Jcm 800 & Jcm 900 1x12 Combo Offset Speaker??

Discussion in 'Marshall Amps' started by JCMfan, Aug 7, 2017.

  1. JCMfan

    JCMfan Member

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    Hi, just curious as to why in both the JCM 800 & JCM 900 1x12 combo amps, the speaker is offset, making the body of the combo much wider than it needs to be?

    Was there a reason for this?

    I just recently picked up a JCM 900 1x12 combo, where the speaker is dead center (where it should be!!), and I'm now looking for a JCM 800 with the same centered speaker.

    Just wanted to know if there was differences of both these combos, and the reasons for having both the offset and centered speakers??

    Many thanks!!
     
  2. Yugedrums

    Yugedrums Well-Known Member

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    I have no idea, but I'm going to just throw out the first thing that comes to mind...

    Maybe it's because the amp chassis it'self is off balance and the speaker was placed on the other side to help balance the entire thing out...? I have no idea if this applies to the amps you're talking about, but I know my Marshall heads are heavier on the side with the transformers, etc and when I pick them up by their handles, they sag down towards that side.

    Purely just a guess though...
     
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  3. ampmadscientist

    ampmadscientist Well-Known Member

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    Sometimes if the power transformer is too close to the speaker, hum will come through the speaker from the power transformer magnetic field.

    (hum w/ standby in off position)

    But it does depend on the speaker...and sometimes the speaker frame is grounded to the chassis, to help reduce the hum.

    Sometimes the speaker is positioned away from sensitive parts of the circuit, like channel switching relays.
    The magnet of the speaker could make the relays stick...unless there was some type shielding added.
    I have seen this relay/magnet problem happen before.
     
  4. Yugedrums

    Yugedrums Well-Known Member

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    That sounds better than what I said. Let's go with that. :thumb:
     
  5. Jethro Rocker

    Jethro Rocker Well-Known Member Silver Supporting Member

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    I suspect it's a bit of both. The transformers on the 6101 are both on the SAME side for some reason making it side heavy and speaker is centered plus it does get some AC hum.
     
  6. JCMfan

    JCMfan Member

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    Thanks for the replies everyone.

    Just out of curiosity, has anyone seen a JCM 800 1x12 combo with the speaker centered??

    If so, anyone able to share links or pics or even the model number of them??

    Many thanks!!
     
  7. Limeshack

    Limeshack Member

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    Doesn't exist in the JCM 800 line. Both the 4010 and the channel switcher model are offset. I think the wider 1x12 cabs sound better personally.
     
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  8. JCMfan

    JCMfan Member

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    Is there any documentation from Marshall somewhere, that this is in fact true? Not that I don't believe you Limeshack, but i've heard that they exist in the JCM 800 line, and am just wanted to verify, one way or the other.

    It's a space issue for me, so I'm really loving the centered speaker on my JCM900 50watt. If it was true, i'd love to have a JCM800 50 watt 1x12 with centered speaker as well.
     
  9. Ufoscorpion

    Ufoscorpion Well-Known Member

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    Does it matter , Can't sound any different can it ?
     
  10. Jethro Rocker

    Jethro Rocker Well-Known Member Silver Supporting Member

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    A space issue? The amplifier portion would be the same size so same size cabinet. Whether speaker is centred or not will not save any space.
     

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