1x12 cab refurb project

[Phil Starr]

Well done, nice to see it is coming along.

[Chienmortbb]

On 29/07/2021 at 21:42, nekomatic said:

I MADE HOLES IN IT

 

 

Horn aperture is four holes with the hole saw, joined up with the power saw. Port aperture is cut with the 127mm hole saw (I've got this set which I don't think could possibly be any cheaper, but it has worked.) This was a bit necky as my mains drill has no speed control, so it's flat out or nothing! Space on the baffle was even tighter than I expected, so the port aperture has ended up taking a tiny bit out of the transverse brace, and I couldn't cut the right-hand edge of the port aperture so just sanded down the pointy bit with the Dremel. It looks terrible, but the horn covers up my shoddy handiwork nicely…

 

 

I may need to drill new fixing holes in it though, as the lower two existing ones end up right on the edge of the baffle, where the join with the batten to block the slot port will be. Port aperture is slightly too small for the tube so will need some sanding (as if there isn't enough to do already) but I guess better that than too big…

 

Last of all, one on the back for the connector plate. I put it in the corner so it looks OK with the cab in either horizontal or vertical orientation, and I made it round because that was easiest, but actually I think it looks kind of cute:

 

 

Don't sand it. Put the port in the freezer, it will contract, then slip it in the hole and as it heats up it will form a tight fit.

[Chienmortbb]

On 01/08/2021 at 16:48, nekomatic said:

Some bracing - I'm going to stop there for now and see how it performs, I can add more if it seems like anything's vibrating

 

 

 

and the slot port blocked:

 

 

Looking very good.

[nekomatic]

Okay so…

 

Battens to add enough depth for the handle screws, and handles in (temporarily, obvs). The random-looking extra bits are there to block the old handle screw holes and connector hole.

 

 

Connector plate for the Speakon, made out of some aluminium faced polymer laminate I happened to have (you know, the stuff they clad tower blocks with 😳)

 

 

 

And just a couple of minutes with the ridiculously effective sanding drum attachment on the Dremel, and the port fits nicely…

 

 

With UniBox I calculated 19 cm for the port based on the final volume being somewhere in the range 45 to 50 L and tuning to 50 Hz. That only leaves about 7 cm between the end of the port and the back panel but I'm hoping that's not too little.

 

Hang about though, if I now fit the horn and the HF driver… I can try it out!! Wait there a minute…

[nekomatic]

First things first: It works! It definitely goes pretty loud, and I don't think I'm sending a hot enough signal into the PA amp to hit max loudness.

 

I would say the sound is a bit 'coloured' to my ears, but that's with just the LF driver connected, no crossover yet. Also I'm listening close up in a small room which is not really going to be its natural habitat. Also also there's no lining in the cab yet.

 

Using a signal generator and putting a fingertip on the cone the tuning seems to be as close to correct as I can determine, maybe 52-53 Hz. Will the frequency change much when I a) seal the hardware properly and b) add some lining?

 

I reckon I can feel a bit of a resonance at about 120 Hz on the rear panel now, and 230 or so on the sides. Might brace the sides a bit. Also there's a buzz at 130-140 but I'm fairly sure that's just bits not properly screwed in and sealed yet, as for example it goes away if I press on the edges of the horn.

 

Next and arduous step is to take all the hardware out again and finish sanding the b_st_rd thing.

 

[Phil Starr]

Well done, I have to say that at this stage I usually spend far too much time playing with a half finished cab just for the joy of making a noise.

 

I've looked at your pics and i like the bracing around the port/horn area which is a particular problem for the 110 we built too. that should be stiffening the back too so long as the front to back brace is firmly fixed. I'm a little suspicious of the frequencies you found resonances at 120Hz is so close to half of 230Hz it's possible energy is being transmitted between the side and rear panels. The easiest solution would be two braces across from side to side. bracing here might well help damp down the rear panel resonance as well. 

 

Which compression driver are you using with the horn?

[nekomatic]

Thanks Phil! Do you mean to add braces from some point on one side panel to the same point on the other one, and would you do those on their own in preference to fitting any bracing along the side panels themselves? Or am I misunderstanding that?

 

Horn is the CDX1-1445. I have all the crossover bits, just need to stop agonising over exactly what the layout should be and build the thing. 

[Phil Starr]

42 minutes ago, nekomatic said:

Thanks Phil! Do you mean to add braces from some point on one side panel to the same point on the other one, and would you do those on their own in preference to fitting any bracing along the side panels themselves? Or am I misunderstanding that?

 

Horn is the CDX1-1445. I have all the crossover bits, just need to stop agonising over exactly what the layout should be and build the thing. 

OK this is effectively our Mk2 cab then, don't tell @steviebut I really liked the SM212/1445 best of all

 

yes you have fairly extensive bracing already, simple cross braces add a lot of stiffness for very little increased mass. Even a simgle batten linking the opposite panels will make  a big difference.  If you have any offcuts of your batten it would be a matter of moments to cut a batten as a tight fit and test it. Plave it slightly off centre if you can . A single brace will effectively divide the panel in two if you place it centrally and you can simply move the resonance up an octave. If you've ever damped a string over the 12h fret you know what that means.

[nekomatic]

NUDE PIX

 

 

 

The baffle didn’t need sanding back to bare wood as I’m painting that black rather than Tuff Cabbing it and I’ve tested the black paint on an offcut and it seems to stick fine over the horrible, horrible Hammerite. Next up, final woodwork, and getting started on assembling the crossover…

[umcoo]

I'd be interested in your experience of Tuff Cab, once you start that bit. I've got an old Peavey I wanted to cover in tolex, but painting seems easier and somewhat cheaper. 

 

Did you get the Tuff Cab from Blue Aran? Seems a lot of things are out of stock there at the moment. Cheers

[Chienmortbb]

On 23/12/2021 at 16:50, umcoo said:

I'd be interested in your experience of Tuff Cab, once you start that bit. I've got an old Peavey I wanted to cover in tolex, but painting seems easier and somewhat cheaper. 

 

Did you get the Tuff Cab from Blue Aran? Seems a lot of things are out of stock there at the moment. Cheers

Tuff Cab is a trademark owned  by Blue Aran for the cabinet paint marketed by Blue Aran. @nekomatichas said that he will not use Tuff Cab although many of us have. It is easy to apply and forms a thick tough skin for the cabinet. It can give several types of textured finish depending on the roller type used to apply it. 

 

 

[nekomatic]

I’m going to use Tuff Cab for the outside of the cabinet, just not for the baffle. 
 

I’ve used it before and found it very easy to apply and get a decent looking finish, using the rollers that Blue Aran sell. There’s a blog post on their website about how to use it which includes some handy tips. 

[Chienmortbb]

6 minutes ago, nekomatic said:

I’m going to use Tuff Cab for the outside of the cabinet, just not for the baffle. 
 

I’ve used it before and found it very easy to apply and get a decent looking finish, using the rollers that Blue Aran sell. There’s a blog post on their website about how to use it which includes some handy tips. 

Sorry I should read posts fully before posting,

[Phil Starr]

Tuff cab is great, it's full of solids so it builds really well. It goes on as a sort of gel, a bit like painting on Swarfega in texture and it stays workable for quite a long time but it sets really hard. The long open time means mistakes are really simple to correct and you can work slowly and carefully 

 

FWIW I have a simple process I now stick to.

 

First make sure all your sanding and shaping is done, sanding back set Tuff Cab is almost impossible it's scratch resistance is also sandpaper resistance.

 

First coat I apply with a paint brush, I apply a thin layer but take care to get it into every crack and crevice. I have tried thinning it to get deeper penetration but it isn't necessary and the adherence is excellent if you have a dust free surface, I've never had any peeling or scratches through to the wood. 

 

Second coat I apply a generous coat of paint all over the cab (again I use a brush) and then use a standard mini roller to even out the spread all over the cab. Having an even coat is important for the texturing. I'm aiming for about 0.2-3 mm depth of paint here all over the cab. Having got it even I then do a very light rollering over each panel in turn using long strokes of the roller all in the same direction. This lifts a texture on the paint which I think of as a 'linen' effect like a coarse cloth finish. The texture will depend upon how coarse your roller is, the thickness of the paint and how quickly you move the roller so slow light even movement is what i aim for. The glory is that Tuff Cab stays open for so long if you aren't happy you can just flatten it and repeat, it's a joy to work with.

 

Final coat I apply an even thicker layer, it doesn't drip so you don't get runs. Again I use the roller to even the paint layer first then do a finishing pass with a coarse roller. I have the coarse foam rollers sold specially by Blue Aran but  I've used thicker mini rollers too and you can get a good effect either way, just different.

 

I've done a lot of house painting so I'm used to a three coat paint finish and three coats might be unnecessary but this is a system that works for me. The attraction of Tuff Coat is that it is so forgiving, take your time and it's hard not to get a good finish

[Chienmortbb]

10 hours ago, Phil Starr said:

Tuff cab is great, it's full of solids so it builds really well. It goes on as a sort of gel, a bit like painting on Swarfega in texture and it stays workable for quite a long time but it sets really hard. The long open time means mistakes are really simple to correct and you can work slowly and carefully 

 

FWIW I have a simple process I now stick to.

 

First make sure all your sanding and shaping is done, sanding back set Tuff Cab is almost impossible it's scratch resistance is also sandpaper resistance.

 

First coat I apply with a paint brush, I apply a thin layer but take care to get it into every crack and crevice. I have tried thinning it to get deeper penetration but it isn't necessary and the adherence is excellent if you have a dust free surface, I've never had any peeling or scratches through to the wood. 

 

Second coat I apply a generous coat of paint all over the cab (again I use a brush) and then use a standard mini roller to even out the spread all over the cab. Having an even coat is important for the texturing. I'm aiming for about 0.2-3 mm depth of paint here all over the cab. Having got it even I then do a very light rollering over each panel in turn using long strokes of the roller all in the same direction. This lifts a texture on the paint which I think of as a 'linen' effect like a coarse cloth finish. The texture will depend upon how coarse your roller is, the thickness of the paint and how quickly you move the roller so slow light even movement is what i aim for. The glory is that Tuff Cab stays open for so long if you aren't happy you can just flatten it and repeat, it's a joy to work with.

 

Final coat I apply an even thicker layer, it doesn't drip so you don't get runs. Again I use the roller to even the paint layer first then do a finishing pass with a coarse roller. I have the coarse foam rollers sold specially by Blue Aran but  I've used thicker mini rollers too and you can get a good effect either way, just different.

 

I've done a lot of house painting so I'm used to a three coat paint finish and three coats might be unnecessary but this is a system that works for me. The attraction of Tuff Coat is that it is so forgiving, take your time and it's hard not to get a good finish

I have never written it down but that sounds similar to how I do it. One extra point, despite the amount of solids in TuffCab, you still need to sand the cabinet smooth. It barely notices but there is a line on one of my cabs where two panels join. 

[Phil Starr]

1 hour ago, Chienmortbb said:

I have never written it down but that sounds similar to how I do it. One extra point, despite the amount of solids in TuffCab, you still need to sand the cabinet smooth. It barely notices but there is a line on one of my cabs where two panels join. 

It's true I have the same problem and that's how i found out how hard sanding Tuff Cab is  Always have to find things the hard way!

 

[nekomatic]

I am declaring the woodwork done. Cross brace:

 

 

Corner ears because the recess isn't deep enough for the grille, and blocks to fix the grille to:

 

 

And maybe unnecessary, but because the handle screw heads aren't recessed I got worried about them scratching some hypothetical uneven floor, so a sort of bezel around the handles:

 

 

And a load of filling (with 50/50 wood filler and wood glue, as recommended by Blue Aran) and sanding. I think I've done enough sanding for a while.

 

Crossover under construction: point to point wiring for the LF side, components soldered to matrix board and point to point wiring for the HF side, and Wago lever terminals to connect to the input and drivers because they're supposed to be more secure than screw terminals?

 

 

I can almost believe the end is in sight!

 

 

[nekomatic]

Painted and Tuff Cabbed:

 

  

 

I went for the Brown Black (or is it Black Brown) colour in an attempt to make it look slightly more furniture-y around the house and slightly less of a big ugly black box, but it's very nearly black anyway. I like it though. I didn't get the finish quite perfect - the roller from Blue Aran had an annoying tendency to start sliding rather than rolling, and I should have made sure to have better lighting on each side I was painting to spot the imperfections, but I'm sure nobody but me will ever notice.

 

Crossover completed and installed:

 

 

I'll glue those inductor leads down before final assembly. But now, let's put the speakers in and try it out:

 

 

I spent entirely too long just playing music through it off the iPod, very loud (sorry neighbours)! First impressions: it shows up that my amp makes quite a lot of hiss, independent of volume settings, so this pairing may not suit for quiet practice after all, but I can't imagine it'll be a problem for rehearsals or gigs. I would say the high end is a bit harsh for actual hi-fi, but would serve perfectly well as a PA speaker. I might just probe the wiring of the crossover HF side though, in case I've made some mistake that's thrown the frequency response out.

 

And last of all, the bass! Well it sounds great - I'm not sure if I was expecting it to go a tiny bit louder, but it's almost certainly all I need for the foreseeable future - except that it faithfully reproduces every detail of my terrible technique, which really needs to be the next project to work on before I contemplate any more amp or speaker related tinkering.

 

All that's left is to stick some wadding in - although I can't say I can hear the need for it - glue the port in, and put the grille and corners on, and this thing may be finished.

[Phil Starr]

Well done for seeing this through, the SM212/CDX! 1445 combination is a lovely one, and as you've spotted really revealing. I'm actually about to order up the last remaining parts so my SM212 will end up with the same pairing. I have too many half finished projects. 

 

Yours is looking great.

[nekomatic]

Lined…

 

…and loaded, grilled and cornered:

 

It's done! A labour of love and no mistake: it would have been way less effort to build a new one from scratch, and probably no more expensive (I'd have needed to buy a few clamps, but on the other hand I've killed a battery on the cordless sander in the process of doing this one), but it's really satisfying to know that I've given the original cabinet a new lease on life. And I'm really pleased with how it sounds and looks! If I can make it along to a Bass Bash at some point I'll be sure to bring it along.

 

Thanks once again to everyone involved in the Basschat designs and the valuable discussion around them, and everyone who's helped me out on here with advice, information and components: I somehow feel I have an extra incentive to do the thing justice now by playing as well as I can and as much as I can through it

 

On that note, here it is with the amp and bass, which I hope will be seeing lots of each other:

 

 

[lemmywinks]

32 minutes ago, nekomatic said:

Lined…

 

…and loaded, grilled and cornered:

 

It's done! A labour of love and no mistake: it would have been way less effort to build a new one from scratch, and probably no more expensive (I'd have needed to buy a few clamps, but on the other hand I've killed a battery on the cordless sander in the process of doing this one), but it's really satisfying to know that I've given the original cabinet a new lease on life. And I'm really pleased with how it sounds and looks! If I can make it along to a Bass Bash at some point I'll be sure to bring it along.

 

Thanks once again to everyone involved in the Basschat designs and the valuable discussion around them, and everyone who's helped me out on here with advice, information and components: I somehow feel I have an extra incentive to do the thing justice now by playing as well as I can and as much as I can through it

 

On that note, here it is with the amp and bass, which I hope will be seeing lots of each other:

 

 

 

Ya got the "boner" Jazz? There was a cream one of those in my LMS a few years ago, really nice bass.

[nekomatic]

9 hours ago, lemmywinks said:

 

Ya got the "boner" Jazz? There was a cream one of those in my LMS a few years ago, really nice bass.

It’s a late-’80s/early-’90s American Standard. What makes it “boner”, or shouldn’t I ask? 😳

[lemmywinks]

2 hours ago, nekomatic said:

It’s a late-’80s/early-’90s American Standard. What makes it “boner”, or shouldn’t I ask? 😳

 

🤣 The extended upper horn, think they were known semi-officially as Longhorn and affectionately as boner basses!

[nekomatic]

I hadn’t actually noticed that mine had a longer horn than others…