Bill Fitzmaurice

Maybe he doesn't have it in his parts bin, but neither G-K nor anyone else uses proprietary parts. Contact G-K, if they can't recommend a source at the very least they can tell you what's in there so you can track it down yourself.

Maybe, maybe not. At least half of what makes a valve amp sound like a valve amp is the valve power amp. Even emulators don't get it quite right, that's why valve amps still exist.

It's absolutely on topic. If you understand what's being said you realize how a 30 watt Ampeg B15 is still capable of doing the job, on any stage.

I measured Big & Rich and Montgomery Gentry at an average of 103dB at the FOH. Deep Purple was the same. Charlie Daniels came in at 104dB. Tim McGraw and Alice Cooper ran at 105dB. True, although most players are going to be pushing closer to 30w average with 120w peaks. Also consider that the FOH where I took measurements was some 25 meters from the stage. Reaching 110dB there would require some 135dB at one meter, well beyond that capability of almost any backline rig. That's why you size your personal rig to drive the stage, and let the PA drive the room. If all guitar players understood this you'd never see more than a 100w 1x12 guitar amp, and never suffer the result of volume wars.

One of my real world experiences was when a local 6500 seat outdoor amphitheater was on the verge of being shut down by the town due to noise complaints. Prior to contacting me they spent $25,000 with a 'professional' audio consulting firm, who did an analysis of how loud the levels in the surrounding neighborhoods would be based on the level at the FOH. They then installed a computerized SPL measuring system in the FOH, which would turn on a very prominent red light if the levels were exceeded. For the remainder of that concert season the red light seldom, if ever, came on. The complaints not only were not reduced, they increased, especially where the bass was concerned. Before the next season of concerts started they hired me to find out what was wrong. It took me all of five minutes to do so. I looked at their sound standard document and the system, and saw everything was reference to A-Weighting. Their measuring system would only read dBA. The acceptable level standard said that the level in the FOH could not exceed 110dB. On the A-Weighed scale it never did. I had them play some recorded music over the system at 100dBA. It was unbearably loud. I then showed them what my Z-Weighted meter read: 125dBZ. I then ran a 60Hz test tone through the system, which I measured at 100dBZ. Their measuring system reading was 75dBA. The next day their computer measuring system went into the bin, while I accepted a position as their sound level monitor, at $1k per concert. 😎 Real world measured results show that even 20dB of dynamic range is seldom exceeded. That I know from the 200 or so RTA's I took at said concert venue's concerts over a period of a few years. Interestingly that figure remained fairly constant no matter what the genre, save one: Metal. Metal acts tended to compress the content so heavily that they seldom had more than 10dB dynamic range. They also tended to be less loud on peaks, due to that compression. They might average 100dB at the FOH but seldom reached 110dB on peaks. OTOH I measured many country acts at 95dB average that would hit 115dB peaks.

Those levels are totally wrong, because they're A-Weighted. A-Weighting should only be used in industrial applications. It's useless with respect to music, as it doesn't measure bass. The primary power pass band with music is centered at 60-70Hz, which when measured with A-Weighting registers some 40dB lower than actual. You may safely add 20dB to those noise dose recommendations when the source is music measured with C or Z weighting.

Valve or SS, when you turn down the volume control on a passive bass you change the tone, because the pickups get loaded down by the relatively low impedance of the volume control, which affects the highs more than the lows. That doesn't happen with actives, as the pickups see a constant high impedance load by the on-board pre, while the volume control being placed on the pre output, which is low impedance, doesn't affect the tone. Wanting the ability to use the instrument volume control without affecting tone is why I went active long before you could buy active basses.

It looks like a guitar cab loaded with Celestion Greenbacks.

It is, and not just a little bit. But if you have a BF two 10 why pair it with this? That BF should handle every watt that your head can put out.

Don't need those either, especially of the Cheeto variety. 🤔

Clipping will never bother a PSU. Too low an impedance load can if the amp is not protected against it, while sending a high level signal into an amp input can damage pre-amp components that aren't able to handle high current sources. When they fail they can take out the PSU as well, but clipping has nothing to do with it.

Clipping is clipping, with both cause and effect being the same, no matter where it occurs in the signal chain. The only reason to have a clipping indicator is to warn the user of the potential for tweeter damage. Ever wonder why guitar amps don't have clip indicators? For one thing they don't use tweeters. For another they're usually clipping. Why?

If it says 'Minimum Load 4 ohms' that indicates an SS amp. Modern SS amps do not have output transformers.

You probably hear it at every gig. It's what constitutes everything from what bass players call 'grind' to what guitar players call 'sweetness', let alone anything involving overdrive. Clipping can't harm an amp. A distortion pedal is an amp in a state of perpetual clipping.

Clipping doesn't hurt anything other than tweeters, and they'll sound nasty long before they should blow. What you, and your (idiot) guitar'd player should be concerned about is hearing loss. I'd say ask Pete Townshend, but you wouldn't get an answer, he can't hear the question.

3dB isn't much, but that was referring to the increase in output with no changes to the amp setting. The additional 6dB of maximum output, when both drivers reach their mechanical limits, is substantial.

There's no such thing as ohmage. Ohms are used to measure resistance, impedance, capacitive reactance and inductive reactance, so if one says' ohmage' it could refer to any or all of those factors. Adding a 4 ohm cab to an 8 ohm cab won't cause anything to blow, assuming the amp is rated for the resulting 2.67 ohm impedance load. Adding a second identical 8 ohm cab will result in a 3dB sensitivity increase compared to a single 4 ohm cab, assuming the drivers are identical save for their impedance. The pair of 8 ohm cabs would have twice the driver displacement of the 4 ohm cab, so they would have 6dB higher maximum output capacity.

Not if it's tuned wrong. How it will work with a driver for which there are no T/S specs is anyone's guess. If you want an inexpensive cab there's plenty of used available.

Headphones have flat response, bass cabs are anything but flat. What sounds good through the one will never sound good, or remotely close to the same, through the other.

Judging by the copied and pasted 'Features' it's the same driver. Since there are no T/S specs, and I very much doubt the builder has the gear or know how to measure them himself, there's no way the cab could have been properly designed. I can't imagine the size of the ports was arrived at by any method other than 'they fit my hands'.

I don't know if it's an Alpha, but at that price it wouldn't be anything more substantial than that.

The Alpha 12 weighs 2.4 kg, the Deltalite II 2512 2.3 kg, so neo doesn't always mean lighter weight. A Delta Pro 12 is 7.4 kg, so that's the price/performance range where neo would save weight. Still, the most weight savings come from using well braced 12mm plywood, rather than sparsely, if braced at all, 18mm.

You mean SLA Pro? The ports aren't ducted because the cab is tuned to 95Hz, for maximum sensitivity and output above 85Hz. That's perfect for mating with subs to handle below 100Hz in a full range PA system, or for use without subs when there's no low frequency content. You'd never want a bass cab tuned that high.

If you have a good PA then your back line cab is more of a personal monitor, as it no longer needs to drive the entire room by itself. There's no reason why you can't still use a 2x15, but if your gear hauling capacity is limited the pack space that 2x15 takes up would be better served carrying a larger PA.

I can't speak to his motives, but I can speak to the engineering. Since a ported cab needs ports and it needs handles it's practical to combine the two where it makes engineering sense. In a bass cab it doesn't. For a port to double as a handle it can't have a duct. Without a duct the port area must be quite small to tune the cab low enough for bass. The problem is that too little port area leads to chuffing noise from the port, while a non-ducted port large enough to not chuff can't tune the cab low enough for bass. I use port handles only in PA tops that are tuned much higher than bass cabs, as those tops are meant to be used with subs handling the lows.