volume control between amp and cab

DankStar

Her Little Mojo Minion
so I don't need an attenuator necessarily (unless that's the only device that will work for my application), but I'd like to slightly bump up the signal to an extension cab versus the stock speaker in my combo.

Basically, the internal marshall g12 heritage sounds louder (and dare I say better) than the extension with a v30 and I'd love to even them out. so what would I need? probably an attenuator on the stock speaker huh. it's like the extension cab isn't really doing anything if it's at a lower volume. grated, the v30 cab is on the ground level, but even when I get my melon down there the g12 seems to dominate.

what's weird is, everyone says how loud v30s are. I'm considering switching out the v30 for a greenback, even though the speaker is rated for 25 and the amp is rated for 30. but if I attenuate on that cab, then I could bring it down to a safe level (but perhaps too quiet again). hmmmmm
 
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Re: volume control between amp and cab

The bench tech at my old company made me one.
The biggest challenge, he said, was calculating the load.
But it works fine!
Dunno about a commercially available spkr level volume control ..
 
Re: volume control between amp and cab

What you want is called an L-pad. It's basically a volume control that handles higher power and allows your amp to continue to "see" the proper load regardless of the setting.

Here's an example: (Pick the wattage and impedance that your application needs.)

L-Pad
 
Re: volume control between amp and cab

Are they the same sensitivity?
 
Re: volume control between amp and cab

The bench tech at my old company made me one.
The biggest challenge, he said, was calculating the load.
But it works fine!
Dunno about a commercially available spkr level volume control ..

so you had a similar issue, or did it serve a different purpose?

are both speakers the same ohm rating? just curious

both are 16 ohms

Are they the same sensitivity?

I don't think there is an official data sheet for the marshall-branded g12 heritage.

------

I wouldn't mind tracking down another g12 and just selling the v30, but they seem to have been only placed in the jtm line, and they don't appear to have been one that people would have yanked out very often since they do sound good. the jtm 1 x 12 would be a cool find too, but I seldom see them for sale and when I do it's usually as a package deal with the combo.
 
Last edited:
Re: volume control between amp and cab

What you want is called an L-pad. It's basically a volume control that handles higher power and allows your amp to continue to "see" the proper load regardless of the setting.

Here's an example: (Pick the wattage and impedance that your application needs.)

L-Pad

That 15 Watt pot is pretty cool. Thought it would be A Lot more expensive.....
Thanks for the link.
 
Re: volume control between amp and cab

so I don't need an attenuator necessarily (unless that's the only device that will work for my application), but I'd like to slightly bump up the signal to an extension cab versus the stock speaker in my combo.

Basically, the internal marshall g12 heritage sounds louder (and dare I say better) than the extension with a v30 and I'd love to even them out. so what would I need? probably an attenuator on the stock speaker huh. it's like the extension cab isn't really doing anything if it's at a lower volume. grated, the v30 cab is on the ground level, but even when I get my melon down there the g12 seems to dominate.

what's weird is, everyone says how loud v30s are. I'm considering switching out the v30 for a greenback, even though the speaker is rated for 25 and the amp is rated for 30. but if I attenuate on that cab, then I could bring it down to a safe level (but perhaps too quiet again). hmmmmm

Matcing backs? Wild guess - halfopen back combo and sealed 1x12 extension? SOME properly designed 1/2 - 1/3 - 1/4 open back designs project better, especially when listening near it, while closed backs beam and project tighter and further away....

Also, the combo amp chassis inside the cabinet might be making the box more ridgid...and/or the box was designed heavier and more ridgid to add durability to support the bigger weight. Solution? Open up the extension, add (nail/screw + wood glue) "bracing" = 1x1" dowels or 0.75"x1.5" boards along some or all inside edges, starting with around the speaker baffle....or at least a tightly wedged and glued in dowel/board running across the middle of the cabs floor, bracing baffle against back
 
Re: volume control between amp and cab

Matcing backs? Wild guess - halfopen back combo and sealed 1x12 extension? SOME properly designed 1/2 - 1/3 - 1/4 open back designs project better, especially when listening near it, while closed backs beam and project tighter and further away....
That was my first thought when reading the original post.
 
Re: volume control between amp and cab

What you want is called an L-pad. It's basically a volume control that handles higher power and allows your amp to continue to "see" the proper load regardless of the setting.

Here's an example: (Pick the wattage and impedance that your application needs.)

L-Pad
I'd like to better understand this. If you add a variable resistor (which is what this device appears to be) either in series or parallel, how can the impedance remain unchanged.

Even if the 8 ohm pot is variably divided into two complimenting portions (i.e. 2 ohms and 6 ohms) and one of the portions is in series and the other in parallel, the math doesn't seem to work out for a constant 8 ohm overall impedance??? What am I missing?
 
Last edited:
Re: volume control between amp and cab

What you want is called an L-pad. It's basically a volume control that handles higher power and allows your amp to continue to "see" the proper load regardless of the setting.

Here's an example: (Pick the wattage and impedance that your application needs.)

L-Pad

I assume that means "Load" pad. Isn't that an Attenuator?????
 
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