Different Ohm loads = change in volume and tone?

[B2D]

I read somewhere (I think it was the Mesa/Boogie technical manual) that lower ohmage loads result in a louder and bassier tone.

Is this true or not? And if it is true is it only a slight difference or is it really noticeable?

I just don;t want my 4x12 Greenback Marshall cab to sound quiet and un-bassy, that's all. it's a 16ohm load.

[Hawkman]

This is true. I rewired the two 8 ohm speakers in my Bogner 2x12's in parallel, producing 4 ohms. When I played my VHT power amp set to 4 ohms, there was a noticeable jump in bass (and overall) levels. However, the sound was not as "tight" to my ears and playing style. So, I eventually switched back to wiring the speakers in series for 16 ohms and I'm happier with that setup. Give it a try if your amp has the 4 ohm impedance selector. Then you can judge how it sounds - and if it's right for you. Good luck.

[mrid]

Yes, I imagine this is why most bass amps and cabs take 2-4 ohm loads. Also, the negative feedback loop is usually connected to a certain tap.

[That90'sGuy]

I like higher ohm levels because it helps to tame a loud amp. For instance, my Triamp normally would put out 100w for 8 or 4ohm cabinets. I chose 16ohms so that makes it run at 80w. Not a huge difference, but it is noticeable and makes getting "that tone" at a lower level just a little bit easier.

[Jeff_H]

I'm running my V12's in my Marshall combo right now in 4 ohms. They are 2 eight ohm speakers. Could one of you tell me how to wire it so I am back to 8 ohms? I'll post a pic tonight, but if I remember the connection points to the speakers right...they are like this.

X X

X X

I'm not much of a wiring guru, so I don't want to blow my tranny (no jokes please).

[Kent S.]

I would say that that probably was Mesa, as they used to encourage experiementing with the load as a tone control of sorts,
So I think you are correct, I believe they in fact did mention that in some of their owner's manuals. Most amps though are still built for their *normal tone* to be at the preferred load ... Mesa's are also made with components that can take the abuse of mismatched loads, at relatively high volumes ... I wouldn't dare do that with say a marshall Valvestate (not that there is anything wrong with the valvestate series ... it's just that, well you get what you pay for ), of course with the vs it probably wouldn't make much of a difference anyway.
To me the difference affects the low end tightness, and some of the upper mids a bit ... B2D ... just try your options and see what sounds best to you. On a somewhat related note ... B2D, are you familiar with how the peavey 5150 presence/resonance circuit works? That resonance control (while not the same thing) may be a bit more of what you are looking for in terms of control (although I wouldn't go modding your Mesa just yet ... )
MRID are you familiar with it's workings?
If not shame on you ... Drop me a PM and I'll send it to you ...

[Hawkman]

Originally posted by Jeff_H
I'm running my V12's in my Marshall combo right now in 4 ohms. They are 2 eight ohm speakers. Could one of you tell me how to wire it so I am back to 8 ohms? I'll post a pic tonight, but if I remember the connection points to the speakers right...they are like this.

X X

X X

I'm not much of a wiring guru, so I don't want to blow my tranny (no jokes please).

It's not possible to wire two 8 ohm speakers to get an 8 ohm cabinet. Series wiring = 16 ohms, or parallel wiring = 4 ohms.

Celestion has a wiring guide on their website Celestion wiring web page

[Jeff_H]

Originally posted by Hawkman
It's not possible to wire two 8 ohm speakers to get an 8 ohm cabinet. Series wiring = 16 ohms, or parallel wiring = 4 ohms.

Celestion has a wiring guide on their website Celestion wiring web page

Thank you. I will look at that tonight when I get home. So using the thought process on this thread....the 16ohm load should sound better than the 4 ohm load....right?

[Kent S.]

Originally posted by Jeff_H
I'm running my V12's in my Marshall combo right now in 4 ohms. They are 2 eight ohm speakers. Could one of you tell me how to wire it so I am back to 8 ohms? I'll post a pic tonight, but if I remember the connection points to the speakers right...they are like this.

X X

X X

I'm not much of a wiring guru, so I don't want to blow my tranny (no jokes please).

Unless I just missed something here altogether ... you can't get 8ohms out of (2) 8 ohm drivers, if you wire them in parallel you got 4ohms, in series you have 16 ohms, the only way to wire for 8 ohms is to use one driver only.
Series looks like this ... the wire are the dots (.....)
SP means speaker terminals, and Tip/Sleeve refer to the speaker cable coming from the amp (if it has plug in speakers ).
Amp (Tip) ............(+) SP (-) ......... (+) SP (-) .......... Amp ( Sleeve)

Parallel looks like this ....
Amp (Tip) ......... (+) SP (-) ........ Amp (Sleeve )
Amp (Tip )..........(+) SP (-) ........ Amp ( Sleeve)

The (+) of one driver jumpers to the (+) of the other, same for the (-) of one to the (-) of the other.

[Gearjoneser]

Tonally, I prefer 16 or 8 ohm cabs for gainy amps.

I like 4 or 8 for cleaner amps, which most of them are.

[B2D]

The amp in question is a Mesa 50w Rectoverb head, with 4 different outputs. Two 8ohm, one 4ohm, and one 16ohm.

I love the Greenback-loaded Marshall cabs but they're 16 ohms only, as opposed to the V30-loaded cabs which have an 8ohm input.

Would it possible to wire one of those Greenback cabs with only 1 input for an 8ohm load?

[Kent S.]

Originally posted by B2D
The amp in question is a Mesa 50w Rectoverb head, with 4 different outputs. Two 8ohm, one 4ohm, and one 16ohm.

I love the Greenback-loaded Marshall cabs but they're 16 ohms only, as opposed to the V30-loaded cabs which have an 8ohm input.

Would it possible to wire one of those Greenback cabs with only 1 input for an 8ohm load?

Well, what is the impedance of the speakers themselves ... not sure what's in the cabinet(s) ?

[Burkwieser]

On my two Randall cabs I have a switch in the back that I can run 4 or 16ohm mono, and or 8ohm stereo. I currently run 16ohm on the current setup. 4ohm just does not sound tight enough to me. Above all though, I preffer 8ohm stereo.