Radiata pine 4x12 with Celestion Blues

[Colossal]

Looking good, Geeze! Are you planning to do a straight or slant cab in the Marshall style or your own thing?

[Geeze]

Looking good, Geeze! Are you planning to do a straight or slant cab in the Marshall style or your own thing?

Hi Colossal!

I'm a B cab guy. I've built 3 A's [4x8, 4x10 & 4x12] and this is the third B. I'm doing the 1" [ish] round over, piping [walnut] and probably EC repro grill cloth as I have a bunch. I'm contemplating dyeing it as well. Undecided on lacquer as that could - depending on who you talk to - affect the sound.

Russ

[Geeze]

Working the corner blocks -

gluing.



I try to cut the fingers and the glue on bits a bit 'proud' then cut/sand flat.





One side cut and sanded.



An inside corner has a small gap. Here is one of the benefits of contrasting wood.



Squirt in some CA + accelerant [who wants to wait?] and sand it flat.



These are the back corner blocks that need to be notched.



At this point the cab weighs 18.4lb.

Russ

[Geeze]

Gone most of yesterday touring the hills.

Gluing up the multi part baffle. Spent some time running the two halves through a drum sander to get them flat in relation to each other. Now in glue up.



Starting on the baffle surround. Due to the additional piping I screw to the finished baffle it is front loaded and attached to cleats on the rear of the surround. I nailed the two sides together to keep the angle consistent and not warp the baffle. A shooting board is a handy tool.



And cut. This is a 2° or so angle.



Naturally I had the 'moment' where I measured the length at least twice then proceeded to cut it 1/8" short. Mumble. That side is in glue up so I can recut it.

Russ

[sluckey]

A woodworker can never have too many clamps! Lotta money in those pics.

[Geeze]

A woodworker can never have too many clamps! Lotta money in those pics.

Ain't that the truth!

The baffle rim is cut with the 2° angle to include the top and bottom bits. If you don't have a magnetic angle device they are worth their weight in gold.



The baffle cleats and the back bracing is sized.



The back is sanded flat and the two pieces glued together.



Time for dinner.

Russ

[Geeze]

More progress.

The baffle surround is in.



The back panel bracing is glued in.



Back panel cut and test fit.



FUBAR strikes - a first for the speaker screw holes - one was drilled off center. Mumble.



Hole drilled out with a forstner bit and I was lucky to have some 1/2" dowel laying about.



Super glue to the rescue.



Baffle screws installed and CA tacked in. I drill the hole undersize and force the screw to 'tap' itself into the hole. Painted.



With all of the parts included the weight is 29.6lb. I'm on the fence on handles at the moment. If the side[s] prove to be too resonant I'll install Scumback handles to stiffen.

Onward and upward!

Russ

[Geeze]

Baffle cleats and baffle installed.





There's a .450" gap surrounding the baffle from the sides to allow for .125" walnut piping and the EC repro cloth which is about .075" thick and a bit of breathing room. I wasted lots of time trying to make the gap a 'press fit' and spent hours trying to get it to fit.

The other thing I'm curious about is - with the exception of the Radiata 1x12s I have always sealed the interior with shellac and then lacquer on the exterior to limit moisture flow.

I've heard for years than finish affects the tone - anyone care to weigh in?

Now for the wiring - after I find the bloody flux - moving is a non stop treasure hunt.

Russ

[Geeze]

I missed some updates.

I'm to here, baffle ring, cleats and baffle cut and fitted.



I got delayed by a recent house purchase and some truly hilly billy electrical wiring not even close to code that started a fire in my crawlspace on Thursday and 'luckily' burnt through the side of house so i could get a hose in there to beat back the flames. I did not want to crawl into the crawlspace with only a vapor level mask. FD came out and inspected with a thermal meter in the crawlspace and squirted some more water. Other than a scorched kick plate and the smell of burnt wood it didn't breech the interior. Electrician came out next day to restore power and will be back to rewire the section and I'll have him inspect the rest of the house as well. Mischief managed.

So I thought I would install the blues before I put the grill cloth on which meant taking them out and putting them back in - nope.

Then in my grand tradition of 'hey, let's do that' and make the project take longer I decided to upgrade my old grill fixture which was sized for the one leg side of the table with lots of rock and roll to the other side with two clamping fixtures.

Old fixture.



New fixture as a screw goes into the baffle.



Fixtures attached and clamped to the bench. I had to drill out relief holes for the speaker mounting screws.



Coffee time.

Russ

[Geeze]

Got to here tonight and ran out of gas and lock washers for #10 screws. Mumble.

In addition to the 'foot' stretcher I used a reversed clamp to apply tension. Worked out but I had to push the wooden box to keep it from popping off.



Rubber grill cloth is a bit a challenge - unlike the paper based you can't wet and heat it. The lines make it easier to keep straight.



No piping yet and the back needs to be drilled for screws.



Got two placed will need a hardware run tomorrow.



Russ

[Colossal]

It's turning into a thing of beauty. Nicely done

[Phil_S]

Many thanks for taking the time needed to document your progress. Kinda plain for what I've seen you do but elegant nevertheless and your attention to detail is excellent. BTW, I am a big fan of people who know how to undrill a hole that's too big or in the wrong place

[Geeze]

Many thanks for taking the time needed to document your progress. Kinda plain for what I've seen you do but elegant nevertheless and your attention to detail is excellent. BTW, I am a big fan of people who know how to undrill a hole that's too big or in the wrong place

Hi Phil,

I stole the plug it and redrill from somewhere because it got documented. I've been concerned about the dwindling attention to creating / working with the hands / brains to bring a concept to life since the early 90's when I sold architectural & manufacturing software and looked at tons of house plans that had two 'great rooms' but no shop / basement or a garage big enough to actually do anything in. So I document to encourage building and the artful fixes of mistakes is part of the deal.

Here's where I got last night. Found the soldering unit, I hope the flux is still good. Went ahead and rounded the corners - cut a 1/2" 45° with a router - a first - then sanded the roundover.







Picked up lock washers and other bits to try to cut down the smoke smell. I'm afraid it will require treating the whole scorched subfloor area.







'Nuff for tonight.



Russ

[Geeze]

Finished - for now. The baffle isn't quite straight so I'll be fixing that when I put in the walnut piping. The cab with speakers installed is 50.0lb which is light for a 1960B.



I had fun wiring it up - first go round I was getting 25ohm?!? I'd measure the first two speakers and they were 5.6ohm and the second pair were the expected 12.8ohm. Wired it wrong in two ways now getting 12.8ohm at the jack. Glad I checked...

With a Satellite 'Cuda [KT66] and single coils the P90's sounded very good and the Tele with La Brea's was spanky and great wind cries mary tones.

Russ

[Geeze]

So far it sounds like I expected - lively and resonant [in a good way]. After about an hour of 100-105dB it seems to be fine structurally. Edge glued joints are very strong - to date - but we'll see in the future. From a production standpoint edge glued baffles / backs aren't economical easily taking 10X time and effort of plywood.







Russ