Bill Fitzmaurice

3dB isn't much, but that was referring to the increase in output with no changes to the amp setting. The additional 6dB of maximum output, when both drivers reach their mechanical limits, is substantial.

There's no such thing as ohmage. Ohms are used to measure resistance, impedance, capacitive reactance and inductive reactance, so if one says' ohmage' it could refer to any or all of those factors. Adding a 4 ohm cab to an 8 ohm cab won't cause anything to blow, assuming the amp is rated for the resulting 2.67 ohm impedance load. Adding a second identical 8 ohm cab will result in a 3dB sensitivity increase compared to a single 4 ohm cab, assuming the drivers are identical save for their impedance. The pair of 8 ohm cabs would have twice the driver displacement of the 4 ohm cab, so they would have 6dB higher maximum output capacity.

Not if it's tuned wrong. How it will work with a driver for which there are no T/S specs is anyone's guess. If you want an inexpensive cab there's plenty of used available.

Headphones have flat response, bass cabs are anything but flat. What sounds good through the one will never sound good, or remotely close to the same, through the other.

Judging by the copied and pasted 'Features' it's the same driver. Since there are no T/S specs, and I very much doubt the builder has the gear or know how to measure them himself, there's no way the cab could have been properly designed. I can't imagine the size of the ports was arrived at by any method other than 'they fit my hands'.

I don't know if it's an Alpha, but at that price it wouldn't be anything more substantial than that.

The Alpha 12 weighs 2.4 kg, the Deltalite II 2512 2.3 kg, so neo doesn't always mean lighter weight. A Delta Pro 12 is 7.4 kg, so that's the price/performance range where neo would save weight. Still, the most weight savings come from using well braced 12mm plywood, rather than sparsely, if braced at all, 18mm.

You mean SLA Pro? The ports aren't ducted because the cab is tuned to 95Hz, for maximum sensitivity and output above 85Hz. That's perfect for mating with subs to handle below 100Hz in a full range PA system, or for use without subs when there's no low frequency content. You'd never want a bass cab tuned that high.

If you have a good PA then your back line cab is more of a personal monitor, as it no longer needs to drive the entire room by itself. There's no reason why you can't still use a 2x15, but if your gear hauling capacity is limited the pack space that 2x15 takes up would be better served carrying a larger PA.

I can't speak to his motives, but I can speak to the engineering. Since a ported cab needs ports and it needs handles it's practical to combine the two where it makes engineering sense. In a bass cab it doesn't. For a port to double as a handle it can't have a duct. Without a duct the port area must be quite small to tune the cab low enough for bass. The problem is that too little port area leads to chuffing noise from the port, while a non-ducted port large enough to not chuff can't tune the cab low enough for bass. I use port handles only in PA tops that are tuned much higher than bass cabs, as those tops are meant to be used with subs handling the lows.

That will only put undue strain on your 2x15. Get a proper PA, because the lack of definition lies in the midrange and high frequency quality of the PA, not the lows.

I have serious doubts that he knows what he's doing. For instance: The two bass vents act as side handles. They are positioned to let cooling air flow to the speaker. On stage they send low frequency sideways which doesn’t muddle the sound you hear. The output of ports is 100% omni-directional. For that matter from a cab of that size the direct output from the cone is omni-directional below roughly 250Hz. 🤔 There are a number of other issues with his claims, but this one alone is enough to convince me that you should probably avoid them.

They'll work, but they're not matched. There's a difference. In any event mid cancellation on the horizontal plane happens when either drivers or cabs are placed horizontally. The cure is easy, don't do that.

That will cause low frequency cancellations. Put one cab on the floor, aimed at the drummer, for him to hear. Put the other on top of it aimed at you for you to hear.

A full crossover really isn't called for, as this isn't a sub/midbass arrangement as you have with PA. In order to make best use of it I'd set the sub low pass between 200 and 500Hz, whatever sounds best. There won't be any phase issues between the sub and the 112s with the sub only working that high, it's only above 800Hz or so where phase interactions between different drivers operating in the same pass band can cause more harm than good.

The line out will drive a sub, and as the sub should have its own volume control so long as the line out from your amp is post-volume control it will control both. However, for the sub to be worthwhile it would have to be at the very least a 115, if not a 118, with at least twice the power as your ABM.

You may have seen somewhere that the inherently low damping factor of tube amps works better with sealed cabs, but it's not true. This explains why damping factor is a non-issue: www.cartchunk.org/audiotopics/DampingFactor.pdf

Not knowing the exact topology of the cab I really can't say, other than it might be a dual chamber reflex. Many examples of dual chamber reflex can be found on line.

By your description it may be a dual chamber reflex. If that's the case the first mention I recall of it was in a book by David Weems, circa 1980.

No problem, since it's fan cooled the only potential issue, heatsink/vent orientation, doesn't exist.

Ampeg may seem a big deal, but in the scale of things bass amps and speakers are small potatoes compared to the PA gear that's the meat and potatoes of LOUD. My guess is that Yamaha finally gave up on trying to crack the American market for amps (do they sell in Europe of the UK?) and probably picked up Ampeg for a song, so now they can get into that market through the side door. It will be interesting to see if they sink any money into R&D.

The BP102 has very poor midrange response. I only use them in subs or with midrange drivers. If you can't match the existing drivers you need to replace all of them, but only after using speaker modeling software to confirm if they'll do what you want to do in your cab.

There's no point. You may think that there's an advantage to the proverbial 'getting all the watts out of my amp', but there isn't. If you did have a 4 ohm cab versus 8 ohms the greatest potential difference in maximum output would be 2dB, which is inconsequential. That's best case, with an amp that's rated no more than 1/4 the cab power rating. With a less skewed amp to speaker power rating, where the maximum output is likely limited by the driver excursion, there would be no difference. The speaker outs are already connected within the amp. That cable would accomplish nothing.

I'll be the first to point out that if a 410 isn't loud enough you should be looking at a better PA, not adding another cab. If you're having trouble hearing yourself elevate and/or tilt your cab back. You don't have hearing receptors on your calves.

The link is to instrument cables, where shielding is required. The sales pitch is pure Monster, and just as silly. Not that there aren't factors to consider with instrument cables, mainly capacitance when used with passives. But low capacitance cable is both common and inexpensive. I found on their site shielded speaker cables, predictably aimed at the home theater/audiofool market. FWIW no one has ever come up with a speaker wire that works any better than lamp cord. Quite the contrary, expensive/complicated constructions tend to work worse. As it this case with all cable crooks what's completely lacking on their site is definitive data to back up their claims, because there is none.