1. Welcome to TalkBass 2014! If you're new here, we just went through a major site upgrade. Please post all concerns and bugs to the Forum Usage Issues forum. We will be monitoring that forum. Thank you for all of your feedback.

    The TalkBass iphone/android app is NOT WORKING currently. We're working on it. Tapatalk IS working, so if you need to use an app, use Tapatalk. Try using your browser though - TalkBass is now 100% responsive to your phone/tablet screen size ;)

    Please read the TalkBass 2014 FAQ for lots of great info on the new software.

oh my Ohms are tired

Discussion in 'Amps [BG]' started by muddpuddle, Dec 22, 2013.

  1. muddpuddle


    Mar 5, 2012
    Likes Received:
    Can anybody help me understand amps and ohms

    I have an old peavy head that's rated 210 amps at 2 ohms. What would be the result of playing through a single 8 ohm speaker
  2. B-string

    B-string Supporting Member

    Nov 21, 2008
    Likes Received:
    I'm sure you meant 210 WATTS not amps. Being a SS amp, use of an 8 ohm speaker would just mean it will produce much less wattage from the amp.

    The "Stickies" are chocked full of ohms/wattage info.
  3. beans-on-toast


    Aug 7, 2008
    Likes Received:
    Oh my is right! That would be 88,200 watts. I figure that you'd probably blow your speaker.

    First step in answering your question is to know what model amp you have.
  4. swamp_bass

    swamp_bass I love it when a groove comes together Supporting Member

    Nov 20, 2013
    Likes Received:
    The general rule is that an amp's output will be half at double the speaker impedance. Many amps aren't quite linear that way, but it's a good general way to approximate.

    So 210 Watts into 2 ohms becomes:
    * 105 Watts into 4 ohms,
    * 60 Watts into 8 ohms.

    Many amps deviate from that general rule. Often amps that are "stable to 2 ohms" use active current limiting at 2 ohms that limits power to approximately the same output as 4 ohms. If that's the case, then your output into 8 ohms would be more like 100 watts.

    So somewhere between 50 and 100 is the ballpark.
  5. nashvillebill


    Oct 13, 2002
    Likes Received:
    That series of Peavey power amps is rated:

    210 watts into 2 ohms at 1% THD
    140 watts into 4 ohms
    80 watts into 8 ohms

Share This Page