Bill Fitzmaurice

The speaker impedance ratings for valves is the maximum, that for SS is the minimum. Use the tap on a valve head that's equal to or more than the speaker impedance, use a total speaker load on an SS amp that's equal to or greater than the amp rating.

No, as the 115 will reach its limits long before the 4x10. The increased sensitivity realized from using the two cabs may give a better result than just the one, but it also may not. Without question the best cab to use with the 410SVT is another 410SVT, if you actually need more than the one.

Bass. That's the reason for the port, which MM incorrectly called a reflex horn, that what RH stands for. It would be of zero benefit for guitar. That doesn't mean guitar players might not have used them, but if so they were lugging around a lot larger cab than they needed to.

That's a common misconception, even among those who really should know better. The size of the driver does not determine how low the speaker will go. A dozen or so other factors, Thiele/Small parameters, along with the cabinet design do. A 115 might go lower than a 410 but it also might not. That would be revealed by the measured SPL charts for the cabs in question, if there were any, but sadly there are not. In any event, Hartke lists the low frequency response limit of both the 4.5xl and 115 xl as 30Hz, although they don't say if that's down 3dB, 6dB, 10dB or more from the base line sensitivity, which is another bit of critical information.

Then you'll end up with a 115 that can't keep up with the 410, so whatever additional low end it might have, and that's not much best case, won't be of any benefit. If you had a clean slate what you should do is find the 8 ohm cab that sounds the best to you, and if one wasn't enough add a second. +1. Your stage rig drives the stage, the PA drives the room. No one needs more than a 4x10 or 2x15, unless it's to impress the kiddies in the audience.

That is a rack version, contained within a case. You may be able to find the manufacture date from the serial number. https://www.bassic.de/attachments/ampeg-dating-pdf.106974/

If you can drape the fabric over your arm and it seems flexible enough so you could make a Game of Thrones worthy garment out of it then it's not cabinet worthy. Tolex is too stiff to be worn.

Even if that was the case the most difference it would make in maximum output would be 3dB, which is audible, but not significant. Those who think there's any real benefit to 'getting all the watts out of my amp' would find their time better spent chasing down unicorns. 😏

It would be of little to no benefit. Using the same frame and motor you can use over a hundred different combinations of voice coils, cones, domes, surrounds and spiders for over a hundred different results. That's how Eminence comes up with OEM drivers. You tell them what you want, they put together various component combinations to realize it. When you're satisfied it's yours and yours alone.

Not that old of a school, I'm afraid. Real old school is when you don't have to remove a single board to replace any parts, let alone having to replace a board. It's not as bad as current amps, but it's still bad enough that the labor charges alone may exceed the value of the amp. I wouldn't toss it, it has value to someone, but probably as parts.

If it was an SVT I'd say find a good man with valves to fix it. The point to point wiring makes it very easy to fix if you know your way around them. But the SVT4 Pro only has a valve pre-amp, the power amp is SS, and it's not point to point wired, but is built on circuit boards. That makes them easier and less expensive to build, but much more difficult and expensive to repair. Based on that I'm inclined to agree with John Gee's assessment.

The only way you'll get specs on those is if Celestion still makes them, and even then maybe not. They still don't publish Greenback specs, not that it matters all that much with guitar drivers.

It depends how old they are. Prior to roughly the mid 1990s they may not be available. They can be measured, but you need the tools to do so. Celestion is one of the worst. They approached me circa 2005 about recommending their drivers in my designs, but were unable to provide any specs. I don't have any specs on file from them prior to 2008, while I have specs on JBL going back to the mid 70s.

50 years ago a 4x12 bass cab and 4x12 guitar cab were the same thing. If you run a bass through a 4x12 guitar cab today the result will be the same as running it through a 4x12 bass cab 50 years ago: it won't go as low or as loud as a modern bass 2x12. Next: Why? It's a form factor that hasn't made sense since 50 years ago. If you need more output than what a modern 2x12 can deliver, which isn't likely but that's a different topic, get a pair of 2x12.

The article is titled A Case Against Subwoofers. Don't blame the subs for the actions of those who abuse them. This quote in particular tells me the author isn't well versed in gear: "If certified low-end experts like O’Malley and Carlson don’t use subwoofers to listen to music, why does anyone?" If I didn't use the subwoofer in my home or car systems when listening to music there wouldn't be anything to hear below 100Hz. He doesn't know diddly about recording studios either. The use of subs didn't end with Pretzel Logic. They're standard issue, and have been for forty years. And he's off with what he says about vinyl. Records do have narrow grooves, to prevent needle jump, and for that reason their bass content is rolled off. That rolloff is compensated for by the RIAA equalization of phono pre-amps. Needle jumping during payback from high bass content can happen, but not when the turntable is adequately isolated.

And there's the reactionary flip side. Where subs are concerned the only time they're counter-productive, either in a club, a stadium, a car or a home, is when they're used to reproduce low frequency sounds that shouldn't be there. To say they shouldn't be used to reproduce what should be there is just as silly as the opposite view.

Nothing catastrophic. But if your desire is the best sound possible (isn't it always?) mixing cabs is not the way to get it.

You could use it in a dual amp setup, along with a regular bass amp and speakers. Turn the bass EQ on the Marshall all the way down, and the mid and high EQ on the bass amp all the way down.

I'm reluctant to make a reply, as this is one of those questions that always ends up at ten pages of bickering back and forth, like the difference between tube watts and SS watts. For an example go to Talkbass.com. The subject comes up at least once a week and it never ends well.

The tweeter isn't the problem, the woofer is horn loaded.

Mixing cabs is seldom a good idea. Mixing direct radiators with horn loaded cabs is a particularly bad idea.

Impressive if true, but I doubt it. It would require driver specs that are unattainable. You can get -3dB at 33Hz with 96dB sensitivity, but not from a cabinet less than twice the size of the Ampeg.

Play it at war volume and your Bluesbreaker will be a Bluesbroken. It won't bother the amp but the speakers won't take it.

https://media.music-group.com/media/PLM/data/docs/P0742/BXR1800H_P0742_M_EN.pdf There's not much that you can't find a manual for, you just have to look, even for gear no longer in production. For that matter it's become common for items to come with perhaps a quick start guide, with the full manual only available on line. I've gotten into the habit of downloading the manual for a potential purchase before buying, to be sure it meets my needs.

What? Read the manual? And risk this?