linkwitzlab dipole sub

[hifidan]

I plan to build this highly acclaim sub but using 10 incheers instead and the 12 inchers.
Do I have to change the box size and how to calculate them
THks
Dan
Seee box at :
http://www.linkwitzlab.com/woofer.htm

 

[454Casull]

You can do whatever you like with it, just as long as it's strong enough, and you remember to get rid of the resonance higher up in frequency (though it's outside of the passband).

Also, if the effective path distance and/or displacement of the drivers aren't great enough, your bass starts to roll off pretty quickly.

 

[johninCR]

I'd just retain the 19" depth and shrink the height and width in accordance with your drivers. Note that it's a woofer not a subwoofer, so expect good clear bass, not thunder at 20hz.

 

[Rudolf]

If you put the 10inchers into the 12" cab, there is nothing wrong about it.
If you make the box just fitting the 10", you get a smaller footprint and you move the resonance higher up in frequency, which will be a benefit. The loss in lower frequencies should be negligible since you will have to equalize for the 6 dB roll off anyway.
Did you realize that you loose >30% of cone area when you switch from 12" to 10"?

Rudolf

 

[hifidan]

10 inch sub

TKS guys,
so I gather that the size of the resonnance chambers is not as important as in a reflex desigh where is you change drivers the whole thing just doesn't work anymore.

 

[johninCR]

Don't think of them as resonance chambers. They're just a wave guide to keep the front and back cone output separate for a certain distance. You just want them to be big enough to not impede air flow and cause noise. For example, with 10's the narrowest chamber width of 3" could be reduced to 2.5 or 2" and the others would depend on the mounting depth of your drivers.
You can also reduce the overall height to whatever you can fit the drivers into. In your case, the only dimension I'd keep would be the 19" depth.