1. Attachments are working again! Check out this thread for more details and to report any other bugs.

2015 non-JBL. Front 6x9 and squaker=4 ohm or 2 ohm?

Discussion in 'Gen 3 Prius Audio and Electronics' started by E46Prius, Aug 22, 2015.

  1. E46Prius

    E46Prius Active Member

    Joined:
    Aug 3, 2015
    314
    218
    0
    Location:
    Costa Mesa
    Vehicle:
    2015 Prius
    Model:
    Three
    I have a Kenwood 2-channel 60w rms amp and Polk DB651 (also 60w rms) ready to go in to power my front speakers off the stock non-JBL navi HU. My friend says the front speakers will be 2OHM as the dash speaker is in line with the door speaker. If this is true, this would put too much strain on the amp and overheat it. Ive read online that the way the Prius is that the front speakers act as components so are true 4 OHM even though they are wired in line with eachother. Will I be safe installing my amp? I will use the stock dash speakers for now and might upgrade later. The other option would be to disable them altogether
     
  2. frodoz737

    frodoz737 Top Wrench

    Joined:
    Aug 26, 2010
    4,297
    2,347
    33
    Location:
    Texas
    Vehicle:
    2015 Prius
    Model:
    Four
  3. lopgok

    lopgok Member

    Joined:
    May 2, 2012
    177
    29
    0
    Location:
    unknown
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    There is no really simple answer.

    The 2 speakers are in parallel. The dash speaker has a small capacitor in series with it, which will greatly increase the impedance at lower frequencies.

    I have no idea what the impedance vs frequency is for the 2 OEM speakers, nor have I seen any published numbers. Putting the dash and front door speakers in parallel is pretty common with toyota, as my 2002 camry does the same thing.

    When I upgraded my dash speakers, I replaced the small capacitor with a much bigger one to allow lower frequencies to be produced by the dash speaker. I also added a 2 ohm resistor in series with the dash speaker and the door speakers. This way, the lowest impedance load should be 3 ohms, rather than the worst case OEM impedance of 2 ohms. People thought I was nuts, but I didn't want to break the OEM head unit, and resistors are cheap.

    If you break the pioneer amp, at least it will be cheap and easy to replace compared to the OEM head unit.
    I suspect it won't break as the pioneer amp is likely much better designed and robust than the OEM head unit.

    If you replace the dash speakers (and you should as they really suck), you might want to put some 2 or 4 ohm resistors in series with them. It turns out that the dash speakers have a much more direct path to your ears, and need less power (all other things being equal) than the door speakers.

    With my setup, I have each speaker being driven separately by my JBM MS-8 8 channel amp. I removed the capacitors and resistors I was using with the head unit, and turned doen the dash speakers a few db, which resulted in a more balanced soundstage.

    You should also replace the OEM door speakers as they suck too. See weasel.com: 2012 Toyota Plug in Prius Stereo for lots of pictures of the OEM speakers and my stereo build.
     
  4. rogan

    rogan Junior Member

    Joined:
    Aug 21, 2014
    50
    7
    0
    Location:
    Auckland, New Zealand
    Vehicle:
    2011 Prius
    Model:
    N/A
    And a 2 channel amp will usually be more than happy running a 2ohm load on each channel
     
  5. peterjsilva

    peterjsilva Junior Member

    Joined:
    May 30, 2016
    2
    1
    0
    Location:
    Monterey
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Advanced
    What were the specs of the resistors you used?


    iPhone ?
     
  6. lopgok

    lopgok Member

    Joined:
    May 2, 2012
    177
    29
    0
    Location:
    unknown
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    They were 25w resistors, which were $1 each at my favorite electronics store. 5w would be large enough...