Bill Fitzmaurice

Because the same settings will sound different in every room. Sometimes you really have to wonder how guys who make money creating sound have no idea how sound works. That's why you take an RTA with your phone. You don't need to guess which frequencies need adjusting or by how much. It's right there for you to see.

You can't adjust EQ from the stage, you have to do it listening or measuring, preferably measuring, out front during sound check.

You might want to consider retiring those cabs. A Barefaced 212 has the same output capability as that of a 3620.

First off, chaining them in series would be 16 ohms. When amps have two outputs they're almost always wired parallel. That's how you get a 4 ohm load from two 8 ohm cabs.

The brand doesn't matter, the specs do. In this case that driver works best in a 300 liter cab, not 90, while the short 3.4mm xmax is barely adequate for electric bass.

You can have a ratio of a ten watts amp to one watt cab and they'll be fine, just don't turn the amp up past the point where the speaker distorts.

The Jensen is not very good. Response is boomy, while it's mechanically limited to 150w.

You only need to calibrate it if you want an SPL reading, which you don't need for seeing the system response.

Did I fail to mention you need separate EQs for monitors and mains? 🫢 EQ adjusts the response to suit the room. However, the room consists of two separate entities, on the stage and in the audience. On the stage you're trying to get maximum intelligibility without feedback, in the audience you're trying to get the best overall sound quality. Seldom the twain do meet.

Bass, and for that matter any instruments, though the PA isn't about volume so much as it's about dispersion. Dispersion is a midbass and higher frequency concern, so high passing the bass at 60 to 80Hz doesn't interfere with it.

High passing both would be double filtering. But that's not necessarily a bad thing. PA pros with high quality DSP crossovers usually use 48dB/octave slopes for maximum mains protection and minimal pass band overlap. It's unusual for the slopes in powered speakers to be that steep, so your thought of trying it both ways is valid.

If you don 't high pass the mains you're at least doubling the stress on their amps and drivers; taking the load off them is one of the reasons for using subs. You also open the possibility of low frequencies from the mains cancelling low frequencies from the subs.

What's the name of the band? The Luddites?

Harshness very often is the result of high THD. That can be sourced with too high a signal level anywhere in the chain, going all the way back to the channel input trim.

+1. That's the myth of underpowering, the notion that clipped signals will kill speakers. If that was the case there could be no such thing as distortion effects. Distortion can toast tweeters, but not because the amp lacks enough power. It's because the abnormally high harmonic content over-powers them.

I did that too, until 20 years ago, when I went to DSP with auto EQ. But you can manually tune EQ almost as easily with one of these on your phone https://play.google.com/store/apps/details?id=radonsoft.net.rta&hl=en_US and one of these for your mixer http://www.flatkeys.co.uk/P!NG.php

EQ isn't optional, it's mandatory. Without it you can't compensate for the room acoustics or tune out feedback. There was a time when I didn't have EQ. That would have been in the early 1980s. 😲

Anywhere between 1/2 and 2x the speaker rating is good for amp power. What manufacturers don't tell you is the mechanical power capacity of cabs, which can be as low as half the thermal rating. Very few have mechanical capacity equal to thermal capacity. To get a meaningful increase in amp headroom requires a 6dB increase. That's four times the power.

Tossing random drivers into a box is a time honored tradition, started by Leo Fender, continued by Jim Marshall. 🤪

Adding a 4" mid will do the job, but 200Hz is too low for the crossover. 800 to 1200Hz is the appropriate range. Read this: https://www.basschat.co.uk/topic/496512-replacement-hi-mid-driver-for-tecamp-puma-110-combo/

Most, but not all. The Simplexx subs are ported boxes, but still employ well braced 12mm construction. That's the scenario if precautions aren't taken, so we do, using DSP to high pass and limit the signal from the amp.

Oh, it has to be Penn and Teller. The sound is pure magic.

Morecambe and Wise?

There is one already, though room for more. https://billfitzmaurice.info/Builders.html

The ones I design don't weigh a ton, because I employ well braced 12mm plywood construction. Commercial cabs tend to use minimally braced, if braced at all, 18mm or heavier material. That's because bracing is a labor intensive process, which adds to cost.