Stupid ohm question....

Discussion in 'Amps and Cabs' started by sfletch, Feb 12, 2008.


  1. sfletch

    sfletch Member

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    I know this is the place to get a quick answer to a stupid question from a non-technical guy like me.

    I have a 25-watt Bedrock combo...currently has an 8 ohm 100 watt Bedrock speaker....(is that overkill? by the way) At the average gig I'm running it at about 25% on the clean channel, and maybe 45% on the dirt channel.

    If I put a 16 ohm speaker in and run it off the 8 ohm jack, I'll lost some output right? So, does that mean I can run the amp closer to "all out" and get the same volume level?

    You see what I'm getting at...can I use a 16 ohm speaker to run the amp closer to a level where it will really be working hard and (hopefully) sounding a little more gutsy?

    I was thinking of a greenback....I thought the woodiness might tame some of the gnarly Bedrock treble....

    Thanks to everyone who knows WAY more than me about amps. Take it easy.

    SF
     
  2. Sean French

    Sean French Supporting Member

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    Going to a speaker with a lower sensitivity will not be as loud thus allowing the amp to be opened up more.A lower watt speaker would be a plus too IMO.Say a 50 to 65 watter.You should be able to mismatch the amp 2 to 1 but,I would stay with an 8 ohm speaker.A mismatch does not always sound good.
     
  3. trey85stang

    trey85stang Member

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    Some amps can handle a mismatch, it all depends on the output transformer. If it is overrated for the application it can probably handle it with no problems... Best to ask the maker/builder if it is safe or not.

    As mentioned above the lower sensitivity speaker route would be a better bet. Do you know what the bedrock speakers rated db level is?
     
  4. JimH

    JimH Member

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    SF - think you've got slightly the wrong end of the stick. This is not the way to go about running the amp higher. As the others said it's speaker sensitivity that's more important. It's the rating along with watts and ohms in the speakers spec sheet - usually 90 or 100 something dB. If the new speaker is -3dB less sensitive than the current speaker it will roughly equate to a 50% drop in watts.

    The issue of the speaker wattage rating - hmmm, well 100W is a little high especially if you run the amp quiet. But if you ran the amp flat out it may well have high peaks around 50. Although again, not a huge problem. - I guess perfect speaker for you (with that amp) would be 50-60W with lower sensitivity and maybe at 50-60W. But even if you find it you may not like how it sounds. Whether you like speakers or not is found out by your ears, not a spec sheet.

    ...I'm thinking this thread is leading towards attenuators..... I feel their presence....
     
  5. mc5nrg

    mc5nrg Member

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    Volume controls on guitar amps aren't high precision controls...45%, 25%.?..even if you don't have the controls dimed you may be using more of the amps available output than you realize.
     
  6. sfletch

    sfletch Member

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    All good tips...thank you thank you.

    The one thing I have some experience with that was mentioned is how an amplifier's volume control is not precise.....I guess I should say I'm running the volume knob at 25% or 50%....however imprecise that is. I have experienced turning an amp up and getting little more volume, but more compression and gain.

    I was trying to use the effects loop as a sort of attenuator...running the send flat out and the return at barely on....as someone once told me that this sort of acts like an extra gain stage with the return being like a master volume. I've also tried running all the EQ controls at a minimal setting so I could run the volume knobs higher....all this in hopes of the amp sounding less anemic at gig volumes. Feel free to tell me I'm totally misinformed on any of these things, I really don't know about amps, and none of these things produced the results I was hoping for. It seems like a really loud amp for its power and size....and it's hard to get out of the kind of wimpy sound region at club volume.

    Lately my solution is to just run an RC booster with a little grit at all times. I am using pretty low-output single coils for most of my playing. Yeah a Les Paul would sound fatter at any volume, but....

    Thanks for the tips. Any good attenuator experience/suggestions?
     

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