A/B Speakers

Discussion in 'General Audio Discussion' started by lilditty, Sep 18, 2013.

  1. lilditty

    lilditty Active Member

    Messages:
    100
    Location:
    Flint, MI
    Hi Everyone,

    Forgive me if this is a dumb question, but I wasn't around in the heydey of most of the stuff discussed on this site :music:

    It seems that the vast majority of receivers I have looked at have 2 sets of speaker outputs. I was curious of the reasoning. Was it common place to hook 2 different sets of speakers up for different listening types, or 4 of the same speaker and crank all 4 or what. Just curious what the main use was for this.

    Thanks!
     
  2. 4-2-7

    4-2-7 Smart Ass Sponsor Subscriber

    Messages:
    22,526
    Location:
    San Francisco Peninsula
    You answered your own question! plus you can have speakers in another room also. It basically gives you options.:thmbsp:
     
  3. 4-2-7

    4-2-7 Smart Ass Sponsor Subscriber

    Messages:
    22,526
    Location:
    San Francisco Peninsula
    Some old receivers even had A/B/C three sets.
    Or Quadraphonic 4 speakers for A and 4 more on B
    With quad it would be like a Car System L/R Front, L/R Rear
     
  4. charles 1973

    charles 1973 Super Member

    Messages:
    2,889
    I used the "B Speakers" on my Realistic Reciever to feed a Pair of Minimus 7 Speakers I had set up in the kitchen with an L-pad to controll the Volume.
     
  5. SoundOfSound

    SoundOfSound Super Member

    Messages:
    4,043
    An important thing to keep in mind is that the A/B switch can alter the load on your amp. If you had two 8 Ohm speakers the new load could be either 4 or 16 Ohms depending on how the A/B switch is wired.

    This is something you have to keep an eye out for so you don't smoke your amp if you decide to use two sets of speakers at the same time. :nono:
     
  6. lilditty

    lilditty Active Member

    Messages:
    100
    Location:
    Flint, MI
    Interesting. Surround sound before surround sound!
     
  7. 4-2-7

    4-2-7 Smart Ass Sponsor Subscriber

    Messages:
    22,526
    Location:
    San Francisco Peninsula
    Ha ha ha you must be young. Yes you are sort of right except that Quadraphonic is the predecessor of the various "Surround Sounds" that came afterwards. Qaud was nice but the industry never settled on a standard "Media" to play on it. So the consumer was lost or had to decide on witch one they would invest there money in. Kind of like Bata vs VCR.

    Look at all the speaker terminals on this quad unit.

    [​IMG]
     
  8. 1tumbleweed

    1tumbleweed Kozmik Kowboy Subscriber

    Messages:
    5,974
    Location:
    Colorado Front Range
    Just so no one gets misled...

    4 speakers does not equal surround sound. For some reason, a lot of people think this, and even insist that they have quad because they have a separate set of speakers in the same room. Quad (and surround) sends a different signal to the rear speakers. Otherwise all you have is "all speaker stereo".
     
  9. 4-2-7

    4-2-7 Smart Ass Sponsor Subscriber

    Messages:
    22,526
    Location:
    San Francisco Peninsula
    Who said that just 4 speakers is Quad or Surround sound within this thread?
     
  10. Markw

    Markw Super Member

    Messages:
    4,248
    Location:
    Northeast New Jersey
    Post 6, directly above, pretty much implies that unless you want to argue that "quad" and "surround sound" are not essentially the same thing.
     
  11. musichal

    musichal poet emeritus Subscriber

    Messages:
    7,953
    Location:
    Norman OK
    And yet, at least as early as 1971, folks were using the "Hafler Hook-up" for rear channel ambience retrieval, which is easily done with speaker wire, or with the Dynaco Quadaptor. In 1953, some R2R tape decks in Europe incorporated a discrete 4-channel system. "Surround" has been around and dabbled with longer than many folks realize. Dolby based his initial movie surround on a matrixed signal similar to the principal behind the Hafler circuit. How one connects an extra pair of speakers determines whether it is a surround-type approach.


    From Wiki: "The first medium for 4-channel sound was the quadraphonic reel-to-reel tape, standard in European electronic-music studios by 1953 and introduced to the American market by the Vanguard Recording Society in June 1969."
     
    Last edited: Sep 19, 2013
  12. 1tumbleweed

    1tumbleweed Kozmik Kowboy Subscriber

    Messages:
    5,974
    Location:
    Colorado Front Range
    You did.

     
  13. 4-2-7

    4-2-7 Smart Ass Sponsor Subscriber

    Messages:
    22,526
    Location:
    San Francisco Peninsula
    We are talking speaker layout! look at OP question. I do not feel the need to confuse the op with all the technicalities of a Quad system. I said pertaining to speaker layout that that Quad is LIKE a cars Speakers system L/R front And L/R Rear. And after stating that, it was helpful for the op to understand "Speaker Layout" & Quadraphonic.:scratch2:

    If you would like to discuss Quad systems, all the Media, demodulators and components needed. Why don't you start your own thread:thmbsp:
     
  14. musichal

    musichal poet emeritus Subscriber

    Messages:
    7,953
    Location:
    Norman OK
    I, for one, got your point the first time around about comparison with a car's fader/balance control.

    However, since you yourself made comments about quad and posted a huge picture of the back of a cool, old model, it seems a bit hypocritical to tell others to take their quad comments elsewhere... no offense, just sayin'...

    As for the OP's question... many of us believe that two speakers are better than four in the same room, with the possible exception of a 'party mode' type of approach, maybe. For more accurate reproduction, it is generally felt that imaging suffers with the use of four stereo speakers.
     
    Last edited: Sep 19, 2013
  15. frommerstop

    frommerstop Super Member

    Messages:
    2,450
    Location:
    Detroit
    And, to add a bit of unsolicited trivia to this. Polk's "SDA" system, was in affect a four speaker stereo.

    Using Hafler's circuit for "ambiance recovery", and placing the pairs of speakers in single cabinets. His "SDA" speakers used twice as many drivers per cabinet, in affect two speakers per side, with the "extra" drivers wired as Hafler suggested back in the '60s. The same thing can be done with anybody's speakers, as long as you want to set up four!
     
  16. JoeESP9

    JoeESP9 ESL's & tubes since 83

    Messages:
    14,447
    Location:
    Philadelphia PA
    I believe the SDA effect and speakers were designed to correct for interaural crosstalk. This is why SDA series speakers have dual tweeter assemblies and a special cable connecting the speakers.

    A time delayed and phase reversed signal is fed to the opposite secondary tweeter assembly to help cancel the right channel signal at the left ear and vice versa. This increases the stereo effect, imaging and apparent depth. This is exactly what the Carver Sonic Holograph did electronically. The original headroom circuit was based on the same sort of thinking.

    The Hafler effect is designed to extract ambience signals.
     
  17. 4-2-7

    4-2-7 Smart Ass Sponsor Subscriber

    Messages:
    22,526
    Location:
    San Francisco Peninsula
    Ya I know you do musichal just trying to show speaker channels in the photo. Op sounds like new and young so I was just trying to keep it simple. I have a fine Sansui quad system set up working as it should. Didn't need a side buster jumping in basically calling me a idiot without knowing me. I like the party sound too and have a setup like that as well. However my high end system is all stereo. So that's three system I have in my house.
    Thanks
     
  18. 1tumbleweed

    1tumbleweed Kozmik Kowboy Subscriber

    Messages:
    5,974
    Location:
    Colorado Front Range
    Jeez Louise. I don't recall inferring anyone was an idiot, just trying to clarify a potentially misleading statement. Don't get your knickers in a twist.

    Now, where's that "ignore" button...:screwy:
     
  19. KevinCorr

    KevinCorr AK Subscriber Subscriber

    Messages:
    1,799
    Location:
    Fairbanks Alaska
    Right. With a sub I had "home theater" years before there were AV surround receivers. Sadly, I still have that, no avr.

    Before that we always bed room, living room sets on the same source.
    I have carelessly run two sets pretty much my whole life and have been lucky. I have two integrated amps now with A/B: the Rotel 1070 and a big monster HK HK 6950R.
     
  20. iwilson

    iwilson Well-Known Member

    Messages:
    620
    Location:
    Brooklyn and the Catskills
    a lot of people used the B to run speakers in another room
     

Share This Page