receiver @ 8 ohm w/ power amp running at 4 ohm??

Discussion in 'Archived Threads 2001-2004' started by Antlue, Mar 27, 2002.

  1. Antlue

    Antlue Auditioning

    Joined:
    Jan 9, 2002
    Messages:
    6
    Likes Received:
    0
    Trophy Points:
    0
    I have a Yamaha RXv-3000 - running at 8 ohms right now. Will be getting Martin Logans for front L&R which requires amplification @ 4 ohms. although the Yamaha has a switch selector for both 4 & 8 ohm loads - I am not comfortable running the Yamaha at 4 ohms (I have 8 ohm B&W rear surrounds and rear centre) - I hear the current draw from the larger ML's might be too much for a receiver. So does anyone out there have a similar setup where you are using a receiver @ 8 ohms and an outboard power amplifier from the mains preout running @ 4 ohms (if that is possible). Some body help!!!!!! Is there a problem with this setup??
    thanks. [​IMG]
     
  2. Chris PC

    Chris PC Producer

    Joined:
    May 12, 2001
    Messages:
    3,975
    Likes Received:
    1
    Trophy Points:
    0
    Lots of people here do exactly that. If you set the receiver to 4 ohms, you will get less power from it, but you will prevent clipping and blowing your amp so your thinking is about right. All you need is a robust stereo amp. Regardless of current, even if your speakers were 8 ohms, you'll get improveed sound quality at least somewhat above the receivers amp sound quality.

    Sure, get an outboard 4 ohm capable stereo amp that has at least the watts per channel of the Yamaha 3000. Say a 100 to 150 watts per channel into 8 ohms amp that handles 4 ohms.
     
  3. jason celaya

    jason celaya Stunt Coordinator

    Joined:
    Jul 1, 2001
    Messages:
    143
    Likes Received:
    0
    Trophy Points:
    0
    I do the exact same thing, i have a denon 3802 w/ a 2 ch denon 5200. all three of my fronts are 4 ohm M&K, It works great , however I do wish I bought a three channel amp in the front just for piece of mind.
     
  4. Arthur S

    Arthur S Cinematographer

    Joined:
    Jul 2, 1999
    Messages:
    2,568
    Likes Received:
    0
    Trophy Points:
    0
    If you are saying you will not be using the front amp channels of the Yamaha to actually drive speakers, but just using the mains pre-outs, I would leave the switch at 8 ohms so their is ample juice for the speakers that are being driven by the Yamaha. The pre-outs will be the same whether you have the switch at 8 or 4 ohms. I am using a somewhat similar arrangement with my receiver only driving the center and perhaps the surrounds. My mains are connected to a 450 watt per channel amp. I have always left the 8-4 ohm switch in the 8 ohm position. Why cripple the receiver if it is well ventilated and doesn't get real hot?

    The Martin-Logan 'stats can be a difficult load. You will want an amp that is very stable into 4 ohm loads with at least 150 watts per side.

    Artie
     
  5. MichaelGomez

    MichaelGomez Stunt Coordinator

    Joined:
    Oct 4, 2001
    Messages:
    134
    Likes Received:
    0
    Trophy Points:
    0
     
  6. Pete Gia

    Pete Gia Stunt Coordinator

    Joined:
    Mar 18, 2002
    Messages:
    87
    Likes Received:
    0
    Trophy Points:
    0
    I agree with most of the other posters. Leave the switch at 8 ohms if you`re going to use an outboard power amp for your 4-ohm speakers;and I respectfully submit that there is NO WAY the cheesy amps that are most receivers will double their power into 4 ohms.-----Pete
     
  7. jeff lam

    jeff lam Screenwriter

    Joined:
    Jun 4, 2001
    Messages:
    1,798
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    San Jose, CA
    Real Name:
    Jeff Lam
    If you are using an external amp, the ohm switch on the Yamaha means nothing. I would suggest using seperat amplification for the ML's anyway. The ohm switch has nothing to do with the pre-out's on the receiver, only the power amp section(actual speaker driving section of the receiver).
     
  8. Wayne A. Pflughaupt

    Moderator

    Joined:
    Aug 5, 1999
    Messages:
    6,207
    Likes Received:
    56
    Trophy Points:
    9,110
    Location:
    Katy, TX
    Real Name:
    Wayne
    Michael,
     
  9. MichaelGomez

    MichaelGomez Stunt Coordinator

    Joined:
    Oct 4, 2001
    Messages:
    134
    Likes Received:
    0
    Trophy Points:
    0
    Pete-here is how it works. Notice I said "almost double your power." In a hypothetical situation, it would double. It is Ohms law.

     

Share This Page