Bill Fitzmaurice

It's all Biden's fault. 😫 Oh, right, you're in the UK. It's all Johnson's fault. 🙄

+1. I alternately chuckle and roll my eyes when I see blokes saying how when they try an amp for the first time, be it on stage, at home or in a store, that they automatically put the EQ knobs at 12:00, because they want flat response, when the reality is that they've probably never heard truly flat response in their life. 🙄 Sir Paul, or is it Lord Paul now, still doesn't read music, and yet somehow he gets by. Neither did over 90% of the top musicians going back to the 1950s. I've worked with school trained musicians who could sight read, and their chops were as lifeless as ten year old flatwounds. IME you've either got music in your blood from birth or you don't.

I use a Jack Lite 12. I have a Jack Lite 15, it's only been used once at an outdoor gig. Indoors I don't need more than the 12. When I designed them I was after a similar tone to my favorite rig when I was touring in the '70s, the JBL 4560A, in a much smaller and lighter package. The 4560A was a monster, but in the days before PA support that's what you needed.

Coming up with a true FRFR cab isn't a problem for me, irrespective of budget. I don't use one because I don't want one.

True, larger drivers don't necessarily go lower, nor do smaller drivers necessarily go higher, as is all too commonly assumed. In a properly engineered multi-driver speaker that's not why larger and smaller drivers, each operating within their own frequency range, are used. Larger drivers are used to provide the necessary cone displacement to deliver the desired output levels in the lower frequencies, while smaller drivers are used in the mids and even smaller drivers in the highs to provide wide dispersion in those frequencies.

Yes, it does. The larger the cone the narrower the dispersion angle as you go higher in frequency. The cone size being too large is the reason for midrange and high frequency beaming. We don't notice it as much as do guitar speakers, because we have less high frequency content, but it's still there. If you're only listening to the cab on-axis the driver size doesn't make much difference, but most of your audience isn't on-axis. With fifteens they'll hear the tone change as they go across the sound field. The same applies when multiple drivers are placed side by side.

A tight fifteen could get you twenty. 😲

You'd think, but they persist. 🙄

The only way that happens is with PA gear. Bass amps and bass speakers have coloration. That's not the result of poor mechanical or electronic engineering, it's intentional. Truly flat response from a bass rig would be as appealing as truly flat beer.

Not everyone would agree with that assessment, myself for one.

Another identical 2x10 cab,vertically stacked. That's not a subjective opinion, it's objective scientific fact, and the science always works, whether you understand it or not. 😉

So long as the amp has a volume control no worries. Two salient points: First, if you're running at half perceived maximum volume an 800w amp won't be running 400w, it will be running 80w. Second, few speakers are able to take even half their rated power before they distort badly. When that happens turn it down. If it happens on a regular basis you don't need more power, you need another preferably identical cab.

Combos tend to be made with portability as their main goal, which means as small a loudspeaker enclosure as possible. That goes counter to Hoffman's Iron Law. If the size of your combo enclosure section is comparable to freestanding speakers then it's not likely that a separate head and speaker would be any better.

All of this is also well known, having been mathematically quantified by 1940. There's even software that will accurately map it out. For instance: https://www.comsol.com/acoustics-module

He could have saved a lot of time, work and wood by reading a book. Everything he 'discovered' and a lot more has been well known in the professional audio community since the 1950s. For instance: http://cyrille.pinton.free.fr/electroac/lectures_utiles/son/Olson.pdf And while he's identified how some changes in response occur he still doesn't know why.

There was no significant difference between the Fender bass and guitar amps of that era, other than reverb and vibrato. Their bass cabs weren't much different either, which was their main limitation of bass.

IME the best FOH sound men high pass the bass somewhere between 60 and 80Hz, and this is with multi-million dollar pro-touring systems. This does the best job of getting tone through the PA that approximates the tone through the backline. The worst sound men don't high pass, resulting in tone that more closely resembles teenagers $5k subs in their $500 cars than electric bass.

NIce, but contrary to advertising claims isolation doesn't do anything to the sound. Where it is useful is with a very soft stage that the amp would otherwise bounce on. http://ethanwiner.com/speaker_isolation.htm

It's a very good idea, when done correctly. While the stage rig will cover the room with the lows very effectively the midrange and high frequency dispersion is pretty bad. Put mids and highs in the PA for dispersion, pull back the lows on that PA channel so as not to overdo those. The same applies to the drums, keys, even guitars. The PA should be providing a balanced mix throughout the room. The problem lies with bone headed guitar'd players who think that they need to play loud enough to blow out candles at 30 meters. PA isn't about volume, it's about dispersion. Most guitar players can't even spell dispersion, let alone understand the need for it. 🙄

It's the rare room where the bass isn't louder out front than it is on stage. On stage there are boundary reflection sourced cancellations, out front there aren't.

No matter, +/-10% variation isn't going to cause a problem anyway. A low voltage brown out is defined as at least a 10% voltage reduction.

Just to make it more confusing: We loudspeaker engineers don't use watts, we use volts. Power delivered varies with current, current varies with impedance, and the impedance of a speaker isn't constant, it varies with frequency. An average 8 ohm rated speaker will have an actual impedance between 5 and 50 ohms, with the impedance being different at every frequency. At equal volume your amp can be putting out 200W at 50Hz but only 20W at 100Hz. We use volts because they're constant into any impedance load, allowing us to accurately calculate a speaker's mechanical limit. And 1+1 doesn't equal 2. Take a look at Ohm's Law and you'll see why. For instance, 28.3 volts into 8 ohms is 100 watts. You'd thank that 56.6 volts would be 200 watts, but it's actually 400.

The more pertinent conversation is the fact that said 400W rating is thermal. The mechanical limit is perhaps half that. The majority of posters in the thread appear to be unaware of thermal versus mechanical capacity. The good news is that it will sound quite awful if you exceed the mechanical limit.

It indicates that the cab is inadequately braced on the inside, if at all. Aside from being an annoyance the energy expended vibrating the cab walls is energy not creating sound, or worse, it creates unwanted sound. This is an example of a well braced cab: https://barefacedbass.com/technical-information/generation-three-enclosures.htm You may not be able to retrofit that extent of bracing, but even a single brace that connects the center of opposing panels has the same effect on vibration reduction as doubling the thickness of the panels.