Played with 2 cabs this weekend, big volume difference -Why?

[tele_jas]

Hi all..... I played an outdoors gig this weekend and it rocked!!! But, I have a question for you all: I had my Triple Rectifier hooked up to two 16 ohm cabinets, one 2x12 and one 4x12 and I plugged them into the 8 ohm speaker outs (figured this out from a previous question on the board). When I started playing, I could bearly hear the 4x12 cab, but the 2x12 was VERY loud. Is this normal? When I unplugged the 2x12 the 4x12 got louder and the same thing when I unplugged the 4x12 the 2x12 got louder. So they were both working, but should it be that way? Is it normal for the 2x12 to be alot louder than a 4x12?

 

[mrdylan]

I bought a 2nd 4X12 last week and noticed the bottom cab seems alot lower in volume than the top and put it off to the top being more in your face I will try swapping them around tonight to see if it makes a difference.

I think it could be outputs ?

 

[tele_jas]

That's not the case with mine since I had them side by side and the 4x12 is a slat cab so it should have been blowing my ears off since it points at my head and the 2x12 points at my knees. I hope it's just a wattage distribution thing (spliting it up between the speakers) and not my outputs going out.

 

[mrdylan]

I hope it's just a wattage distribution thing (spliting it up between the speakers) and not my outputs going out.

This is what I was leaning towards a power distribution issue

Like I said I was just going to put it off to it being the fact that it was on bottom so maybe most if not all have this issue and just never noticed before having it the other way around I would think it would even itself out if it is indeed the output distribution.

I will switch the plugs tonight and see if it makes a difference.

 

[vulture2600]

it would make sense that the 2x12 is louder and heres why:
if the 2x12 and the 4x12 have the same total impedance, that would mean
the individual speakers have different impedances. the 2x12 would have
8 ohm speakers and the 4x12 could have 4, 8 or 16 ohm speakers.
if the 4x12 had 16 ohm speakers, each one is resisting more current
than the dual 8 ohm speakers in the 2x12.
however, if the 4x12 had 4 ohm speakers, i would think the 4x12 would
be way louder. maybe im backwards on this, but it makes sense in my head
(the same way women dont)

 

[mrdylan]

Swapped the plugs and there was no difference the top still seems much louder than the bottom.

I have 2 Marshall cabs so they can't be wired differently maybe your volume difference is much more notcibale than mine and mine is just the way it is ?

 

[LHanson]

I would think, given matched output transformer/speaker impedance and reasonably close speaker efficency, that the 4x12 would be louder, or at least be percieved louder due to increased bass response related to the increased cone area.

Maybe the 4x12 has a shorted speaker or shorted wire? Try not to use it until it you check out the wiring etc. since amps don't like severe impedance mismatches.

 

[screamingdaisy]

What kind of speakers was each cab loaded with?

 

[tele_jas]

the 4x12 is a Peavey 5150 with Sheffield 1200 and the 2x12 is a Genz Benz G-Flex and I'm not sure exactly what speakers are in it?

 

[no soul]

simple solution, sell the 4x12 and buy another Genz Benz.

 

[cheekymonkey]

it would make sense that the 2x12 is louder and heres why:
if the 2x12 and the 4x12 have the same total impedance, that would mean
the individual speakers have different impedances. the 2x12 would have
8 ohm speakers and the 4x12 could have 4, 8 or 16 ohm speakers.
if the 4x12 had 16 ohm speakers, each one is resisting more current
than the dual 8 ohm speakers in the 2x12.
however, if the 4x12 had 4 ohm speakers, i would think the 4x12 would
be way louder. maybe im backwards on this, but it makes sense in my head (the same way women dont)

Not sure that I follow this logic. The cabinets are resistive loads, if they are both 16 ohm loads then you should be getting similar volumes despite the type of speaker, or individual speaker current draw etc.

Since you say that one cabinet is much louder than the other I'm wondering if the cabinets are both actually the same resistance. Can you get an ohm meter and check? I agree that the 4x12 would have more presence than the 2x12 (makes it sound louder) but the large difference in volumes makes me think something else is going on.

 

[seajay]

Cool forum! After reading this thread, I had to register to try to explain what is going on here...

The way I understand it, the power is not being evenly distributed among each speaker in each cab:

One 2x12 and one 4x12 are each hooked up to a speaker out on the amp. Therefore, 50% of the amps power is going to each cabinet.

The power is then further divided among each speaker in each cabinet:

2x12 --> 50% divided by 2 speakers = 25% of total power per speaker.
4x12 --> 50% divided by 4 speakers = 12.5% of total power per speaker.

So each speaker in the 2x12 is being pushed harder than each speaker in the 4x12, which could explain why the 2x12 was louder than the 4x12.

Also, if the speakers in the 2x12 are more efficient than the ones in the 4x12, they will appear louder.

At least this is how it was once explained to me.

I hope this helps.

 

[justanotherguitarist]

I was in a similar situation when i plugged my 2x12 marshall combo into my 4x12 cab (usually goes with whatever head i have at the time, roadster atm). I could barely hear the sound coming from the 4x12 and most of the sound coming from the 2x12 speakers in the combo. There was only a small difference in speaker output (60W per speaker in the cab and 65W per speaker in the combo). The resistive load from the cab matched the output of the combo (it has a stereo poweramp so it was 8ohms either side into two stereo 8ohms inputs in the cab).

After ruling out any user error i couldnt figure out the why... fairly similar same situation to telejas

 

[Ken j]

The cabinet wiring may also play a role. I would think that a 4x12 has a series/parrallel circuit. A 2x12 16 ohm cab is most likely series. This all points to power distribution along with different speaker efficienices as others have stated.

 

[phyrexia]

Back from the dead!

Simple solution. Sheffields aren't as efficient as G-Flex speakers. Furthermore, the GFlex cab is ported and is louder than a regular closed back 2x12 of the same size.

Just like a Thiele is louder than a Recto 2x12, I would venture to guess the G-Flex cab is oodles louder than your Peavey 5150 cab.

 

[Jonberrier]

One 2x12 and one 4x12 are each hooked up to a speaker out on the amp. Therefore, 50% of the amps power is going to each cabinet.

The power is then further divided among each speaker in each cabinet:

2x12 --> 50% divided by 2 speakers = 25% of total power per speaker.
4x12 --> 50% divided by 4 speakers = 12.5% of total power per speaker.

This guy is dead on. If you want all the speakers to react the same get a 8ohm 412. Each cab is 16ohm so they both get equal power (50w to the 212 and 50w to the 412). A lot of people talk about adding a 212 to their halfstack adds to the bottom end. In reality, the speakers in the 212 are working harder so they have more volume.

Peace