Playing 4 speakers at once

Discussion in 'Audio Hardware' started by dennis1077, Dec 24, 2018.

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  1. F1nut

    F1nut Forum Resident

    Location:
    The Mars Hotel
    It then becomes what some call all channel stereo. However, it's really just a mess of sound with no defined sound stage or imaging therefore lacking an on-axis position.

    Sinking? LOL......thanks for the laugh.
     
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  2. SandAndGlass

    SandAndGlass Twilight Forum Resident

    Just an observation...

    It doesn't really sound like a "mess of sound", more like perfect sound everywhere. Since there is no point source, there is no imaging. Imaging is but one characteristic of reproduced sound. Imaging by itself is not all that important to my enjoyment of sound. The reason that there is no defined sound stage, is because the soundstage is so large, it is everywhere.

    In real life, sound comes from everywhere. Most everyday sounds that we hear are a combination of both direct sound and reflected sound.

    Same thing in my audio room. There really is no single sweet spot, but there are sweet spots many places in the room. You don't have to sit in a specific place, you can stand up, move around, turn around and everywhere you stand or go, there is sound and it comes from everywhere (or as close as it can recreate "everywhere" within this room).

    This is a fairly large room of about 450 sq. ft. There is a lot of specialized gear in this room and it has taken a lot of time, a lot of effort and lot of gear, to achieve this effect. It is NOT just plopping down four box speakers.
     
  3. F1nut

    F1nut Forum Resident

    Location:
    The Mars Hotel
    At a live performance the musicians are in front of you and if it is an amplified performance the speakers are in front of you as well. Of course, there will be direct and indirect sound. The same is true in your audio room. Therefore, by running all channel stereo you are creating something that isn't as it would be in a live performance.

    Again, not as it would be in a live performance.
     
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  4. quicksrt

    quicksrt Senior Member

    Location:
    Los Angeles
    I have a question for you, do recordings have "imaging" engineered into them?

    Of course they do. A left to right spacial image. A set of rear speakers does not harm this imaging. It's not something created in the room as you earlier implied, it's in the recording. We as listeners are welcomed to enter this sound field - the stereo image.

    And no wrong again (I'm sorry), a group of musicians is not always in front of listener. Sometimes a listener is on stage with the group. Sometimes the listener is actually playing in this group. There are not set rules on how the imaging is executed in a stereo recording. Four speakers lets the listener climb into this image and leave the room size and specs out of the equasion.

    I doubt you'll be able to agree with anything here but it needed to be said. The fact that four speakers can put the listener inside of the stereo image much like headphones do.
     
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  5. SandAndGlass

    SandAndGlass Twilight Forum Resident

    Live performances have P.A. systems that, while generally having left an right channels on the mixing board's, are generally mixed in mono.

    This being due to the fact that not everyone is seated directly in front of the stage.

    The audience on the left side of the stage wants to hear everything on the stage, not just what is happening on their side of the stage.

    This same is true for the audience on the right side of the stage.

    There is no imaging in a mono mix, never has been, never will be.

    In recording studio's, instruments are generally recorded with an individual microphone or multiple microphones.

    Basically each instrument or instruments that are recorded that way are captured on a individual mono channel or channels.

    When "mixed" into stereo, the original signal(s), being mixed are not from a stereo source, Being that there is no original stereo source, there is no "real" imaging that is being captured in the first place, no real room ambiance.

    The "stereo" recording that you are hearing is actually a "panned" monaural signal, with all "imaging" being artificially created.

    In other words "fake". Which is fine, but let's call it what it really is. A recording studio is to audio, what Industrial Light and Magic is to movies.

    In most rooms at home, a stereo is almost never set up so that it will be optimum for the reproduction of imaging.

    Which means, that you will need point source speakers (or speakers which have the tweeter's and mid frequencies at or about head level).

    Then, both pairs of speaker's need to positioned for optimum placement to the listener. This includes at least 4' - 6' distance away from any room boundaries (rear and side walls, ceiling and floor). The listener will also need to be positioned at the precise distance away maybe sitting on a stool, away from boundary walls and reflections, and so that the direct sounds engulfing the listener are not being interfering with by the surroundings.

    The listener will not be seated sunken into a comfortable sofa, no coffee table for a drink, maybe a cup holder attached to the stool?

    Listen, if you want imaging, some sacrifices must be made for audio's sake. Oh, and no turning your head!

    You talked about having two speaker's for home audio reproduction and have mentioned both direct and reflecting sound (in the context of a live performance).

    In a home settings, reflections are not necessarily bad. If you are in a room, there will be natural reflections.

    Reflections fill out the sound within a room and create a wider sound stage. The problem is, room reflections will reduce "imaging", so it is a trade off.

    If "imaging" is all that precious, how come I am not seeing pictures of member's rooms, where their systems are not set up in a similar manner that I have described above, to produce the optimum imaging?

    I do give some of our member's member's credit that is due them. They are those member's who who have the listening "chair", which is positioned at the optimal point in their listening room's for the best imaging.

    Of course, some member's do pump sound into their rooms and actually get up and walk around and are otherwise mobile, while listening to their music. That is all well and good and more representative of the real world. Of course, imaging has now been thrown out the door.

    Here is the funny thing. If you are going to get up, walk around in the listening room. A room with multiple stereo speakers, will give you a more enhanced effect as to variations of sound. Every where you walk, stand or face, the sound will be different, due to the proximity of the different speakers and their placements within the room.

    I actually have people do this, during demonstrations that I give to my guests.

    If someone wants to use two speakers and they feel that is their preferred manner to listen to music in their rooms, I think that is perfectly fine.

    Likewise, if people choose to listen with multiple speakers in their audio rooms, that also is perfectly fine.

    I don't think that either way, people should be lectured on the "correct" method to listen to audio.

    Listening experiences are, by their nature, completely subjective.

    Likewise, from my standpoint, it is incorrect to comment on how another person's audio system sounds, not having been there and experiencing it first hand.

    S&G
     
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  6. F1nut

    F1nut Forum Resident

    Location:
    The Mars Hotel
    You guys keep trying to convince yourselves, but it's still a mess of sound.
     
  7. SandAndGlass

    SandAndGlass Twilight Forum Resident

    Oh come on, I can understand that it can certainly be a mess of sound.

    I also get the part that most people would no recognize what good sound is, if it kicked them in the back side.

    But, being that there are three (actually four with the Zu's) system's in the room and I can run any of them independently of any other of them for that perfect two speaker stereo sound, and I do. Sometimes I only run the front mains, sometimes only the rear towers.

    Sometimes only the all tube A7 system.

    This is not something that was hastily thrown together, rather it was something that was five years getting to the point that I had it.

    If I thought that using only a single pair of speakers sounded better, than I would use only a single pair of speakers.
     
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  8. Frost

    Frost Forum Resident

    Location:
    Chicago
    threads like this make me understand why you cannot trust online reviews of audio equipment. Theres people who arent 19 who think putting more speakers in a room running the same stereo signal makes for better audio. Ugh. Ever see 4 speakers in a recording studio all playing the same time? how about a mastering room? Now, I wont argue that the user putting 4 speakers in a room might not enjoy it and have fun so if so, go crazy and have fun, experiment, and enjoy learning. However its the wrong way to do things and will hold back your stereo image, depth, and likely evenness of sound as it changes at every seat from comb filtering.
     
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  9. SandAndGlass

    SandAndGlass Twilight Forum Resident

    There are actually people who are not nineteen and do know and recognize what good sound it and understand what it is to put together a system that has good sound and multiple speaker's.

    Sounds like you have been keeping up on your reading?
     
  10. dennis1077

    dennis1077 Forum Resident Thread Starter

    Thank you for the detailed response. Still not sure I grasp this but it's processing.

    The following quote seems to hold my answer. I'm not educated enough to understand basics like running speakers in parallel.

    "You don't have to connect up two speakers that are of the same Ohm's, having different Ohm rating doesn't make any difference. What does make a difference, is that if you connect an 8-Ohm speaker in parallel with a 6-Ohm speaker, the resulting load will be 3.42-Ohms."

    Let's say I hook up two 8-Ohm speakers to the Speaker A terminal. I then hook up two 4-Ohm speakers to the Speaker B terminal. I then play all four speakers at the same time. Would this be running speakers in parallel?

    The manual DOES warn against using using speakers under 8-Ohm when playing all four speakers simultaneously.
     
  11. 62caddy

    62caddy Forum Resident

    Location:
    PA
    The answer to the first part is yes and the combination of 8 & 6 ohm speakers will result in a 3.42 load which is probably pushing the limits of your amplifier. However, do keep in mind it's also relative to the amount of power the amplifier being asked to supply - meaning at lower/moderate listening levels, there may never be a problem running both pair. The manufacturer is rightfully erring on the side of caution in advising against running into an output impedance below 4 ohms.

    Even that that, there is still every possibility of the amplifier shutting down if run for prolonged periods at full output into 4 ohms. It's not as if something suddenly happens at 4 ohms that doesn't occur at 3.42. It's a function of average volume level (output) and duration, as well as load. When the load is greater (lower impedance), you have to give in on combinations of the other two.

    Just run things normally but monitor the heat from the unit. If it's getting excessive, either shut down one pair of speakers or lower the volume.
     
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  12. SandAndGlass

    SandAndGlass Twilight Forum Resident

    You don't have to run two speakers that have the identical impedance. You do have to calculate the overall impedance, as I did, using your speakers as an example.

    There are typically two different ways to hook up a pair of speakers, in series or parallel.

    Two 8-Ohm speakers hooked up to speaker A terminal in series would be 16-Ohms, while the same two speakers hooked up in parallel would be 4-Ohms.

    Two 4-Ohm speakers hooked up to speaker A terminal in series would be 8-Ohms, while the same two speakers hooked up in parallel would be 2-Ohms.

    We know that when your amp is using both pairs of speakers A & B, that your amp is hooking them up in parallel.

    So, If you were to take the two 8-Ohm speakers hooked up in series to speaker A terminal and the the two 4-Ohm speakers hooked up in series to speaker B terminal, you would have a load of 12-Ohms overall, which would be OK.

    Now try the same math yourself figuring out the total load of the same speakers all hooked up in parallel.

    Hint, you will be calculating the load of 4-Ohms in parallel with 2-Ohms, using the same math as I did in my example.

    So it would be written as 1/4 (Ohms on speaker A terminal) + 1/2 (Ohms on speaker B terminal) = 1/RT, the you solve RT.

    OK, I'll help...

    1/4 = .25 and 1/2 = .5

    .25 + .5 = .75

    1/.75 = 1.33 Ohms = VERY BAD!

    It all depends how you hook up your speaker's. :)

    P.S., don't blame me, I did not invent this stuff!

    One way works, the other way dos not.
     
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  13. Dillydipper

    Dillydipper Space-Age luddite

    Location:
    Central PA
    I've got Alexa in the next room babbling at me, something about why she can't play the Spotify. Mono's comin' out of two speakers on the teevee...and it's a news channel. And there's a recording on the speakerphone on my cordless totally ignoring me as if I had any reason to pay attention to a phone call I can neither interect with, or instruct to remove my name and number from its' list. So, that's four speakers.

    No sir; I don't like it. :mad:
     
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  14. The FRiNgE

    The FRiNgE Forum Resident

    Why does quadraphonic sound fantastic? Each speaker produces a different set of instruments and/or vocals. These mix very nicely in the listening space. Why does two channel stereo through 4 speakers not sound fantastic? Two speakers produce the same instruments and/or vocals. It sounds bad! The timing cues become smeared, the audio signals do not mix well in the listening space, and tonality corrupted by comb filtering. Anyone not familiar with comb filtering, and how fatiguing it is, and bad sounding, please look it up. Don't connect 4 speakers on a 2 channel system in the same room. It's a mistake on many levels.
     
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  15. SandAndGlass

    SandAndGlass Twilight Forum Resident

    No, it is not.
     
  16. 62caddy

    62caddy Forum Resident

    Location:
    PA
    Respectfully disagree that excellent results cannot be obtained from multiple pairs of two channel speakers used simultaneously in the same listening space and the negative effects of comb filtering are greatly overrated.

    While there may be some penalty to imaging, the benefit of spreading amplification across multiple pairs of speakers carries no small advantage- namely higher SPL with lower distortion, larger coverage area and extended LF response. Of course, this depends on the configuration of the room, speaker placement and the selection of the speakers themselves, as not all speakers necessarily work well together.

    If done right, the improvement from multiple pairs of speakers can be dramatic, IMHO.
     
    Last edited: Dec 26, 2018
  17. SandAndGlass

    SandAndGlass Twilight Forum Resident

    And the key words are...

     
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  18. harby

    harby Forum Resident

    Location:
    Portland, OR, USA
    Two 8 ohm speakers at the same time = 4 ohm load. The one pair of 6 ohm speakers make this an even more challenging load. Use the switch as recommended to avoid blowing up the amp.

    You'd think with two sets of speakers, you'd get the "average" of the sound signatures of both speakers. What hasn't been mentioned is the efficiency and sensitivity difference between the speakers. You may end up with one set of speakers barely contributing to the sound you hear.

    Additionally, there will be phase response differences that will add to the already problematic phase cancellations from having two sets of uncoordinated tweeters going. You may have serious irregularities in the frequency response, frequencies where the additional woofers are cancelling instead of adding, and where moving your head around is enough to affect the sound each ear hears.
     
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  19. Bill Mac

    Bill Mac Forum Resident

    Location:
    USA
    If one wants to use four speakers in a room for two channel music that's cool with me. But it's not something that I would do. I have a decent system including nice speakers and very much enjoy two channel music playing in front of me as if it was a live performance.

    With that I have a full 5.1 system that sounds excellent for multichannel music. I'm listening to Donald Fagen's Kamakiriad DVD-A in 5.1 as I type and it sounds great. But for listening to two channel music especially jazz I much prefer using just my front speakers. It's all a matter of preference with no wrong or right way IMO :).
     
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  20. Thomas_A

    Thomas_A Forum Resident

    Location:
    Uppsala, Sweden
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  21. SandAndGlass

    SandAndGlass Twilight Forum Resident

    OMG! All that terrible stuff will happen!

    Or the OP could stop worrying about the impending doom, that he and his system that surely faces and just take a piece of wire, hook them up and listen and see what actually does happen?

    [​IMG] How about if we don't use the two different sets of speaker connectors and wire both speaker's to a single pair of connectors, in series. See the diagram above. This is not difficult to do. A a degree rocket science is NOT a requirement.

    Just place your speaker's close together when you try and connect them together like this.

    For each side, use your existing long speaker wire and connect one wire to the + connector on one speaker box and one wire to the - connector on the other speaker box.

    Cut yourself off about a yard of speaker wire or electric lamp cord, rip it apart down the middle, so you have two separate pieces of wire. Connect one to the open + terminal of the one speaker cabinet and connect the other end to the - terminal of the other speaker cabinet.

    Save the other individual piece of wire for the other pair of speaker's and do the same with that pair.

    After completing this task, you will now have wired your two speakers together in series.

    An 8-Ohm speaker wired in series with a 6-Ohm speaker is a total of 14-Ohms, which will be easier on your amplifier than driving either the 8-Ohm or the 6-Ohm speaker by itself.

    No need to bother with the "switch".

    Your amplifier will not blow up and the sun will not go dark (not for a few more years anyway).

    You will now be running both sets of speakers with your receiver.

    See how you like them.

    My prediction is that running both pairs of speakers, will yield a larger fuller sound in your room.

    If, for some reason, you do not care for the sound of running two speakers, remove the jumper wire between the two speaker cabinet's and switch one wire of your main speaker wires to one speaker cabinet or the other.

    Life will continue...
     
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  22. 62caddy

    62caddy Forum Resident

    Location:
    PA
    In theory, the bumble bee should not be able to fly. So sometimes it is better to be a bumble bee than a theorist...
     
    Last edited: Dec 27, 2018
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  23. harby

    harby Forum Resident

    Location:
    Portland, OR, USA
    That will not give you good sound, or even allow you to evaluate what it might sound like when connected properly. I'll just quote:

     
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  24. SandAndGlass

    SandAndGlass Twilight Forum Resident

    While I do prefer to connect two speakers together in parallel.

    His amp is not really all that powerful, nor is the OP likely to be too experienced at connecting up multiple speakers to a single amp.

    So I thought that I would suggest starting him out with a serial connection, just to give him an idea.

    There you go with what is "proper".

    There is nothing improper in connecting two speakers in series. Given the OP's amp and the outside possibility that it might just "blow up", I figured that this might be a bit more on the safer side.

    We certainly don't want exploding amps! Good golly no.

    The little series speaker connection diagram is one I found on a web site "Wiring Diagrams | Eminence Speaker ".

    They manufacture speaker's. Perhaps you may want to contact them about their improper method of wiring a speaker?
     
  25. harby

    harby Forum Resident

    Location:
    Portland, OR, USA
    Eminence drivers are not generally found in a dissimilar mix of full-range loudspeakers with crossovers.

    They are used in complements with identical drivers, such as in this 4x12 guitar cabinet:


    [​IMG]

    Somebody wiring a Marshall stack may indeed employ a series+parallel configuration, and need the guidance offered there.
     
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