Make a sealed can ported

[Kevin Dean]

Trace Eliot use to do a cab the you could place inserts into circular ports to make it a sealed cab ,so how difficult can it be , regarding tuning just start with a small circular hole & increase the diameter until you get a sound you like .why bother with all the maths etc ? 

 

 

[Bill Fitzmaurice]

Using all the maths etc. you can get it right the first time, and for that matter determine if it's worth doing at all. You'll also know why a small circular hole is probably a bad idea.

Edited November 26, 2017 by Bill Fitzmaurice

[LukeFRC]

6 hours ago, Kevin Dean said:

Trace Eliot use to do a cab the you could place inserts into circular ports to make it a sealed cab ,so how difficult can it be , regarding tuning just start with a small circular hole & increase the diameter until you get a sound you like .why bother with all the maths etc ? 

 

 

 

Why not try it and find out? I mean like all engineering, maths and understanding how things work are optional extras aren't they?

[LITTLEWING]

I don't know if I've been lucky but I've fitted a few ports to small bass combos and had absolutely fantastic results which has made them sound like something a few hundred pounds more. Notably a cheapy (£20) Gumtree 40watt Stagg combo with two 8" speakers in, I cut out holes and added two three inch bass ports close to the corners and the bottom of the box, left the length as they came and the bottom end is bleedin' enormous. 

I imagine as cabs and drivers get bigger there's an element of design to get it sounding right though.

[Balcro]

As Bill says, "why not do it right the first time" or words to that effect.

If you do it wrong, it might initially sound impressive because the speaker will sound louder, but at the same time you can dramatically affect the power handling & reliability of the drive-unit in the cab. Turn up the wick and snap, crackle, pop!

Some drive-units will cope with the changes because they're versatile enough to "work" in both closed or
ported cabinets. Many won't. It usually depends upon the internal volume of the box and the choice of drive-unit.

Why not just ask the question "is it feasible"? On this forum, given the exact drive-unit specification and the volume of the box, I and several others can usually give you an answer in under an hour, but I suspect in most cases it will be negative.

Edited November 26, 2017 by Balcro
formatting

[fretmeister]

Surgery. Why bother with anatomy and all that? Why not just....

 

 

[stevie]

On 26/11/2017 at 00:57, Kevin Dean said:

Trace Eliot use to do a cab the you could place inserts into circular ports to make it a sealed cab ,so how difficult can it be , regarding tuning just start with a small circular hole & increase the diameter until you get a sound you like .why bother with all the maths etc ? 

 

 

You are Michael Gove and I claim my five pounds!

[Guest bassman7755]

On 26/11/2017 at 07:51, LukeFRC said:

Why not try it and find out?

Cutting a random hole in a cap could in theory cause the driver to unload and destroy itself at low frequencies.

[Bill Fitzmaurice]

That's worst case, and would take a very large hole. Still, there is a science to this, and if you don't understand it don't mess with it.

[Kevin Dean]

Oh very well I suppose I better work it out , when I say that I will get my mates Son who works for JBL to work it out for me .

[MoonBassAlpha]

..... is the correct answer!! 

[Elfrasho]

I'm very much in the 'flip it, why not give it a go and see what happens' camp.  Not everyone needs to know how things work.  noone gets hurt, and as long as you're prepared for the worst case scenario then I say go for it! ? 

 

 

(Terrible advice) 

[Bill Fitzmaurice]

The captain of the Titanic said pretty much the same thing when he ordered full speed ahead, in an iceberg zone, at night.  Needless to say he was not prepared for the worst case scenario.

It's one thing to emulate another captain, James T. Kirk, by boldly going where no man has gone before. But this particular voyage of discovery was completed by Theile and Small right around the same time that Kirk's first foray was, circa 1969. The OP has no need to reinvent the wheel, no matter how hard one tries it will always be round.