Optimum volume AV-15(?) closed box?

[Kitchenmaster]

I´m planning to use eight AV-15X (or H) in closed boxes for my home theather in Sweden. The room have been designed by a very competent swedish acousticians (Ingvar Ohman) and I plan to start the expand of our house this summer where the theather will be placed. After a long search I´ve find these nice woofers wich I think will cover my high expectations, but still be cost efficient. I´m not interested to use IB.

To reach the infra frequencies I want to use closed box, but to get as high efficiency as possible I prefer a larger box than normally in these use cases. My reason to use larger boxes:

1. A lower preassure inside the box (reduce the distorsion)
2. A higher efficiency in low frequence minimize the need of low freq gain. (reduce thermical distorsion)

My questions to You:
A. Would You use a X or a H woofer for a optimum closed box, used for home theather?
B. Which volume would You recomend as optimum for this woofer? 150 liters? 200?
C. Do You think I will get a good flat result without a low freq gain, by just use the room gain to get the correct "house curve"? (The room will be 4,5 * 5,4 * 2,3 meters with hard walls, except the bass trap in the back of the room to get a flat response. No windows in the room)

Regards / Kitchenmaster

[simon5]

AV15X is better suited for large boxes, 200 liters sounds real nice.

You will need some EQ down low, room gain is only 2-3 dB per octave, and a closed box frequency response drop 6 dB per octave or more.

[Kitchenmaster]

Big thanks for the quick reply simon5! In this case, I feel confortable to use eight AV15-X in sealed boxes.

My active filter have a possibility to tilt the frequence curve up to 15 db between 0 - 80 Hz. I hope I get the correct curve with some measurements and testing.

I´ve done internet search to find some kind of distorsion measurements for the AV-series, but without success. Frequence curves I find a lot of on different forums, but not different distorsion curves. Does anyone on this forum that have a link to that kind of measurement?

[simon5]

I doubt you will find them. You can find distortion measurements for the TD line of drivers on the other hand.