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Playing 4 speakers at once

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

  1. SteelyNJ

    SteelyNJ Forum Resident

    New Jersey, USA
    The other car I had with a very high "fun factor" (but for completely different reasons) was a 1985 red mid-engine Toyota MR2!
  2. The FRiNgE

    The FRiNgE Forum Resident

    Looks like we've hijacked this discussion, very sorry, check out the sound of that exhaust! Two speakers, 4 speakers, closed box, ported, electrostatic or horns.. here is the quality sound of pipes decently recorded!
    SandAndGlass and SteelyNJ like this.
  3. classicrocker

    classicrocker Life is good!

    Worcester, MA, USA
    I had the same car. Little 1.6L engine that you had to rev the heck out of to make it go but man that car was tight and handled like a dream. Nothing could keep up with it on a winding road.
    SandAndGlass, The FRiNgE and SteelyNJ like this.
  4. SteelyNJ

    SteelyNJ Forum Resident

    New Jersey, USA
    Yes, but it had a super high "red line" so you could REALLY rev it and get some juice out of that little workhorse of an engine. I don't recall the exact horsepower rating but I believe it was under 120! Talk about a precise, tight, short-throw gear shifter and an easy clutch. That thing was a pure joy to drive!
  5. SandAndGlass

    SandAndGlass Twilight Forum Resident

    And, I suppose that was going uphill or downhill?
  6. SandAndGlass

    SandAndGlass Twilight Forum Resident

    I had a little white MR2 back in the 80's. It was a fun car to drive. It could out handle everything.
    SteelyNJ likes this.
  7. shokhead

    shokhead Head shok and you still don't what it is. HA!

    0-60 in 5.1 with no hill:agree:
    SandAndGlass and SteelyNJ like this.
  8. Bill Hart

    Bill Hart Forum Resident

    One of the fiercest exhaust notes I ever heard was a Ferrari 512 BB LM- these were dinosaurs, never raced officially by Ferrari, run by privateers- made in a series based off the 512 Berlinetta Boxer (a flat 12) that was never officially brought into the states as a street legal car, though they were homologated here by 3d party shops. (I had one of the stock not LM versions, funnest Ferrari I owned to drive). The LM was another animal though. It sounded like a screaming banshee on start up. These were huge, old fashioned cars, you still see them run at events like Goodwood, etc. Actually frightening when it was cranked up, and at full chat on a track, it had a glorious sound. (Not one of the Van Gogh level cars like the '50s and early '60s racers, and not modern, these were gettable by mere mortals not so long ago). Now, ?
    The FRiNgE, SandAndGlass and SteelyNJ like this.
  9. harby

    harby Forum Resident

    Portland, OR, USA
    Steering things back on course... I had four speakers at once in my Ford Taurus SHO (which also beats a GTO's 0-60 time of 6.7): Four 10" Kickers in an isobaric series-tuned 4-chamber 6th order box. Had to give it up, as it kept on blowing out the weather seal of the back window.
  10. SandAndGlass

    SandAndGlass Twilight Forum Resident

    Is there an English translation for this?

    I'm getting that there are four bass speakers... but the rest is alluding me?
  11. harby

    harby Forum Resident

    Portland, OR, USA
    This is the basics of the design, but two of these:


    The speaker chamber on the left is like a normal ported speaker. The porting there extends the low-frequency response further than most port reflex designs, though. Let's say it is tuned to 30Hz, for example. The port area in this alignment can sometimes take up as much volume as the enclosure itself to ensure low port air velocity at the low tuning.

    The chamber on the right, which actually tends to be smaller with a shorter larger port than the diagram, is tuned to a higher frequency, let's say 90Hz. The port is like a low-pass filter for the entire subwoofer output as well as increasing the Q around the port frequency.

    Isobaric - the speakers are ganged so they have twice the motor force, essentially allowing half the box space. When they are face-to-face and wired out-of-phase, non-linear excursion distortions from cone design are cancelled out.

    It is called a bandpass enclosure because of the built-in low pass filtering of the second chamber, which also serves to remove harmonic distortions and the first port's noises at frequencies above the design. Ridiculously efficient in the almost two-octave range.
  12. SandAndGlass

    SandAndGlass Twilight Forum Resident


    I have seen designs similar to this, using two driver's facing each other, and also various tapped horn designs, such as the one below.

    I didn't realize the part about the chamber's being two different sizes.

    This is my main sub, which is a 15" horn loaded sub is to the side of the left A7 cabinet. It is powered by a 1,600-Watt Crown XTi-2000 amp. It can produce a sustained SPL of 133 dB, continuous program material.


    Naturally, it can do what it was designed to do. But... I was considering some of the tapped horn designs or looking into some of these other technologies, because, at the time, I was considering to step things up a notch. Maybe a cabinet with dual 18's.

    Being that this cabinet is as large as it is, I would need to different approach for a cabinet with dual 18's, space wise.

    Even if, dual 18's were not logistically possible, due to physical size restrictions, a cabinet with dual 15's, would be the next best thing.

    I like that your "box" is small and "Ridiculously efficient in the almost two-octave range."

    I really can't stand how the majority of people integrate a sub at home. Even worse, is how an even higher percentage of them, integrate a sub in a car.

    I'm not arguing that there is not bass, just that I find their bass to be unpleasant and something that I personally cannot abide by.

    This design appears to be able to be able to deliver clean and accurate bass at high SPL's, properly driven.

    As to your SHO, it was a kick ass Taurus. I used to sell them back in the 90's. I remember that the engine was designed and built by Yamaha. It was a very fast car!

    So you had one of these boxes in your car, with four chambers and four speaker's? I can see where the sound pressure could blow out window seals.

    It's funny. You get into a standard 3.0L Taurus and it is a DOG! You drive one with the 3.8L engine in one, and it has decent performance. With the SHO, my main concern was for the compact transmission being to take the tremendous amount of torque that was generated by the Yamaha engine.

    It appears, that the window seals could not handle the "torque" from your subs. :)
  13. Tim 2


    Alberta Canada
    Kind of reminds me of an isobaric bandpass design.

    There's something about the deep rich bass from an 18" sub that even multiple smaller drivers can't match.
  14. SandAndGlass

    SandAndGlass Twilight Forum Resident

    Yes, 18" bass driver's in a nice bass cabinet can do wonderful things.
  15. shnaggletooth

    shnaggletooth Senior Member

    I'm trying out having a pair of Dynaco A25's set up with a pair of small JBL Control 25's placed between the two.

    Two sets of speakers, set up side-by-side, played simultaneously, with the receiver's A-B both switched on -- will this always be comb filtering?
  16. F1nut

    F1nut Forum Resident

    The Mars Hotel
  17. SandAndGlass

    SandAndGlass Twilight Forum Resident

    Yes, but it probably won't be something that you even notice.

    The simple question is, do you like the sound better with two set of speaker's playing or only one set playing?
    Hymie the Robot likes this.
  18. spj747

    spj747 New Member

    I run two pairs of speakers from a Creek 100A integrated amp. Dali Opticon 6s at the front and Zensor 7s to the side. Also have a Naim Mu-so on top of a cabinet between the Opticons, connected to the Creek's pre-amp out, which I sometimes add in as well - for an extra-layered sound. No doubt purists will cringe - but what matters is whether or not the sound is pleasing to the listener surely. I generally only use the front speakers on their own when I'm able & wanting to turn up the volume well up. I find I don't get a full enough sound on one pair alone at a low to middling volume. Asked Mike Creek about driving 2 pairs simultaneously and he said "No problem - what it's there for .. if the speakers match well & compliment each other - go for it." "If there are problems with the loading & impedance, the amp will run warmer than it should - just keep an eye on that."
    SandAndGlass likes this.
  19. ChefE

    ChefE Active Member

    Orange County, CA
    I have a Sony receiver that also has the switch for 8 ohm and/or 4 ohm speakers. What about my 6 ohm Valkyrie speakers connected to "speakers B" and "speakers A" connected to my 4 ohm Triad silvers or the 8 ohm Altec Model 14?
    The receiver owners manual says switch it to 4 ohm when the receiver is OFF. Turn on, then I can play speakers A and B together. Basically use 4 ohm setting when driving both sets of speakers in 2 channel listening. Adding a powered subwoofer to the 'Sub Out' supposedly takes some of the weight off the receiver's amplifier, therefore allowing it to focus on the 4 speakers.
    Personally I like listening to two sets of speakers when each adds to the overall listening experience. It's also handy to have two different pairs for the times when a lower volume is needed and a higher volume is needed. Such as 3am on a Wednesday living in a small apartment or on summer weekend day and no one is at your new house.....
    Just be conscious of the volume level, duration, air flow to the receiver, and your speakers ability to sound good--and your ability to know when they don't.
    Hope that helps some.
    SandAndGlass likes this.
  20. Henry J

    Henry J Forum Resident

    Asbury Park, NJ
    Sorry to bump this thread, but I cannot find my answer anywhere, and thought one of you fine folks can answer it.
    I have a preamp with 2 pre outs.
    Right now I have one output to my power amp driving my 8 ohm tower speakers.
    I want to add the option for a 2nd set of speakers.
    I will soon purchase a 2nd power amp for my 4 ohm book shelves.
    My question is,,,,,is it best to get the 2nd amp with a volume control to fine tune the volume?
    Or how also can I balance the volume with out a control?
  21. SandAndGlass

    SandAndGlass Twilight Forum Resident

    You can get a second amp with a volume control or you can get an analog remote volume control.

    The main central point of control in my system is provided by the Peachtree iNova. It is used as a source selector, ESS Saber DAC and Class-A SS preamp. All power amps are outboard.


    (The headphones are Hi-FI Man HE-400 planer open back headphones.)

    The iNova has a preamp out, which is controlled by the volume control and a line output, which is not.

    I split the preamp out signal using three pairs of RCA ''Y" adapter cables. One pair goes to the front main Emotiva 250-Watt XPA-2 (gen 1) power amp. The second goes to the surround sound processor for the sub. And the third pair goes into the Peachtree musicBox integrated, which is the small amp sitting on top of the iNova.

    I use this small amp for the headphones and also to control the volume of its preamp outputs. I run a RCA cable from this to the 50-watt SS amp that powers the rear speakers.

    I control the volume of the front mains using the volume control on the iNova. I use the volume control on the musicBox to control the rear volume, relative to the front volume.

    There are a third set of speakers, my vintage Altec Lansing A7's. The line output from the iNova goes to a tube preamp and then to a separate tube power amp.

    The preamp does have a volume control but it sits directly behind me and is not handy. What I do instead, is leave the preamp volume up and I have an analog (wired) volume control inline between the tube preamp and the tube power amp. That is the black self contained knob hanging over the rear of the sofa, in the photo.

    This places all three volume controls at my fingertips, where I can adjust all three systems individually, on the fly, to achieve the overall balance, when all three systems are playing from the same source. I can also play with just the front and rear SS systems.

    Just shows that there are a variety of ways to accomplish this.

    The room photos and the photos showing each rear tower is on page one of this thread.

    This is the old rear projection TV, which was replaced in the summer of 2017.


    The Emotiva XPA-2, 250-Watt 72-lb. SS power amplifier, is located on the bottom shelf below the TV, on the right side.

    The processor is an Emotiva MC-700 4K processor.

    Directly below the TV is the Oppo UDP-203 4K player, that is connected to the Emotiva processor via an HDMI cable.

    This is how it currently looks with the new TV.


    The Oppo is used as a transport for CD's, going digitally into the iNova, to be converted to analog by the ESS Saber DAC.

    To the right of the rear power amp is an Audio Electronics Constellation (a former division of Cary Audio) 6SN7 tube preamp.


    This is the 50-Watt rear power amp.

    The rear speakers are powered by the small SS Emotiva 50-Watt Fusion Flex amplifier with two inputs, one for stereo listening and the other for the HT rear channels.


    Both of these sit directly behind where I sit.
    Last edited: Feb 21, 2021
  22. quicksrt

    quicksrt Senior Member

    City of Angels
    I've found that I prefer the sound levels to be the same for each of the four speakers no matter where I am in the room. None of them drawing attention to the fact the four speakers are in use listening in stereo. It is simply more areas of the room are on axis. Its still stereo the same as before.
    SandAndGlass likes this.
  23. Classic Car Guy

    Classic Car Guy "catch me if you can..."

    Northwest, USA
    I remember the ads on that car. There was big billboard sign that says "The Fun is Back" it was a red MR2. The guy at the dealer ship asked me "are you ready for the '86?"
    Then I pointed out to the salesman.. "That car could have been instead of the Delorean" and I was pointing out on the Back to the Future billboard. Those were the days...:-popcorn:
    SteelyNJ likes this.
  24. SandAndGlass

    SandAndGlass Twilight Forum Resident

    I had a MR2 back around then. It was like having a minituature Ferrari. Hard to find a more fun to drive two person car.
    SteelyNJ likes this.
  25. SandAndGlass

    SandAndGlass Twilight Forum Resident

    That's really what I do. There is consistent sound almost everywhere you go, walking around the room.

    It has the benefit of being able to play music at a lower overall volume level and still having sound fill the room more evenly. This is something that cannot be accomplished with only two speakers.
    Tim 2 likes this.

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