BI -WIRE

[Guest " "]

it is not line level since it has a variable output greater than 150mv.

line level is fixed at 150mv.

most adaptations of using a powered output such as a head phone out put jack for driving an amp should assume that the device can provide .75 to 1.25 volts. That could cause a lot of input distortion on a 150mv line level input.

[darkside]

Ok, but what about using two power sources, since I havent gotten a straight answer yet[^o)]

[Guest " "]

let's start all over. what do you have, and what would you like to do.

[ironwoods]

Hey, what type of input options are available on the Creative Labs Sound Blaster Audigy 2 Value?

[darkside]

speakerfritz- What I want to do is have my PC/PMU as one audio source

on my RFs and a receiver as another. Since there are two sets of

binding posts, i figured this could be done, but now am not sure. What

I am after is a way to get music w/o having to have my PC on, as it is

a space heater

ironwoods- The Audigy 2 Value has mic and line-level inputs only

[Jay481985]

The two corresponding binding posts are not meant for two different hookups. It is meant to either biwire or biamp. The top binding post leads to the HF horn, the bottom binding post is LF. When you remove the jumper, the metal piece connecting them you will have two different crossovers where you should not separate and send two different signals.

[WMcD]

Let me see if I understand what you (1) suspect, (2) how things really work and then (3) explain bi wiring. Then we move on to (4) why the speakers have this. And later (5) why cars had fins. Some of this may be beyond your present understanding. Yet I want to be technically accurate.

1) I believe you saw these two pair of binding posts on the back of the speakers and got to wondering: Is this a way of hooking two otherwise independent stereo systems to the speaker (of course half of stereo pair).

1.1) Further by example, I've got my old time college system, and my new Ipod with outboard amp. Maybe both can be hooked to the speakers and I can play one or the other; maybe both at the same time. And is that the function of the two binding posts? Are these two ports into the speaker. Sort of like Aux 1 and Aux 2 on the input to receiver-amplifier.

1.2) The answer is no. In fact, I don't know of any speaker which has that capability. That is why it is done at the receiver-amplifier.

2) How things work. In the orchestra, small instruments make high freqs (violin) and big instruments make low freqs (bass fiddle). Some, like drums and pianos make both. But we'll come back to to small - high and big -low issue in speaker system design.

2.1) Let's step back and realize that in just about all the chain of devices in the audio system carries both high and lows, the full spectrum of sound. That starts at the recording microphone (full range which picks up all the instruments) and and goes through the recording mixer, the recording device, the radio transmitter, radio receiver, vinyl player, tape player.

If you want to get a little wacky: The sound event gets stored in Aunt Ethel's closet on a shellac 78 disk for 50 years, and then is played by by an enthusiast and podcast. It eventually gets fed into an amplifier in our home.

2.2) The inner workings and output of a conventional amp has the full spectrum of sound.

2.3) Then it goes down the speaker wire pair and to the speaker system box. Note here, there is no division of the high and low frequencies. Some people wonder about this.

2.4). Let's look at how a normal two-way speaker works. That is to say one with a woofer for lows and tweeter for highs. There is one pair of input terminals. Marked plus and minus or red an black, just to keep track of polarity. Like flashlight batteries.

2.5) The tweeter and woofer are there for the same reason that violins and bass fiddles are different sizes.

2.6) The signal goes into the conventional speaker box and internally, there is a strap which you can not see. It might be just an ordinary solder connection.

2.7) The strap feeds two filters, one is a high pass to the tweeter, and one is the low pass to woofer.

2.8) Somewhat poorly understood is that the high pass filter works because it does not draw low frequency current through the strap. The low pass works because it does not draw high frequency current. Actually voltage is applied to both but they, respectively don't draw current.

2.9) On a technical matter (for others reading). The high pass filter has a high input impedance at low frequencies, and vice versa. Flip that around for the low pass. This is why each driver can be 8 ohms and in parallel through the filters, but do no combine to 4 ohms.

2.9) In theory everything works out. Very generally, the tweeter plays the violin, the woofer plays the bass fiddle. Both play the drum and organ according to the notes played.

3.0) So what is wrong? I think nothing. But others look at 2.3 with some question. They propose that maybe the high and low frequency electrical signals in one wire pair some how mess up things. I believe this is non-sense because of 2.1 and 2.2.

3.1) The arguement by them is that there is some sort of intermodulation in the wire because of conditions which are, by them and others, poorly understood.

3.2) The solution by the bi-wiring camp is to have a strap at the back of the speaker box. In 2.6 we saw that it is internal.

3.3) In the two terminal pair (four posts) one pair feed the tweeter and one pair feed the woofer. They are strapped by a pair of shiny beautiful conductors. This a speaker box which can be bi-wired. It can be bi wired by removing the strap. Now there is an alternative.

3.4) The alternative is to run two pair of wires from the output of the amp (for this speaker box) from the amp to the two inputs to the box. This way the tweeter and the woofer has their own wire feed. The 3.1 issue is avoided.

3.5) This is some accuracy to this because of 2.8 and 2.9. The internal filters in the box do act to restrict current in the two wire pairs to their respective frequency range.

3.6) You will recognize that some of this is a matter of where the "strap" is positioned. In conventional systems it is inside the box. With the bi-wirable it is external. We can leave it be and not bi-wire. If we remove it and bi-wire, we've moved it back to the amplifier output, where the bi-wires meet.

4.0) In my view, this biwire is theory is nonsense. I must be careful to not offend good people here who find merit.

4.1) The bi-wiring theory came into fashion about a decade ago. I can only image that retailers got requests for bi-wireable speakers. Contemporary with this was the Super-Wire theory. Then you need two pair of Super-Wires. Some salemen may push them (shame) but some buyers, I'm sure, demanded them.

4.2) It is easy to accuse various camps of mutually supportive husterism and naivity. In the middle is the market which wants (at least some) biwiring and the manufacturer who wants to please the market.

5.0) In my view it is like cars with fins. The buyer says, "This seems like a good idea and it is pretty, but let me ask, is there any real benfit?" The manufacturer says, "Well, if you think there is a benefit, we'll make them. " Then other people start thinking that there must be a benefit or buyers and sellers would not want them. More cars get bigger fins. Sales go up. For some period.

5.1) The whole bi-wiring thing is part of tweeking, hot rodding and home construction. We present and critque ideas and results. I'd like to think that these weed out items which have no technical merit and thereby make room for new ideas.

Best,

Gi

[darkside]

Jay- alright, that's what I was looking for. I didn;t think so, but wanted confirmation

William- In regards to #1, not quite. I knew what the two post sets

were for, bi-wiring, bi-amping, I'm not a complete dunce [], but I

appreciate the info. I knew the posts' intent but just was wondering if

(BIG IF HERE) there were other possible uses, and I have found that there are not.

SO, I've come up with a better solution. Possibly ditch the PMU sub/amp

and just get a receiver. Not only can I have music anytime I want like

that, but it will save space like crazy....

[Guest " "]

you need a min-plug mixer. it will take multiple 1/8th mini-plug sources and feed them into one input. you control from the mixer. the below is about 40 bucks.

http://app.infopia.com/Shop/Control/fp/user/Shop/Control/Product/fp/SFV/31341/vpid/2102902/vpcsid/0/rid/120428

This is a brand new, factory sealed Azden CAM-3, On-Camcorder Mini Audio Mixer.

Mix sound as you shoot from 3 external mics.

Three 1/8" inputs and one 1/8" stereo output.

Can be attached to camcorder or hand-strap.

3 1/4" W x 2 1/8" H; weighs 3 ounces.

No batteries required.

[Mr. Widget]

5.0) In my view it is like

cars with fins. The buyer says, "This seems like a good idea and it is

pretty, but let me ask, is there any real benfit?" The manufacturer

says, "Well, if you think there is a benefit, we'll make them. " Then

other people start thinking that there must be a benefit or buyers and

sellers would not want them. More cars get bigger fins. Sales go up.

For some period.

Bi-wire equals cars with fins... that is an

excellent analogy.... I'll try to remember it when someone asks why his

new speakers have those extra connectors on the back...

The thing is, if it makes you feel good to use expensive cables or

twice as many expensive cables... that's great... you feel good.

Widget

[Jay481985]

placebo effect anyone?

[darkside]

Problem solved, bought an H/K HK 3380-Z and just use my ipod when not the radio []

[Jay481985]

Good, I have the hk 3480 and it is a good reciever. Though what is the z ?

[darkside]

In all honesty, I have no idea [], its just what is labeled on the box. Maybe something to do with that its a refurb....

[Jay481985]

maybe......

[darkside]

meh...

[Jay481985]

hmm.....

[darkside]

LOL, pointless posts to increase post counts FTW []

[Jay481985]

okay?...... [8-)]