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| Back in the early '90's I bought my first decent speakers. They were Mirage bi-wire capapable. The salesman told me about the benefits of bi-wiring and the importance of "good" cables so I soon bought some high dollar Audioquest cables and did notice the difference. Then moving on to the bi-wire theory I was told to use the Audioquest to feed the bass an that I didn't need a great cable to feed the highs, just regular 14g monster cable would suffice. Now to my questions: is it true about lesser quality cable for the highs? And should the 2 cables for bi-wiring come from the same amp terminals or if the amp is 4 channel, can the highs come from channel A and the lows be pushed by channel B? So all 4 channels pushing 2 speakers- Any knowledge would be helpful. Thanks-Jim |
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Porcdoc | Jim, I never heard of Bi Wiring .Perhaps you can draw amental picture of it. As far as wire gage goes for speakers, in theory a high frequency speaker can use a wire gage that is smaller than a bass speaker. Resistance of the speaker is inversely proportional to the frequency its re- producing. Low frequency requires a lot of power because as the frequency into a bass speaker(for example )gets down below approx 80 hertz(cps) the resistance of the coil in the speaker effectively drops going closer toward a short circuit.So if you start with a low resistance speaker, say 4ohms, the resistance drops and your wattage(power to the speaker increases. As far as using any A/B arrangement, be aware that doing that might put your speakers in parallel which further decreases the resistance of your speaker setup and increases power consumption.If not thought out well, this could A) Blow your speakers B)blow your amplifier output stages(or fuses if so equiped) C)both of the above.Speaker resistance or ohm values are nominal and change with input frequency ,keep that in mind .Resistance wired in parallel halve while resistances in series add. The lower the resistance gets ,the more power is drawn and heat is generated. Regards Porcdoc. |
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Porcdoc | Jim, A correction to my previous comments! Everything stated is correct accept the term"inversely proportional" is the wrong term. It should read"Directly Proportional".The ohm value in a coil driven speaker goes lower as freq. goes lower and vice versa. I had a senior moment. |
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Anonymous | Porcdoc, sounds like you certainly know the technical aspects of speakers and sound. Please check out this link for images on bi-wiring schemes. http://www.davidmannaudio.com/faq/faq3.html And this link for bi-amp schemes. http://www.davidmannaudio.com/faq/faq12.html |
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Porcdoc | unless you have a true "bi-amp" just using the "a" /"b" speaker terminals on modern reciever/amps will cause a degredation of sound ,power or both! It could also contrbute to the early demise of the amp. or at least blow the small value power stage fuses that are in the crkts. to keep you from blowing the out put stages when you overdrive them by a comination of too much current/power(on the bass) coupled with speakers connected in parallel which compounds the problem. Most instruction books I,ve read warn you if you use "a"+"b" that you should use 6 or 8 ohm speakers to do that. Unless "a"+"b" is in series, in which case the power available drops and so do'es the overall effect of the set up. I know this might be confusing but electronic principles (physics laws) can,t be revoked. To get around this the industry made a pretty good decision by keeping low frquency away from the small speakers and instead sending the low frequency signal to the selfpowered woofer which itself has an amplifier ---so you dont strain the amp you are using to crank up all sound/power just to get the wall trembling effects. |
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Anonymous | I just bought what I think is a big bargain at a local thrift store. It is a very heavy Onkyo amp/pre-am model A-7090 I think,(I have it in storage presently).I am not familiar with it,but I am guessing it must be a vintage 70s or 80s solid state amp. It apperently has three channels and is rated at 310 watts. The strange thing about it is each channel has 2 sets of binding posts.That is to say, 2 negatives and 2 positives for speaker A and the same goes for the other 2 channels B & C. Could this feature be for bi-wiring?Or am I missing something? I would appreciate any information. |
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hardcastle | bi- wiring is where your speaker has 4 binding posts on the rear.1 pair feeds the highs and the other feeds the lows. The source can be a single terminal from the amps rear. I think with the situation you describe, your amp is capable of bi-amplification. Check the links on earlier posts to see if it makes any sense. |
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| Hows it goin, I am a bassist and i have rig that is great but i want it to be better! i've got a Fender BXR 400 series head with Bi Amp Capabilities, and is a 600W Head at 8ohm! (damn awesome) and i have a SovTek 4x10" Cabinet at 8ohs which is 400W and i want to get a 15" cabinet to gain 200W and run a Bi system. The question that i wish to ask is that how do i? and what do i need? to create a Bi amp set up (stereo) to devide low end and high end??. My Head also has High/B and Low/A connections I'f you can help me that will be great thanks. Yours Sincelly, Damien |
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Anonymous | (PLEASE HELP) i have a car amplifier and i want to hook it to my home sterio . i have already connected the power wires to a car battery tht i have i wont get power because there no place to hook the remote wire that runs from the amplifier to the audio souce like my sterio dosent have any place to connect the remote wire to. so if there is any body out there who can help please e-mail me at xdhillonx@aol.com |
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Joong-In Rhee | Anonymous You can goto radio shack and get a electric power converter - explain what you want to do, and they will have things to make it work. |
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neil hunwick | can i bi wire my 6 ohm technics speakers with an amp which has main,remote or both speaker switch but for both the min is 8 ohms thanx |
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Anonymous | Run some audio RCAs to the amp from the receiver, if the amp can take it. Then depending on which is more powerful, your receiver or amp. Run the more powerful to the bottom binding posts. That is for the lower frequences. (You can also bridge the two, some have special inserts that connect the binding posts, so its like a normal 2 binding post connection.) Some people even try to run two speaker cables from the same out on the receiver, but having a seperate amp is more ideal. |
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installguy | when you biwire,the speaker x-over at the end of the wire only "calls" for the frequences it needs to operate the speaker that is connected. that means the sound in each speaker wire is cleaner and less destortion between frequences because it only has those used for the speaker.also if you use high end speaker cables (monster cable)you can time align the speakers. high frequences travel faster through wire and air than low frequences so if you increse the wire length of the woofer you can make up the differace in time. the woofer wire in the monstercable is wraped around the tweeter wire so that the overall cable looks to be one length. if you had the formula for speaker wire length time alignment you could make the cables your self. |
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Anonymous | The fact that Porcdoc has never heard of bi-wiring should be a clue. 1. your speakers, when NOT set up for bi-wiring have the input to the woofers wired in parallel to the input to the mid/tweeters (each via their portion of the crossover circuit inside the speaker). If your speakers are bi-wire capable, this is real obvious: the parallel hook up is the removable jumper between the terminals. IT IS THIS PARALLEL COMBINATION THAT SETS THE 'NOMINAL' SPEAKER IMPEDANCE (8 ohms, for example). 2. when bi-wiring, you are simply moving that parallel connection FROM the speaker end of the speaker wire TO the amp end. Your amp does not 'see' ANY difference in impedance! Why does it help, then? Because the speaker wire inductance serves to isolate the interactions of the bass signals from the treble signals; it also reduces the impedance/phase interaction between the hi-pass section of the crossover with the low-pass section. 3. Using the 'speaker 1' and 'speaker 2' terminals for bi-wiring simply moves the woofer/tweeter parallel connection one step further upstream, into the amp. This has no performance advantage over hooking both sets of wires to the same terminals (but may be more convenient). IT WILL NOT CHANGE THE IMPEDANCE 'SEEN' BY THE AMP! There is NO danger in doing this! |
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Anonymous | Neil, as stated above, bi-wiring, whether you use one set of terminals, or you use the A and B terminals, will NOT change the impedance you amp 'sees'. Most amps have some guardband. If your 6 ohm speakers are working now,and not damaging your amp, then bi-wiring will not change that. |
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Anonymous | Damien, a few thoughts: 1. if you separate the outputs on your power amp, each will have equal power (not a 200 watt/400 watt split). So, you might want to get a 2nd speaker rated for at least 300 watts if you want to use all the power available. 2. I'm not sure what frequency range is considered 'high' vs. 'low' for a bassist. You will have to figure that out, then buy or build a crossover to split the signal accordingly. You can buy a used active crossover for less than $100 on ebay, which will allow you to play around with the cutoff frequencies to suit your tastes. 3. the crossover SHOULD go between the preamp section of your head unit and the power amp section. are these input/outputs available? Maybe the hi/B, low/A connections do this, I can't tell. Is there a cutoff frequency shown for each? If you cannot insert an active crossover between the pre-and power-amp sections, you will have to build a passive crossover for use at the speaker input. At the power levels you want, this will be really tricky. Better to run full-spectrum through both speaker cabinets, I would think. |