d-basser

Like the 3D prints, good to see other Fusion users around here

Thanks for the input @stevie. I think what I have gone for is similar to what you are suggesting, a 'window frame' brace below the speaker and one cut around the back of the cone, both of which connect to the baffle (as much as possible) as well as the other sides. I have also tried to brace the baffle at the bottom between the ports. All off with the CNC company now so can't change it if it is wrong 😂

Someone should snap this up, mine has served me well for years and still sounds fantastic! Seriously versatile amp.

Little bit of a necro thread but I'm bringing this plan back to life. Sat on the back burner for a while with work being crazy (who'd have thought starting a tech company then hitting a global pandemic would be tricky eh) but with joining a new and loud band recently I'm going to need some extra oomf in the old amp department.

Nothing exciting to show just yet but I've ordered most of the bits needed. Working with a local company who can CNC the ply for me so this should be a neat little solution. Opted for the design that was similar to the basschat cab in terms of bracing but I've modified it with recessed joints in the corresponding panels (dado joints?) so this should go together nicely.

Pics and progress to follow

Currently working on the most important feature: what colour should I make it? Thinking a nice oxblood tuff cab finish with either a black metal grill or black speaker cloth

26 minutes ago, Pea Turgh said:

Please do a build thread.  I love build threads.

Will populate this thread with progress pics as soon as I have them 

no table saw here so I am hoping for the main cutting to be done by the supplier. Don't mind doing speaker and port cut outs etc myself. I'll get in touch with Timbmet over the next few days to get a quote

Thanks for that @Chienmortbb. Did you opt for poplar for weight on the BC design? Would it be ok at 12mm or would birch be a better bet?

Cheers @Phil Starr, that is a very useful summary of options. Think I'll play around with options and see what seems to work. I can promise you now my woodworking won't be as pretty as the drawings!

Now to find somewhere around Glasgow that does suitable plywood. Am I right in saying void free birch ply is the weapon of choice?

On 03/03/2019 at 09:25, Phil Starr said:

Cross bracing which Bill clearly prefers is a perfectly good way of bracing cabs, I assume he gets his 24mm figure by simply adding the thickness of his two 12mm panels. I wonder how he derives his 30mm figure? The big advantage of cross bracing is that it is easy to do and it uses very little material so adds little to the weight. The disadvantage is that it stiffens the panel at one point crating an antinode but allowing the panel to vibrate elsewhere. 

Would there be any merit in doing a bit of a hybrid cross brace / spline to spread the contact point with the panel. Something like this:

19 minutes ago, Chienmortbb said:

Much of the work has to be empirical, trial and error.

Being an engineer (and a bit of a masochist) the trial and error is part of what I enjoy, otherwise I would do the sensible thing and build one of Bill's designs or save up for another of Alex's wonderful cabs.

Drew it up with BFM style bracing, looks like it should be easy enough so may well try this first.

8 minutes ago, LukeFRC said:

How do I never find these ebay auctions! 

It hasn't arrived yet so still that chance it is just a photo of driver in a box 😂

7 minutes ago, Bill Fitzmaurice said:

Like the arguments about mixing cabs, mixing driver sizes and tube versus SS watts discussions on this topic always seem to end up in an endless back and forth with no resolution, so having said what I have to contribute I'll now bow out of the thread.

Second Luke's sentiment, your expertise is always appreciated. 

S12 or S212 would have ideal but the 3015 was 50quid on ebay! Too good to pass up

9 minutes ago, LukeFRC said:

How much off is the simplexx size wise for what you need to do? The beauty in using a design someone’s already done is that you can build it and never need to think about port end correction, or baffle step or anything like that...

Not a million miles, Simplexx is 24" x 25.5" x 13.5" (w x h x d), my design is currently 48cm x 64cm x 35cm so around 19" x 25" x 13.75". Realistically it is just a narrower cab however I will be carting the thing up and down to a 3rd floor flat so narrower is much much easier.  

Looks like I've got some reading and thinking to do this morning, feel I may have started a bit of a bracing battle. 

Thanks to everyone for the input and info, great stuff. Hope Bill isn't grumpy about me not opting for the Simplexx, designs look great and I'll almost certainly build an S12 or two in the future. 

@Dan Dare that is designed for the LF version, different driver 

OK, back to the digital drawing board, cheers for the info

Thanks @Bill Fitzmaurice, don't know why but I am not a big fan of the corner ports aesthetically. I can completely see why they are great for doubling as braces but if I could avoid using them I would like to. Form over function, terrible I know.

One other option I was thinking of was to go for a slightly more elaborate bracing design similar to the one used on the mkII basschat 1x12 design, I have drawn up the rough idea below. Would this be better than my initial design or do I need to completely rethink bracing?

I managed to pick up a Kappalite 3015 (not LF) stupidly cheap on ebay and I am wanting to build a cab to house it. I was going to build a BFM Simplexx 15 but the overall dimensions are a little big for what I want so those plans will be kept for some future project or other. Instead I am wanting to build something loosely based on the Greenboy Bassic 15 and the Gen 1 Barefaced Compact. These are both designed for the 3015 so should be a good starting point. Also I have a Gen 1 BF Midget so something akin to a Compact may compliment it well if I choose to combine them.

I haven't built anything like this before and I am yet to get my head around WinISD but I do know my way around a CAD program so I have mocked up the following:

Designed with 12mm ply, this would give me a total internal volume (prior to subtracting bracing etc) of 2.856 cu.ft, this is pretty damn close to the the 2.825 cu.ft Eminence recommend for a medium vented cab in the driver docs. Ports would be 2 x 4" dia. 6.86" length, again from the documentation eminence provide. Bracing is based on the Fearful designs from the Greenboy site. 

I would appreciate input from those more knowledgeable in these things, are there any glaring mistakes or oversights in design so far? Are there any modifications you would recommend?

Cheers!

Cheers for the further info, interesting stuff. 

Another query - would a pair of these be a mental idea? Ultimately I am looking for something I can run with an oldschool / doom metal band (think sabbath etc), want to have a nice thumpy sound and compete with loud drums and guitar without having a massive amount to move or carry (live in a 3rd floor flat 😫). 

Thanks for the informative response, interesting points. Certainly sounds like adjustments on the amp rather than the cab are the way to go.

Loving the look of these and will have to give it a go at some point. Out of interest, would it be possible to put in some kind of switchable or adjustable crossover like the Barefaced Big Baby? Like the idea of something that could dial in a more 'old school' sound if I needed.

Is this cab 4 or 8 ohm with the new speakers?

I like my LM Tube 800 with my Barefaced Midget (not the current gen), probably on the small sides for your needs but if you can scrape the money for a Berg then maybe consider a larger Barefaced as that would give you something small and portable for small gigs but loud and bassy for larger shows