Bill Fitzmaurice

The problem isn't the power ground, it's the signal ground. With unbalanced 2 wire interconnects the signal ground and power ground are connected, which can lead to ground loops. The usual cure is lifting the signal ground at one end of the connection. You never lift the power ground. Properly configured 3 wire balanced connections don't have ground loops, as the power and signal grounds are not connected.

You need to use a combination of lowered gain on the amp and lowered volume on the bass. Amps with passive and active inputs get around this by padding the level of the active input, but it you only have a passive input you have to do the padding yourself.

https://www.ranecommercial.com/legacy/note110.html

For sure the Bassman was a POS. The amp was a slightly modified Bandmaster, the speaker was an un-modified Bandmaster. In '65 there wasn't much else to choose from. The first speakers that managed to handle my Bassman's 50 watts were a pair of Kustom 4x12 columns. 😲 Being 30 years before there was an internet my first exposure to the science of speakers was when I found Olson's 'Acoustical Engineering' at my college library, which prompted me to start designing and building my own speakers in 1969. That Bassman was the last factory made speaker I owned.

+1, with a caveat. Upper midrange and high frequencies are very directional, so no matter how loud they may be on-axis they can be impossible to hear off-axis. Guitars with proverbial laser beam dispersion are the most obvious example, but it applies to every instrument, even the bass. You can stand behind a bass cab and hear the lows perfectly well, but the mids and highs not at all. A perfect monitor mix high passes above the frequencies that are audible without going through them, while providing the mids and highs that otherwise can't be heard. This applies to mains as well. Even in smaller venues the reason for putting everything through the PA isn't volume, it's dispersion.

Fender shorts the output because that doesn't hurt valves, while running with no load does. Every valve amp should do the same. Using the tap with the same rating is nice when you can do it, but when you can't using the tap that's closest to the load without being lower is perfectly safe. That's again because valves are the opposite of SS. SS is rated for the minimum load impedance, valves are rated for the maximum load impedance. 59 years using valve amps tells me otherwise. My first Fender was a '65 Bassman. I bought it new.

You don't need anything below 100-125Hz as you'll hear that from the mains, and if you put it in the monitors it will make everything muddy. I run the same mix as out front, as I'm mixing from the stage and want to hear in the monitors what the audience hears. I run just loud enough so everyone can hear everyone else.

Back when we didn't know an ohm from a watt we used to run our Fender amps with 4 ohm taps with 1 ohm loads with no ill effect.

Valves are the opposite of SS, they work better into a lower impedance than the tap rating. With a 2.67 ohm load use the 4 ohm tap. Realistically it won't make much difference, other than for peace of mind. Where you'd have an issue is using an 8 ohm load on a 2 ohm tap. That could lead to premature output valve replacement.

Apologies if this has been mentioned already, but the single most useful function I found when I went digital was individual input level meters on every channel. Mixing from the stage isn't easy when you can't hear the mix, but it's not so bad when you can look at the board and see the mix. With analog the only indicators I had were green for signal present and red for input clipping. The next most important feature was compression and limiting on every channel, with effects coming in third, rendering outboard gear unnecessary.

I didn't say that they don't sound good. My only issue was with the false information put forth on the video, the intent of which is obviously to disparage what he doesn't sell in favor of what he does. I get it, that's what advertising does. But BC's should be aware that's what it is, advertising, not a technical document. BTW, even short line arrays have a distinct advantage over point sources in smaller rooms. They have tighter vertical dispersion, which puts more sound to the audience and less at the ceiling and floor.

Some point sources work well enough, in small settings for the most part they're perfectly OK. But they don't compete with lines when using more than two cabs per side. (BTW, 99.9% of the time when you see point source cabs arrayed it's side by side, which actually reduces the horizontal dispersion. They should stacked vertically, the top cab upside down, which places the high frequency elements as close as possible in what's known as an M-T-T-M). The explanation given in the video why lines are problematic is totally incorrect. The sound from the individual elements in the line do not arrive at the listening positions at different times as individual wave fronts. With correct spacing the wave fronts from each element all integrate into a single coherent wavefront. If that wasn't the case line sources would have not almost completely take over the high end PA market. https://audioroundtable.com/misc/nflawp.pdf

I can't imagine anyone with half a clue saying that, but I guess there's plenty of PA operators who don't have half a clue. 🤥

It's nothing new here. Dodge, Buick, Oldsmobile, Pontiac,Chrysler, Plymouth, Chevrolet, Cadillac, all were originally stand alone companies before being consolidated under the General Motors and Chrysler Motors companies in the early 20th Century.

That was just an example. There will always be a cancellation notch where the speaker radiating plane is 1/4 wavelength out from the wall. The frequency depends on the distance, the longer the distance the lower the frequency. There are two ways to eliminate it. One is flush mounting the speakers in the wall, which isn't an option for the most part, although it is common in theaters. The other is to not have the speaker 1/4 wavelength from the wall below the speaker baffle step frequency (where the baffle is 1 wavelength in dimension, and dispersion goes to less than 180 degrees). For the 30 to 300Hz frequency range that's roughly between .3 and 3 meters. That's more or less impossible to do with large 3 way full range speakers, and is one reason why they've pretty much been replaced by separate subs and mains. You can place subs close enough to the wall so that it's not 1/4 wavelength out at any frequency within its pass band, and tops far enough away from the wall so that they're not 1/4 wavelength out at any frequency within their pass band. But you can't if they share the same footprint.

Wall or corner loading doesn't just give more output in the lows, it also prevents boundary reflection sourced cancellations. If your sub is two meters out from the wall you will have a cancellation notch centered at 42Hz. That's non-negotiable. As for the notion that wall or corner placement will give too much low end that's what volume controls are for. Some 75% of the energy required of PA comes from the subs. Anything you can do to improve the efficiency of the subs via placement will give cleaner output from both the subs and the amps driving them. Aiming the subs at the wall or into a corner makes for even lower distortion, as distortion manifests as harmonics in the directional frequencies above the sub pass band. They're attenuated by aiming the speaker backwards, while the output in the sub pass band is unaffected. I've been stand mounting my tops for thirty years and have yet to have a mishap. Perhaps it's because I have my Rottweilers stationed below them? If you have in ears exclusively there's no need for the precautions required with floor and/or side fill monitors.

You absolutely neither need nor want anything below 100Hz in floor monitors. Whatever is down there you'll hear from the mains or subs, because they're omnidirectional below roughly 200Hz. Having content below 100Hz in the monitors can even reduce overall low frequency output, because the distance between the various sources can result in phase sourced cancellations. All you want from monitors is the directional mids and highs that you can't hear from the mains. The main advantage to knowing the science behind low frequency production and dispersion is you can walk into a room and know where you'll get the best placement results just by looking at it. If you don't understand the science then your sub placement will be like playing darts...while drunk...and blindfolded. If you don't care about the results just hope that the audience doesn't either.

The seemingly small number of Eminence employees is because they source most of their components from Asia, so the Kentucky facility is mainly used for R&D, assembly and marketing. They opened Eminence Dongguan as it didn't make sense to have components shipped to the US for assembly and then shipped back to Asia. I don't see much changing with the new ownership, which was precipitated by the retirement of CEO Bob Gault. What's most likely for now is business as usual, with B&C being the parent of B&C, 18 Sound and Eminence, much like Harmon is the parent of JBL et al.

I've never encountered a situation where the sub and top could not be separated, as the sub can go pretty much anywhere. They don't even need to be facing the audience, or even able to be seen, because they're omni-directional, and the long wavelengths they produce aren't blocked by obstacles.

It had four notch filters for feedback control. Their frequencies weren't adjustable so they weren't very effective.

I bought my first SM58s in 1973. I doubt they were around much before that. They were an updated version of the 565. They were the first low impedance mics I owned, before that it was all high impedance, with 1/4" plugs. Mixers as we know them today hadn't been invented yet. The only mixers that could use low impedance mics were recording and radio broadcast mixers. I had to add another gain stage to the first generation Shure Vocal Master we were using to get it to work with the 58s.

It's not likely, with the exception of drum mics. But two points. First, sub output is omni-directional. Be they in front or in back of you the mics will still pick up the same content in the sub frequencies. Second, there's no need to put them in back of the band to wall load them. They can go off to either side, as not only are the subwoofer frequencies radiated omni-directionally, they're also not directionally locatable with our hearing. No matter where they are the directional cues for their content won't come from them, they'll come from the harmonics of the low frequency content which comes from the tops. If you're at all serious about PA the comments made here by Downunderwonder, Phil and myself are Gospel. Where low frequencies are concerned getting it right with PA is far more complicated than with bass amps, as nothing about how sound below 100Hz works is instinctive. You have to be taught. The guys who automatically put subs under mains split to either side have not been.

Lots of things aren't particularly noticeable if you're not able to make side by side comparisons. When you put subs under tops you not only lose boundary loading, by not have them close to a wall, you also can have cancellation notches when they're 1/4 wavelength out from a wall. If they're split by less than two wavelengths you will have power alley comb filtering. That's the science, and the science is never wrong. There are three reasons why people put subs under mains. #1: "That's how everybody does it". #2: "It's the only way we know to do it". #3: "We don't know any better way to do it/we don't know why it's the wrong way to do it". Now you know.

Replacing drivers is both a science and an art, and if you don't know what you're doing you shouldn't attempt it. For instance, the 250 watt rating of your cab is thermal. In most cases what limits a cab's output isn't the thermal rating, it's the mechanical rating. You could load it with a pair of 300 watt drivers that have no more mechanical capacity than what you have now. How would you know? You have to be an expert to make that determination. IMO if you want to get the most possible from a 2x10 and you're not an expert spend the money and get a Barefaced. They have the highest mechanical capacity available.