Bill Fitzmaurice

Tell that to Derek Smalls. ☺️

Pedals are made to go into bass amps. Rack mount pre-amps are made to go into power amps. I'm sure there are exceptions, but the only way to know if any combination is to make sure that the output voltage of the pedal is at least equal to the required voltage to drive the power amp to full output. Unfortunately neither your SPB-1 nor your GSS provide those specs. The impedances aren't the problem, it's the output voltage of the pedal and the input voltage sensitivity of the power amp.

The SBP-1 is a floor pedal, not an active bass, but you're on the right track. Floor pedals by and large are gain configured to drive a full on bass amp, not a power amp.

I drive a BMW. How do I load my gear? Very, very carefully.

Create your own riser. A road case for your cab or combo would work well without needing extra pack space.

What's happening is that the low frequencies from the subs are not directionally locatable, as their wavelengths are too long compared to the distance between your ears. Really. Binaural hearing allows us to triangulate sound source locations only when the wavelengths are short enough so that the ear/brain can detect the difference in the arrival times at the left versus the right ear. That occurs on average above 100Hz. Since we can't tell where the low frequencies are coming from we take the directional cues from their harmonics, which are coming from the tops. This is what allows us to place subwoofers away from the tops, in both live sound and home theater. My HT folded horn sub sits 30cm to my side in my living room, where it does double duty as a table. My mains are 3 meters in front of me. I cannot tell that the sub is next to me, the bass seems to be coming from the mains, even when movie low frequency sound effects are reaching 120dB.

You're getting all the width to the sound field as is possible already. The midrange drivers insure that the upper woofer doesn't go high enough to get beaming from it, bi-amping insures that the lower woofer doesn't go high enough to get beaming from it, and having the midranges vertical insures the widest possible dispersion from them. Plus the tweeter takes over where the midranges start to droop off-axis. The tweeter in the lower box should be shut off.

The port isn't right for sure. A port of that diameter is appropriate for one ten, but not four. That raises the question as to if the cabinet volume is correct. I suspect it's too small. The idea behind this cab is a good one, but the execution appears to be lacking.

Try it. The speaker will distort at levels far below what it would take to damage it. If it does turn it down and/or reduce the bass EQ.

Don't double post. 😒

No one can give a definitive answer without knowing what you have for an amp and cab. I can say that you've fallen into the watts trap. Watts don't determine how loud or low your rig will go, not with respect to the amp, not with respect to the speaker.

So we'll call that 30L tuned to 65 Hz. Two that will work well are the Celestion TF1230S and Lavoce WAF 122.50.

And the port? If there is one.

Precise measurements of the cab are the first step.

While it may sound bass heavy the reality of reggae is it's midbass heavy. This is an RTA of The Wailers, through a no holds barred million quid system, taken in the FOH, the best seat in the house. Most of the energy is between 60 and 180Hz.

These quite different experiences point out that it's not the brand that matters, it's the specific cab. One might as well be asking 'Any experience with Toyota?' That depends. Toyota Aygo? Or Toyota Mirai?

Not 4x but 2x at any rate. Indoors the bass bins get boundary reinforcement, outdoors they do not. That translates to no less than 6dB less output to the audience outdoors. Doubling the cab count realizes 6dB additional output.

Hire, with a sound man. In terms of what you need for outdoors versus indoors it's at least twice the kit.

That would be my guess.

Ask your girlfriend if size matters. 😲 Where speakers are concerned cone area doesn't, cone displacement does. But box size is the other way around. All else being equal (though it never is) the larger the box the lower it will go. What this boils down to is that without a lot of information that speaker manufacturers don't provide you can't know how any two cabs will compare. If I was to venture a guess I'd say the Mesa is more capable than a single Big Ben.

Any that have a gain and a master volume.

It also only fully worked at lower volumes, the effect being reduced as the volume control was raised.

Axial frequency response of the 210 and 410 will be almost identical. It would favor the 410 with enough voltage for the 210 to suffer from power compression both thermal and mechanical, but that's a different question than what the OP asked. True, the mids will sound louder off-axis. Not quite. In the OPs scenario the voltage to each cab is the same. In the case of the 210 the displacement (T/S spec Vd) is doubled. When you double displacement with the same voltage to each driver, as is the case with parallel wiring, you get a 6dB increase in sensitivity. Doubling Vd again with the 410 would get you another 6dB with parallel wiring, but with series/parallel wiring the voltage to the individual drivers is halved, which reduces sensitivity by 6dB for a net zero gain over the 210. To realize the 6dB higher maximum SPL from the 410 compared to the 210 you'd have to turn up the volume to double the voltage output, which then results in all four drivers receiving the same voltage as those in the 210. The takeaway here is that it's not the power or cone area that counts. It's the voltage and the driver displacement.

OK, so if the same driver is used, and the same box volume and tuning per driver is used, with parallel wiring the 2x10 will be 6dB louder than the 1x10. If the 4x10 is parallel wired it will be 6dB louder than the 2x10. However, chances are the 4x10 can't be parallel wired, because the impedance load would be too low for the amp to handle. It would likely be wired series/parallel. In that case it would be the same as the 2x10. The 4x10 can go 6dB louder than the 2x10, but only by turning up the volume. And all the conditions must be met. If any or all of them aren't then the calculation doesn't work.

It's getting worse. ChatGPT is really bad, because what it posts comes from searching sources on line. When the search turns up bad information it passes it on without peer review. 😒