help with ghetto blaster project

[quintus1985nl]

drivers picked dissensions made

i have read that crossing a tweeter very low is a bad idea
sow i am going back to the original plan

a sub woofer crossed very low to a sealed full range speaker
since the board does the crossover don't need big expensive coils
i will have approximately 25w of low distortion power at 4 ohm

i am sticking with the Peerless by Tymphany SLS-85S25CP04-04 3-1/2" Paper Cone Woofer


Peerless by Tymphany SLS-85S25CP04-04 woofer kopen - SoundImports

for the full range i will be using Peerless by Tymphany NE65W-04 2" Full Range Woofer

Peerless by Tymphany NE65W-04 woofer kopen - SoundImports

i never made a crossover over before but reading the graphs i am thinking something like 400hz?
i believe the lower i cross the more booming the sub woofer will be

did i make a good choice with the full range driver?

i will design the depth and calculate the total cabinet size tommorrow
port will be a bit larger then first and 10mm larger than the drawing 40mm drainpipe 36.4mm inside
air velocity 17 at 17watt bit of flaring good enough?