. Slow down. :D

He's not talking about "Surround B" amps.

He simply has the ability to connect 2 pairs of speakers to the front channel amps. The "B" connections are just parallel connections off the same 2 front channel amps.

If they were separate amps he'd be bi-amping and he's not. He's simply taking advantage of the extra set of binding posts to not have to twist his wires together. That's all.

And, no, it's not causing his hum.

[sivadselim]

liberalz,

It sounds like you have a ground-loop hum.

What happens if you disconnect your CATV connection from your setup?

[liberalz]

liberalz,

It sounds like you have a ground-loop hum.

What happens if you disconnect your CATV connection from your setup?

I haven't tried that yet, but I did try unplugging the cable box from the electricity board, no improvement.:mad:

So far i tried the following with no success:

1. Tried different process (i think it's the wrong term), like ProLogic 11, Neo 6 etc.
2. Different input connection
3. Turning subwoofer off
4. bi-wiring using only A post

I tried something, by accident though, I turned off one of the lights yesterday that I usually have on when i listen to music, and it seems like buzzing disappeared (or reduced would be the right word). Well i would be able to confirm this after some serious listening.

I also read some articles from this site, the buzzing noise to me does not increase with me adjusting the volume, if so what does it mean, i don't understand. (I should have paid more attention to my physics cources :mad: )

[MDS]

I don't really want to get into whether or not bi-wiring is beneficial.

But if you're going to argue against something, you should at least understand the other side's argument.

You're post doesn't really address the the purported reason for bi-wiring at all. Of course the same full-range signal is fed down both sets of wire.

And as far as the impedance is concerned, bi-wiring does not "present the receiver with a lower impedance load than it can handle reliably".



Just what is the other side of the argument that I am missing? The other side would be 'bi-wiring is beneficial' - it is not. If it is obvious to you or anyone else that the full-range signal is sent down both sets of wire then it should also be obvious that there is no benefit to doing it.

[sivadselim]

Just what is the other side of the argument that I am missing? The other side would be 'bi-wiring is beneficial' - it is not. If it is obvious to you or anyone else that the full-range signal is sent down both sets of wire then it should also be obvious that there is no benefit to doing it.
Bi-wiring may or may not do anything. But you ARE grossly oversimplifying what it is purported to do.

A speaker with the jumpers removed and only the tweeter posts connected will only emit sound from the tweeter (and midrange, if applicable). A speaker with the jumpers removed and only the woofer posts connected will only emit sound from the woofer. So there IS an actual physical separation of the crossover's hi-pass and low-pass filter components when you remove the jumper.

Do a search; there is a lot of discusion about it out there.

http://www.vandersteen.com/pages/Answr7.htm

http://www.sonicdesign.se/biwire.html

http://www.bwspeakers.com/index.cfm/fuseaction/local.faq/ObjectID/F5CA2E9F-3D20-11D4-A67F00D0B7473B37

[Seth=L]

Bi-wiring may or may not do anything. But you ARE grossly oversimplifying what it is purported to do.

A speaker with the jumpers removed and only the tweeter posts connected will only emit sound from the tweeter (and midrange, if applicable). A speaker with the jumpers removed and only the woofer posts connected will only emit sound from the woofer. So there IS an actual physical separation of the crossover's hi-pass and low-pass filter components when you remove the jumper.

Do a search; there is a lot of discusion about it out there.

http://www.vandersteen.com/pages/Answr7.htm

http://www.sonicdesign.se/biwire.html

http://www.bwspeakers.com/index.cfm/fuseaction/local.faq/ObjectID/F5CA2E9F-3D20-11D4-A67F00D0B7473B37
No, there isn't just think about were your power is coming from.

I am not disputing that A and B are not seperate amplifiers, I already know they use the same output stage. The point is most receivers allow you to select a, b, and both A and B. When A and B are on, regardless if it uses the same output stage for both it will not run A and B, and all the surround channels at once. The only receivers I have seen that don't do this are really expensive or really cheap, as the cheap ones don't even allow you to run A and B at the same time.

Now I ask myself, "why not make it able to run A and B at once on cheap receivers or A and B and Surround channels on decent receivers?" I would certainly think they have a reason, it may be impedance, or maybe it isn't, point is they do this, and they do it for a reason.

[MDS]

Bi-wiring may or may not do anything. But you ARE grossly oversimplifying what it is purported to do.

A speaker with the jumpers removed and only the tweeter posts connected will only emit sound from the tweeter (and midrange, if applicable). A speaker with the jumpers removed and only the woofer posts connected will only emit sound from the woofer. So there IS an actual physical separation of the crossover's hi-pass and low-pass filter components when you remove the jumper.

Do a search; there is a lot of discusion about it out there.


Yes, there is a lot of B.S. out there...

I am not oversimplifying. The proponents of bi-wiring are overestimating. The purported benefit is to feed the tweeter ONLY the highs and the woofer ONLY the lows, but bi-wiring doesn't accomplish that regardless of whether you have one xover or two separated by a jumper - each still gets a full range signal and blocks the part it doesn't want. But go ahead and believe what you want...I don't care to discuss it any further.

[Seth=L]

Yes, there is a lot of B.S. out there...

I am not oversimplifying. The proponents of bi-wiring are overestimating. The purported benefit is to feed the tweeter ONLY the highs and the woofer ONLY the lows, but bi-wiring doesn't accomplish that regardless of whether you have one xover or two separated by a jumper - each still gets a full range signal and blocks the part it doesn't want. But go ahead and believe what you want...I don't care to discuss it any further.
If a speaker system has a very good crossover, there would be no point to Bi-wiring at all, Bi-amping is another story though. Bi-amping of course does not apply to this discussion, oh well.:)

[sivadselim]

The purported benefit is to feed the tweeter ONLY the highs and the woofer ONLY the lows, ...........
I've never seen ANY proponent article on bi-wiring claim that.

THAT is definitely an over-simplification. :rolleyes:

Do some research.

[mtrycrafts]

BTW, if he connected 2 pairs (4 total) of identical speakers to A and B, then he WOULD be presenting twice the impedance to the reciever. But bi-wiring that way with a single pair will not present any different impedance than if he bi-wired off the "A" posts only. It's the same thing.


Yes, in this case you are correct. Impedance is frequency dependent and you would not be parallelling the lows and the highs in the same sense as two resistors. Or, when two similar speakers are placed on the A and B posts, each driver is in parallel then and halving the impedance.

[sivadselim]

I am not disputing that A and B are not seperate amplifiers, I already know they use the same output stage. The point is most receivers allow you to select a, b, and both A and B. When A and B are on, regardless if it uses the same output stage for both it will not run A and B, and all the surround channels at once.

You're wrong.

And you quoted the wrong quote of mine, I do believe.

On his receiver (and you can go to the Yamaha site and read it's intsruction manual), "A" and "B" are parallel connections off the same 2 LEFT and RIGHT channel amplifiers. So, the receiver doesn't "care" if he uses the second set of "B" posts to bi-wire his speakers. It will perform the same as if they were single-wired OR bi-wired off of the "A" posts. It's all the same as far as the receiver is concerned.

On some receivers, "A" and "B" are NOT parallel connections from the same amp and "A" has a right and left channel amp and "B" has a right and left channel amp; 4 amps total. On these receivers, yes, you usually have to assign the "B" amps to either your surround speakers or to a second set of speakers on the front channels. You can also use the 3rd and 4th amp to bi-amp a single set of speakers.

But that is NOT how his receiver works.

On his receiver, it's perfectly fine to use those "B" binding posts to facilitate bi-wiring (not bi-amping) and his completely separate surround amps will still work fine to power his surround speakers at the same time.

My 2-channel ROTEL RB-1080 has 4 binding posts per channel; 4 for the left (2 positive, 2 negative) and 4 for the right (2 positive, 2 negative). You can use these, easily, to bi-wire speakers. An 8 Ohm speaker connected either singly (2 binding posts), biwired off a single pair of binding posts (2 binding posts), or biwired with all 4 binding posts will still present the same 8 Ohm impedance to the amp. You can also use the extra pair of binding posts for another pair of speakers. In this case, if you connect two 8 Ohm speakers to each channel (4 speakers total), the amps WILL then see 4 Ohms of impedance. But there is no setup switch or anything on the amplifier to tell it what you are doing with the extra binding posts.

[mtrycrafts]

If a speaker system has a very good crossover, there would be no point to Bi-wiring at all,


How so? By your implication, then a speaker with a not so good crossover would benefit from a buy-wiring?

[Sheep]

OK, time to clear up this A+B crap.

Running both A and B at the same time, to the same speaker, is not going to do squat, just like buy-wiring.

If however, you run 2 different sets of speakers, then you will half the impedance.

When I did my C1 vs P150 shootout I had the P150s on my B and the C1s on my A. When I was trying to compare the sound, I ran them both and the same time, and both sets of speakers played. Where you're getting this only 1 will work, it will turn one set off crap I don't know, but its not true. Any High Current reciever can handle both at the same time, but not at high levels. If you crank it, the receiver will shut off.

SheepStar

[sivadselim]

Where you're getting this only 1 will work, it will turn one set off crap I don't know, but its not true.
I agree, but if the "B" channel does represent a separate pair of amps, he is correct. On these types of receivers you can't use the "B" channel for a second set of speakers in another room, for example, AND use the same amps for your surrounds at the same time; they must be assigned.

But in the case of this receiver, the "B" posts are simply that; parallel binding posts off the front channel amps. The ON/OFF switch is there so that if you do use the "B" posts for a separate second set of speakers in another room, for example, they can be silenced. If you use "A" and "B" to bi-wire your front speakers, for example, you just leave "B" on all the time.

And using the "A" and "B" posts, in this case, to biwire a single pair of speakers presents the same impedance as single-wiring them. An 8 Ohm speaker is still an 8 Ohm speaker, either way.

[MDS]

I've never seen ANY proponent article on bi-wiring claim that.

THAT is definitely an over-simplification. :rolleyes:

Do some research.

Yes, do some research for yourself and not the marketing drivel from speaker companies. If not to separate the highs from the lows to feed each respective driver then what exactly do you think bi-wiring will do? The answer has already been given: NOTHING AT ALL OF VALUE.

[sivadselim]

If not to separate the highs from the lows to feed each respective driver then what exactly do you think bi-wiring will do?
That's what you need to go read about. :)

No one claims that that is what biwiring does.

[Sheep]

I agree, but if the "B" channel does represent a separate pair of amps, he is correct. On these types of receivers you can't use the "B" channel for a second set of speakers in another room, for example, AND use the same amps for your surrounds at the same time; they must be assigned.

But in the case of this receiver, the "B" posts are simply that; parallel binding posts off the front channel amps. The ON/OFF switch is there so that if you do use the "B" posts for a separate second set of speakers in another room, for example, they can be silenced. If you use "A" and "B" to bi-wire your front speakers, for example, you just leave "B" on all the time.

And using the "A" and "B" posts, in this case, to biwire a single pair of speakers presents the same impedance as single-wiring them. An 8 Ohm speaker is still an 8 Ohm speaker, either way.

Yes, thats exactly what I was trying to say.

SheepStar

[liberalz]

I used the same receiver, sometime ago, to switch back & forth between impedance at the back of the receiver from 8 to 4 ohms with my Mission speakers which was slated to be a 6 ohms (I believe). The sound was very different, 8 ohms sounded way better.

But at present with my bi-wire set-up & receiver impedance switch set to 8 i don't see any impedance issues.

I agree with sivadselim, I don't think it causes any impedance problem in my bi-wired set up.

Parrallel connection with 2 8 ohms, i think is (8+8)/2=8, am I wrong.

[Sheep]

I used the same receiver, sometime ago, to switch back & forth between impedance at the back of the receiver from 8 to 4 ohms with my Mission speakers which was slated to be a 6 ohms (I believe). The sound was very different, 8 ohms sounded way better.

But at present with my bi-wire set-up & receiver impedance switch set to 8 i don't see any impedance issues.

I agree with sivadselim, I don't think it causes any impedance problem in my bi-wired set up.

Parrallel connection with 2 8 ohms, i think is (8+8)/2=8, am I wrong.

It would be 16ohm and 16ohm. When put together on the same load, it turns into 8ohm.

SheepStar

[MDS]

Parrallel connection with 2 8 ohms, i think is (8+8)/2=8, am I wrong.

1 / (1/8 + 1/8) = 4 Ohms.

[sivadselim]

I agree with sivadselim, I don't think it causes any impedance problem in my bi-wired set up.
No, with your receiver it's not a problem.

Parrallel connection with 2 8 ohms, i think is (8+8)/2=8, am I wrong.
1 / (1/8 + 1/8) = 4 Ohms.
If you biwire an 8 Ohm speaker off the 4 parallel posts OR off of a single pair of posts of an amp channel, then it's still seen as an 8 Ohm load by the receiver on that amp channel.

If you connect 2 separate 8 Ohm speakers off the 4 parallel posts OR off of a single pair of posts of an amp channel, then the receiver sees a 4 Ohm load on that amp channel.

[MDS]

Still waiting for your explanation of what bi-wiring is supposed to accomplish.
Theoretically at least, I already know what it accomplishes in reality.

[sivadselim]

Still waiting for your explanation of what bi-wiring is supposed to accomplish.
Theoretically at least, I already know what it accomplishes in reality.
Just do a f*cking search on any of these audio forum sites. It's one subject that has definitely been discussed ad nauseum.

You've got over 2900 posts. I know you didn't just fall off a turnip truck.

[MDS]

Just do a f*cking search on any of these audio forum sites. It's one subject that has definitely been discussed ad nauseum.

You've got over 2900 posts. I know you didn't just fall off a turnip truck.

My challenge to you is to explain bi-wiring because you keep saying 'that isn't what it is supposed to do'. If you actually knew anything about it you would be able to explain it in a few sentences - but you can't, so you deflect the question by saying 'go search'.

You're a real class act!

[majorloser]

There is no difference between using a jumper bar on the speakers and connecting the two wires of a bi-wired scheme to the same terminal on the back of the amp. It is still a parallel electrical connection between the high and low drivers/crossovers.

I've heard the argument that using two wires will decrease the total wire impedance and electrical losses through the cable. But I challenge anybody to open up their amp and look at the wire connected to the inside of the speaker terminal. That internal wire is the weakest link. There is no gain by running one cable of a larger gauge or running two cables for a parallel load compared to that internal wire.

As was stated before, bi-amping is another story. Now the driver loads are divided between two amplifiers.

BTW- two 8 ohm parallel loads will give you a 4 ohm total load. Two 8 ohm loads in series will give you a 16 ohm load.

Now everybody start playing nice ;)

[mnnc]

uhhhm...what about the hum part? I'm trying to learn something here. And as far as this a/b stuff is being debated, my take is to just use the amp section of whatever product it is that's being used as it was intended to be used. Simple L/R out to L/R in concerning each spkr. Or buy mono amps...a whole stack of them. Jeez!

[Seth=L]

Still waiting for your explanation of what bi-wiring is supposed to accomplish.
Theoretically at least, I already know what it accomplishes in reality.
Take the internal x-over out and use a high end external, that is the only way I see bi-wiring posing any advantage. Actually that really isn't biwiring either is it. Only one set of wires going into the x-over.

[MikeBC]

I think the answer to the hum problem was in the first reply to the OP in this thoroughly hijacked thread. . .