Easy 12" cab build

[Obrienp]

2 hours ago, Phil Starr said:

It'll take me a while to model the response of some of the drivers available today but this looks very do-able. The thickness of the ply isn't going to add a lot to the weight, just remember it's the internal dimensions you need to worry about so you'll need to allow for that when you cut the panels. For example going from 12mm ply to 18mm would make the cab wider by 6mm each side and it would need to be 12mm wider overall. Thicher panels means less pracing so you can shave a bit there.

 

Think about the 4ohm driver a little more. You will gain at best 2db which is just noticeable and for acoustic gigs you won't need that much, I use a BC110T for open mics and it is really overkill. I do a lot now with my 6" design and we've recently put up a design for an 8 which works well, all this with a Warwick Gnome 130W into 8ohm. This cab is around the size of your Monza and roughly the same weight you could go smaller IMO. The 8" cab uses the same 'easy build' construction so is effectively the same cab with smaller panels.

Thank you for the advice @Phil Starr. I hadn’t thought about thicker ply changing the internal dimensions. I will have to do some calculations to make sure I am getting at least 30 litres internally. 
 

I have decided to go for @Chienmortbb’s 12PR320. It will save me quite a few quid over buying a new one and keep the overall cost down. I wanted to do a 12” simply because I have 10” well covered by my Monzas and BF Two10. I had a little Mark Bass 8” combo and that has somewhat put my off 8” drivers, even though the real limitations were in the EQ department. Illogical I know.

[Obrienp]

50 minutes ago, pete.young said:

 

Or just buy a Gnome/Elf and use that with the Monza.

I have a Gnome iPro and I really don’t like it with the Monza. It is possible to get a sound I like with that combination but the EQ settings have to be really radical and there is nowhere to go for variation once it is dialled in.

 

I already have the HB GPA-100 power amp, which I use occasionally for guitar with a multi effects pedal as preamp. I have also used it with a Monza and Bass Flyrig V2 for rehearsals and small gigs. The advantage of the Flyrig is that it has two preamp channels and all the effects I use built in, a tuner, plus a good DI (it’s raison d’etre). It just reduces the kit required in cramped conditions. An active cab would reduce it further but I really don’t like the affordable options available at the moment. I could use a 12” active PA cabinet but it doesn’t look right. Also I want the challenge of building a cab and the sense of achievement when it’s built.

[Obrienp]

33 minutes ago, basstone said:

Slightly off topic, but may be of interest - I have a 700RB for sale on this forum. They are great sounding versatile amps. Mine is a 2 x 10" combo which is reassuringly heavy but the head could be used very effectively in a project like this?

Thanks for the offer but I already have the GPA -100 power amp, plus I currently have 4 amp heads. I really need to cull the herd a bit rather than enlarge it.

[basstone]

Just now, Obrienp said:

Thanks for the offer but I already have the GPA -100 power amp, plus I currently have 4 amp heads. I really need to cull the herd a bit rather than enlarge it.

Understood, I thought it may be of interest to others considering a DIY bi-amped cab project 🙂

 Good luck with the project and keep us posted

[Obrienp]

1 minute ago, basstone said:

Understood, I thought it may be of interest to others considering a DIY bi-amped cab project 🙂

 Good luck with the project and keep us posted

Sounds like a good option for somebody. 👍

 

I’ll keep you posted. Probably in panicked calls for help when I mess up😏. Just collecting the parts at the moment.