Bill Fitzmaurice

He who dies with the most tools wins. 😏 After wasting decades searching for tools I finally put these in my basement, garage and workshop:

Looking at the pictures of them the connectors don't appear to be Neutrik, and one advertisement for them says that they make their own. I've seen many reports of problems with Speakons but never with genuine Neutrik.

According to the Phil Jones owners manual both the 2 positive and 2 negative connections are in parallel, resulting in each PJB speaker connection capable of handling peaks of up to 80 amps. That would be of great advantage if you're using the cables for arc welding. 🙄 For electric bass speakers 20 amps capacity is sufficient for most any amp I'm aware of. If all you're pushing is a measly 500 watts that's 11 amps into a 4 ohm load.

Business card stock is perfect for a cone tear, it's very similar to the material the cone is made from. It's only when the damage is in the surround that a more exotic material is required, so that the surround remains flexible. That material is silk screen, which is similar to the material that the surround is made of.

It appears that the SS4 cable is simply Neutrik NL4 connectors and a four conductor cable with an absurd price. You should be able to make your own with two of these: https://www.bluearan.co.uk/index.php?id=NEUNL4FX&browsemode=category plus a length of this: https://www.bluearan.co.uk/index.php?id=JAMBC420DL1M&browsemode=category The cable conductors are color coded, so it's not rocket science figuring out how to connect the 1+ pole of the one to the 1+ pole of the other, likewise for the 1-, 2+ and 2- poles respectively. 2mm cable in a 1.5 meter length will safely and effectively handle 1500 watts per pair, so for the parallel pairs of this home made SS4 equivalent the capacity is 3000 watts. However, a cable shouldn't just stop working for no reason. Check the connectors for wires that have come loose.

Unless you have a valve amp that doesn't have an 8 ohm tap there's nothing to be gained by using a 4 ohm cab.

You're lucky it didn't end up permanently silent. That would have been no laughing matter.

Glue alone might not hold well. Copydex looks to be a good adhesive, use it to glue a piece of business card over the hole and you should be good for a while, if not permanently. Do remove the driver to do the job, so you can push the bits of cone back into place from the back. From a cosmetic standpoint you could glue the patch to the rear of the cone, so it won't be a visible repair.

It's a phase sourced cancellation caused by the distance between the pickups. The same thing happens with one pickup when it's a humbucker, but at much higher frequencies, as the distance between the coils is so short. That's why a Les Paul or any humbucker equipped guitar doesn't have the highs of a Strat or other single coil pickup guitar.

I did the same to my Superfly shortly after I got it. One reason was to give me a place to put the fan I needed to use to keep it from overheating. It's the same case I previously had my Hartke 3500 mounted in, so I still ended up with a net weight reduction of some 10kg or so.

Whatever is the problem it's inside. It could be anything from power supply caps that are toast to a simple cold solder joint between a component and the PC board. Easy enough to diagnose and fix if you're an experienced tech. If you're not an experienced tech you need to take it to one.

It's this picture that left me shaking my head: Cabs like that are the reason why I started building my own in 1969. There were some very well designed bass cabs back in the day, EV B115M and B215M and the JBL Cabaret series are a couple that come to mind. Nobody bought them, because they were sold as separates, and in those days you always bought the amp and speaker as a set. The largest amp manufacturers were Fender, Marshall and Vox, and their bass offerings were basically guitar amps without reverb or tremolo. The only amp manufacturers from the 60s that were first and foremost electric bass oriented were Ampeg and Sunn, and not coincidentally they had the best bass speakers as well.

Pictures of the 1553 show it to be two tens and a fifteen sharing the same air space, with a port that has no ducting. Even though the drivers all share the same air space the jacks are set up for optional bi-amping. It's the kind of bizarre Mickey Mouse engineering that guitar cabs can get away with, but not bass. As it dates to the early 1980s chances are the drivers are musical instrument rather than true electric bass drivers.

I use Eminence exclusively. My Jack 12 is loaded with a 3012HO, my Jack 15 with a 3015. My Jack 10 PA mains use 2510s and NSD 2005 compression drivers, my T39 subs use 3012LFs. My Wedgehorn 6 floor monitors use Alpha 6s. If I was on your side of the pond where Eminence is more expensive than here I'd probably use European woofers in my PA gear.

You should change the graph scale to show only up to 250Hz, as above that the software isn't accurate. Sensitivity is most important between 50 and 90Hz, as that's where power demands on the amp are highest. Looks good to me. I'd only use it when crossed over to a midrange driver no higher than 2kHz. Maximum SPL is low because it only has a 150w voice coil. For your purposes it would probably suffice. People who like it probably mean that they like it better than the OEM driver they used it to replace, and that's logical, because it's a better driver than most OEM tens. It's not just for PA. As far as that goes the Beyma has specs that are much more PA oriented. That's typical of most European manufacturers. American and British bass drivers, like Eminence, Celestion and Fane, all evolved from guitar drivers. In the 1960s none of them even made real bass drivers, and guitar drivers weren't called guitar drivers, they were all called musical instrument drivers. When bass drivers were created in the 1970s and beyond American and British designers tried to retain as much as possible the midrange response of those earlier musical instrument drivers. European manufacturers didn't have that experience to draw on, nor much in the way of musical instrument OEM business in their home countries, so they went after the PA driver market.

A disconnected driver becomes a passive radiator, upsetting the tuning of the cabinet, which could result in blowing the remaining drivers.

I made my speakers and my bass. My amp is an Ashdown Superfly, which I probably wouldn't recommend to others, as it's very underpowered, but the high sensitivity of my speakers compensates for that.

The thermal power rating and displacement limited power are both considered in the Max SPL chart. So is sensitivity, making it more useful than the maximum power chart. A maximum power of even a thousand watts is of little use if sensitivity is only 85dB. Not considering that is why those who use stereo or auto sound woofers with very high power ratings end up sorely disappointed with the result.

The transfer magnitude chart only considers sensitivity. If you're driving a few watts that's significant, but who does that? The very low end doesn't matter that much, most of what you're after lies in the 60-90Hz pass band. I'd say the Pulse looks to be the best of these three. Try it again with 4o to 45Hz tuning. That rise at 100Hz could result in a bit of boom. I wouldn't stop there, try some more twelves, particularly the Eminence Deltalite II 2512 and Delta Pro 12-450.

Model them all in the same size box, whatever you're comfortable with, and try them with the same tuning. When you model in different size boxes with different tunings you're not comparing the drivers, you're comparing the boxes. The spike around 2.5kHz is the driver break up mode, a bad thing with PA or stereo, but it's what's mainly responsible for what we call an aggressive tone.

I played 70s rock in the 70s, and 60s rock in the 60s for that matter. I have no interest in trying to get the same tone I had then. We bass players were constantly changing amps and speakers as new tech became available, and there was no such thing as gear nostalgia. I finally settled in with my current rig twelve years ago. It does everything I want it to, so I'm done with the hunt for tone nirvana. Even though my tone now bears little resemblance to what it was in 1965 or 1975 it's not the least bit out of place when I play songs from those days. It's better.

In that case model the drivers you're considering paying the most attention to the Maximum SPL chart, which considers sensitivity, thermal power handing and displacement all in one place. Overlay a few drivers, using a different graph color for each. The software is only accurate to perhaps 300Hz, so above that compare the data sheet SPL charts.

If you don't know how to use speaker modeling software don't try to design your own cab. It may look easy, but it's far from that.

Speaker break in is optional. You can use an accelerated method to do it over night, though the neighbors wouldn't take kindly to it, or you can just use it. One or two gigs will get it to its maximum potential. The changes in response are real, so ignore the wags who deny that break in occurs, but they're also slight, so don't expect anything major. Most of what you'll hear is yourself getting used to how it sounds.

The magic is eight tens, not Ampeg. The next best thing is a pair of 2x10 or 2x12, vertically aligned. Half of the 'magic' is a lot of cone area, the other half is having the uppermost drivers up high where you can hear them.