Midrange box on a 3-way

[E Biddy]

How do you determine how big the chamber for the midrange should be for a 3-way? Do you play with the box size until you get a curve that looks good down to your crossover point or do different speakers sound better in larger (or smaller) spaces?

[Pete Schumacher ®]

How do you determine how big the chamber for the midrange should be for a 3-way? Do you play with the box size until you get a curve that looks good down to your crossover point or do different speakers sound better in larger (or smaller) spaces?

Big enough to hold the required stuffing to damp out the rear wave. The higher you cross, the smaller you can make the box. But, make it as large as feasible.

[E Biddy]

Thanks Pete, so if I have the room bigger is better (within reason).

[Pete Schumacher ®]

Thanks Pete, so if I have the room bigger is better (within reason).

Yes. The more stuffing you can get in there, the better it will absorb the rear wave, and the lower in frequency it will still be effective.

For my Scan 15W 5.5" mid, I used about 6 liters, stuffed with fiberglass and capped with dacron fiber putting it between the mid and fiberglass. I used a 14" long, 6" ID PVC pipe, with two layers of roofing felt glued to the interior of the chamber to damp any wall resonances. That produces some of the cleanest mids I've ever heard.