Creating Dual Subwoofers with 2x STX W. 27.400.8: Volume, Plywood Thickness & Amplifier Tips

Hello
I decided to make 2 subwoofers on these speakers, each subwoofer has two speakers.

mid frequencies: p.audio sn6-200f
treble: Vifa BC25SC06-04

1) How much volume is needed for two speakers?
2) Will there be enough thickness of 21mm plywood ?, the front wall is double.
3) how does it feel to be a bass in a room of 20 square meters?
4) Phase inverter is going to do back

and another question on the amplifier, how it will be better 2 speakers in parallel or for each
170 watt speaker with 8 ohm real power?

And in general, who used these speakers in any projects, let me know how they play exactly the bass

Co do wzmacniacza radziłbym BiAmping, zawsze to łatwiej zrobić zwrotnicę i taniej.

Acording to supply I think the best is BiAmping with active crossover. And passive filter between Mid and Tweeter. I am worry about midwoofer because the Xmax is small. When crossover is second order it could damage the coil. I have got that problem with mixing similar power combination. THat problem not exist on active cut-off with 24dB/oct 4-order.
Acording the STX they like to have seriously Power. And have some extra watts Even 500W it is OK for them. Also problem with 8ohms - You will use that speakers at 2x 4Ohm = 8Ohm and 170Watts series connection for safer mode or you or 2x8ohm parallel with over 170Watts ~circa 250W @ 4ohms should have your amp.

Also with that SPL in only 20 sq.meters you need only one STX. You need to add extra decibels when the speakers have different Impedance. When you have 4ohm woofer or combination with 4ohms of more speakers.

I want to use an amplifier for 1 speaker, there will be 4 amplifiers for 4 subwoofers
Amplifier power 300 w per channel, enough?
all speakers are 8. and midrange, and high.

What will the bass return be from 4 stx?

Because of reduce impedance 2x power is going up (circa +3dB) in configuration 4Ohm bass 8ohm middle and 8ohm tweeter. It is reffer to situations:

Bass 87dB 4ohm will have same voltage sensivity like 90dB 8ohm Mid and 90dB 8ohm tweeter.

It is also similar to
2x 87dB 8Ohm parallel configuration of 87dB@1W and rest of speakers 90dB at 8ohm

impact on values of filter for same resonance freq. Impedance 2 times smaller = inductance 2 times smaller and capacitance 2 times bigger.

Dodano po 2 [minuty]:

do not be afraid of sensitivity when you can properly set the proportions on amp factors of group of prefiltered amps.