Bill Fitzmaurice

1 hour ago, Dan Dare said:

 

 With a vocal only PA, you can take a feed from the bass rig and cut the lows from it on the mixer, so only the mids and highs pass through the PA cabs. That will give you some articulation out in the room (with the low end coming from the stage rig) without turning what comes out of the PA to mud. I often do exactly that and it works fine.

PA should always carry the instruments, and again the reason is dispersion. Low frequencies have no problem filling a room as they're not highly directional, or directional at all below roughly 250 Hz. But that's not the case with mids and highs, so if you want 'not a bad seat in the house' the mids and highs from everything should be in the PA, drums included. Not necessarily loud, but just enough to give a uniform sound throughout.

41 minutes ago, Beedster said:

‘Most’? So there are some we’re allowed to use then? 

As with all rules there are exceptions. If one uses a dust cover/dome that's of stiffer and lighter material than the cone, especially if it's bonded to the voice coil, it can act as a smaller midrange radiator, giving broader mid dispersion than the cone. That used to be fairly common with JBL, Altec, EV and other driver manufacturers. It's still used, but the downside is a pronounced midrange break up mode. With instrument speakers that can be desirable, but the more 'hi fi' oriented the driver the less likely it is to be employed.

13 hours ago, Stub Mandrel said:

 

18s don't bring the words 'crisp' or 'detailed' to mind.

In general no, but consider Jaco. His Acoustic 361 cab was not only loaded with an 18 but it was also a front loaded folded horn, a design that attenuates upper mids and highs. He didn't get stinging pop and slap highs, but what he got was still mighty good. It's but one more example of why one cannot generalize results based on driver size alone other than dispersion.

Tube versus SS watts has been covered here ad nauseam to the extreme. I'm sure you're just trying to be helpful but what you're saying has been covered here in detail going back over dozens of threads for as long as this forum has existed.

54 minutes ago, BigRedX said:

So why do we keep defining the sound of a cab by the number and size of drivers it contains?

The same reason why far too many define the performance of an amp by watts. 😉

4 hours ago, W1_Pro said:

I really like the idea of having the small box on a stick at ear height. I wish a commercial manufacurer would build something like this- actually they may do, but I'm not aware of it. Can you post pics when the build is complete?

 

There are many versions of this available as PA cabs. There are none marketed as bass cabs but without a doubt some players are using them. I don't see it being a bass player thing, as we generally prefer the least complicated arrangement. Besides, one need not have a small box at ear height to hear mids and highs. Tilting a standard cab accomplishes the same thing.

3 hours ago, crazycloud said:

 I agree with the earlier comments about dispersion, but for 40y I've gotten around that with multi way cabs

Which proves the point. A common assumption is that midrange drivers are paired with woofers to extend the high frequency response. That's true to some extent, but the main reason for using midrange drivers is they deliver wider dispersion than woofers. That's because they're smaller. Tweeters are smaller than midranges for the same reason. Time was when you had to use a fifteen to get enough cone displacement for the lows along with a midrange for dispersion in the mids. That hasn't been the case since the turn of the century.

1 hour ago, chris_b said:

I wouldn't want to go back even 10 years in speaker history. IMO we have some great cabs being designed and made right now, and 2 of the best are being made in the UK.

Current state of the art in driver design was realized closer to 20 years ago. What's changed since then is more and more sources are producing state of the art drivers.

54 minutes ago, DGBass said:

 will a modern high quality 10 or 12 with an 8mm excursion be able to move as much air as a modern high quality 15 with an 8mm excursion?

Of course not. But a fifteen cannot realize the dispersion of a ten, or a twelve, which is their primary advantage, while still being able to deliver enough output to fill the stage, leaving the heavy lifting out front to the PA.

2 hours ago, Lozz196 said:

Membership revoked!!

Old yank proverb: If it ain't broken don't fix it!

1 hour ago, chris_b said:

I do have a problem with the OP criticising  the bass player for only using 1 bass all night!!! Less is always more.

I've never owned more than one bass at a time. For that matter I've only owned a total of four since 1965, 25 years with my current bass.

That One 10 defines physics. Moving air isn't just an expression, it's how speakers work. A high quality modern ten with 8mm excursion capacity will move as much air as vintage fifteen with 3mm excursion.

Don't assume that if you can't see them that the amps and speakers aren't there. They may be back stage or under it, in isolation booths.

38 minutes ago, Wombat said:

What?

No, Watt. James Watt. ☺️

One watt is the rate at which electrical work is performed when a current of one ampere (A) flows across an electrical potential difference of one volt (V). Period.

Watts aren't meaningless, but almost. Otherwise how do you explain the Ampeg B-15? 🤥

What we used to call gear groupies. ☺️

The return jack is a mono 1/4 inch. It won't work with a stereo input.

2 hours ago, W1_Pro said:

  I have a feeling (responding to Reds point above) from watching their social media all of the boxes are real and loaded.

Could be, but plugged in? the last time I saw ZZ Top they had two dozen or so Magnatones on the stage.  I asked their road manager how many they were actually using. He told me Billy and Dusty were using two apiece, the rest were 'eye candy for the kiddies'. 😄

Here's the deal on Sovtek and Chinese tubes: In the West military devices, like radar and communications, converted to SS early on, being much lighter than those powered by tubes. The USSR didn't have the SS tech that the West did, so they stayed with tubes much longer. Tubes also had the advantage of being immune to electromagnetic pulse, which fries SS devices. That was a concern during the Cold War. Without the demand for tubes for the military and civilian devices other than musical instrument amps, and because making tubes is environmentally a problem, Western tube sources disappeared. Since Soviet gear still used them, and they didn't care about environmental issues, tube suppliers in the Soviet bloc remained. Musical instrument amps remain as the #1 users of tubes, most of which still come from Russia, China and Slovakia. Those that are still made in the West are much more expensive, as their manufacturers have to adhere to environmental regulations that pretty much don't exist in Russia et al.

33 minutes ago, BigRedX said:

 

I suspect that at least some (if not most) of them were empty lightweight boxes just for show.

 

There's nothing wrong with having an image and the wall of cabs is almost mandatory in some genres. 

And for that there's this:

Those are tube conversion sockets, allowing the use of a tube other than the original. https://www.tubedepot.com/t/other-stuff/yellow-jackets?srsltid=AfmBOorm7EPnxQenwo22TciGXI6p0wev-H5TymKMmUU23zzT-vgP2Z51

I vaguely recall a SS tube replacement existed back in the day, but if it had been successful it would still exist. There was a big scramble for a SS tube replacement when most tube sources went out of business in the 70s-80s. Nothing much ever came of it.

Dispersion, dispersion, dispersion. It's inversely proportional to the size of the source. The main reason for larger drivers is they can move more air than smaller drivers. If you use multiple smaller drivers you can move just as much air with higher efficiency and wider dispersion so long as they're vertically aligned. Fifteens work best where dispersion isn't a concern, which means either in sub or in 2 way or 3 way cabs where the fifteen is only run to 800Hz or so.

Do a search. This topic has been thoroughly discussed in multiple threads. It's unfortunate that your guitarist didn't do his homework before buying the DXR15s. You'd get a much better result with a pair of DXR10 and an 18 inch sub.

Playing arenas with no PA? 😄