Bill Fitzmaurice

That's the advertising claim, but how often do you see truth in advertising? About as often as you see an honest politician. 😄

It's possible that the power transformer has dual primary windings that will allow it. A schematic would probably show if that's the case. Singapore is a tech center, so finding someone knowledgeable shouldn't be difficult.

In case anyone wonders why a 9x10 the answer is impedance. If you use 8 ohm drivers you can't wire eight of them for an 8 ohm load, you may only get 1, 4, 16 or 64 ohms. You can wire a 9x10 as triplets in parallel, the three groups in series for an 8 ohm load. Or you can wire nine 4 ohm drivers for a 4 ohm load. That gave Ampeg more driver options than the 32 ohm they used in the 8x10.

It has to be for the look. The actual need for those died with the invention of the true electric bass specific ten and good PA.

I'd get the 212. The vertical driver placement gives wider midrange dispersion than a 410.

Despite the size it's not a sub, it's a bass guitar speaker. Used as a sub performance won't be great. https://products.electrovoice.com/binary/18BX Engineering Data Sheet.pdf Used for bass guitar it will work pretty well, although the midrange dispersion angle would be narrow.

Not really. At least 90% of what we know about loudspeaker design today was quantified by Harry Olson in 'Elements of Acoustical Engineering', published in 1940. The only major omission was Thiele/Small parameters, which date to 1965. Olson's work was very well known by Hi-Fi and theatrical sound manufacturers. I doubt one in ten musical instrument speaker manufacturers are aware of his work even today. I'd be surprised if even one in a thousand bass players are aware of his work, even though where giants of loudspeaker design are concerned he stands head and shoulders above most. FWIW the violin first appeared circa 1530. Stradivarius started making his circa 1660.

It's what's caused me to walk out of the last two concerts I went to. 😒

Hum could be power amp sourced, but not necessarily. A bad connection somewhere in the amp could be the cause, as could a blown component in the power supply. DC doesn't cause hum, because DC doesn't make any sound. Loud hum indicates AC that shouldn't be there, as in the case of a bad power supply.

Where bass cabs are concerned refer to an earlier post: the radiating surface of the 4x10 is wider than that of the 1x15, so its midrange dispersion isn't wider than the 1x15, it's narrower. Placing cabs side by side makes the radiating surface wider, so horizontal dispersion is narrower, by half. Vertical stacking also gets drivers closer to your ear level, so you hear the mids and highs better on stage. That's subwoofer placement, not bass cab placement. Subs don't radiate midrange, so side by side and vertical gives the same result.

I suspected that. The damping reduces internal reflections back to the cone. Those reflections arrive back at the cone at various degrees of phase, depending on the distance from the cone to the reflecting surface, and the frequency. They can cause both peaks and valleys in the speaker response. Valleys tend to not be particularly audible, but peaks are.

I suspect the difference in brightness is related to the amount of internal damping used, if any.

That's part and parcel of the myth. To some extent it was true 50 years ago, when there was enough difference between the response of, say, fifteens and tens that there could be some benefit to using both. That's when the myth began. But for the last thirty years the only difference between drivers based purely on their size is the angle of midrange dispersion. The larger the driver the narrower the angle. That's why midrange drivers are smaller than woofers, and tweeters are smaller than midranges. It's about dispersion as much as it is about extension. Take the venerable 1x15/4x10 for instance. Time was that 1x15 would probably have had a driver that went lower than tens, especially as the tens were likely guitar drivers. Being guitar drivers they would have gone higher than a bass fifteen. There was some benefit to mixing them, although ideally there would have been a crossover employed. That ideal was seldom present. Flash forward to the mid 90s or later. 4x10s are now loaded with true bass drivers, so they may go just as low as a 1x15. They have more total driver displacement than a 1x15, so not only do they go just as low, they also go louder. The 1x15 has gone from being the anchor to being the weak link in the chain. OTOH the radiating surface of the 4x10 is wider than that of the 1x15, so its midrange dispersion isn't wider than the 1x15, it's narrower. So where's the benefit of using a 1x15/4x10 today? There is none, unless they're at least 30 years old.

Because as with Forest Gump's box of chocolates you never know what you're going to get. Some combinations work, some don't, and there's no way to know without trying. If you have a shop full of cabs to try that's OK, but otherwise it's not practical. With identical cabs you know what you'll get, and it will be even better from the additional sensitivity with two than with one. On that, virtually any two cabs together will sound better than either on its own, because of the increase in sensitivity and radiating area. Whether two different cabs will sound better than, or even as good as, a matched pair you can only know by trying all of the possible permutations.

They were, loaded with JBL D140 rated for 150w each, and that was in the 60s. The more or less current equivalent 2226H are 600 watt rated. It was the JBL drivers that made Sunn 200S the best bass cab in the late 60s. Fender used them as well in their Dual Showman, but that cab was sealed, which gave poor results with the low Q JBLs. The Sunn was ported, so they worked much better. Sundholm called them rear-loading folded horns, but they weren't. He called them that because he didn't know what a rear-loaded folded horn was. His seat of the pants design was a reverse taper bass reflex. Even though he didn't really know what he was doing they still worked a lot better than sealed.

The size of the motor/voice coil doesn't directly relate to driver sensitivity, but as often as not higher sensitivity drivers have large motors/coils. What is curious is the 100w rating of the 2x15. The reason behind four inch voice coils is they can shed heat better than smaller coils, allowing for high power handling. A four inch coil only rated for 50w makes no sense. That's not the only thing on their site that makes no sense.

As I recall the original Sunn amps made by Conrad Sundholm used Dynaco kit power amps.

It may look unorthodox but if your drummer has trouble hearing you turn the lower cab towards him. It won't affect the non-directional low frequencies but it will allow him to hear the directional mids and highs.

The concept that a 15 complements a 210 is a myth. Sometimes it works OK, but not always by any means. The thermal power handling is moot. What matters is the mechanical power handling, a spec which unfortunately never makes it into the advertising. Doubling the driver count with identical drivers quadruples the effective mechanical power handling, while avoiding potential destructive phase interactions.

The only sure match is another cab loaded with the same drivers.

If I was to have a speaker for upright use only I'd load it with an eight inch. The upright low frequency limit is much higher than electric bass, so there's no need for the lower response or low frequency output capability of larger than an eight. An eight will go high enough to make a midrange and/or tweeter unnecessary, and will have 1.5 times the midrange dispersion angle of a twelve. For higher output requirements I'd use a stacked pair. On the low frequency limit, the two instruments do have the same fundamental frequencies, but the main content lies in the harmonics, not the fundamentals. When an open E is played on electric most of the content is at 82Hz and higher, when played on an upright most of the content is at 123Hz and higher.

The LPad goes between the high pass filter and the tweeter, so it's 8 ohm. Besides, you can only find them in 8 ohm. Where questions are concerned better to ask than to have a problem.

That's normal for +/-3dB. If you see a bass cab claiming response to 40Hz that's probably -10dB. It's absolutely not -3dB.

They may be back but at those prices it won't be for an extended stay. 🤥