stevie

Are you going to reveal this inside knowledge?

It is indeed a crossover, mcnach, but it's very unlikely to be a variable crossover, which is what the reviewer that Dave quoted earlier is describing. Everybody and their dog uses an L-pad on their bass cabs. When an L-pad is used, the crossover frequency does move slightly by dint of the fact that the level of the HF is being raised and lowered. But that's perfectly normal.

Or just use your tone controls.

The F112 has a fairly extended bass response, which sounds beautifully fat and powerful on its own. It goes lower than most other bass cabs, but the price it pays is a lack of sensitivity - the normal tradeoff. It's quite common for players to find an extended low end troublesome in some playing situations.

Would you back that up with some actual information?

Simply put, an L-pad is a volume control acting on (in this case) the tweeter.

I think you'll find it's just a standard L-pad volume control on the tweeter, Dave.

Wouldn't it be easier to paint the baffle rather than tolex it?

Yes, with Winisd or any similar program.

That's very generous of you @rubis. I eventually decided to order a roll - so I'm now well stocked. I didn't appreciate just how big a roll is, but hey, it'll come in handy. 😁

Lightweight amps I've had are the Ashdown Mibass 500, the Markbass LMIII and the Aguilar TH500. I've ended up with the Ashdown RM500. It's got the most sensibly specified eq and does the 'slam' thing that not all lightweight amps do well.

@Lespaul1 Where did you get your LaVoce from? Do they have a UK distributor now?

I'll jump in and say that's a very good explanation.

The Bergantino CN212 contains two drivers rated by the manufacturer at 300W AES. I know because I've seen what they use. Bergantino rate their speaker at 700W. Why?

The dispersion angle of a 12" driver is about 90-degrees. So you're not going to increase the dispersion below that frequency using a 90-degree horn. In fact, you'll limit it to 90-degrees down to 700Hz. At least in theory. The horn on that speaker doesn't look big enough to maintain its dispersion down to 700Hz.

It's sad that the average bassist can't evaluate cabinets by comparing their manufacturer's specs. It should be possible, but it isn't. That's because the manufacturers don't provide specs in a usable format. There are standards for power handling, but hardly anyone quotes them. It makes more business sense to exaggerate. So when Barefaced say their cab is 600W rms or 800W rms depending on which way the wind's blowing, how does that compare with the 600W cabs from, say, Vanderkley? Well, Vanderkley's power ratings are to AES spec, which may not be perfect for our purposes, but at least it's a standard. So I can compare the (thermal) power handling of a Vanderkley cab with any other cab that uses the AES standard. Which is how it should be. Another example of a manufacturer who has tried hard to provide meaningful specs is Mesa Boogie. Although they don't actually say so, Mesa also use the AES spec for power handling. And although they don't provide frequency response curves, their low frequency extension figures are informative. In the PA world, most good vendors supply detailed specifications about their products which, by and large, are accurate and useful. That's because an important section of their target market are professionals who know whether the manufacturer is telling the truth. So the manufacturers, on the whole, don't lie because doing so harms their reputation. This is why Behringer, for example, has such a poor reputation in the professional sound reinforcement world. So, to get back to the OP's question. Why would a supposedly 500W driver morph into a 600W driver when you put it into a cabinet and into an 800W driver when you add a tweeter? Fair question. To find out, you need to ask another question: what standard are they applying to their specs? If they (or anyone else) don't quote a recognised standard or specify their measurement process, their figures are meaningless, i.e. they're making it up.

@rubis - would you like to sell me some of the felt underlay you have left? I can't source it locally and the cost of a roll from the mail-order suppliers is a bit steep just for an experiment.

For anyone wondering whether they should bother, I'd just say that this is a very friendly and good-humoured get-together, extremely well organised, with a wide range of interesting gear on show, and some fabulous, home-cooked food. Don't hesitate!

In principle, yes, that's right. I used to stick my head in the box and say 'testing, testing'. Even though I use more scientific methods nowadays, I still do it. If it sounds hollow, add more damping until it sounds dead.

Best practice for internal speaker damping is not to overdo it, especially with a ported system (which I assume this is). You're right to keep the damping well away from the slot ports. So try what you have and then carry out a before-and-after listening test, paying particular attention to the lower bass. If you find that the damping is removing too much of the very bottom end (quite likely if you cover all the walls with foam), take some out, or use a thinner material like BAF wadding (pillow or duvet stuffing). My go-to material is now felt - so I imagine that felt carpet underlay would work well. I've wanted to try it myself for a while but I've never found anyone willing to sell me a couple of square metres.

Ooh - this is going to look good.

What problems? Looked like a great cab to me.

That big roll of Marshall covering and two big tins of Evostik make more sense now.🙂 I'm really looking forward to seeing this tolex-covered version.

Yes, excellent work Jonannes. The grille material is a great choice for the natural wood finish – it's fencing panel if I'm not mistaken. To make a picture-frame grille, use some pine batten - width between 9 and 11mm and depth 18-21mm. As far as positioning the cab is concerned, it's been designed to be flat response on the ground. If you raise it up, like in your photo, you'll lose some bottom end, which you could also interpret as having too much top end. Don't worry about not being able to hear yourself. The horn directs the mids and highs that get lost in traditional cabs towards the player's ears. The other benefit of having a proper compression driver/CD horn crossing low down is that the mids and highs that are a vital part of the sound of the bass reach the audience properly. In traditional bass cabs, these frequencies get lost the further back you go. Which leads to the muffled, indistinct bass tone we've all heard a thousand times.

For builders who haven't got round to fitting the grille yet, and others who are cutting their own wood, the four corner standoffs are triangular in shape, made from 21 (or 20mm) x 30mm softwood batten. The height is 21mm and the outside dimensions of the triangles are 30mm x 30mm. You simply glue them into the corners and paint them the same colour as the baffle. You can also cut two rectangular pieces 30mm x 12mm from the batten and glue them to the sides of the cab. Once you've painted them, stick some of the thin foam strip onto them that you used under the handle. Builders who had kits from the last batch received these parts along with the 4.8mm x 19mm flange-headed screws and M4 neoprene washers. At a guess, a full picture-frame batten in 20mm softwood weighs close to half a kg. So using the standoffs not only saves time but it also gives you a useful weight saving.