Bill Fitzmaurice

There is no ideal amp wattage, for any driver. The usable range tends to be between half and twice the driver thermal rating. For a K140 that's 75 to 300 watts.

It's not going to be made up, but even Eminence uses a pass band averaged figure, which doesn't say anything about what it will do where it matters for bass, below 100Hz. Besides, if you don't know what your original driver has for response there's no way to predict how a replacement will compare.

In general higher sensitivity is realized at the cost of low frequency response. That's why guitar drivers tend to have higher sensitivity than bass drivers, which tend to have higher sensitivity than PA subwoofer drivers. However, you can't trust manufacturer sensitivity ratings, as they tend to play fast and loose with the details, like at what frequency it was measured. 105dB/watt seems wonderful, but not if it was measured at 2kHz. The only way to be sure if a driver swap is worthwhile is to use speaker modeling software to compare different options. The fly in that ointment is that it's usually impossible to get the necessary Thiele/Small specs on OEM drivers.

For that price you could not only make your own, you could also buy the tools to make it. 🤔

I'm not wild about being down 14dB at 50Hz. I'd go with a larger box and lower tuning to get 50Hz no more than --6dB, otherwise you might as well not have an E string. -6dB at 50Hz is my benchmark for a ported bass cab. As for the peaky response around 100Hz in your examples that's what results in boom.

You can try David Coomes, Doncaster, UK. [email protected] He builds cabs of my design, I don't know if he does any others.

I know that Ampeg used four conductor XLR for a while, four conductor so that one wouldn't plug an amp output into a console input. It was better than 1/4 inch, not as good as Speakon. A major problem with XLR is that they couldn't handle large gauge wire. I used some speaker connectors back in the 80s that resembled giant oversized XLRs. I don't remember the brand name, they were essentially put out of business when Speakons came along.

Inevitable if you insert or remove a plug when the amp is powered up, which one should never do, otherwise no worries. The man problem is the very small contact area between the jack and the plug tip. It doesn't take much corrosion to make for a bad connection, so the plugs should be treated on a regular basis with contact cleaner, which will migrate to the jack to keep it clean as well.

1/4" can be very finicky. Maybe it's because they don't like being asked to do something totally different than what they were designed for, 20th century telephone switchboards. 😏

Simple solution, use the Speakons.

Two of the most successful studio monitors of all time were the Yamaha NS10 and the Rogers LS3/5A. Google them to see response charts that show both to be about as flat as the Alps.

It's not difficult. Whether or not it's worthwhile is a different question. Why advertise anything that it's not? To make a sale.

Maybe they sound like valves, maybe not, but unless they come out with 6L6 or EL34 replacements they still won't duplicate the sound of an all valve amp.

It's not the voice coil thermal rating that counts, it's the driver displacement. Back when my 50 watt '65 Bassman was new the Fender 212 couldn't handle it, nor could two. I eventually wound up with a pair of 412s before hitting the books and learning how to design my own cabs. In retrospect I owe Leo Fender a debt of gratitude, as he set me on the path to making my living as a speaker designer. I do agree though that 3012s would be overkill, a pair of 2012s would suffice for a lot less money. Betas aren't bad either.

I'd line that with polyester batting, it will clean up the mids considerably. I'd investigate the tuning as well, you may not be taking full advantage of the 3015 capabilities. I doubt that the cab is braced either.

I can't see the need for more than a Kappalite 3015 with only 100 watts pushing it. If you're not getting the volume you need you should be looking at a better amp, not more speakers.

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.