Bill Fitzmaurice

He may, he may not. When I do my initial sound check in a smaller room without major PA support I do it from out on the dance floor, adjusting my volume and tone for the best result there. Whatever that ends up sounding like on stage I live with.

Functionally a send and an active DI should be essentially the same. They may differ in whether they're pre or post EQ. The amp block diagram would reveal that.

At the very least either lift the cab or tilt it back to aim the drivers as close as possible to your ears. One of the reasons why the 8x10 gets so much love is its height allows you to hear the mids and highs.

Google 'boundary sourced low frequency cancellation'. You get it when you're close to boundaries. It goes away when you move away from them.

That. The cone area of a five inch cone, Sd, is around 100 square cm. Four of them is around 400 square cm. An average twelve is 530 square cm. Just as significant is the excursion limit, xmax, which combines with Sd to give displacement, Vd. Vd defines how loud a driver may go. An average five inch Vd is 50cc, making it 200cc for four. An average twelve Vd is 300cc, a high end twelve Vd is 500cc. There are a number of other factors which impact how low a five can go. They can go as low as larger drivers, but to do so they sacrifice sensitivity, which means less output per watt of input. I'm a big fan of fives myself, in the right context, which IME is as a midrange driver used in conjunction with a larger woofer.

You need sufficient gauge to handle the current without overheating and not cause voltage drop. At 1 meter it doesn't take much. Wire gauges are typically used in the same locales that use inches and feet, mm where they use metric, for the same reason. This is a must read if you don't know anything about cables. It's aimed mainly at the hi-fi crowd, as they tend to be more easily scammed by cable mountebanks than professional musicians, but the physics still apply. http://www.roger-russell.com/wire/wire.htm

I have no issue with buying rather than making your own, even though it's a ten minute job. But at least buy something that's reasonably priced, twenty quid tops. The reliability factor is determined by the quality of the connectors. Those I linked from Blue Aran are as good as it gets.

That's an insane price for a one meter cable. As for all the claims they make, they're piffle, the entire lot. A pair of these, along with a meter of zip cord from a local hardware store, is all you need. https://www.bluearan.co.uk/index.php?id=NEUNL4FX Just be sure to get Neutrik, not an imitation. The knock-offs have been known to cause problems. You're a bass player. You're supposed to be the smart one in the band. 🙄

When you've got four identical woofers sharing the same airspace you're not going to get a significant difference in response from each pair even if you were to bi-amp them, let alone dual amp.

The BN10-200X is displacement limited to 120 watts, so a 500w/8 ohm amp would have no problem driving four of them to maximum output. If you can't find one rated for 2 ohms rewire them to series/parallel for 8 ohms. BTW, you didn't bi-amp if you didn't have an electronic crossover. You were dual amping.

You might not need as much power as you think, nor dual heads. I may be able to confirm it knowing what drivers you have.

Actually it's small, low and sensitive. Money does enter the equation, as longer xmax drivers capable of going low in small boxes tend to be more expensive, but they still can't get around the sensitivity, so to go loud requires more power, which means a more expensive amp as well.

That has nothing to do with the magnet material. A higher Fs and other factors give the BN300S higher sensitivity in the mids, but also result in less low frequency extension. One of the highest sensitivity drivers ever made was JBL D130, which had an AlNico magnet. It also had very poor low frequency response, but that was an acceptable trade off in 1948, when 25 watt amps were state of the art. It was also designed some 17 years before the advent the Thiele/Small specs. Only after that did designers realize that the main way to get higher sensitivity, more magnetic flux, doesn't increase sensitivity linearly across the full audio spectrum. It tilts it to the mids and highs. Where electric bass is concerned you want to compare sensitivity where it matters most, 50 to 80Hz. You can't do that with manufacturer data sheet charts, as they are measured with the driver mounted in a wall, and don't show the results in an enclosure. You need to use speaker modeling software to do that.

Chances are you can't find one, not that it matters. Cab ratings are thermal, and next to meaningless. What matters is the mechanical displacement, how much air the driver cones can move without creating high distortion or suffering physical damage. You can find out the displacement if you know what drivers are being used and have their Thiele/Small specs, but cab manufacturers are loathe to reveal that. Barefaced does, with good reason. They boast as much displacement as anyone, more than most. It's the main reason why they're held in such high regard. https://barefacedaudio.com/pages/how-speakers-move-air-volume-displacement

K12H-200TC If the xmax spec is 2mm they have more headroom than most guitar drivers, the Greenback is 0.7mm, but the rest of the specs if similar to the K12H-200TC aren't well suited to guitar. I'd be very wary, as even the BN-12 300S has only 2.5mm xmax.

My concern about the K12T-200 is xmax. I can't find specs on it, but the K12H-200TC xmax is only 2mm. That's half what I'd consider the minimum acceptable. It results in a real world mechanical power limit of 25 watts. One can only speculate if the K12T-200 xmax is that short, but given the age of it and knowing Celestion came very late to the party where real bass specific drivers are concerned I wouldn't want to assume otherwise.

IMHO those who have that attitude have no idea what a 'pure' tone is and would be shocked to see the measured response of their rig. No component has flat response, starting with the bass, ending with the room where it's being played. If tone controls weren't meant to be used they wouldn't be there.

Maybe it does, maybe it doesn't, but since the speaker doesn't have flat response it just doesn't matter. The amp probably has an EQ pre-shape as well, most do. Where EQ is concerned set it where it sounds best via trial and error. When it sounds good it is good.

The 2x8 ohm will be 6dB louder than 1x8 ohm. That's from the combination of 3dB additional sensitivity from the halving of impedance and 3dB additional sensitivity from the doubling of cone area. It will also have 6dB more maximum output, as the Vd (displacement) is doubled. That makes it 3dB louder at the same volume setting as the 1x4 ohm, and 6dB higher maximum output than the 1x4 ohm. There's a saying in automobile circles that there's no replacement for displacement. It applies to speakers as well, because loudspeaker cones are pistons.

The 4 ohm will be 3dB louder, as the cone of the 4 ohm driver moves further with the same applied voltage. However, where maximum output is concerned they're the same, as both have the same maximum excursion. It just takes more voltage into the 8 ohm to get there, which takes only a slight increase of the volume knob, say from 5 to 6. Not from 5 to 10.

He has a point. If one driver is sufficient to provide all you need, or ever expect to need, for output then 4 ohms has its advantages where the amp voltage headroom is concerned. But 4 ohm tens and twelves are rare, because 2x cabs are far more common, and manufacturers aren't going to make many 4 ohm drivers when most of the demand is for 8 ohms. The exception is fifteens, which are more commonly offered in 4 ohms because most fifteen users only need one.

I quit going there before they could kick me off. Maybe it's different now, but ten years ago it was one of the worst moderated forums I've ever come across. IMO anything that can't be said in a paragraph using non-technical language is a waste of time for all involved. KISS isn't just the name of a band. 😉

It will, but it has nothing to do with power, everything to do with voltage. The amp puts out the same voltage into any load. (A good thing that is, because the actual impedance isn't a constant, it varies with frequency, so if this wasn't the case every frequency would be at a different level.) If all else other than impedance is equal, which it never is, with the same voltage applied the cone of the 4 ohm driver will move further than the cone of the 8 ohm driver. This results in a 3dB increase in output. There can be tone differences as well, because all else isn't equal, including but not limited to inductance and moving mass. As for the perceived increase in dynamics at high levels, that's also voltage related. An amp's dynamic response suffers when it's pushed close to its voltage output limit. Using a lower impedance driver gives more voltage headroom from the amp, which gives better dynamic response. This begs the question 'why not always use low impedance drivers?'. The answer is that the lower the impedance the higher the current draw, which can create its own set of problems.

Not your fault, industry fault. What makes speakers go louder is increasing the voltage output of the amp. Watts never should have been used to define amplifier output, or speaker capacity. But they were, and now we're stuck with it.

Yes, with a valve amp, so that the output valves can be pushed into hard clipping while keeping the voltage to the speakers low so that they're not too loud and not overpowered. Tom Scholz sold one, and I believe Marshall did as well. Useful as that is on guitar it's not what I'd want to use with electric bass.