Bill Fitzmaurice

With bass cabs I use the Eminence BGH25-8. It's rated at 25 watts, because that's all there is above 2kHz with 500 watts program. There are few, if any, off the shelf 4 ohm crossovers, but off the shelf crossovers aren't very good. I design my own. This is an 8 ohm 2kHz 4th order high pass filter, which you can't buy from anywhere in the UK. The capacitors are poly or mylar, rated for at least 100 volts. The coils are air core, of the smallest available wire gauge with no more than 0.5 ohms DCR. A plus/minus 10% tolerance of the component values is permissible. This is a 4 ohm 2kHz 2nd order low pass filter. The capacitor is a non-polar electrolytic (NPE), rated for at least 50 volts. The coil may be solid or air core; what’s critical is that the DCR (resistance) of the coil for a 4 ohm system be less than 0.2 ohms. A plus/minus 10% tolerance of the component values is permissible. Being 4 ohms you can't buy one of these either. I always build my filters on separate boards, it's too easy to get confused with the layout and wiring putting them on the same board.

If you want to go twice as loud you need to increase power not by a factor of two but by a factor of ten, so going from 15 to 30 watts is futile, especially if you don't increase the speaker size. To make a change worthwhile you need 50 watts into a ten, minimum.

Ports can go anywhere, as their radiation pattern is omnidirectional. But most players, let alone people in general, aren't aware of that, so they tend to avoid cabs that don't look conventional. Being well aware of this commercial cab manufacturers tend to avoid breaking out of the cookie cutter mold. What's the first comment you see about a new product? It's almost always about how it looks. Too bad we don't hear with our eyes. 🫢

Bottom porting is perfectly feasible. It doesn't lower the tuning all that much, maybe by 3Hz. It acts more like a flare than an extension of the port. You just have to use cabinet feet at least 2.5cm high.

If they were on the dimmer circuit the low voltage would have been a major problem, so that probably wasn't it. But inexpensive dimmers create RFI/EMI that radiates through the air, which can cause what you experienced.

Offhand I'd say it's a 3012LF magnet structure judging by the depth of the recess in the mushroom.

Not if it's a 12. It could be a 3012HO, could be a 3012LF, which has a deeper rear 'mushroom'. Or it could be an OEM version of either. TBH neither the HO or LF are ideal for electric bass. An OEM with specs midway between them, along with the longer voice coil that the extended mushroom allows, beats them both. I've worked with a few of those designing commercial cabs.

A single brace connecting the middles of two 12mm panels gives the same vibration resistance as using no brace with 24mm panels. That's why I don't use 18mm in any of my designs, while some use only 3mm and 6mm, with no vibration issues.

+1. Doubling the power isn't worth carrying the second amp around. At the very least you want to double the voltage swing capability, which translates to four times the power.

Since they have much lower EMI than standard transformers tightly packed components is one reason for using toroidals. One of their characteristics is they don't have stray magnetic fields caused by the ends of the cores, because the cores have no end. Whatever EMI they do radiate travels in all directions. They're also smaller and lighter, but are much more difficult to make, so they cost more. Why you had your result is puzzlement. 🫢 OP, you may find this of interest. Scroll to post # 33 https://www.talkbass.com/threads/eden-toroidal-transformer-buzz.391552/page-2

One of the advantages of toroidal transformers is they have very little EMI, and in theory rotating one should have no effect. I can't say why doing so worked for you.

Green wires are almost always ground wires, and a disconnected ground wire is one of the usual reasons for hum. The trick will be finding where it's supposed to be connected.

I wouldn't blame it on the monitor. Think about what happens when your drummer leaves his sticks on top of a floor tom and you play a bit. The sticks rattle, especially at a certain note, because the head is vibrating, and not because the cab is sitting on the head. It's because the tom head is resonating in concert with the acoustic output of the cab. When a stage or riser or anything else in the vicinity resonates when you play it's for the exact same reason. The only fixes are to either strengthen the resonating surface making it too stiff to vibrate, damping the vibrations by fully covering the surface with a heavy carpet, or dialing out the resonant frequency causing the vibration with EQ.

Probably because they're not distributed in Canada or the US.

Once over the border the tracking should be handed over to Canada Post, but that does you no good if you don't have the Canada Post tracking number. I assume it's not the same as the USPS number.

There's no such thing as mechanical coupling that causes the riser to resonate. There have been a few studies that prove this is the case, this is one: http://ethanwiner.com/speaker_isolation.htm What will cause the riser to resonate is the acoustical output of the speaker. That will usually occur at a single frequency. The best way to prevent it is with a parametric EQ that allows you to cut the speaker output over a narrow range, sweeping through the frequencies until you find where it kills the resonance. Another option is to raise the speaker to 1/4 wavelength above the riser, which will cut that frequency, but finding how high to lift it is a trial and error process.

At half power you only have 3dB of headroom, whereas what you need for very clean is 10dB. That means running at 1/10 power. That makes it seem like you need a lot of power, but the reality is that on average it's rare to be putting out more than 20 watts. If that were not the case generations of players would not have been able to gig with an Ampeg B15. Where 1,000 watt amps are concerned that tends to be a specmanship situation. Very few can actually maintain that for more than a few milliseconds. If you look at amps with honest specs, PA amps from the likes of Crown, QSC and the like, take note of their power draw. It's typically measured at 1/8 to 1/12 power. That reflects their actual long term output at very low distortion. Note that where the 30 watt Ampeg is concerned the reason it was gig worthy is the natural compression of valves. Without compression it takes a lot more power to stay clean. By the same token using a compressor with SS allows a lot less power.

It uses a coax version of the Eminence Delta Pro 15, so there's no reason to need 300 watts. 100 valve or 200 SS should suffice.

Clean is far more a matter of the speaker than the amp. Where amps are concerned 1% distortion is high. Where speakers are concerned 10% distortion is within the normal range. The cleanest amp in the world will still sound dirty with speakers that are dirty.

If you think that's bad get a load of this, and I do mean load: https://musysic.com/products/musysic-professional-4-channels-2x9600-watts-d-class-1u-power-amplifier-mu-d9600 😄

I wouldn't call my drummer of the last 35 years gentle. But he doesn't let his ego get in the way of his musicianship. None of the better drummers I've ever worked with, whether I was on stage or in the FOH, were pounders. That's a very long list, and where FOH is concerned includes some very familiar names, including Ringo.

Absolutely it's drums and guitars that threaten one's hearing. If you, or for that matter they, need protection they're playing too loud. I remember doing that. Back in the days when we didn't know the difference between good and loud we played good and loud! In our defense that was when PA support didn't exist. There's no excuse for it today. The backline carries the stage, the PA carries the room.

😄 I was in Baghdad while you were still in your dad's bag. I played in my first band in 1965. Some of the guys in my circle of musician friends back then were Steven Tallarico, Joe Perry and Tom Hamilton. Maybe you've heard of them? They wanted me to join them in 1970, but I was in college and didn't want to go full time as a touring musician at that point. After I got my degree I did.

If the bass on stage is so loud that you need ear protection it's too loud, period. Low frequencies don't cause harm the way high frequencies do. Taking that into account industrial noise ordinances use the A-weighted scale, which doesn't register low frequencies. There's also the matter of the bass usually being louder out front, where you don't have boundary reflection sourced cancellations that are usually present on club size stages.