Does this look right?

CH46ECH46E Posts: 581
Im trying to wire up 3 single voice coil 4 ohm subs on one channel. If i can get 2.7 ohms like this pic shows ill be good to go.

This look accurate? And would all three subs receive the same amount of power? Ok to put them in one ported chamber?

dofrat9ur10c.png

Comments

  • FestYboyFestYboy Posts: 2,525
    Ok, so sub 1 and 2 make an 8 ohm load that is then paralleled to another 4 ohm load... To me that becomes something like a 5.x ohm load.

    I could be wrong though.
  • mhardy6647mhardy6647 Posts: 18,397
    It is as the Yboy says in principle, although I think he slipped a digit someplace doin' the arithmetic :(
    Ohm. He is the Law. B)

    dofrat9ur10c.png

    Resistances (or Impedances)* in series are additive.
    Rt = R1 + R2 + ...

    Resistances (or Impedances) in parallel follow a rule like this:
    1/Rt = 1/R1 + 1/R2 + ...

    In the illustrated case: R1 and R2 are in series, so Rt for those two is 8 ohms.

    R3 is then wired in parallel to (R1 +R2), so, in this case:

    1/Rt = (1/8 + 1/4)

    1/Rt = 3/8

    Rt = 8/3 = 2.67 Ohms

    _________________
    * Voice coils passing AC waveforms (music!) are reactive devices and as such the parameter of interest is impedance as opposed to resistance (which applies only to DC circuits or those without inductive or capacitive components). Technically, impedance is called Z and resistance is R, but both quantities obey Ohm's Law :)
    "It's like watching a roomful of people who couldn't get through college algebra discussing the flaws of quantum physics theory. I guess it could be fun, but it's ultimately a waste of time." -- seen on audiokarma

    "Some amps run on self bias, some amps run on fixed bias. But his amps run on confirmation bias." -- seen on audioasylum

    "Writing about hifi is like dancing about architecture" -- paraphrasing some wag (possibly Frank Zappa)
  • FestYboyFestYboy Posts: 2,525
    When the doctor speaks, knowledge is bestowed. I neglected the least common denominator (derp).
  • mhardy6647mhardy6647 Posts: 18,397
    Well, you know what they say:
    Give a man a fish, and he is fed for a day.
    Teach a man to fish, and you won't see him for the rest of the weekend.
    "It's like watching a roomful of people who couldn't get through college algebra discussing the flaws of quantum physics theory. I guess it could be fun, but it's ultimately a waste of time." -- seen on audiokarma

    "Some amps run on self bias, some amps run on fixed bias. But his amps run on confirmation bias." -- seen on audioasylum

    "Writing about hifi is like dancing about architecture" -- paraphrasing some wag (possibly Frank Zappa)
  • CH46ECH46E Posts: 581
    Well, after looking at all the specs for the class d amps i was looking at, i think i just need to source one more driver and make it 4 and just run two 2 ohm loads.

    Thanks for the ohms law lesson!
  • mlistens03mlistens03 Posts: 1,405
    CH46E wrote: »
    Thanks for the ohms law lesson!

    Ditto!
    2 channel
    Speakers: Mission 770 Freedoms
    Integrated amp: Technics SU-v75 and matching tuner
    CDP: Technics SL-PC20
    Cables: Monoprice, Monster, Acoustic Research, and a few generic ones
    TT: Technics SL-3200, direct drive
    Cartridge: Shure M97xE

    Pc gaming setup
    Receiver/amp: Yamaha RX-V665
    Computer: Lenovo g50 (soon to be upgraded to a Dell Precision 690 which is far from stock!!)
    Interconnects: Amazon basics HDMI, Acoustic Research HDMI, Monoprice speaker cables
    Speakers: Boston Acoustics CR75s

    Random equipment on standby:
    Onkyo TX-v940, JBL woofers and tweeters, single Klipsch KG .5, Yamaha guitar amplifier, Peavey Rage 158 guitar amplifier, Kicker comp 12” subwoofer, single Bose 802 series II, a whole bunch of 1”-3” full range drivers, Infinity Crescendo 3007s (on sale), Polk LSi25s
    txcoastal1 wrote: »

    You don't tell her you read the manual, and you tell her you know what the problem is, and you fixed it, because that what men do, fix things
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