What's wrong

[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.

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 )

 

[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.

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.

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.