10" vs. 12" speakers

[boobtube21]

Reading other's comments in another thread got me thinking...are there genuine differences in sound related to speaker size, or does the difference lie in how the individual speaker is voiced for its intended purpose?

I've got a SF Vibrolux that I find has a pretty strong midrange response...great for pedal steel...not so much for my taste on guitar. I have two sets of Weber 10" speakers that have been in and out of it, plus the originals. They all sound like they have a spike in the 800hz or so range, but if I wheel up the Twin and plug its speakers in (Weber Blue Dog and California), the treble and bass response are both greatly improved. I wonder if this is the 10" vs. 12" factor, or if all three sets of 10s that I own are voiced in that similar of a fashion.

OR...is the Vibrolux such a mid-rangey circuit that it accentuates the sonic difference between these speakers that much more?

Any thoughts?

[phantomman]

I once had a '66 Vibrolux Reverb that I installed a pair of JBL K110s into (basement rats ate the cones out of the original Oxfords). It was, without equivocation, the worst mistake I've ever made. The amp sounded absolutely horrible. Switching to a pair of Alnico CTS 10's was a marginal improvement, as was plugging the amp into a 2 x 12 '64 Bandmaster cab with a pair of C12Qs. The amp actually sounded its best through a 4 x 12 1960A Marshall box. Only then did the amp sound fat and punchy -- very similar to a Super Reverb. You might try a pair of Eminence Ragin' Cajuns in yours......the specs look promising.

HTH

[Gris]

Lots of differences. Generally, the smaller the speaker the faster the response. Other than that many differences depending upon how the speaker was voiced/made.

I have experimented w/ diferent 10s in a SF Lux. Everyone has their own tastes, so no generalities apply.

Beware the Cajun. An excellent speaker but a VERY funky one w/ a unique voice.

The Weber 10F150 (50 watt version) seems to be the baseline speaker for these amps.

Although I am an alnico guy when it comes to 12s, with 10s I often prefer ceramic.

My fave combo in that amp was one Tone Tubby ceramic 10 and one Cajun. But, again, the Cajun is a very funky/different speaker. It's a love/hate thing.

If you stated what sound you are going for I could help you more specifically.

ps - two weber Calis w paper domes would offest the amp's midrange response.

[boobtube21]

Weber 10F150's are what's in there now. I'm necessarily looking to radically alter the sound of the amp, like I said I love it for steel. The other set of 10's I have for it are the 10F125-0. They sound a little different, and the breakup is much earlier but they still have that mid spike.

I'm just curious if:
-10's as a general rule sound different from 12's in this way,
-it's my speaker choice so far,
-the Vibrolux circuit is known for this.

EDIT:I guess I could also try changing out the .01 phase inverter cap to a .001 like the BF specs. I did this before, but had the stock speakers in which were kind of screechy, and it sounded a little thin with those. Hmmm...

[Gris]

Actually, the Lux circuit is somewhat scooped and the BF circuit as well. OTOH, 10s in general ARE 'middy-ier' and the 10F150 is ever so slightly middy on top of that. Again, the Cali seris is a flatter freq response, but the highs will cut your head off unless you go with a paper dome. The perfect non-gain spkr for that amp is the old Jensen C10P with the alum dome - very sparkly.

[boobtube21]

Well I swapped out the .01 cap for the .001...and while I was in there checked the bias. It was a little low at 42mv or so, 70% is 52mv. So I kicked it up to 49/51 (can't get both tubes perfectly even 'cause I BF'd the bias scheme )

It sounds a little less middy and a little more lively now. Once again through the Twin's speakers it has a lot more sparkle though. Not sure what to do about that. Using the same amp with two different tone requirements is a tough one...I'll have to sit and chew on this for a while...thanks for your comments guys.

[chuckocaster]

i personally like 12's for guitar, it all comes down to physics and acoustics. 4x10's do have more surface area than a 2x12, but to my ears the 2x12 sounds bassier and smoother.

it's really all about personal preference. seems like you enjoy that amp through 2x12's, maybe that's the answer? i don't know.

best of luck cologne.

of course this is all coming from a dyed in the wool true blue certified . so take a couple of grains of salt, not just one.

[Gris]

I'd have somebody good cut it for a 1x12. Guess you'd have to attach an inner 3/8" 'false baffle' since the 2x10 scheme would overlap...

[boobtube21]

Well, I don't want to mess with it too much. I like knowing that some of my stuff is worth what (or more than) I paid for it, so I don't want to do anything that will leave scars when I remove it. Believe me, I've thought about building a new/taller combo cab for 1x12".

It also occured to me that instead of the 2 1x12's I'm building out of the Twin, I could build a single 2x12", then put both the Twin and Vibrolux amps into their own seperate head boxes...and mod the normal channel on the Vibrolux, to voice it more for steel.

Then I can use the Vib for both if I can get away with it (better tone), and if I need sheer volume for clean steel, I've got the Twin head too.

Sounds like I need to make another trip to Home Depot. (sigh)

[phantomman]

The Vibrolux wants to see a 4Ω load at the end of its signal chain. With a single 12" speaker and a presumed impedance of 8Ω, your amp will only develop about 28 watts.

[Gris]

Yeah, I went the head route about 3-4 years ago and haven't looked back. I use one Lux like 40 watt clean head and one 14 watt dirty lil thang w/ a switcher into a cab that I use both a 2x10 and 1x12 baffle with. I go back and forth on 1x12 vs. 2x10.

[rudutch]

http://www.eminence.com/pdf/redfang10.pdf

http://www.eminence.com/pdf/redfang.pdf

[Wilko]

I find that the vibrolux sound is not so much mid heavy as it is lacking bottom. 2x12 has much more bottom available.

That's where the Pro Reverb Comes in.

I played my Vibrolux for along time and loved it with fatter sounding guitars because the inherent "lack of bottom"--it sort of evened out.

[boobtube21]

See, I find mine to be the opposite Wilko. True it doesn't have that much bass response, but low mids are in abundance and it kind of makes Strats and Teles a little fatter...in a way I don't want. Could be the speakers I put in there, I don't know. It does sound nice clean with the 335 though, very sweet jazzy tone.

Haven't had a chance to crank it up since swapping the PI cap out though...at low volume it already sounds like it's gonna help. If all else fails I'm seriously considering the idea of a 2x12 that alternately serves a Vibrolux and Twin head, as the situation requires.

I've now gone from a head and cabs, to combos, to heads and a cab.

[jerryjg]

10's are punchier , tighter, more dynamic with more presence than 12's, which sound fuller, more round, and have wider range with deeper spongier low end response.
One should have both 4x12 and 4x10 cabinets in their artillery.

[Offshore Angler]

I like one of each. One 12 and one 10 mixed in my cab. One I will occasionally play my stuff with a single 15 closed back extension at times when I need a little more bottom punch without it getting flabby.

[jerryjg]

Originally Posted by Offshore Angler

I like one of each. One 12 and one 10 mixed in my cab. One I will occasionally play my stuff with a single 15 closed back extension at times when I need a little more bottom punch without it getting flabby.

Yep. I have a 4x12 cabinet equipped with two 10" and two 12' Silverbells planned one day for my '65 Bassman or Plexi Traynor. 2x12 is cool for blackface bassman tone, but my favourite is punchy Super reverb tone out of an open backed 4x10.

[Kap'n]

The absolute best sound I've ever gotten from a Fender 2x10 is a Weber 10A150 and a 10A125. It's a huge sound.

To be honest, it's the best sound I've gotten out of a Fender reverb combo period.

[disclaimer - I have worked for Weber, so if you feel that influences my ears, tell me to piss off]

[phantomman]

It's hard to pigeon-hole every different-sized speaker (even those made by the same manufacturer, using similar materials) into a one-size-fits-all generalization. However, the math does not lie. Here are the radiating area specs for each size of loudspeaker based on the standard πRR formula for the area of a circle......

8" ≈ 50 sq. in.
10" ≈ 79 sq. in.
12" ≈ 113 sq. in.
15" ≈ 177sq. in.
18" ≈ 255 sq, in

Thus, assuming voice coils of equal construction and efficiency, and magnet structures of similar materials and charge, it can be inferred that a 15-inch speaker will move twice the air as a 10-inch speaker -- hence, it will be louder than the smaller cone. A similar relationship can be expected from a comparison of the 8-inch and 12-inch speakers.

However, this formula only applies when comparing single drivers of two given sizes. In the case of a matched pair of drivers such as 2 x 10s, by doubling the number of radiating coils the equation is altered significantly. Using a theoretical pair of 10s, it can be expected that they may be some 3dB louder than the single 15-inch speaker due to the exponential doubling of the inductive load of the second voice coil.

HTH

[Kap'n]

Air movement, per Phantomman's post is a good indicator of how well an amp will fill a room, but there's a lot to perceived loudness.

Sensitivity is a factor, but just important is frequency response. Think of how loud that damn piezo buzzer is in a smoke alarm with a fraction of a watt of power.

I like to move a fair amount of air with little power. Dispersion without being LOUD.

[Offshore Angler]

Originally Posted by phantomman

Thus, assuming voice coils of equal construction and efficiency, and magnet structures of similar materials and charge, it can be inferred that a 15-inch speaker will move twice the air as a 10-inch speaker -- hence, it will be louder than the smaller cone. A similar relationship can be expected from a comparison of the 8-inch and 12-inch speakers.


HTH

Not true because of the mass effects. A speaker is a linear motor so its second order response will be dependent upon the mass of air it moves. To get a linear response in air movement as a function of speaker diameter - the power would need to be increased as the diameter increases. It's going to be related to the square of the diameter divided by four. Like you said, the math does not lie.

For a given power input, with everything else the same, the 10" and 12" speaker would do the same amount of work and hence, move the same amount of air.

[Kap'n]

Originally Posted by Offshore Angler

For a given power input, with everything else the same, the 10" and 12" speaker would do the same amount of work and hence, move the same amount of air.

Sure - the volume of air moved will be the same, but when folks talk about moving air, they're usually referring to more radiating surface. Sound that's less directional and more room filling.

[Gris]

All I trust are my ears. And my ears tell me some things about speakers that are somewhat counter-intuitive; like, for example, 15" speakers can have more highs than 10" speakers. Really the difference in size to me is more about speaker repsonse/speed and texture than how 'big' they sound. The 'smallness' of 10" spkrs can be 'fixed' by using 2 or 3 of them. My ears tell me 10" speakers are mid-ier/punchier/faster and 12" speakers have more color and texture and a very, very slight delay, whereas most 15" speakers just don't do it for me at all; however; some are pretty good with the right head. Of course, there are great variations between speakers of the same size.

[Offshore Angler]

Originally Posted by Kap'n

Sure - the volume of air moved will be the same, but when folks talk about moving air, they're usually referring to more radiating surface. Sound that's less directional and more room filling.

Yeah, but the power is the same regardless. Power is the measure of how much work the speaker does. We can assume the effected air is adiabatic. What we can infer - is that since the air moved is the same, the smaller speaker will have a bigger amplitude, and hence a higher SPL. That's why tiny buzzers can be so loud on very low power. They run a single frequency and high amplitudes.

Now granted above is neglecting a lot of other things going on liek frequency distributon that will certainly affect the power distribution over the frequency spectum, and damping effects,...but the base physics are stil what they are. It comes down to power, which is how much work the speaker does over a time interval.

[phantomman]

Originally Posted by Offshore Angler

Not true because of the mass effects. A speaker is a linear motor so its second order response will be dependent upon the mass of air it moves. To get a linear response in air movement as a function of speaker diameter - the power would need to be increased as the diameter increases. It's going to be related to the square of the diameter divided by four. Like you said, the math does not lie.

For a given power input, with everything else the same, the 10" and 12" speaker would do the same amount of work and hence, move the same amount of air.

I cite as my sources the late Abraham B. Cohen -- author of "Hi-Fi Loudspeakers And Enclosures" and former managing engineer for University Loudspeakers, Inc -- and the writings of Harvey Gerst, former design engineer at JBL who developed the "F-series" musical instrument loudspeakers.

[Gris]

Gerst knows spkrs. He turned me on to the D123!

[Offshore Angler]

Originally Posted by phantomman

I cite as my sources the late Abraham B. Cohen -- author of "Hi-Fi Loudspeakers And Enclosures" and former managing engineer for University Loudspeakers, Inc -- and the writings of Harvey Gerst, former design engineer at JBL who developed the "F-series" musical instrument loudspeakers.

Yeah, well, the math doesn't lie. Unless he can change the laws of physics that statement is fundamentally flawed. If anybody can show me mathmatically using sound engineering principles that he's correct - which they can't - I stand where I am.

Let's start with SQRT(gammaRT) and derive it from there. Assume the air is adiabatic and neglect attenuation. Also, to make it engineering 101 and not real-life, assume the mass of the voice coils and cones are the same for the 12" and 10".

I will certainly agree that a bigger speaker moves more air than a smaller one at the same amplitude, but for a given power ( and I think that may be where you are confused) the amount of air moved would be the same, and the amplitude would be different.

In other words the bigger speaker moves more air, but requires more power. That should be obvious to even the least technical person. It takes more power to drive something bigger than something smaller.

So what does that mean to a guitar player? If you put a bigger speaker in your amp, it needs more power to drive it. So you need to turn up the power section and viola, you amp sounds "bigger". It's neat how it all works out.

[phantomman]

As you prefer......

[Wilko]

Physics will show that there is no "free energy".
You'll only get the power out that you put into it.

The power lost effects the "Efficiency" of the speakers.

I would like to see evidence that a 15 with the same applied power and voice coil would be louder than a smaller speaker.

[Gris]

Yeah, we really are talking apples and oranges here because - as the late, great Ted Weber taught me - there is soooo much more that goes into speaker sound and volume than cone surface size. The size of the magnet, the size and weight of the voice coil, the size, shape and material of the dome and on and on.

[Offshore Angler]

Originally Posted by Wilko

Physics will show that there is no "free energy".
You'll only get the power out that you put into it.

The power lost effects the "Efficiency" of the speakers.

I would like to see evidence that a 15 with the same applied power and voice coil would be louder than a smaller speaker.

All other things being equal, the bigger speaker will be less efficient. It has more mass, more damping, more edge issues and gives off more heat.

[Offshore Angler]

Originally Posted by Wilko

Physics will show that there is no "free energy".
You'll only get the power out that you put into it.

The power lost effects the "Efficiency" of the speakers.

I would like to see evidence that a 15 with the same applied power and voice coil would be louder than a smaller speaker.

Unless we convert some of the mass of the speaker into energy, he, he.

[Kap'n]

Originally Posted by Offshore Angler

All other things being equal, the bigger speaker will be less efficient. It has more mass, more damping, more edge issues and gives off more heat.

But they aren't usually equal. Larger speakers usually have larger magnets - more gap energy.

[boobtube21]

Well FWIW I did some recording with this amp on guitar a few weeks ago, and it sounded pretty stellar. It is much better for guitar now since the PI cap swap, not as good for pedal steel, but I'm over it. I can drag the Twin around for steel with the loud band, and get away with using the Vib for steel and guitar with the other band.

Maybe I'll put in a toggle to switch between caps, though I'll probably want to put it on standby before switching.

[boobtube21]

Oh and another thing...most of the mid spike I was getting I think was a result of how I was mic'ing the amp->SM57 right on the grill, at about 30° angle.

I find now by backing it off about 3-4" from the grill, aiming straight at the cone about midway between center and edge, it gets a nicer sound, less in your face mids. It also sits in the mix a little better.

[twangmeisternyc]

This thread has been quite impressive...