nekomatic

Nabbed a couple of the last few tickets for Rise And Fall Of The City Of Mahagonny at ENO on Monday. You know, the one with that Doors song in it. 

Yes! It’s still slightly outside my planning window at the moment but I’m watching the topic and will confirm or deny when able. 
 

I wonder how many BC 8" cabs we can assemble in one place?

Riot Jazz at Manchester Albert Hall. Upstairs for the first time - it’s not the very best sound compared to some venues, but a great view. That’s mininekomatic2’s trombone teacher on the right. A cracking good time was had by all. 

One other thing to be aware of is that there’s no guarantee that the current generation of free or cheap to use generative AI tools will stay available forever, let alone get better and better for the same free or cheap price. All the companies providing them are running on vast amounts of venture capital based on hypothetical vast future profits, which nobody can explain how free or cheap AI models will actually deliver. A lot of people are predicting that this business model has to fall apart sooner or later. 

3 hours ago, nekomatic said:

If you want to use a port with a square cross-section rather than a round one, I think you just need to make the length and the cross-section area the same. So if the area of the circle (pi * r^2) was say 25 cm^2 then a 5 x 5 cm square port of the same length should give you the same tuning. 

I’ve re-read this and it might be confusing - what I mean is, the cross-section area of the square port should be the same as for the cylindrical port, and the length of the square port should be the same as the length of the cylindrical port. 
 

As I understand it the straightforward calculation for port dimensions assumes that the inside end of the port is in free space inside the cabinet, not next to the cabinet wall, so that’s why calculating the right size for an end slot (or triangular corner port, etc) isn’t so easy. 

If you want to use a port with a square cross-section rather than a round one, I think you just need to make the length and the cross-section area the same. So if the area of the circle (pi * r^2) was say 25 cm^2 then a 5 x 5 cm square port of the same length should give you the same tuning. 
 

By ‘slot port’ I understand a slot in the baffle with no extra depth behind it and I believe the dimensions of that are harder to calculate correctly, especially if the slot is at one end of the baffle. Can you sketch what you had in mind, and is there a particular reason not to use a cylindrical port? Personally I’d just go with the latter, I found it easy enough to construct. 

On 26/01/2026 at 09:22, knirirr said:

We're attracting a variety of players and also audience and it's getting to the point where it's hard to fit everyone and we're over-running or missing people out, or both. Not sure how to fix that.  

Do your soloists generally turn up with one tune that they simply must play, or are they flexible about playing on any tune that they know? The organiser of the jam I go to seems pretty good about sorting people out so everyone gets to play on something, even if it’s not always their first choice. That and not letting anyone drag a solo out for too many choruses. 
 

Still, being too popular is a good problem for a jazz jam to have!

18 hours ago, chris_b said:

I've been house bass player for a jam that's been running on the first Monday of the month for 26 years. We've seen 4 or 5 managers come and go in that time and the new management has decided that they don't want us sending the bucket around! They don't like the look (ffs). They get about 4 people in on a Monday night and about 100 on our jam night. We're looking for a new venue.

I assume you’ve thought of politely suggesting that if they don’t like the bucket going round then they could always just pay you, out of the extra bar takings that the jam brings in. 

On 30/12/2025 at 17:28, tauzero said:

Finish at least some of the hardware projects I've started (cab, basses, electronics).

Haha, I also need to do this. There is one Project Of Doom in particular that I need to either get done or finally abandon. 
 

Stop starting, start finishing, as the maxim goes. 

Didn’t see this thread before but it’s great to hear about all your goals. Good luck with them all!

I want to make a jazz trio happen this year - I’ve got a good pianist lined up, who I also get on well with, but no leads on any half decent (but not so decent that they’re fully occupied doing paid gigs) drummers. I’ve heard you can sometimes find one under a big pile of hen’s teeth. 

Yeah, ‘too much power’ shouldn’t be a problem if the iron is temperature controlled. 

I’ve not used one myself but I might look at this one - the handle size might be a bit cumbersome for the tiniest jobs but it’ll have enough power to deal with pots and connectors even with lead-free (and I do think we should all be going lead-free nowadays). I’d get this tip with it. 

The thing I like about the Antex irons is that it’s very easy to change the tips - they just slide on and off over the element - which means you can easily use the right size one for the job, and for soldering larger parts like connectors with lead free that can make the difference between impossible and straightforward. 
 

I’m not sure if anyone else has a similar design or if it’s an Antex patent. 

A thing that would make me practice enough. 
 

From the fact that the cabs are secondhand and one socket is worse than the other, I’m very inclined to suspect that it’s those sockets that are bad. Maybe they’ve been repeatedly used with a non-genuine Speakon plug that has damaged them. The obvious thing to test would be whether you see any problem with a different cab. 
 

The good news is that it looks like it should be easy to remove the connector panels and replace the faulty connectors on the cabs. If you don’t fancy doing it yourself it shouldn’t be too expensive to have a tech do it. 

Did you buy the amp, cabs and cables together or did you already have the cabs?

Can’t remember exactly but I’m pretty sure I just squeezed mine flat between a couple of pieces of wood and a couple of clamps. 

2 hours ago, p4ul said:

Afrobeat Jam in a record shop - House band invite players to join them for improv jams, no sign up sheet, no Ukuleles yet. Got to have some chops to keep up with the HB but welcoming and good vibes, musically interesting.

Ooh, nice!

May not be what you had in mind by ‘funky’, but as a ’90s indie kid (and adoptive Manc) I couldn’t not post this. 
 

Get an observatory, you lot - this is the cab design thread!

😉

6 hours ago, rwillett said:

I have to confess to using some paints and stuff sometime ago that stank to high heaven, and for some reason t'CFO isn't keen to repeat the exercise. I have no sense of smell (lost it 2014) so I have no issues which is part of the problem, she can smell it and I can't.

Tuff Cab has very little odour, fwiw, so hopefully your equivalent one is the same. 

3 hours ago, rwillett said:

I did look at anodising some telescope parts years ago, the theory looks quite easy, its the practise that worries me...

If you're banned from even painting indoors I don't think anodising is going to be on the cards!

A few weeks back we happened into a pub in Didsbury, not that far from us, and found it full of flyers for a forthcoming Jazz Jam - which isn't something you see that often. So on the day of the Jazz Jam I turned up and found an excellent young guitar-led trio going by the name of Fisherman Dice, and… no jammers except me! But they were dead friendly and let me sit in for three tunes, and mentioned that they run a bi-weekly jam over in Chorlton, of which I got the impression that it was well attended, and last night I went along to that and found the same bassist and drummer but a different guitarist and… no jammers except me. But they were dead friendly and let me sit in for three tunes   

Anyway the Didsbury one was a new venture by the manager of the pub, which changed hands not long ago, and despite the low attendance he said he was keen to repeat it, and I've let the Fisherman Dice guys know that if he does and they can bring a keyboard next time (which the Didsbury venue has space for but the Chorlton one absolutely doesn't) then I can pretty much guarantee a couple of pianists who go to the other jam I've been going to, and possibly some soloists too. So it would be nice if that could become a thing. But my ulterior motive of finding a drummer who'd be interested in getting together with one of the aforementioned pianists to do some occasional trio stuff is no further forward…

1 hour ago, rwillett said:

The round speaker grille is great but the delivery is the same price as the grille. 100% delivery costs feels wrong to me for some reason.

CPC sell them so if you can think of sixteen quid’s worth of other stuff you need from CPC (and who amongst us can’t do that?) then you can get free delivery. 
 

To be honest even if you have to pay delivery I’d struggle to find a cheaper way of making a decent grille, as long as you have the means to cut it (I used a Dremel but am sure hacksaw or tinsnips would do). Note that the plastic edging is just a stretch fit around the round grille so you can re-use it (with glue) for the rectangular version. 

2 hours ago, rwillett said:

Clearly people use metal grills and they look great, but wondered if they need to be 10mm (or another minimum distance) from the speaker or the holes need to be a certain size, do you need rubber mounts on them to stop them vibrating?

The speaker specs will tell you the maximum cone excursion, Xmax, which for this driver is 5.5 mm. Sometimes they give a separate larger figure for the excursion where damage will occur, but I think if we go past Xmax that means we’re into the realm of abusing the speaker anyway. So the cone should move at most 5.5 mm forward (or backward) from its rest position, add a couple of mm for (waves hands) stuff, and I guess that should be fine. 
 

I don’t think the size of the holes matters acoustically, but guess the percentage that is hole rather than not hole might do? I’d say picture what a speaker grille usually looks like and go for something not too different from that. 
 

You want to avoid the grille vibrating too much at an annoying frequency, so I would probably mount it as rigidly as you can. I screwed mine to blocks round the edge of the baffle and one in between the speaker and port and that seems fine.