Bill Fitzmaurice

I specify the BGH25-8 in my Simplexx bass cabs. In part that's because it doesn't extend higher in response than what electric bass needs, reducing hiss, in part because with a 2nd order low pass/4th order high pass crossover it can run to 2kHz. That eliminates the typical upper mids hole in cabs that cross over an octave or more higher, and provides dispersion above 2kHz that no woofer can match.

Power is determined by voltage and current, P= V x I. Neither power nor current define how loud a speaker will go. Current, and therefore power, is determined by the load impedance, and the load impedance of a speaker isn't constant, it varies with frequency. With the exact same decibel level you can be running 100 watts into the speaker at one frequency and 5 watts at another frequency. The reason why they're at the same level is because voltage determines level, and voltage doesn't vary with the impedance load. We really should never be talking about watts, always about volts, but that bridge was crossed and then burned almost 100 years ago, so there's no going back now.

True, though the required reinforcement may also be carbon fiber, keeping the weight down. What this results in is a more labor intensive building process, which is in part why CF is so expensive. The other reason is that CF itself is expensive, because most of what's available is being used by high volume users like Boeing and Airbus, even Tesla. A small speaker company can't compete with them for buying power. At the other end of the scale the reason why 18mm plywood has long been the staple material is because you can get away with minimal bracing, which cuts labor cost, which keeps overall cost as low as possible, at the expense of weight.

Technically speaking the primary reason the sound on stage and in the room is different is boundary reflection sourced cancellations. When the distances between you, the speaker and the walls and ceiling are relatively short these cancellations make the low end thin. Out in the audience, where those distances are much longer, cancellations aren't as severe, if they exist at all, and the low end is fuller. If you're boosting the lows to get a full tone on stage it can be too much out front. That doesn't mean twiddlers and their subs aren't a problem. They are, mainly because the range of subs goes a full octave lower than bass cabs. Sound men who know what they're doing account for that by high passing the bass channel strip somewhere between 60 to 80Hz.

This repeats the common misconception that the doubling of current delivery, which results in a doubling of power, into two cabs versus one has anything to do with the 6dB increase in output. It doesn't. As I already noted what determines loudness is cone displacement, which is determined by voltage swing, which is the same into either one or two cabs. Level voltage into twice the displacement gets 6dB. The only limitation to this is when the amp is being run full tilt. Most amps are not be able to maintain the same voltage swing into two cabs as one when they're running at full capacity, due to power supply sag. But at volumes that aren't taxing the power supply you'll get 6dB every time. I'd be inclined to think it's the amp. Distortion on the low notes happens when the speaker runs out of excursion and/or the amp runs out of headroom. If speaker excursion was the problem it should happen with both amps. Another possibility is that the bass EQ of the GK was considerably higher than the Elf. That would cause both the amp and speaker to run out of headroom at a lower overall level than with the Elf. The way to test that is to try both amps at low volume, setting their EQ to sound as much alike as possible, and then see what happens when you take the volume up.

Wishful thinking, in no small part because the sound out in the room can vary wildly from the sound on stage. For that reason I do my personal sound check with a long enough cord so I can stand well out onto the dance floor. If that results in it being shite on stage I live with it, because what the audience hears matters far more than what I hear. If there is a knob twiddler in play I listen to his mix at the FOH to be sure he's not totally fouling up the works. IME at even the highest echelons maybe half the FOH engineers get the bass right. Most of those who do are also either recording engineers or bass players, if not both. When faced with the option of either leaving a concert early or going medieval on the twiddler's buttocks it's almost always because he's ruined the bass mix. Come to think of it, the only recent exception was when I had to walk out on Willie Nelson. He's a genius writer, a good vocalist, but the worst guitar player I ever heard. I swear he played every song in a 7/11 time signature, even though his band was attempting to play in 4/4 despite him.

Pre or post your speakers aren't going to sound the same as the PA, so it doesn't matter that much, as the board channel EQ likely won't be run flat anyway. Which means that your out front tone is at the mercy of the sound guy anyway...😫

Strictly speaking you will get 6dB of increased speaker sensitivity, which is the equivalent of a quadrupling of power. You don't get anything 'extra' from the amp, because what determines loudness is cone displacement, which is determined by voltage swing, which is the same into either one or two cabs. Level voltage into twice the displacement gets 6dB. Where the OP is concerned if one 110 seems nearly adequate then the additional 6dB of sensitivity that will result from adding a second identical 110 should be fine.

Be very judicious in the use of a sub-harmonic generator. A generated tone one octave down played at the same volume as the original note will double the power requirement on the amp and speaker, and driver cones could be pushed past their mechanical limits.

https://www.sweetwater.com/store/detail/GFWGTRAMP100--gator-frameworks-gfwgtramp100-collapsible-combo-amp-stand

Shame, you could have got 1000 milliliters for the same price.

That goes to marketing. Selling a bottle of 1000 mg pills makes it sound like you're getting something much better than a bottle of 1g pills.

It depends on the application. 22nF or 47nF would be common in electronics, but never in a crossover. The value range there mainly runs between 2uF and 100uF.

Usually you'll see R and Z listed in ohms, with R referring to DC resistance and Z impedance. C for capacitance is measured in microfarads, uF, Le for inductance is measured in millihenries, mH. You seldom see capacitive reactance, Xc, or inductive reactance, Xl, both measured in ohms, other than in a spec sheet for a given capacitor or inductor. You do see the result of Xc and Xl in Z, as impedance is the sum of R, Xc and Xl. R is a constant value irrespective of frequency, but both Xc and Xl vary with frequency, and along with them Z.

It's called impedance because ohmage is what you pay to Clapton. 😊 Besides which, impedance and resistance aren't the only things measured in ohms. There's also capacitive and inductive reactance. You'll never see a proper engineering document that doesn't say which of those four is being referred to with respect to a value in ohms.

The head doesn't distribute power. The relative impedances of the cabs does.

That's the case with my Superfly. The manual is specific on that fact. Of course that does little good if one doesn't bother to read it.

You may, but they're designed to operate into a fixed driver impedance. Drivers don't have a fixed impedance, for instance a typical 8 ohm woofer may have an actual impedance of 20 ohms or more at the crossover frequency, so the results will be far less than optimal. Designing a crossover is just as involved as designing the rest of the speaker. Both. That's part of why you can't build a speaker like ordering Chinese food, with a woofer from Column A, a tweeter from Column B and a crossover from Column C. But you'd be surprised how many manufacturers do just that. A few years back I designed an award winning 112/6 speaker for a manufacturer. The driver/box design process took a matter of weeks. Getting the crossover exactly right, which included seemingly endless Beta testing by at least a dozen users, took months.

No acoustical engineer would say that. Maybe an EE, but they tend not to be familiar with speakers. They are, and that's not a good thing. There's only one reason to use a 1st order highpass with no low pass, that being it's the least expensive option. You cannot use a rheostat, as it does not present a constant impedance load. One must use an LPad.

That's not a crossover, it's a high pass filter, and a very poor one at that. It only attenuates below its corner frequency at a 6dB/octave rate. Worse, as the power density of a signal increases by 3dB with each octave drop in frequency the net attenuation is only 3dB/octave, which is barely enough to provide any protection for the tweeter. With no low pass filter on the woofer it will still produce enough high frequency content to destructively interfere with the tweeter output. A good crossover will at the very least consist of a 12dB/octave low pass filter on the woofer and an 18dB/octave high pass filter on the tweeter. This is commonly referred to as a 2nd order low pass/3rd order high pass crossover.

You must use a crossover to send the lows to the woofer and the highs to the tweeter. This keeps the impedance correct and prevents the tweeter from being blown. Even piezo tweeters, which are advertised as being able to be run without a crossover, really need one. One reason why they get a bad rap is that they're almost never used with a crossover.

When you add a second identical cab in parallel you get a 6dB increase in both sensitivity and maximum output. That's the equivalent of quadrupling the power into a single cab, so it is most definitely a big change. That would only happen if the two cords weren't of like polarity. The reason why they say not to do so is because it won't add to output, and you might have two cords that aren't of like polarity.

Thermal switches are cheap, being so common on computers, so I don't see any reason to not have one, and they do extend fan life.

If you only leave it on it may not get hot enough to turn the fan on. You probably have to play through it to generate much heat.

What you're dealing with there is the amp gain structure. Time was that some manufacturers would intentionally tailor the gain structure to give more volume at the lower end of the dial, so that when trying different amps in the store their amps would seem louder. That difference would disappear once the volume knob was turned up to halfway, but doing that tended to get you thrown out of the store. With most gear today being bought on line there's nothing to 'gain' from that scheme anymore.