Marshall: 1x12 quieter than 4x12?

[dtirer]

I have a 74 JMP 50 watt which is obviously quite loud. I basically use the amp in the low input of channel 1, with the volume on 2. Has a good amount of hair, lots of punch.

I play through a bogner closed back 4x12 with green backs. I recently played this head through some non descript 2x12 and noticed how much more manageable it seemed volume wise. I'm wondering if a large 112 (maybe even the bogner one) would be somewhat quieter at the same settings on the amp? What other factors should I consider?

 

[LPMojoGL]

Yes. Less speakers of the same db rating will have less overall output.
1 speaker with a lower db rating will be much quieter than 4 with a higher db rating.
Maybe look at the 100 watt Scumback M75.
Or possibly the new 65 watt Celestion, or the Celestion G12-65.

 

[ledzep618]

^ You are not totally right (but also not totally wrong):

If the speakers are the same, adding more of the same speaker does not increase volume. Likewise reducing speaker number, keeping the drivers the same does not reduce volume. The output is split evenly between the 4 speakers in a 4x12, whereas a 1x12 speaker puts out full output of the same signal. a 4x12 will have a different, fuller sound with different dispersion characteristics. Namely a better bass response, but I can assure you the overall volume is the same.

You are right however, that for example 1 speaker with a high dB rating with be louder than 4 quieter ones. For example, 1 Eminence C-Rex, rated at 103 dB will be significantly louder than the same amp run through a 4x12 of 97 dB Greenbacks. I have gigged a DRRI with a C-Rex and drowned out a 50 watt marshall going through a GB 4x12.

Also, as LPMojo mentioned, if you run a 50 watt head through a 1x12 make sure you get a speaker that can handle the juice. A 50 watt Marshall pushed is probably peaking out closer to 85 watts. I wouldn't get anything under 100 watts personally. I have fried multiple single 65 watt speakers with a 36 watt Reinhardt Titan dimed for outdoor gigs.

 

[sixty2strat]

The math might say it is not quieter but I have run a 74 50 watter with 4x12 1x12 and even an 8x10. I found that reducing the speaker moves less air and makes it less "loud" is the sp db or wattage being used the same...no idea but 1x12 is slightly less audible. WILL IT turn a cranked marshall major in to a princeton on 4 no. but there is a little less presence. I have a50 watt 76 lead n bass combo with green back ri and my 74 head with a 4x12 is louder

 

[walterw]

If the speakers are the same, adding more of the same speaker does not increase volume. Likewise reducing speaker number, keeping the drivers the same does not reduce volume.

we just had a long juicy thread about this; multiples of the same speaker are louder than singles, within a certain range of frequencies.

speaker output vs. wattage is logarithmic, where twice the wattage into the speaker is not twice as loud, but only a little louder;

that means 2 speakers may each be getting half the power of one, but they're each only a little quieter, so the pair end up being louder than the one even with the same total amp power.

the rule is:

double wattage=+3dB (as long as you're not in power compression)

double speakers=+3dB

 

[walterw]

anyway, smaller cabs are obviously useful in taming 50 watt marshalls for club use; i use a 100w 2203 through various 2x12 and even 1x12 cabs and it makes that beast manageable.

 

[vintage66]

I always thought greenbacks, being not very efficient, tamed volume vs higher wattage speakers plus they sound great. I'd be interested to know if there's a 1x12 that can approximate the sound of greenbacks in a closed back 4x12.

 

[lang.murphy]

This is fairly apropos to my current rig set up. (Just a home player... not a pro.)

I have a clone 1987 head. I have a 1960TV cab (4x12) and a 1933 cab (1x12). The 1960TV has greenbacks, the 1933 has a single 70w driver. The 1933 is closed back with a 2" port. The 1960TV currently sits on top of wheels. The 1933 sits directly on the floor.

With my amp at the same settings, when demoing both cabs, the 1x12, which sits directly on the floor, has more low end punch than the 1960TV that sits above the floor on its casters.

In terms of one being "louder" than the other... not readily apparent, at least at lower volumes. I hear more of a difference in tone, which I attribute to the speaker model and the fact that the 1x12 is sitting directly on the floor. That said... I have dimed the amp with the 4x12... haven't dimed the amp with the 1x12 yet. (Needless to say: dimed running through a 4x12 is, hahaha, just about the best experience EVAH!)

Ultimately... if it came down to: "I have a gig... I can drag either my 4x12 or my 1x12 down to the gig..." I'd, being an old f'er, go with the 1x12, even though I prefer the 4x12, tone wise. And that's based on the fact that I'm not a pro. If one is a pro, one might have different priorities... especially if one has roadies. lol

 

[dtirer]

wow guys thanks for all this info. Perhaps when I was trying my Marshall through the 212, I was just perceiving a little less 'bigness', and maybe not a volume drop.

I remember Bogner making a large-ish 1x12, with ports. Thought, I just saw their new site go up and it doesn't seem they make that anymore.

 

[rburkard]

Less speakers mean less perceived volume. Get a good 1x12 closed cab loaded with a good "low efficiency" speaker that can handle your 50 watts head and you are able to run the amp hotter than you would do so with your 4x12 or even 2x12.
Rene

 

[Dave_C]

I have a 74 JMP 50 watt which is obviously quite loud. I basically use the amp in the low input of channel 1, with the volume on 2. Has a good amount of hair, lots of punch.

I play through a bogner closed back 4x12 with green backs. I recently played this head through some non descript 2x12 and noticed how much more manageable it seemed volume wise. I'm wondering if a large 112 (maybe even the bogner one) would be somewhat quieter at the same settings on the amp? What other factors should I consider?

All else being equal, the overall output level across all frequencies remains exactly the same, but the frequency response changes in the 4x12 case due to phase cancellation at the higher frequencies and increased bass at the lower frequencies up to a cutoff frequency determined by driver spacing. Due to Fletcher Munson effects, the 4x12 will actually be perceived as quieter and/or less piercing because of the phase cancellation on the bands we're most sensitive to while also sounding fuller and deeper due to the increased bass response. But, the total energy reaching our ears will be exactly the same.

 

[GT100]

All else being equal, the overall output level across all frequencies remains exactly the same, but the frequency response changes in the 4x12 case due to phase cancellation at the higher frequencies and increased bass at the lower frequencies up to a cutoff frequency determined by driver spacing. Due to Fletcher Munson effects, the 4x12 will actually be perceived as quieter and/or less piercing because of the phase cancellation on the bands we're most sensitive to while also sounding fuller and deeper due to the increased bass response. But, the total energy reaching our ears will be exactly the same.

Sorry Dave but you are wrong.
Generally speaking doubling the speakers increases Sound Pressure Levels by 3db.

I asked Celestion this very question and they did the experiment and sent me the results: https://www.thegearpage.net/board/index.php?threads/1138789

This math says the same thing btw:http://www.engineeringtoolbox.com/adding-decibel-d_63.html

Lloyd

 

[GT100]

^ You are not totally right (but also not totally wrong):

If the speakers are the same, adding more of the same speaker does not increase volume. Likewise reducing speaker number, keeping the drivers the same does not reduce volume. The output is split evenly between the 4 speakers in a 4x12, whereas a 1x12 speaker puts out full output of the same signal. a 4x12 will have a different, fuller sound with different dispersion characteristics. Namely a better bass response, but I can assure you the overall volume is the same.

You are right however, that for example 1 speaker with a high dB rating with be louder than 4 quieter ones. For example, 1 Eminence C-Rex, rated at 103 dB will be significantly louder than the same amp run through a 4x12 of 97 dB Greenbacks. I have gigged a DRRI with a C-Rex and drowned out a 50 watt marshall going through a GB 4x12.

Also, as LPMojo mentioned, if you run a 50 watt head through a 1x12 make sure you get a speaker that can handle the juice. A 50 watt Marshall pushed is probably peaking out closer to 85 watts. I wouldn't get anything under 100 watts personally. I have fried multiple single 65 watt speakers with a 36 watt Reinhardt Titan dimed for outdoor gigs.

Sorry but you are wrong,
Celestion did the measurements for me: https://www.thegearpage.net/board/index.php?threads/1138789

Also the math backs it up: http://www.engineeringtoolbox.com/adding-decibel-d_63.html


Lloyd

 

[ledzep618]

^ Interesting...i'll have to look through those PDF's later, because that claim is against everything I have ever heard, experienced, and the general laws of audio physics. But read the PDFs, I will!

 

[rburkard]

This is not correct. Mathematically you get 3db more output for each additional speaker, unless the load and or amp volume changes. In the real world, and here you are right, you would not achieve quite this increase with a 2x12 or 4x12 due to phase cancellation.
Rene

All else being equal, the overall output level across all frequencies remains exactly the same, but the frequency response changes in the 4x12 case due to phase cancellation at the higher frequencies and increased bass at the lower frequencies up to a cutoff frequency determined by driver spacing. Due to Fletcher Munson effects, the 4x12 will actually be perceived as quieter and/or less piercing because of the phase cancellation on the bands we're most sensitive to while also sounding fuller and deeper due to the increased bass response. But, the total energy reaching our ears will be exactly the same.

 

[lespaul6]

I asked Celestion this very question and they did the experiment and sent me the results: https://www.thegearpage.net/board/index.php?threads/1138789

This math says the same thing btw:http://www.engineeringtoolbox.com/adding-decibel-d_63.html

Lloyd[/QUOTE]


great info here... thanks..

 

[Britishampfan]

I run single speakers with my superlead, my soundcloud clip is a superlead and a 1/10 open back.

You could talk loud ( kinda yell) to someone over the sound. It easy to smoke speakers so you have to be careful with lower wattage speakers and watch the output.

I can get pretty crunchy at a low volume and I like speaker break up.

Much less loud IMHO- even a 2/12 vs 4/12 but I like pedals and I don`t crank my amp so YMMV

That being said, some complain about a Princeton reverb on stage now so it may not help.

 

[GT100]

This is not correct. Mathematically you get 3db more output for each additional speaker, unless the load and or amp volume changes. In the real world, and here you are right, you would not achieve quite this increase with a 2x12 or 4x12 due to phase cancellation.
Rene

Actually, if you look at the data Celestion provided (see my previous post) you will see that phase cancellation (with multiple speakers) isn't significant after all.
It really is +3db (average) at guitar frequencies.

Lloyd

 

[freaksho]

gentlemen, the math definitely does not support this claim. it is true that 3dB represents twice the power, but as that wiki page states it requires adding a second source of equal power, which would be like adding a second amp and a second speaker. what you are talking about is simply splitting the same power between multiple speakers, which cannot physically add power if you keep the total impedance the same. it just can't. by that logic if you keep adding more and more speakers then you magically keep increasing your amp's power output. so does a 100W amp thru a 1x12 somehow turn into a 200W amp with a 2x12? or a 400W amp with a 4x12? or an 800W amp with two 4x12's? and so on. obviously that makes no sense.

there is no mention of impedance in the Celestion experiment pdf's but if i had to guess i'd say they did not switch the impedance selector on the amp when adding the second cab and ended up reducing the total impedance by half, thereby doubling the power and getting that ~3dB average shift.

i'm not saying the resulting sound does not have a real & significant impact - it does. and it will very likely require you to reach for your volume knob. but if you don't touch the volume knob and keep the impedance constant then there simply is no change in total power output. and the governing equation is actually quite simple: P=(I^2)(R). it's called Ohm's Law.

 

[GT100]

gentlemen, the math definitely does not support this claim. it is true that 3dB represents twice the power, but as that wiki page states it requires adding a second source of equal power, which would be like adding a second amp and a second speaker. what you are talking about is simply splitting the same power between multiple speakers, which cannot physically add power if you keep the total impedance the same. it just can't. by that logic if you keep adding more and more speakers then you magically keep increasing your amp's power output. so does a 100W amp thru a 1x12 somehow turn into a 200W amp with a 2x12? or a 400W amp with a 4x12? or an 800W amp with two 4x12's? and so on. obviously that makes no sense.

there is no mention of impedance in the Celestion experiment pdf's but if i had to guess i'd say they did not switch the impedance selector on the amp when adding the second cab and ended up reducing the total impedance by half, thereby doubling the power and getting that ~3dB average shift.

i'm not saying the resulting sound does not have a real & significant impact - it does. and it will very likely require you to reach for your volume knob. but if you don't touch the volume knob and keep the impedance constant then there simply is no change in total power output. and the governing equation is actually quite simple: P=(I^2)(R). it's called Ohm's Law.

You read the page wrong.
It clearly shows that two equal sources increases the Sound Pressure Level 6db.
When you cut the power in half (each speaker gets half the power) you go down 3db in each speaker.
So the end result of doubling the speakers is really +3db just as Celestion measured for me.

Lloyd