Bill Fitzmaurice

If it's bi-amped the crossover will prevent lows going to the 210. When not bi-amped turn down the bass EQ.

That wouldn't be affected by the cab height, as low frequencies radiate omni-directionally. Mids and highs are directional, so the cab must be higher to hear them well.

Even at 125Hz 'A' weighting is 20dB off from actual. To bring that into a more meaningful context 20dB is the difference between 10 watts and 1,000 watts. 😳

If it was high frequency feedback that's a possibility, albeit a slim one. If it was low frequency feedback it was just too loud.

Not really. You can get by with a C weighted meter, for instance: https://www.amazon.com/Professional-Backlight-Accuracy-Measuring-30dB-130dB/dp/B01MZ0IUGY/ref=asc_df_B01MZ0IUGY/?tag=hyprod-20&linkCode=df0&hvadid=312357852128&hvpos=&hvnetw=g&hvrand=7748314164138405611&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9002322&hvtargid=pla-348660547600&psc=1&tag=&ref=&adgrpid=62539486699&hvpone=&hvptwo=&hvadid=312357852128&hvpos=&hvnetw=g&hvrand=7748314164138405611&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9002322&hvtargid=pla-348660547600 I was hired by a major outdoor concert venue that was being threatened with imminent shutdown because of noise complaints from the neighbors, despite having already paid a 'professional' sound control company $50k for a sound metering system. The complaints were about excessive bass up to two miles away. It took me all of five minutes to see what their problem was. The system was 'A' weighted. According to it the levels off-site never exceeded 75dB. But it didn't measure bass, so the actual off-site levels were routinely hitting 105dB and more below 100Hz. I wrote a new sound control protocol for them, then attended their concerts for three years to ensure compliance. It paid me better than playing, so I had no complaint. The noise complaints went away as well.

dB (A) is useless for music, it doesn't measure bass. You must have a dB (C) meter at the minimum, dB (Z) being preferred. https://www.noisemeters.com/help/faq/frequency-weighting/

In the case of under-hung voice coils the calculated xmax was zero. That caused more than a bit of consternation for loudspeaker designers. Eminence was one of the first to adopt Klippel. Circa 2004 they had to switch voice coil former suppliers, as DuPont stopped supplying Kapton to the industry. Changing the formers changed the driver specs, so they had to measure them all with the new formers to update their data sheets. They had recently acquired a Klippel analysis rig, so from that point used it to measure xmax dynamically. Most manufacturers have since followed suit.

All drivers exhibit this behavior if sufficient power is applied to push the cone past xmax. However, at higher frequencies the voice coil may burn out first. Even when present one might not be aware of it when it's not severe. The fact that speakers have a point beyond which more power applied only creates higher THD has been employed by Klippel GmbH in redefining how xmax is measured. It used to be calculated by comparing the voice coil length and magnet top plate thickness. It's now the excursion at which THD reaches 10%.

That's not only not unusual, it's common. How sound waves work isn't the least bit intuitive, so it's a field where you must be taught. Figuring it out on your own isn't impossible, somebody was the first to do so, but it's not easy.

Yes, assuming the amp can handle the halved impedance load.

Boundary reflection sourced cancellation. It can boost it as well, via cabin gain. I'm afraid not. What is happening is that the cancellation modes that exist within the walls don't exist outside of them. It's the exact same reason why volume on or near the stage can be less than at the back of a room. That phenomenon gave rise to the myth of wave propagation. Running out of driver excursion will do that, but not the room. Continuing to crank the volume results in increased compression and THD. It won't hurt an amp, and may not hurt the speaker. It's how guitar amps get a sweet cranked sound. Guitar drivers are made with a short excursion, xmax, to make it happen with as little power as possible. Bass drivers have long excursion to prevent it from happening to the greatest extent possible.

It will, by up to 6dB with another identical cab depending on the particulars. That's the equivalent of quadrupling power.

They still are. 😉

All things considered if I had to settle for store bought I'd have a pair of 8 ohm 210, stacked with the drivers vertical. When two aren't required leave one at home.

Whatever. I still use real measurements that we got from good King Henry VII, not that latecomer Napoleon.

Neo cabs aren't necessarily lighter. For instance, one of the most common tens is the Eminence Beta 10. It weighs 3.1 kg. The neo Deltalite II 2510 weighs 2.1 kg. In a 410 the driver weight difference is only 4 kg. Neos are quite a bit lighter when you're talking about premium drivers, but most bass cabs don't use premium drivers. It's a different story with the cab material. A 120 mm x 240mm sheet of 18mm Italian Poplar weighs 21 kg, the same size of MDF in 15mm thickness weighs twice that. You have to look at the weight of the finished cab, not just the driver magnet material.

It's a real thing, in concert sound applications, with arrays that are at least 3 meters high, either stacked or hung so that the lowermost cabs in the array are well over the heads of the close in audience. The lower cabs are tilted down to aim at that close in audience. Doing so with an array the size of that Yamaha is as useful as the inclusion of mammary glands on a male bovine. They're obviously trying to cash in on a buzzword that potential buyers may have heard but don't understand. I'd expect that from Bose, but not Yamaha. 🙄 As for ten 1.5 inch drivers delivering high quality sound over long distances, clearly their definition of long distances isn't the same as mine.

The 410 is a classic example of how not to build a speaker. Placing drivers side by side halves the midrange dispersion compared to vertical placement, while creating comb filtering in the highs. That. It gives maximum horizontal dispersion, no comb filtering, and places the upper drivers high enough so that you can hear the mids and highs without having to stand 3 meters out.

Diversity is just what you don't want. The two cabs would be both augmenting and detracting from each other, depending on frequency, while the 410 would likely be cruising comfortably while the 115 is stressed. Mixing different size drivers to take advantage of the main difference in how they work, which isn't response, it's dispersion, is SOP with hi-fi and PA. But in hi-fi and PA crossovers are employed so that the different sized drivers are not operating within the same frequency bandwidth. They've done that since the 1920s. Electric bass cab manufacturers as a whole are just a wee bit behind the curve. 🙄

+1. Get another identical 115. Not only will it work, it will work better than mixing cabs.

That goes to the history of tweeters in bass cabs. They were added to enhance high frequency response at the lowest possible cost. Midrange drivers would have been a better choice, but they were much more expensive, so tweeters were employed instead and the die was cast. 4kHz is fine if your style works with that. I prefer at least 8kHz myself. But even Marcus doesn't need anything above 10kHz.

Most look pedestrian, other than the two fifteens to the right and the EVM 12 next to them.

4x1300 watt should have tipped you off. Yes, such amps exist, but only from the likes of Powersoft, and only for mucho dinero.

Way back when 25 watts was a big amp bi-amping was employed to give more power to the system, and to save HF drivers. When a full range amp was pushed to clipping, which was common when the power available was so low, that clipping resulted in harmonic levels far above normal, and that would toast high frequency drivers. That's no longer an issue today, but modern digital crossovers allow very high filter slopes. 24dB/octave is the practical limit with passives, while 48dB/octave is common with digital signal processing. Very high slopes allow running high frequency drivers to lower frequencies, for better system dispersion, and much better driver protection. Your example is one where b-amping is worthwhile. Effects, be they time based or distortion based, work in the mids and highs, so ideally they go though their own amp and speaker, with the lows remaining unprocessed through their own amp and speaker. Chris Squire more or less invented this technique, using a bass amp for clean lows and a cranked Fender Twin for the distorted mids and highs.

Not necessarily. For one thing you'd need at least two premium fifteens to handle even 800w. Passive crossovers can handle that. The crossover wouldn't likely be below 800Hz, so the size and price of the components wouldn't be a problem. The amount of power loss with a well designed crossover is insignificant. Bi-amping and tri-amping make sense with large PA systems, but where electric bass cabs are concerned it's an unnecessary level of complexity. That was probably because they didn't sell well. My preference is for a 2 way, albeit crossing over to the HF element at 2kHz. The typical 2 way bass cab crosses over at 4kHz, resulting in poor off-axis response in the 2kHz to 4kHz octave. There's also no reason for having response above 8kHz. Even slap and pop doesn't go higher than that.