Bill Fitzmaurice

The load presented by a speaker has capacitive and inductive components, but it is mainly resistive. Where speakers are concerned capacitance is minor. Voice coil inductance is significant in that it increases impedance, but that reduces current draw, so where power factor issues are concerned it's not an issue. There are instances where a crossover can cause problems with respect to power factor, dropping Z lower than DCR, resulting in what's referred to as a difficult load for an amp, but that's in hi-fi. I've never seen it in pro-sound.

Volts multiplied by amperes is the very definition of watts. 1/8 power is the benchmark for measuring long term continuous amp performance as that's -9dB from maximum, which is the minimum amount of headroom required to prevent clipping during transient peaks.

You may be able to use the existing box with a new baffle, which should leave room for a line of eights or tens plus a line of tweeters.

You always get twice the power when you double the current via halving the impedance while maintaining the same voltage swing. That's an immutable law of physics. What can happen with not only Class D but with every amp class is that there's power supply sag at full power into a lower impedance load, so the amp can't deliver twice the current while maintaining voltage swing. That's why the full power rating doesn't double with halved impedance load. At less than full power it does double.

The truth of the matter is that the benefits of column speakers were well known going back to the 1940s, the main one being vertical pattern control. They worked far better than point sources in reverberant spaces, like clubs and other large gathering places . Perhaps the most noteworthy installation of them was in St. Paul's of London circa 1950. They worked well there for some fifty years before being upgraded with modern line sources. The demise of the column speaker came for two reasons. Foremost was the lack of high frequency drivers, so they sounded dull compared to point sources that had high frequency drivers, like the Altec A7, which spawned hundreds of similar designs. But there was also the fact that most users had no idea why they had good vertical pattern control, or for that matter what vertical pattern control was, let alone what comb filtering was and why placing PA cabs side by side was the worst possible configuration. It didn't help when trapezoid array cabs were introduced. They were supposed to make horizontal dispersion better, instead they made it worse. No matter, they were what buyers wanted, and manufacturers were more than happy to supply them.

I know, but that's not how it works. Cone excursion, which creates the sound waves we hear, isn't created by power, it's created by voltage swing. The voltage output of an amp is a constant into any impedance load. When you have one driver/speaker driven with a given voltage the cone will travel 'x' millimeters. When you add a second identical driver/speaker parallel wired the amp will deliver that same given voltage into both, so both cones will travel 'x' millimeters. This results in a doubling of the cone displacement. When you do that sensitivity goes up by 6dB, as does maximum SPL. Power only enters the equation insofar as the halving of the impedance load with the doubling of drivers/speakers parallel wired also doubles the current draw on the amp. Doubling current while maintaining constant voltage doubles power, but it's not that doubling of power that gives higher sensitivity or maximum SPL, it's the doubling of the cone area while maintaining constant excursion via constant voltage.

Nope, because then you lose the advantage of sensitivity and vertical pattern control of the column. The right way would be to use at least four tweeters arrayed vertically to one side of the woofers, in this fashion.

The main difference it that the old style 12" loaded columns usually didn't have tweeters, so they weren't much good above 3kHz. Columns equipped with tweeters would have been far superior to the woofer plus HF horn cabs that replaced them, but AFAIK no one ever made one.

You can't leave half a 210 at home when you only need a 110.

They're quite good. They don't have the thermal capacity of the Deltalites but they have what really matters, xmax. At 5.2mm the 2012 has more output capability than the 2512 with 4.9mm. I run a 2012 in my personal JackLite 12 cab and it does the job nicely, while weighing almost nothing.

Doubling the cab count gets you 6dB of additional sensitivity/maximum output, which is the equivalent of increasing power by a factor of four. The higher power output from the amp when the impedance load is halved doesn't result in the increased output, it's just a byproduct of the process. Putting the second cab atop the first makes the mids and highs more easily heard, which also increases the perceived loudness. If that's not enough then a better amp can be tried. While the 500w rating of the neo Rumble 112 is so much fluff it's loaded with a Basslite 2012, which has a real world mechanical capacity of 150w. A pair of them could handle a lot more amp than the TC the OP has.

Meters always measure DC resistance, which is on average 20% lower than impedance. It takes a much more complicated tool to measure impedance.

The reason for using an FRFR speaker is to remove speaker coloration from the equation, not to have overall flat response. Then the only tone shaping is done by the amp. In theory if you provide that tone shaped signal to the PA via a DI, which must be either in the amp post EQ or driven by the amp output, the sound in the PA will be the same as that from the stage. In theory, because it requires that the EQ at the console be left flat, that the PA subs aren't boosted in level, and that the in room response be the same in the audience as it is on stage. It's one of those ideas that seems to make sense but very seldom proves to actually work, because sound engineers are seldom if ever content to leave things alone. You may think that your tone is your business, but they tend to think that it's theirs.

Sadly you didn't get my drift. 😁

Since you have a driver that can't be used and a speaker that can't be used you've got nothing to lose by trying it.

Well this thread is a disappointment. I thought basshead56 might actually be Tal Wilkenfeld. 😄

Yeah, but audiophools are nuts. These are the same guys who believe in all the nonsense debunked here: https://www.skeptic.com/eskeptic/10-01-06#feature True Hi-Fi makes no alterations to the sound. With recordings that's a good thing, as all of the EQ and other effects required to get the desired result have been applied in the studio. IMO electric bass requires alteration to the original signal, via EQ and speaker coloration and if you care for it effects, to give the best result. Even if the bass was recorded straight to the desk in the studio the chances of it not being EQ'd and compressed in mixdown are slim to none.

200 honest watts is sufficient. Finding honest specs is the problem. No matter how much power the amp has your average PA twelve inch speaker won't take much more than 50 watts before distortion sets in, so 200 watts gives plenty of headroom. That opens a different can of worms, one you've already been made aware of. I still stand by my rule that you only get one chance to do it right the first time.

Ask ten people what makes an amp hi-fi and you'll get twelve answers. Besides, the amp is only half the equation. Speakers that have no coloration are rare. There are some that are so colored that pretty much any amp will sound the same through them. I wouldn't worry about how any amp or speaker might be classified and just use what sounds good.

A vented cab should be lined with an inch or two of damping. If sealed it should be totally filled.

Where the circuitry is concerned Behringer is perfectly OK. Where they cheap out is on connectors, both external jacks and internal ribbon connectors, so they're not as physically durable as many more expensive options.

There will be times when you won't want to bother, but I'd approach it with the attitude that it's better to have the capability and not need it than to need the capability and not have it. That mainly falls on the mixer.

Maybe that's why you're still playing small pub gigs? 🤔 I get what you're saying, it is a lot more work to run everything in the PA. I've done so since the 1980s because no matter how small or large the venue I want to sound as good as possible. As for sound checking I hardly do any. Auto EQ sets up the system to the room in a matter of seconds, and since I can see what's happening with the board even with the mains power amps off I'm not bothering patrons either. The only thing I spend much time on is the monitors, as I know if they're right the FOH will be right too.

When mixing from the stage I run the same mix in my monitors as out front, so I can hear if something is off. I also have a mixer with full LED output level metering on every channel, so what I might not hear I can see.

They have in common Eminence drivers that don't have long excursion capability. If you go to something like Barefaced that has long excursion drivers you can get the same output from a smaller box using half the driver count. But, and there's always a but, the tone and timbre that shorter excursion drivers contribute to the result isn't going to be there. Whether or not that works for you is 100% subjective. We all do, it's unavoidable, even among those who know better. http://seanolive.blogspot.com/2009/04/dishonesty-of-sighted-audio-product.html