I wonder can anyone out there help me?

I have put in bi-wire behind the walls for my new home theater. Because of the shape of the room (9ft x 18ft), I've been advised that dipoling rears on the side walls will give a better effect than single wiring to the rear walls. So that's where the cable is set up to.

When I was going to bi-pole, I thought that it was as simple as twisting together the two -'s and the two +'s at the Amplifier, and wiring the separate - and + cables to the 4 posts at the speaker end (having removed the cross over bit).

To dipole, I've been told that what I need to do is swap over the tweeter + and - inputs. OK, I reckon I can work that out.

But now another guy (installing some other equipment) has said no way should I do this as it will blow the amp. According to him, +/- can never be crossed over if they are wired to a single output on the amp - as this will blow a fuse in the amp.

Is that right? What to do?

BTW, rear speakers are Monitor Audio Silver Fxi and amp is Marantz SR 6200.

Thanks in advance

I think your a bit confused in your terminology...

Bi-pole is not Bi-wiring. I think you are talking about Bi-wiring in the section where you say "When I was going to bi-pole" Then yes, you can do that, if your speakers have two pairs of binding posts, simply remove the link and run two sets of wire from the same amplifier output. I've never really heard much of a difference doing it this way, but possibly a bit more power handling.

Well, you can wire any speaker you want out of phase and it will not blow any fuse anywhere. You are simply making the cone move in the 'opposite' direction as it should. It's an AC source so your just changing the direction of the motor.

I believe in the instructions for the FXi there are directions on how to wire these speakers Bi-polar or Di-polar (not Bi-wire....Bi-polar and Di-polar are wiring methods for making the speakers in phase or out of phase with each other, normally there are two sets of drivers in speakers like this, one pair facing the opposite direction of the other). Check it out, I don't think you have to open up the speaker to do this. Come to think of it, I think there is a switch on the back of them.

Hope this helped.

If I may throw in my two-cents worth here:

Bi-wire simply means using more than one pair of wires to feed a single channel's signal to a speaker, with the links removed. The wires are paralleled at the amp, and the high and low sections of the speaker receive the same signal, just through separate wires. You should keep polarity constant at both ends.

Bi-amping means that the high and low sections of the speaker are fed the same channel's signal, except through separate amplifiers. Ideally, the high and low frequencies are divided by an active crossover ahead of the amps, and the crossover components bypassed. This would require opening the speakers, and probably voiding the warranty.

If the crossover components are not bypassed, and you just use the speaker's high and low terminals, you don't need an active crossover, just a Y-cord to feed the amps. The amps will have slightly less control of the speaker drivers' motion.

Now, this brings us to bi- vs. di-polar wiring. This is done only when the speakers have separate terminals for the drivers on opposing faces of the speaker enclosure.

If the polarity is kept constant, then the drivers on the two faces move outward (relative to the speaker enclosure) and inward together; this is bi-polar. My Definitive Technology speakers use this configuration, and it actually most resembles the way real sound waves propagate through a space from real sound sources.

If one face has the polarity reversed relatively to the other, then you have di-polar, which is used to reduce the ability to audibly pinpoint the speaker location in the room. This is the way sound radiates from planar speakers (such as Magnepans) and normal speaker drivers not enclosed. THX and other preferences specify this configuration.

Note that a speaker with only one set of drivers can be bi-wired, but once again, the polarity should not be reversed to one set of terminals; this will only reduce the quality of the sound about the crossover frequency between the woofer and tweeter.

You certainly can wire bi-wireable speakers either for di- or bi-polar connection. In fact, if I were going to wire my speakers for bi-wiring, I would connect the wires polarity-correct at the speakers, and, if and when the desire hit me, change the polarity at the amp end of the wires.

The advice about blowing fuses was misguided, and assumed that the negative connections inside the speaker were joined independently of the external links, which is untrue. With both links removed, the high and low sections are completely isolated, and no shorting will occur. Only a speaker with links on only the positive terminals would present this concern.

I hope this info was helpful. For more in-depth info, do a search on "bi-amping" and "bi-wiring" in the search section.

Larry
www.fineelectricco.com