SWR Goliath Jr 2X10 refurb of carpet covered cab

[JohnDaBass]

I have a SWR Goliath Jr 2 2 x 10 incoming and if the carpet covering is secured tightly I am considering giving the carpet fabric a coat or two of Tuff-Cab.

I am hoping that the acrylic will soak into the carpet fabric and create a really tough finish. ( all most like Tolex)

Anyone on here used Tuff-Cab on carpet or is it wiser to remove the carpet fabric?

Edited December 18, 2023 by JohnDaBass
renamed

[JPJ]

Most of the older SWR cabs I’ve owned have suffered from detachment and shrinkage of the carpet covering, particularly on the bottom of the cabs. My recommendation would be to remove the carpet, but I’ve done this once and will never do it again voluntarily as it was a complete PITA. I ended up having to belt sand the whole cab to get the sticky glue residue and the remainder of the carpet off. 

[Dan Dare]

Originally, the carpet covering used on cabs was Ozite, which was developed as carpeting for vehicles. Other "rat fur" type products are used, too, but they are all pretty similar. Being synthetic material, it isn't particularly absorbent and the glue layer beneath it (as referred to by JPJ) will help prevent any paint finish from soaking in. I think there's a good chance you'd end up with a horrible mess if you tried to paint a carpet cab with Tuff Cab, which is intended for hard surfaces. Imagine the finish you'd get if you tried to paint your carpets at home and that will give an idea of the likely result.

 

There are articles online about removing carpet finish from cabs, but they all warn of the aggro involved in getting the glue off (again as JPJ points out), not to mention the carpet itself, which is tough stuff and won't peel away neatly (it tends to delaminate, leaving patches of black fuzz and glue, which is hell to remove). If it's still sound, you can revive carpet covering with a stiff brush which will spruce it up to an extent unless it's really badly worn.

 

I've thought of removing the carpet from my Berg' cab for a while now and Tolexing it to match my other cabs, but have chickened out so far because of the potential issues and the fact that it isn't in too bad shape. I think I'll put it off until it gets to looking really awful.

[Downunderwonder]

I have read a few accounts of people stripping carpet off cabs for tolex. They are all woeful tales. I don't think anyone does it more than once.

 

And yeah, paint over the carpet would be a job for a skip once done methinks!

 

Maybe if you belt sanded the carpet first...

 

Yeah, nah. Give it a haircut and call it good.

[basstone]

Same experience here removing carpet from a big bass combo cab. A hot air gun helped but I still ended up doing lots of sanding then finishing using tuffcab paint applied with a foam roller. Looked like new when finished and very durable.

[Phil Starr]

I can testify that removing carpet is a truly horrible job. I rebuilt some Yamaha PA subs years back and managed to peel off the carpet and ultimately stick it back down but cleaning up the adhesive  from the panels was awful. I don't think Tuff Cab will be flexible enough to form a continuous coating or that it will be 'Tuff' on a soft fabric undercoat.

[JohnDaBass]

Ever since I built my Easy build lockdown BC110 combo

 

I have been minded to build a second BC110 to stack under the combo. Last year I picked up a couple of Celestion BN-10-300X speakers in a sale and planned to build two identical BC110 1x10 cabs with sizes changed slightly to suit stacking one under the BC110 combo or two sitting under the Fender Rumble 800 combo.

 Fortunately up popped on here a SWR Goliath Jr 2x10 cab at price that was way lower than the cost of the materials and labour for building the two BC110 cabs.

 

The SWR cab was in surprisingly good condition for a cab that was built in the early 80’s.

I started the refurb topic to seek advice on the carpet covering before receiving the cab, When it landed all it needed was a thorough clean up with carpet cleaner replaced the corner protectors with metal chrome ones, and good vacuum inside to remove years of dust & fluff.

 

It appears that this may have been one of the very early SWR Goliath Jr 2x10 cabs which were apparently built by Eden for SWR. The cab had rear ports with either Eden speakers or PAS 10’s.( the later SWR cabs had a front facing shelf port and used Eminence speakers and the Go-Light versions had Neo Eminence 10’s)

 

Edited December 18, 2023 by JohnDaBass
spelling

[JohnDaBass]

The ports seemed to be very short and the speaker wiring had been changed to series, 16 ohms, from the original parallel 4 ohms. The horn was not working because one side of the fuse holder had broken and the fuse was loose in the bottom of the cab. The horn worked fine after soldering a link wire between the fuse holders. The horn was a Japanese Fostex  75w, 025H27 which had a range of 4,000 to 15,000 Hz and a recommended crossover at 4,000Hz.

 

So I purchased an Eminence BGH 25-8 as recommended by @Bill Fitzmaurice and plan to run the two BN10-X300s full range as suggested by @stevie on this thread.

 

 

The cabinet itself was very well made and constructed from 15mm 7 layer plywood with excellent bracing side to side and front to back. But it weighed the same as Saturn some 30 kgs with the original ceramic magnet speakers. There was a great deal of attention to detail in the construction, staples used to secure the back of the “T” nuts to the baffle, sound dampening fabric tacked on all the internal walls and properly omitted around the ports.

Great spring loaded handles with their inner metal faces also dampened with stick-on acoustic foam.

 

 

Edited December 18, 2023 by JohnDaBass
error

[JohnDaBass]

The crossover is apparently 4,000Hz which is way too high and using @Bill Fitzmaurice, @stevie guidance it should be more like 2,500Hz.

The photo shows the components used and I have used a Sharpie to draw on the topside of the PCB the copper track circuit from the underside.

X-over SWR-1.pdf

 

There are two 3.3 microfarad caps in series and a 0.17mH inductor across the positive and negative speaker lines.

Can anyone suggest a simple way to modify the crossover circuit from 4,000Hz to 2,500Hz?

Or will it be necessary to build a new PCB following @Bill Fitzmaurice circuit?

Edited December 18, 2023 by JohnDaBass
error

[JohnDaBass]

The ports that were on the cab suggested on WinISD that it was tuned to about 80Hz ( blue). I replaced the ports  with 2 x 75mm Dia X 110 long to achieve somewhere between 48 & 50 Hz (Red)

 

The roll off at 60Hz sugests that the PAS Or Eden speakers did not go that low and seemed to focus on a strong mids profile.

[Downunderwonder]

80hz strong is what you want for 4 string bass.