adjustable 2/4 ohm amp...

Discussion in 'Audio' started by Troopie's Tonka, Aug 1, 2003.

  1. Troopie's Tonka

    Troopie's Tonka 1/2 ton status

    Oct 3, 2002
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    Aiken, SC
    ok, I have a linear power 150 watt amp(per channel). I can open it up and set it for 2 ohm or 4 ohm. Right now, I am using both channels to push 2 12's at 4 ohms. The speakers are single voice coil. I don't know the specs of the speakers, they are cheap lightning bolts from best buy. Can I run the speakers parallel, dropping the load to 2 ohms, and change my amp to 2ohms, then run them into a bridged channel? Is it better sending 150 watts to each speaker at 4 ohms, or running them parallel, and sending 300 bridged watts to them at 2 ohms? And the amp is not power regulated, whatever that means, I don't know.
  2. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

    Mar 5, 2001
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    Austin, TX
    Well.....I guess the simple answer is that there is no such thing as "free power"!!!

    The amp can only put out a fixed amount of power....the watts will change based on the ohm loading, but the resulting effect is the don't just "magically" get twice the power from an amp by dropping the ohm load.

    In FACT, when you start bridging channels and playing games with the ohm load you usually LOSE some power. Take a look at some amplifier spec sheets sometime....the "bridged" power number never seems to be EXACTLY double what the "per channel" power rating is.... there are some losses and inefficiencies when you re-configure amps like that.

    If you like the way the system sounds now, leave it alone. It's going to run cooler at 4 ohms and probably have lower distortion too......
  3. rampage

    rampage 1/2 ton status

    Mar 20, 2001
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    Humboldt/Pacifica, CA
    Also, no two speakers are identical, they each have their own characteristics including impedance. If you put the speakers in parallel then one will be driven harder than the other (the one with the lower impedance). This would be more evident with cheapo speakers. Amps also become more unstable with low impedance loads. Even though the amp says it can drive a 2 ohm load it is better to drive a high impedance load.

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