#1
i am planning on building a vertical 2x12" cab for both my ampeg 70 and my 18 watt clone. i know how to build cabs and have build several head cabs, and sub boxes for cars for friends, myself, etc. i have no problem laying them out and building them.

here is my question.

if you are building a partially open back cab/maybe convertable for a wide range of speakers with different specs. how much volume would leave for each speaker, so what wouild you do?


i am not doing what i normally do, normally i would run the numbers, and build it exact. this one is going to be mainly for versatility.

several sets of speakers are going to be going through it in time, i am sure like every other cab. i move speakers aruond all the time.

for the record i am using void-free birch 3/4" plywood, and am doing this right, as well as the construction methodolgy.
WTLT 2014 GG&A

Quote by andersondb7
alright "king of the guitar forum"


Quote by trashedlostfdup
nope i am "GOD of the guitar forum" i think that fits me better.


Quote by andersondb7
youre just being a jerk man.



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#2
bump for the night crew.
WTLT 2014 GG&A

Quote by andersondb7
alright "king of the guitar forum"


Quote by trashedlostfdup
nope i am "GOD of the guitar forum" i think that fits me better.


Quote by andersondb7
youre just being a jerk man.



****** NEW NEW NEW!
2017-07-07 2017-07-07 Update and a Chat On Noise Constraints *** NEW FRIDAY 7/7
2017-04-13 RUN AWAY from COMPUTERS!!! TCE? RANT ALERT!!!
2017-03-02 - Guitar Philosophy 1001- Be Prepared For the Situation (Thursday 2017-03-02)
2017-02-21 How to Hot-Rod the Hell of your Stratocaster for $50! (Tuesday 2017-2-21)
Resentments and Rambling from a Guitar Junkie
---> http://trashedengineering.blogspot.com/
#3
Hi, interesting question. For open back there isn't a problem; the cab doesn't really load the speaker and the only dimension that is important is the distance from the back of the cone around the baffle to the front which determines the roll off point. Since the roll off in bass isn't very sharp even this isn't critical.

For sealed cabs the air volume in the cab acts as a damper on cone movement and a mass on the cone which forms part of the tuning of cab and speaker, so it can affect both the 'quality' and cut off point of the bass. Too small a cab will end up boosting bass above roll off and rolling it off early whilst failing to control cone movement making the bass woolly and ill-defined.

Nearly all sealed guitar cabs are too small from a technical point of view but guitarists like that sound.

I think if I was doing this as a test bed then I'd build something the size of a Marshall 4x12 or one of the bigger 2x12's. You can always reduce the internal volume with a few bricks to see what effect a smaller cab would have or even make up a few sealed boxes of a known volume so you can adjust the internal air volume at will. Old designers used to use the brick trick (lol) to optimise cabs before Thiele/Small worked out the physics for us. If you are going to use the cab live put the speakers in a vertical line.

Hope this helps
#4
Quote by Phil Starr
Hi, interesting question. For open back there isn't a problem; the cab doesn't really load the speaker and the only dimension that is important is the distance from the back of the cone around the baffle to the front which determines the roll off point. Since the roll off in bass isn't very sharp even this isn't critical.

For sealed cabs the air volume in the cab acts as a damper on cone movement and a mass on the cone which forms part of the tuning of cab and speaker, so it can affect both the 'quality' and cut off point of the bass. Too small a cab will end up boosting bass above roll off and rolling it off early whilst failing to control cone movement making the bass woolly and ill-defined.

Nearly all sealed guitar cabs are too small from a technical point of view but guitarists like that sound.

I think if I was doing this as a test bed then I'd build something the size of a Marshall 4x12 or one of the bigger 2x12's. You can always reduce the internal volume with a few bricks to see what effect a smaller cab would have or even make up a few sealed boxes of a known volume so you can adjust the internal air volume at will. Old designers used to use the brick trick (lol) to optimise cabs before Thiele/Small worked out the physics for us. If you are going to use the cab live put the speakers in a vertical line.

Hope this helps


the thing is is that i am using the remainder of the birch i do have, so its got to stay within that size. that is why i thought of going open back, if i have enough wood to build a closedback cab, i would prefer it, but i am doubting i do. it will definitely be a vert 2x12" though.

i guess if i go open back, just use all the wood i can and make it a reasonable size. it will be rear loaded if that makes any differeces.

i have build cabs out and worked out the T/S before and had great success, but i have never built one for nonspecific speakers.

thanks.
WTLT 2014 GG&A

Quote by andersondb7
alright "king of the guitar forum"


Quote by trashedlostfdup
nope i am "GOD of the guitar forum" i think that fits me better.


Quote by andersondb7
youre just being a jerk man.



****** NEW NEW NEW!
2017-07-07 2017-07-07 Update and a Chat On Noise Constraints *** NEW FRIDAY 7/7
2017-04-13 RUN AWAY from COMPUTERS!!! TCE? RANT ALERT!!!
2017-03-02 - Guitar Philosophy 1001- Be Prepared For the Situation (Thursday 2017-03-02)
2017-02-21 How to Hot-Rod the Hell of your Stratocaster for $50! (Tuesday 2017-2-21)
Resentments and Rambling from a Guitar Junkie
---> http://trashedengineering.blogspot.com/