#1
So i play a lot of high gain metal, and have a Harley Benton 112 vintage with a vintage 30 in it. And i play a lot of metal such as Lamb of god, Keith Merrow, slipknot, pantera and machine head. I am aware that for metal you should have a closed back cab for the enchanced bass response and tighter low end. Is there any way to somehow DIY a close back for it?

Thanks
#2
Usually open backed cabinets are smaller than they need to be if they are closed back. This is why a lot of combos, made for portability in the first instance, have open backs. So, remove the two back panels and insert an extension which makes it half as big again, just paint these mat black.
#3
PSimonR Hey, sorry , but i dont rally understand what you mean when you say remove the two back panels, as i thought there is only one?. And how do you insert the extension? thanks
#4
According to the picture here

http://www.thomann.de/gb/harley_benton_g112vintage.htm?sid=4715b1259fada5876ae5dd089f51dc34

There is an upper and lower rear panel. Remove them both. Remove the connection panel from the top on.

You then have a cab without a back.

So you make a half cab (use ply the same thickness as the cab walls) that fits inside the back. Screw it to the batons that held the original backs on by using the hold that you have made in the back to fit the socket panel. Fit the socket panel, having exerted and re-soldered the wires.
#5
PSimonR Aahh okay, i get what you mean. Thanks a lot, but wouldnt it be simpler to just screw on one solid piece of wood without extending it? Or are there air pressure issues etc?
#6
Quote by oskos2001
PSimonR Aahh okay, i get what you mean. Thanks a lot, but wouldnt it be simpler to just screw on one solid piece of wood without extending it? Or are there air pressure issues etc?


Actually looking at the size of this cab compared with the speaker it's probably OK just to put a new solid back on it, I'd drop some acoustic wadding inside it too.

http://www.wilmslow-audio.co.uk/baf-wadding-289-p.asp - maybe just stuck to the walls and the new back.

Extended cab will be more efficient but maybe not by much.
#7
PSimonR Sweet, thanks a lot dude. looks like i have a project on my hands haha
#8
I put a hinged half back on mine so I can open or close, or anywhere in between
Last edited by Tempoe at Jul 7, 2016,
#9
oskos2001

No problem. The issue with making a cabinet too small means that the speaker cone cannot move as much as it's supposed to and therefore does not absorb as much energy as it should. Ultimately this would overheat the speaker coil and cause it to fail, but I think this cab is big enough for this not to happen.

If you want the techy stuff on cab design, and can get the data for your speaker then you can use this (but I wouldn't bother).

http://www.diyaudioandvideo.com/Tutorial/DesignBuildSpeakerBox/
#10
Yea just looking at it now theres quite a lot of space in between the back of the speaker and the back of the cab. And is the input just like soldering the jack on a guitar?
#11
Quote by oskos2001
Yea just looking at it now theres quite a lot of space in between the back of the speaker and the back of the cab. And is the input just like soldering the jack on a guitar?


Yes, with a single speaker it doesn't matter which way round its wired either.

You should be able to take the screws off the jack socket panel and push it into the cab, make a hole the same size in the new back and push it though again - so you shouldn't even need to un-solder it. (or your speaker may have push on connectors - but be careful with these, it's easy to break the "card" material they are usually mounted on.

If it were mine, I'd put an extra jack socket on connected in parallel. a) because they sometimes break and that's not good when you're at a gig b) to allow another speaker to be connected.
Last edited by PSimonR at Jul 7, 2016,
#12
PSimonR ilsure look into it, and one last question. Should I get premium voidless birch or just mdf/plywood?
#13
Quote by oskos2001
PSimonR ilsure look into it, and one last question. Should I get premium voidless birch or just mdf/plywood?


In terms of sound quality it is best to use a non-resonant material, so mdf is probably better, in terms of strength for giging, endurance would be the criteria so plywood would be better. I think void less birch ply is a waste of money, not really needed for this sort of speaker but take your pick.
#14
Okay, thanks dude. Iv ended up getting some mdf. Haven't started building it yet though