112 vs 212 for Tiny Terror

johnnyblues · Post by **johnnyblues** » Mon Sep 15, 2008 6:33 pm

Would having an additional 112 speaker for the Tiny Terror increase it's clean headroom? What's the difference in running a 112 setup vs 212 in terms of volume and clean headroom?

Cheers!

Will Loftin · Post by **Will Loftin** » Mon Sep 15, 2008 6:53 pm

With a PPC212, you will have more low end (even more with a PPC412) because of the volume of air inside the cabinet. The mids will be less 'forward'. It will round out the sound of the amp, making it sound fuller.

johnnyblues · Post by **johnnyblues** » Mon Sep 15, 2008 7:33 pm

Thanks Will. So in dummy orange user terms, that equates to more clean levels?

Does it have the same effect if I connect a 2x112 setup?

Will Loftin · Post by **Will Loftin** » Mon Sep 15, 2008 9:13 pm

No, I would not say more clean headroom at all. The headroom of the cabinet, meaning before it is driven into saturation, is already pretty high with a 60 Watt speaker on a 15 Watt amp, so you would not notice a difference with 1 or two speakers. The headroom of the amp is more affected by the level of the input gain, which on this amp is pretty high. For more clean headroom, back off the gain control some and don't use really hot pickups, or turn your volume knob down on the guitar.

Not the same effect when you run 2 112's, as the volume of the cab stays the same per cab... if anything you'll notice a more pronounced effect of forward midrange and less low frequencies (not necessarily a bad thing).

johnnyblues · Post by **johnnyblues** » Mon Sep 15, 2008 9:31 pm

Alright good stuff! Thank you!

Andy H. · Post by **Andy H.** » Tue Sep 16, 2008 9:01 am

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Will Loftin
 No, I would not say more clean headroom at all. The headroom of the cabinet, meaning before it is driven into saturation, is already pretty high with a 60 Watt speaker on a 15 Watt amp, so you would not notice a difference with 1 or two speakers. The headroom of the amp is more affected by the level of the input gain, which on this amp is pretty high. For more clean headroom, back off the gain control some and don't use really hot pickups, or turn your volume knob down on the guitar.

Not the same effect when you run 2 112's, as the volume of the cab stays the same per cab... if anything you'll notice a more pronounced effect of forward midrange and less low frequencies (not necessarily a bad thing).
<hr height="1" noshade id="quote"></blockquote id="quote">I'd agree with what you say about the cabinet headroom but not that that (as far as speakers are concerned) is actually the main factor at play here Will. (Totally agree of course with your comments on input gain, but that is solely an amp thing and not an amp / speaker interaction.)

Even with a significantly more powerful amp, eg a 30 watter, a single V.30 speaker will never get anywhere near to being pushed hard enough enough to distort significantly (cone breakup). With these speakers that doesn't happen until they are pushed pretty hard. Speaker breakup with the 15 watt amp simply isn't relevant!

What is a factor is the overall cab sensitivity, (= efficiency = volume out for a given power input in dB/w/m). That does tend to increase a little when adding identical speakers, especially if placed close together.
See here:
<blockquote id="quote">quote:<hr height="1" noshade id="quote">(John Phillips) http://www.thegearpage.net/board/showth ... p?t=108692

Adding more speakers (assuming correct impedance matching) does seem to increase volume even though the power is now shared between more speakers so each is driven less hard. Exactly how much depends a lot on the cabinet design and maybe even the room it's in though - and only about 1-2dB from double the number of speakers; although you usually get better dispersion with more speakers, so the amp might sound quite a lot louder from off-axis.<hr height="1" noshade id="quote"></blockquote id="quote">
<blockquote id="quote">quote:<hr height="1" noshade id="quote">(John Phillips) http://www.thegearpage.net/board/showth ... p?t=278219

You get about 1 to 2dB more when doubling the number of speakers, depending on the cabinet (and even that runs out eventually, you can't just go on doubling and getting more volume indefinitely).

In theory, the volume should be the same because the same power is being fed to double the number of speakers, which then see only half each, and so the total should still be the same.

But in practice, speakers are less efficient the harder they're driven, so if you halve the power input to each one, you don't quite halve the volume output. Add them back up and you get more total volume. This doesn't go on for ever though, once the speakers are down at low power they don't still get more efficient by lowering the power further.

But there's enough difference in the power input to a typical cab at guitar-amp volume to make a difference, and a 4x12" is usually a bit louder than a 2x12", all other things being equal.<hr height="1" noshade id="quote"></blockquote id="quote">

So johnnyblues if you set your TT to its maximum clean output, the same power level will give slightly more volume through more speakers = more clean headroom. Somewhere between 1-2dB which while not at all dramatic on its own may just make a useful difference on stage in a band mix situation. The increase in sound spread mentioned above may well be useful too as closed back cabs do tend to be fairly directional with volume dropping off when you listen from off axis. I don't think the effect of adding an identical PPC112 cab would be quite the same (either tonally or volume wise) as going to a PPC212, but there will still be an increase in volume, especially if you put the two cabs together.

BTW if anyone doesn't believe that adding identical speakers increases overall sensitivity / volume for a given amp power output I'd suggest trying the same amp at the same clean settings in a decent sized room through a PPC112, PPC212 and PPC412. Then come back and tell me there were just some slight tonal changes...

Andy.

johnnyblues · Post by **johnnyblues** » Tue Sep 16, 2008 10:29 pm

Well thanks for the clarification Andy. I might forego the 112 cab and just go ahead and grab a 212.

Will Loftin · Post by **Will Loftin** » Tue Sep 16, 2008 11:03 pm

Hey Andy H.... I think you may have misread, or I should have clarified, (why I dislike forums) what I said....

When I said:

<blockquote id="quote">quote:<hr height="1" noshade id="quote"> as the volume of the cab stays the same per cab...<hr height="1" noshade id="quote"></blockquote id="quote">

I meant the cubic volume, not the loudness... sorry. Yes, I agree that two cabs is going to be louder than one, if they are close to each other.

Since you're talking about 2 112 cabinets, it means that the dimensions, also the cancellation and build-up of specific frequencies are going to be roughly the same for both cabs. You will hear a slightly more pronounced effect of this with two cabs.

Something else to think about is the distance of the speakers from each other! The further the speakers are from each other, the more phasing that is likely to occur, and especially the possibility of cancellation of lower frequencies. The distance the speakers are apart and distance of the listener in relation to the speakers will all affect how long it takes a certain frequency of a given wavelength to travel that distance. At some point, certain frequencies are going to be out of phase enough to cancel or attenuate.

When it comes to guitar cabinets, none of this is necessarily bad, as it matters more what sounds good and what doesn't!

<blockquote id="quote">quote:<hr height="1" noshade id="quote"> The headroom of the cabinet, meaning before it is driven into saturation, is already pretty high with a 60 Watt speaker on a 15 Watt amp, so you would not notice a difference with 1 or two speakers<hr height="1" noshade id="quote"></blockquote id="quote">

Again, I think you are missing what I'm saying due to my syntax. When I said that it does not make a difference, I mean it will not make a difference in the amount of headroom. I was not speaking about loudness here (notice I didn't mention loudness in my statement). I was trying to clarify headroom of the cabinets for johnnyblues, which is what I mean by it won't make a difference.

The headroom is not going to be noticeable based on how many speakers you have as long as the total Wattage of the speakers is that much more than the output of the amp.

Sorry I wasn't clear enough in my post... it made sense to me!

V30's are 60 Watt speakers (each), btw

Andy H. · Post by **Andy H.** » Wed Sep 17, 2008 12:03 pm

Hi Will,

I was just answering the question johnnyblues posed!

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by johnnyblues
 Would having an additional 112 speaker for the Tiny Terror increase it's clean headroom? What's the difference in running a 112 setup vs 212 in terms of volume and clean headroom?

Cheers!
<hr height="1" noshade id="quote"></blockquote id="quote">

As I read it he wasn't asking about the clean head room of a cabinet. (Or of the amp.)
He wanted to know about any real world sonic differences he could expect (in terms of getting louder clean sounds!) if using his TT with a second 112 cab, or how running a 212 cab would compare to running a 1x12. So the question was about the 'amp + cab system', not bits of it in isolation.

I did mention that the volume difference would be more pronounced if the speakers / cabs are in close proximity. That is indeed an important factor.

Thanks, I'm well aware that V.30s are 60wRMS rated drivers.

'Vintage 30' is badly named
I mentioned an example of a 30w amp, saying that it wouldn't be driving a V.30 hard enough to go into significant compression. (A 60w amp would of course!)

What I'm not quite getting here Will is that first you say - in normal text... <blockquote id="quote">quote:<hr height="1" noshade id="quote">Yes, I agree that two cabs is going to be louder than one, if they are close to each other.<hr height="1" noshade id="quote"></blockquote id="quote">
...and then follow it in bold with...
<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Will Loftin
 The headroom is not going to be noticeable based on how many speakers you have as long as the total Wattage of the speakers is that much more than the output of the amp.<hr height="1" noshade id="quote"></blockquote id="quote">

I disagree there you see, for the exact reasons I stated: Increasing the number of (identical) speakers increases the effective overall speaker sensitivity / efficiency. By around 1-2 dB for a doubling of the number of drivers. That means that for a given wattage output, eg the maximum clean output of the amp, you will get a little more volume - a higher actual SPL.
That does effectively increase the clean headroom of the amp / cab system - exactly what johnnyblues was asking about!

Of course the amp itself isn't behaving any differently - it won't be capable of putting put out any more watts while still staying clean. But a multiple speaker system will make a little more use of what clean power it has. In terms of available clean volume (= clean headroom in my book) that will in fact increase by going on a couple of decibels.

Again try the 1x12 / 2x12 / 4x12 experiment, same amp, same settings, decent sized room. It is quite testable!

Perhaps you are using some definition of 'clean headroom' I'm not quite locked on to here, or limiting it to part of the system without looking at the whole amp / cab system. But in simple terms to me 'clean headroom' means available clean volume (SPL!

) before going into distortion. That, bare bones, was the original question. And yes, that will actually increase!

Andy.

johnnyblues · Post by **johnnyblues** » Wed Sep 17, 2008 6:23 pm

Thanks for all the answers (Andy and Will). I'm learning a lot.

I guess my next question would be: is an additional 2db (max) of more clean volume substantial to whence I only had a 112 setup or is it negligible?

Will Loftin · Post by **Will Loftin** » Wed Sep 17, 2008 8:12 pm

No problem, Andy. I think we're both saying the same thing but going about it a different way...

At the end of the day, what matters most is what sounds good to you. Personally, I think a 212 sounds better than 2 112's. Actually, I prefer the sound of a 412 over all, though it doesn't make much practical sense with a Tiny Terror.

The OB212 sounds great, too, if you like open back cabs!

Andy H. · Post by **Andy H.** » Thu Sep 18, 2008 10:54 am

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by johnnyblues
 Thanks for all the answers (Andy and Will). I'm learning a lot.

I guess my next question would be: is an additional 2db (max) of more clean volume substantial to whence I only had a 112 setup or is it negligible?
<hr height="1" noshade id="quote"></blockquote id="quote">Well it probably wouldn't be as much as 2 dB. One decibel is about the smallest volume change the human ear will notice. 2dB is easily noticable but not dramatic.

Have a quick look here:
DECIBELS
...and listen to the sound samples to get an idea of what decibels are about. You can ignore the complicated maths - just read the bits that make sense!

Also turn your computer volume down a bit at first as the sound samples start loud and get quieter.

As I say in isolation the volume difference won't be at all dramatic. Probably the tonal changes Will mentioned will be more noticable. But in a band mix it might just make a worthwhile difference. However the TT isn't ever going to give you tons of clean headroom. It is a loud wee amp if you don't mind getting dirty, but for louder clean sounds output power as well as speaker sensitivity is important, and 15 watts clean isn't that much. Dirty sounds always sound much louder than clean sounds of similar power levels - just the way the human ear works...

Andy.

ESBlonde · Post by **ESBlonde** » Fri Sep 19, 2008 12:34 pm

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by johnnyblues
 Thanks for all the answers (Andy and Will). I'm learning a lot.

I guess my next question would be: is an additional 2db (max) of more clean volume substantial to whence I only had a 112 setup or is it negligible?
<hr height="1" noshade id="quote"></blockquote id="quote">

Johnny, in the real world clean headroom won't be enough to be noticed in the 1 or 2 speaker scenario with the TT. Normal hearing can percieve a loudness increase of 3dB as louder than before at reasonable listening volumes. If you really need all the volume from a TT and it has to be the TT so you can't just buy a bigger amp, then look at getting a loudspeaker with a greater sensitivity.

Examples from Celestion

Super 65w 12" 97dB
Vintage 30 12" 100dB

So the latter cone (Vintage 30 at 60w) similarly loaded in identical boxes would be perceived as louder than the super 65 when both are connected to the same amplifier. That sensitivity is the important figure for you.

I just used Celestion as an example, you can get some 12" guitar cones that have a sensitivity of 102dB or even 103dB, just be aware that different cones have different sound characturistics. Multiple cones in the same box tend to sound a little more thraoty to my ears.

HTH

johnnyblues · Post by **johnnyblues** » Fri Sep 19, 2008 3:08 pm

Awesome. So a speaker change is in order then.

Many Thanks to all who replied...

Andy H. · Post by **Andy H.** » Tue Sep 23, 2008 10:21 am

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Joker
 Seems like there's still a lot of uncertainty about whether the increased volume is due to the line array theory for multiple speakers placed closely together, speaker effeciency variations with power input levels, or simply the cabinet size.<hr height="1" noshade id="quote"></blockquote id="quote">

Why not a bit of each? Doesn't just have to be one factor involved!

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Joker
 Mr. Phillips (is he suppose to be an expert or something?

) appears to attribute the increase primarily to variable speaker sensitivity and cabinet size. He doesn't mention placing speakers close together (line array theory) at all. In fact, he says multiple speakers should give better dispersion, but the line array theory is based entirely on volume being increased in front of the array and decreased to the sides (E.G. less dispersion).
<hr height="1" noshade id="quote"></blockquote id="quote">I see and appreciate the ":mrgreen:" Joker! [:p]

Well, since you asked...

John is the sort of guy that the 'experts' (TM) over at TGP forum (including numerous known amp designers and builders) look to for good info when they aren't sure...

Very nice guy too. As I've mentioned before he used to be my amp / instrument tech when I lived in Scotland. Knows the meaning of 'bodge job', just doesn't hold with that particular technique himself. If you'd ever seen some of his work first hand you might agree...

The second time I ever met him he recut the nut of my main fretless bass and set it up properly for me. Literally kneeling on the floor of a mates tiny guitar shop he was minding at the time, and chatting away to me while doing it. (Among other things he mentioned just how often factory made fretlesses came with a nut cut about right for fretted basses!) Perfection (TM) was achieved within about five or six minutes - case open to handing me the bass for approval.

(Ask yourself just how many techs would have the confidence to do such surgery on your gear while you are actually looking on. And for that matter how many times they might have to re-tension the strings to check progress along the way! John has a very good eye for the job and nailed it first time - including a quick truss rod tweak...

)

His work inside amps is also most neat. And he has worked on virtually ever type ever made often enough to know their little strengths and weaknesses and just exactly what makes them tick. So yeah, 'expert' (TM) would probably be fair. 'Craftsman' (TM) would be also be totally appropriate!

BTW, apart from being a hard working professional tech, John is also a very active musician, so he knows both sides of that coin equally well. Watching him working with my studio engineer friend while doing his bands CD was one of the most enlightening (and enjoyable!) experiences of the 7 years I lived at the studio.

He also became a good enough friend that he and his wife and kids were among the just 40 close friends and relatives from the UK and Holland at our wedding. (Just so as you know!

)
 <hr noshade size="1">

We've discussed the multiple speaker / SPL thing here before of course <s>Sooner</s> Joker.
http://forum.orangeamps.com/viewtopic.php?t=1913
http://forum.orangeamps.com/viewtopic.php?t=2942
http://forum.orangeamps.com/viewtopic.php?t=3801

Not sure we are any further along the road though. If you know any more now than you did then please do help us out here. Right now I have no doubt about the reality of the effect - I've had plenty of opportunities to test it out with different amps / speakers over the years. But I certainly don't claim to understand exactly what is going on... [:p]

Andy.

112 vs 212 for Tiny Terror

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