Can I run 4 ohm and 8 ohm speakers on the same receiver?

louhamilton
louhamilton Posts: 209
I have a sony STR-DE675 reciever that runs an 8 ohm Sony 5.1 satellite system. I was planning on upgrading the speakers first to LSi's and then upgrade my reciever to a Denon down the road.

I just realized that the LSi's are 4 ohm speakers.

What outcome will I experience if I get an LSiC and/or LSi9 first and run them with my 8ohm Sony surround speakers? Will I need to re-look my speaker thoughts and go with the RTi's at 8 ohms?

Thanks,

-Lou
Post edited by louhamilton on

Comments

  • steveinaz
    steveinaz Posts: 19,538
    edited October 2005
    I don't think its ever a good idea to run 4 ohm speakers off a receiver. 99.9% of receivers out there just don't have a robust enough power amplifier section to do 4 ohm speakers justice, especially lower efficiency 4 ohm speaks. But that's just my opinion.
    Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
  • reeltrouble1
    reeltrouble1 Posts: 9,312
    edited October 2005
    If you are thinking in terms of HT the RTi line are made for this, RT means Reference Theater. For music well, lots of debate, but I like the LSI over the RTi all day.

    That little Sony will not like the 4 ohm loads of the LSI line, at the least you will wont have enough current to really make them sing, at the worst you will damage your receiver and speakers.

    RT1
  • Tritonman
    Tritonman Posts: 159
    edited October 2005
    The Sony is capable of pushing 4 ohm loads, and supposedly is rated full power at 100w @4ohm per channel.

    But..as people have stated above..its not a good idea. You would require more power than the receiver can deliver to fully appreciate the line of speakers...also at the risk of blowing the speakers due to distortion based on insufficient amperage as well as damaging your receiver in the process.

    You also do not want to run a mixed ohm environment as the 4ohm speakers will be louder than the 8ohm.
  • reeltrouble1
    reeltrouble1 Posts: 9,312
    edited October 2005
    Power actually Current is going to be your problem, just not enough electrons dancing down the pipe.

    Mixing speaks well its funky but OK, you will need to calibrate with a sound meter, but you still are going to have a current problem, dont think watts think current. You want a high current amplifier.

    RT1
  • McLoki
    McLoki Posts: 5,231
    edited October 2005
    I called Onkyo about this when I was purchasing my LSi's. They said that I could run a 4 ohm load (but it is not officially recommended) but I should not put different ohm speakers on different channels.

    I called Cinepro after I got my amp and asked the same question and they said I could hook up anything I want anywhere I want with no issues. (2 ohms on up)

    Based on this response I would say it just depends on the quality of the amplifier you are running. Without knowing for sure, I would bet your sony is alot closer in quality to my Onkyo AVR rather than my Cinepro amplifier.

    Michael
    Mains.............Polk LSi15 (Cherry)
    Center............Polk LSiC (Crossover upgraded)
    Surrounds.......Polk LSi7 (Gloss Black - wood sides removed and crossovers upgraded)
    Subwoofers.....SVS 25-31 CS+ and PC+ (both 20hz tune)
    Pre\Pro...........NAD T163 (Modded with LM4562 opamps)
    Amplifier.........Cinepro 3k6 (6-channel, 500wpc@4ohms)
  • MacLeod
    MacLeod Posts: 14,358
    edited October 2005
    Agreed^^^

    Ohms are only a measure of resistance and an amp needs resistance to hold it back otherwise itll make 100% power which will quickly overheat it and quite possible kill it.

    A better built amp will handle the power itll make with less resistance like 2 ohms where a cheaper amp will fry itself with anything less than 8 ohms to hold it back. So like McLoki said, you pay more for an amp itll be built better and stronger and able to handle making more power, i.e. lower impedance speaker loads. You pay less and get the cheap amp it wont have the durability or build quality to tackle anything lower than 8.
    polkaudio sound quality competitor since 2005
    MECA SQ Rookie of the Year 06 ~ MECA State Champ 06,07,08,11 ~ MECA World Finals 2nd place 06,07,08,09
    08 Car Audio Nationals 1st ~ 07 N Georgia Nationals 1st ~ 06 Carl Casper Nationals 1st ~ USACi 05 Southeast AutumnFest 1st

    polkaudio SR6500 --- polkaudio MM1040 x2 -- Pioneer P99 -- Rockford Fosgate P1000X5D
  • Eric W
    Eric W Posts: 556
    edited October 2005
    You can mix various speaker impedances on the same receiver, however I'd be concerned that Sony receiver does not have the current capable of driving the LSi (the 9's particularly) to a loud enough level.
    -Eric
    -Polk Audio