Bill Fitzmaurice

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. 😒

If there's no voltage there's no signal, nor current. The strings vibrating in the magnetic field of the pickups induce both current and voltage. You can't have the one without the other except with a theoretical superconductor.

The last I used was a '59 Bassman, for guitar. I can hardly imagine one on bass, as it only took ten watts to hit xmax with four Jensen P10Qs in an open back cab. But Carol Kaye did most of her early studio work through a Fender Super Reverb, which was similar. That's because she was originally a studio guitar player. One day the scheduled bass player for the session didn't show up, so she plugged a bass into her guitar amp. And it's why you can hear a touch of reverb on the bass in many Beach Boys recordings. But that was in the studio, where not a lot of volume was required.

And that's why Mesa Dual Rectifier amps give you the choice. 😉

We're not saying that you didn't witness what you witnessed. We're saying the cause of what you witnessed isn't what you think it was. And why would you? Without technical training one cannot be expected to make a diagnosis of why a driver failed. The value of threads like this one is it allows those without technical training to learn from those who do. But one can only lead a horse to water. From there on what happens is up to the horse.

True. One reason why earlier Fender amps are preferred is they have valve rectifiers, which have better sag characteristics than those from the mid 60s and later that have solid state diode bridges. That additional bit of sag contributes to the soft knee compression of those amps.

You usually get double the power at small signal levels. In most cases you don't get it at full power due to power supply sag.

You're not wrong. It's perfectly safe to use an amp rated at even ten times the speaker rating so long as you employ the volume control. It's perfectly safe to use an amp rated at one tenth the speaker rating as well, even if you crank it into hard clipping, so long as you don't have a tweeter. The myth of underpowering came about decades ago after JBL published a document on how amplifier clipping could damage 'the high frequency components of their loudspeaker systems high frequency devices'. It probably took three re-tellings of the tale, if not less, before 'clipping can damage high frequency components' morphed into 'clipping kills speakers'. Engineers like myself have been countering that notion ever since, but it's like a never ending game of whack a mole. The truth of the matter is succinctly summed up in this quote: There's no such thing as "underpowering" a loudspeaker. The loudspeakers really don't care about the shape of the waveform. A square wave is not by itself a killer of tweeters, woofers, etc. Well over 90% of the power put into a loudspeaker driver turns into heat, whether the waveform is square or not. Overpowering (thermal damage from too much power) and over-excursion (excessive cone travel, typically from low frequency energy) are what damage loudspeakers. Bob Lee Applications Engineer, Tech Services Group QSC Audio Secretary, Audio Engineering Society Rebuttal is welcome from anyone claiming to have Bob Lee's level of expertise.

Porting would give you a bit better result, but not enough to make it worthwhile IMO, the box is too small. You'd need to go up to at least 50 liters not including the space taken up by the port.

A critically damped sealed box, which is to say Qtc of 0.5, is going to be very large. But as it's a sealed speaker it's not going to have high sensitivity at low frequencies, which explains why they're seldom used even in home theater.

🤫 Once again: Clipped wave forms are harmful for tweeters, as they can increase the power in the high frequencies well above what what the tweeter normally receives. But no matter how hard the clipping the power will never exceed what the woofer normally receives in the lows. That's the science, and the science always works, whether you understand it or not. As to blowing a 100w speaker with a 50w amp, for instance, yes, you can. Most 50w amps can deliver transients of 6dB above rated power, and that's means 200 watts. Is the amp clipping? Sure. Does the clipping cause damage? No. Over powering does. BTW, a distortion pedal creates clipping, far more clipping than any amp is capable of creating. If clipped wave forms hurt woofers distortion pedals would not exist. Neither would synthesizers.

That's the myth of underpowering. It's already been discussed in this thread with full explanation why it's not true. 😒