Cab conversion

[angelodp]

I am using this cab, for a 1x12 extension cab. It had a solid state amp in it. At the moment I have a 12" 160hm Lead 80 in there and it does sound very good. Its completely enclosed as you can see. Just wondering if doing a bit of carpentry on this baby might not help. I could port the back of perhaps even port the inner upper shelf?? Just looking for ideas to improve this cab. I assume that taking it from enclosed to ported will open the speaker up a bit and add some dynamics?? Alas I know very little about cab design.

best Ange


[IMG:800:822]http://i260.photobucket.com/albums/ii9/ ... /Cab-1.jpg[/img]

[IMG:800:816]http://i260.photobucket.com/albums/ii9/ ... /Cab-2.jpg[/img]

[Structo]

Adding a port may or may not help a cab.

You might get lucky and have it help.

But a port is usually calculated for diameter and length along with the volume of the enclosure to be efficient.

It probably wouldn't hurt anything to try it but it may be hit or miss.

[Bob Simpson]

unless the smaller round hole in the front baffle is for a tweeter, your cabinet looks like it's already ported.

If the speaker is not the original one for this cabinet, maybe you could tune it ( assuming it is a port... ) for this speaker with an adjustable length tube...

Bob

[angelodp]

That small hole was for a tweeter, I suppose that does act as a port. Any additional suggestions on tuning this in.

[jjman]

You need to plug the tweeter hole or install a lone port there. The port would need to be calibrated ("tuned") based on mathematics that I don't know. Under the current setup there are probably some out-of-phase waves coming out that hole. Especially since the rest is sealed.

[Aurora]

Anyone, - or me, - will need internal dimensions of the cab, and an exact spec - or better the T/S parameters Vas, Qt,Qe and Qm - to do this calculation. T/S params can be found in the manufacturers spec sheet, or maybe a vendor of this element lists them....?


EDIT: Maybe I should've known this to be a Celestion Lead 80......?
Did a quick search.... no T/S paramaters to be found, and something tells me this works best in an open back cab..... if possible, try to remove the back panel and give it try. Then partly block off the back to say 1/3 , 2/3....
To calculate anything near a reasonably correct reflex port, the parameters a really necesseary. Cut and try could work, though, with one of those variable length ports..........another way is to block the tweeter hole and give it a try.....

[angelodp]

Actually it is a WGS British Lead 80 watts. I get the internal dimensions shortly, T/S & the rest ?? Not sure what that is.... I'll see what I can do about that.

[Aurora]

O -found it.... but no T/S params.....

Somehow I do have a feeling that we're back to my previous musings...

[angelodp]

Cab internal dimensions are

17.5" wide x 13.5" tall x 9" deep