Bill Fitzmaurice

I can show you eighteens that only go to 60Hz and fives that go to 30Hz, so it's no. As for the missing fundamental, that's useful tech to a point, that point being when for whatever reason you can't use a speaker capable of going low, so at least it seems like it goes low. You don't see it used in pro-sound, because there's a lot more to deep lows at high SPL than just what it sounds like, namely what it feels like. The missing fundamental won't flap your pants in front of your rig, or pound chests out front.

The missing fundamental effect is real, but the harmonics that create the effect are electronically generated. The only way the speaker enters into the equation is that since it doesn't have to play the fundamental it can be smaller.

The differences aren't subtle at all when what's being measured is the off-axis response at a distance. That's where size actually matters.

Quite right. What I meant to say is that with lower impedance the cone will move further with the same applied voltage, and the further the cone moves the louder the sound. Current goes up, which causes power to go up, but the downside to that is too low a load impedance draws more current than the amp can comfortably deliver, both with respect to the power supply and the output devices. What's key to the oft mentioned 'I want to get all the watts out of my amp' is that to sound twice as loud requires ten time the power. At maximum output the average amp will only deliver 1.7 times the power into 4 ohms versus 8 ohms.

That's because an amp will deliver higher voltage into a lower impedance load. No matter, the difference in what you'll actually hear is slight, if any. There are a lot of factors that determine how loud a rig will go, and watts are only a minor part of the equation.

True, and if it has a tube rectifier you get more compression than with diodes.

SS or valve? SS OK. valve only if it has a 16 ohm labeled jack.

If you can hear the fan you're not playing loud enough!

The only way to know for sure is to use speaker modeling software to compare both drivers in that cab. You need the Thiele/Small specs on the Ashdown driver to do so, which may not be available.

Headphones have much flatter and wider response than speakers. The ideal headphone has no coloration, while all bass cabs have some coloration, and most bass cabs have a lot of coloration.

The math is quite daunting, if you do it yourself. Thanks to Bill Gates and other software developers you don't have to. Loudspeaker modeling software does all the heavy lifting.

There's no problem playing active bass through any rig, if it clips the input just turn it down. The problem you'll face with the BA 330 is it's not going to be able to handle lows at more than coffee house levels.

In general the higher the excursion the lower the sensitivity, although it's not a hard and fast rule, as excursion alone doesn't determine sensitivity. It's not easy to compare apples to apples here, but two drivers that use the same motor with different excursions are the Eminence 3012HO and 3012LF, at 6.2mm 100dB/w and 9.1 mm 95dB/w respectively. They also have different response, which is related to their different excursion, but only in part, as other parameters affect the result. This goes back to the fact that be it a raw driver or a finished speaker you can't consider just one or two specs, you must consider them all. With raw drivers that's usually not a problem, as most driver manufacturers publish all the driver specs. With finished speakers it's usually not possible, as very few publish all the specs, if any.

You can only turn the volume up so much before you either toast the voice coil or slam it into the back plate. Every 3dB reduction in sensitivity equals a doubling of power for the same output, assuming the amp has the required power to give. Your questions reflect the primary problem with specs. When they're incomplete what they don't reveal is usually more significant than what they do.

-3dB at 40Hz or any other frequency is meaningless in and of itself. I can show you 6 inch loaded speakers that are legitimately -3dB at 40Hz. The problem is that they only have 85dB/w sensitivity. Search: 'Hoffman's Iron Law'.

Or not. FRFR can apply to a small 1x10 PA main. It can also apply to a 2x15/2x6/tweeter monster. Most PA mains are FRFR, but by no means are most FRFR speakers PA mains. The confusion over this explains why this long dead horse continues to be beaten to excess.

That's the fault of the room, not the speaker. Reflections off nearby walls and the ceiling create low frequency null zones. If you're standing in one of those null zones the bass will disappear. When you move away from the null zone the true output of the cab will be heard.

FRFR means full range flat response. Ideally that's what PA is, but you can't get flat response to low frequencies at stage volumes without either the cab being large or there being a separate sub.

The thermal power rating is meaningless in and of itself, just as the driver diameter is meaningless in and of itself.

You don't necessarily have to keep the volume at zero, depending how the amp is laid out. Usually if you plug in to the send that prevents any signal from reaching the power amp unless you also plug into the receive jack.

Those specs are way shy of being useful. For instance, while it may be -10dB at 35Hz, what is the 1w/1m SPL? 98dB? 88dB? That's critical information which is lacking. I can say just by looking at it that it won't have a big low end, because the trapezoid shape causes the box volume to be too small to have a big low end.

Lumping all 212s, or for that matter all of any speaker configuration, into the same performance category is as valid as saying all vehicles with 380HP engines perform the same. There's a big difference between a 380HP BMW Z4 and a 380HP 2.5 ton pickup truck.

Sure. If I was looking for a vintage head it would be an Ampeg V4, which is rated similarly for power but it's a very different animal, quite gig worthy. I'd pass on any vintage speakers, the technology there has advanced far too much. You can get the same output, or more, from a modern 212 as with a vintage 412.

You can't go by the specs, as they're far too incomplete to be of any real use. I can say that the vast majority of powered PA, even those loaded with 15s, are made to work best in the vocal range, with the lows handled by subs. They also don't have pre-amps voiced for bass. That makes them very much a try before you buy proposition.

Since the channels are Normal and Bass and there's no tremolo, vibrato or reverb it's a bass rig. It is an updated Fender Bassman, Musicman being the company Leo Fender founded after selling Fender Musical Instruments. Based on that I'd expect it to be much like a Bassman, which means it's a guitar amp without tremolo, vibrato or reverb. The head is probably OK for low volume gigs, but the speakers were always the weakest part of the Bassman, and I'd expect the same with this.