<blockquote id="quote"><font size="2" face="Verdana" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Will Loftin</i>
<br />No, I would not say more clean headroom at all. <b>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.</b> 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"></font 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 <u>is</u> a factor is the <u>overall</u> cab sensitivity, (= efficiency = volume out for a given power input in dB/w/m). That <i>does</i> tend to increase a little when adding identical speakers, especially if placed close together.
See here:
<blockquote id="quote"><font size="2" face="Verdana" 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"></font id="quote"></blockquote id="quote">
<blockquote id="quote"><font size="2" face="Verdana" 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"></font id="quote"></blockquote id="quote">
So johnnyblues if you set your TT to its maximum clean output, the same power level <u>will</u> 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 <u>will</u> 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.