Impedance setting on AVR

Greetings, I picked up a pair of MXT70s for my front mains on a 7.2 system. The sticker on the back of the cab and the instructions for the speakers say the recommended setting on the amp should be set to 4ohms. My receiver does have an impedance setting in the menu but the instructions are unclear.

I have 2 12" Klipsch self powered subwoofers, which I assume have no effect because they have their own amps. I also have Klipsch center and 2 pairs of surrounds all rated for 8ohms. The setting in the AVRs menu looks like it applies to all the speakers because I have no options that I can find to set any of them individually or in pairs based on their intended use from the amp.

I was just on the Polk website registering the speakers and the specs section says they are set up to work on any amp from 4 to 8ohms. I know some of the more simple impedance rules for setting up subwoofers in car audio but that's just basic easy stuff with 1 or 2 mono amps and 2 to 4 (4 to 8 if DVC) or stereo amps etc. but it's simple because its all either adding or dividing in "blocks"; 1,2,4,8,16 ohms etc and either halving or doubling the power the amp(s) will be pushing accordingly. For some reason, even though home audio uses the same principles it confuses me because 6ohm loads and bi-wiring and bi-amping get thrown into the mix and I just haven't taken the time to sit down for a minute and figure it out.

I should understand it better because my last car install was in my Rogue with the Bose system and I had to basically reverse engineer it to make sure I was tapping the right wires to get the audio signal for my subwoofer amp without messing up the Bose DSP and **** up the entire system which is also tied into the Navi, cams, wheel controls, etc.

Anyway, if my thinking is right, where the specs on the site say the speakers are set up to work with either 4 or 8 ohm amps, I should just leave the AVR setting at 8ohms because I don't think that I want to let the Klipsch speakers have 4ohms to play with? Or is it like other electrical rules where the devices won't want any more than they will need? I'm asking because I know when hooking up drivers in car audio, it's not good to wire up the voice coils for a 1ohm load if the amp isn't rated for it and I'm bouncing that off my apparent mind block on this particular issue. My brain is saying that if I set the AVR to 4 ohms. the 8ohm speakers are going to be getting too much power, or not enough??? Grrrrr, I'm smart as a whip on some things but then something as seemingly simple as this will totally fry my circuits LOL. Any anfo/advise, etc is greatly appreciated and thanks in advance.

Comments

  • pitdogg2
    pitdogg2 Posts: 24,471
    edited December 2021
    Leave it set at 8 ohm.


  • tonyb
    tonyb Posts: 32,902
    yes, leave it set at 8 ohms. Changing it will only restrict current to your speakers.
    HT SYSTEM-
    Sony 850c 4k
    Pioneer elite vhx 21
    Sony 4k BRP
    SVS SB-2000
    Polk Sig. 20's
    Polk FX500 surrounds

    Cables-
    Acoustic zen Satori speaker cables
    Acoustic zen Matrix 2 IC's
    Wireworld eclipse 7 ic's
    Audio metallurgy ga-o digital cable

    Kitchen

    Sonos zp90
    Grant Fidelity tube dac
    B&k 1420
    lsi 9's
  • mhardy6647
    mhardy6647 Posts: 32,922
    edited January 2022
    tonyb wrote: »
    yes, leave it set at 8 ohms. Changing it will only restrict current to your speakers.

    ... and possibly save the amplifer section from immolation if asked to deliver more than that of which it's capable.
    Fortunately amplifiers R cheap nowadays. :#
    (Amperes aren't always so cheap)

    Just sayin'. ;)