Vonrebel Posted March 14, 2002 Share Posted March 14, 2002 Is it healthy for a speaker to be hooked up to both A and B channels, ? Twice the power from left anf right A and B channels ran to both mains? Is this bi wiring? LOL Quote Link to comment Share on other sites More sharing options...
lynnm Posted March 14, 2002 Share Posted March 14, 2002 Hello Vonrebel Yike!! Hooking one speaker across both channels is a bad idea to say the least and could easily destroy your amp and might also result in the loss of the speaker. That sort of wiring would be essentially the same as shorting the amp. Even if the amp did not do a Three Mile Island the sound would be Gawdawful. Bi-wiring consists of removing the connecting strap on the back of a speaker that has 4 terminals,(separate inputs for low frequencies and high frequencies),and running a separate line from SAME channel of the amp for each set of posts. This procedure would have to be carried out for each channel. Some of us here feel that bi-wiring yields an improvement in sound quality but many other knowledgeable users disagree. The benefits then are somewhat questionable. ------------------ It is meet to recall that the Great Green Heron rarely flies upside down in the moonlight - (Foo Ling ca.1900) This message has been edited by lynnm on 03-14-2002 at 06:11 PM Quote Link to comment Share on other sites More sharing options...
JohnA Posted March 14, 2002 Share Posted March 14, 2002 It won't hurt anything. It also won't increase power to the speaker. The A+B switch connects the A terminals and the B terminals to the same output point inside the amp. Therefore, it cannot allow more power out of the amp (unless, maybe, you are using itty-bittty 24 gage speaker wires). It is NOT biwiring unless you hook the A wires to one of the dual terminals on the speaker and the B wires to the other AND switch to A+B, PLUS remove the speaker's jumper bars. You ARE asking about A+B rather than L+R, aren't you (connecting L+R to the same speaker terminals would be pretty stupid)? John This message has been edited by John Albright on 03-14-2002 at 06:17 PM Quote Link to comment Share on other sites More sharing options...
Vonrebel Posted March 14, 2002 Author Share Posted March 14, 2002 I was inquiring, running two separate sets of speaker wire.. One pair from B left and another pair from A left to the same set of post on the left speaker. Same thing on the right for the right speaker. Thinking I would get 100 watts from A + 100 watts from the B = 200 watts? Quote Link to comment Share on other sites More sharing options...
WMcD Posted March 14, 2002 Share Posted March 14, 2002 Lynmm was assuming you're connecting across the pluses, which evidently you're not. But I agree with the Yikes. John A. and you are on the same wavelength. This is a bit presumptious of me, but the question evolves from a few questions about amplifier design. Essentially, for a given left or right channel, there is one internal amplifier, that is to say, one for left and one for right. There are not A and B amplifers for a given channel. Many amps have outputs for A speaker or B speaker, or both. The output switch just connects the amp to one output terminal (A) or the other (, or both (A + . In the "both", the speakers are wired in parallel to the amp. It is the same as if you wired them in parallel to one output from the amp. Therefore, you're not getting more amp output. It is a good question, none the less. Glad you brought it up. Gil Quote Link to comment Share on other sites More sharing options...
Jolly Roger Posted March 15, 2002 Share Posted March 15, 2002 I have often thought about hooking up two sets of surronds and using the a+b setting on my Denon. I have to believe it won't hurt the amp or the setting wouldn't be on there. What do you guys think? Tax the amp too much? Sound like crap? Just curious... Quote Link to comment Share on other sites More sharing options...
Ray Garrison Posted March 15, 2002 Share Posted March 15, 2002 In most integrated amps or receivers that offer an "A" "B" speaker selector switch, all that's going on is that inside the amp, the output is wired in parallel to both sets of speaker connectors, with the "A" "B" switch connecting or disconnecting the connectors. That is, picture an amp that does not have a speaker selector switch. You have a wire connecting the output transistors to the speaker connector. To add an "A" "B" switch, you attach another speaker connector, run another wire in parallel from the output transistors to the second connector, and install a switch that lets you select one, the other, or both connectors. Except for any benefits gained by doubling up the wire (lower resistance maybe), there's absolutely no difference between connecting your speakers to the "A" outputs, conecting them to the "B" outputs, or connecting them to both outputs. The only reason it's there is to make it easier to connect two different sets of speakers. You could accomplish effectively the same thing by running two different sets of wires from one speaker output. ------------------ Music is art Audio is engineering Ray's Music System Quote Link to comment Share on other sites More sharing options...
Guest BobG Posted March 15, 2002 Share Posted March 15, 2002 All true but some low current amplifiers (too many unfortunately) wire the A set in series (rather than parallel) with the B set. That will change sonics as compared to a parallel configuration of the HF and LF sections. Quote Link to comment Share on other sites More sharing options...
Underhanded Penguin Posted March 15, 2002 Share Posted March 15, 2002 So many things can be said about biwiring. It boils down to this: It provides extra signal bandwidth to the speakers. But since cables don't come much lower than 12 gauge, biwiring with 2 12 gauges would give you that extra headroom that is useful when you have very long speaker cable runs. There are other factors to consider in speaker cables, such as composition, number of twists, strands etc,but in general, the thicker the cable is, the less resistance there is for the signal to pass through to your speakers. Whether this is audible or not is another question. Try it out! It worked for me. -UP ------------------ Liv Tyler as Arwen: "If you want him, come and claim him!" - Translation: "I am very hot." Quote Link to comment Share on other sites More sharing options...
dougdrake2 Posted March 15, 2002 Share Posted March 15, 2002 quote: Originally posted by BobG: All true but some low current amplifiers (too many unfortunately) wire the A set in series (rather than parallel) with the B set. That will change sonics as compared to a parallel configuration of the HF and LF sections. Bob - For my own education...Is this done so that the impedance goes up if a B-pair of speakers is added rather than down, which might overload the amplifier (especially, as you say, in low current amps)? Doug ------------------ My System Quote Link to comment Share on other sites More sharing options...
tidmack Posted March 15, 2002 Share Posted March 15, 2002 Good topic fellas. . . So is it bad for the amp or speakers to run both the A and B channels at the same time with two pairs of speakers? Jeff Quote Link to comment Share on other sites More sharing options...
JohnA Posted March 15, 2002 Share Posted March 15, 2002 Jeff, It is not bad to run a pair of speaker on each channel (left and right), no matter what the impedance of each speaker AS LONG AS you don't push the amp. Amps are damaged by heat. Heat is caused by current. Low impedance draws more current. The lower the impedance, the higher the current. If you limit the power output, most amps can be operated at 1 or 2 ohms. At 1 or 2 ohms, though, the safe power output (that keeps heat below safe limits) may be so low the amp may not be useful. That's why manufacturers state minimum impedance is 4 ohms, typically. John Quote Link to comment Share on other sites More sharing options...
Jolly Roger Posted March 15, 2002 Share Posted March 15, 2002 Jeff, thank you. Same question I had, I guess I didnt state it correctly. Quote Link to comment Share on other sites More sharing options...
WMcD Posted March 15, 2002 Share Posted March 15, 2002 I have not seen amps where A and B are switched / wired in series. But Bob has much more exposure to the industry than I do. When this is done, it should be that if you don't have a "B" set wired in, then the "A" set will not work with the amp set to A+B because an element of the series circuit is missing. Something to keep in mind if we get some sqawks on that. Gil Quote Link to comment Share on other sites More sharing options...
Vonrebel Posted March 16, 2002 Author Share Posted March 16, 2002 So hooking up (one) speaker to both Lf Ch. A + Lf Ch. B Ch on the recv. and then turning on both A+B ch, will not hurt the speakers or the Receiver? Nor will this double the power sent to the speaker? Quote Link to comment Share on other sites More sharing options...
lynnm Posted March 16, 2002 Share Posted March 16, 2002 Von - My Apologies!! Sorry for my earlier panicky response - "Old Boy" <Grin>,(You have taken a look in Grays Anatomy pp. 14-19) As suggested earlier - I misunderstood your question about wiring a single speaker to both A and B channels. I thought you were suggesting that one might be able to or could/should simultaneously feed both the left and right outputs of a stereo power amplifier into a single speaker. Wiser heads have intervened and suggested I learn to read - (buncha buttinski's) <GRIN> As pointed out by John and William; - I can see ye only because me 'ead is so firmly planted that I can see out me mouth!! ------------------ It is meet to recall that the Great Green Heron rarely flies upside down in the moonlight - (Foo Ling ca.1900) Quote Link to comment Share on other sites More sharing options...
WMcD Posted March 16, 2002 Share Posted March 16, 2002 Yes, the bottom line is that I don't see a problem running wires from both outputs as you describe. However, be careful with polarity. You must make sure that the plus wire from either output wind up at the same (plus) terminal of the speaker. If this gets reversed the wires will create a short circuit across the output of the amp. As mentioned in other posts, this is not bi wiring or bi amping. However, by switching to A+B you'll be effectively doubling the cross section of the feed wire(s). You might report on whether you hear a difference. Gil Quote Link to comment Share on other sites More sharing options...
Vonrebel Posted March 17, 2002 Author Share Posted March 17, 2002 William G To tell you the truth I'm afraid to try it. LOL If I do I'll report the findings. Quote Link to comment Share on other sites More sharing options...
boa12 Posted March 17, 2002 Share Posted March 17, 2002 von, you can try it but there's no good reason to do it. whether your talking of running the a&b to the same terminals, or like the a to the high terminals & the b to the low terminals of the rf. maybe someone could confirm this. thought i've read in my a/v receiver manuals that you can't do multi-channel like 5.1 when A+B is selected. pretty sure that was the case on my 1st sony de935 a/v receiver. but i've never tried a+b on an a/v receiver. only reason i see is if u have 2 pair of speakers for music & you want to do like 4 speaker stereo music. ------------------ My Home Systems Page This message has been edited by boa12 on 03-17-2002 at 02:50 PM Quote Link to comment Share on other sites More sharing options...
Vonrebel Posted March 17, 2002 Author Share Posted March 17, 2002 The reason for connecting to both a + b would be to tap both channels sending doulble the watts to the speaker, which would increase power. Quote Link to comment Share on other sites More sharing options...
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