The art to speaker cabinet construction - a box or an acoustic instrument?

KingSub

I made a 1x12 can out of recycled wood a few years ago.
It was very much trial and error, but I went with a semi closed back, solid/thicker sides and top/bottom, and a thinner plywood front to mount the driver on. Also a slightly angled front.
Seems to project nicely, plenty loud enough too.

https://farm8.staticflickr.com/7238/26872599711_10f954e2b3_c.jpg

https://www.thefretboard.co.uk/discussion/75090/recycled-hardwood-1x12-cab#latest

lukedlb

@KingSub that's a lovely 1x12 and judging by the equipment in the photo I wouldn't have expected any less. Is it stil going strong today? 

KingSub

Yep, still being used as my main player.
Was gigged for a year or so, and then I had a break from live stuff due to daughter no. 2 arriving.
Recently started playing with another band, and it's doing sterling work.

GoldenEraGuitars

I have a mid 70s Marshall cab. It’s been kicked to hell and back, is as heavy as a small country and is solid as a rock. The speakers are broken in, some of the tolex is hanging off, it has a mixture of factory screws in it and generic woodworking screws. It’s grille cloth is ripped and I’m convinced there are several piss stains on the front of it.

Why does it sound epic? It’s signed by Jim Marshall inside. Or maybe it’s those screws... or maybe the piss.... mmmm. Maybe I’m overthinking this

KingSub

Piss marinade is well known in woodworking circles to give wood a lovely tone ;-)

GoldenEraGuitars

KingSub said:

Piss marinade is well known in woodworking circles to give wood a lovely tone ;-)

Might I add that it’s proper aged piss too... probably at least a 40 year old vintage variety

Winny_Pooh

I think Bartel is one of the few really experimenting with the speaker as instrument  concept. 
If I had to guess boutique makers probably experiment and settle on something close to regular designs given that they basically work.
Same with a les paul, strat or D28

Anecdotally I'd heard that some Marshall  cabs sound better when stripped of tolex.

lukedlb

Winny_Pooh said:

I think Bartel is one of the few really experimenting with the speaker as instrument  concept. 
If I had to guess boutique makers probably experiment and settle on something close to regular designs given that they basically work.
Same with a les paul, strat or D28

Anecdotally I'd heard that some Marshall  cabs sound better when stripped of tolex.

Yep. I’m doing my second one and wouldn’t necessarily advise doing it yourself. 
https://imgur.com/gallery/yHniDnQ

GoldenEraGuitars

I wonder if stripping the paint off a boss ds1 gives it more head room? 

lukedlb

I believed that the hifi use of mdf not to colour the output was a good thing for a guitar speaker until I had one. Awful heavy things and dead in some cases, not to mention the damage the mdf can suffer. On a positive note, I got some great speaker cones out of them. 

lukedlb

I’ve heard the choice of wood for the rear panel on the old Marshall 4x12 is what makes the difference in the 70s. 

Anyone know the name for the piece of wood that goes from the middle of the baffle to the rear panel?

i do hope some of the speaker builders on the forum will chime in with help on naming the parts. 

ICBM

lukedlb said:

I’ve heard the choice of wood for the rear panel on the old Marshall 4x12 is what makes the difference in the 70s. 

Anyone know the name for the piece of wood that goes from the middle of the baffle to the rear panel?

Centre post or soundpost.

Marshall changed from ply to particle-board (chipboard) for the back panels on the 4x12”s in 1971 - although very rarely you can find ply later, I had a ‘72 checkerboard B cab with a ply back once... stupidly sold, it sounded fantastic. Still a pig to move though .

lukedlb

Centre post / sound post 
bracing
framing

nick79

One thing i have forund (and i've posted about this before) is that by removing the bottom speakers from my 4x12 sounds fantastic - Dutuning is the word for it i think. 
It keeps the low end you would expect from a closed back but also gives the huge spread of sound you get from an open back. And for bonus points its a bit lighter to lug around too!

lukedlb

nick79 said:

One thing i have forund (and i've posted about this before) is that by removing the bottom speakers from my 4x12 sounds fantastic - Dutuning is the word for it i think. 
It keeps the low end you would expect from a closed back but also gives the huge spread of sound you get from an open back. And for bonus points its a bit lighter to lug around too!

Exactly what I intend to do with my stripped 4x12.

lukedlb

Could any of the carpenters out there inform us about the differences in ply? The 8-ply on one of my cabinets is very thin compared to other cabs, especially compared to the baffle ply I bought. Acoustic properties? Strength? Weight?

lukedlb

@nick79 the DR Z Best 2x12 uses the front port (Thiele Port). Interestingly, Dr Z says, " Low end is determined by the port width, mid response by the shelf depth, and top end by choice of speakers."
Moreover, " Placed vertically, the Z Best delivers a tuned, focused sound yet has the airy qualities associated with open back cabs due to the front port. When placed horizontally, you pick up more low end as the front port is then coupled with the floor."

lukedlb

https://www.tdpri.com/attachments/forte-build-1-jpg.117926/

lukedlb

Side ports exist too. Never seen them before (except on a leslie 16 where it makes sense as the sound is thrown from left to front and out the low front port). Does anyone have any experience of Forte 3D cabinets (or replicas)?

Check this out:
https://avatarspeakers.com/shop/guitar/3d-212-vertical-forte-replica/

lukedlb

The forte 3D replicas built by avatar offer 3 versions: 1x12, 2x12 vertical (separated) and 2x12 horizontal.
The wood is routed with weight reduction channels. I wonder if that has an impact on the sound. Reflector panels on both the sides and the rear panel help bounce the sound out of the side speakers.