The HWK 15 plans call for a 6" diameter port I can get 5.75" ID PVC is this close enough or do I need to change port length or?.
I was reading an old forum post where the person said they had tuned the HWK 15 to 13 Hz--is this changing the original design?
What software would one use for this subwoofer if the 13Hz tune is different from Steve's design?

Would I be better to wire the 2 subwoofers (8 ohm) to give a 4 ohm load in order to take advantage of teh higher output of the (which is 4 ohm stable)?

Fr.Ray

Port length and diameter will affect the tuning. It is really up to the person or persons personal taste that will determine how to tune the HWK. There are many speaker arrangements that can help you accomplish the 16Hz tuning you desire. The environment the HWK will be located in or around will affect overall tuning. Trial and error will be your best bet. Start with Steve's standards and go from there. As for speaker impedance try to run the lowest possible ohm load your amp will allow without overheating. I have used 4" flared ports(Parts Express) in the bottom of my HWK15 to lower its response but also had to shorten the top port to 6" X 6" to cut down back pressure/turblence from both the top and bottom ports due to the modification. I say build it, test it, and then boom it.


HT-EXT

asiquis,

The plan is to put all 4 woofers in mine, I have these RadioShack drivers laying in the garage for about 18 years now.
This box is the only one (that I know of) that has place for four drivers and isn't the size of a truck.
But I will try to get them in from the center chamber, as this has a lower tuning then putting them in from the top and the bottom side. It does give a smaller center chamber though.
I vote for a removable side too, like speakerfreak7 said in the other thread
https://www.decware.com/cgi-bin/yabb2/YaBB.pl?num=1186777776#2.

Wiring will be:
each clamshell = 2x 8ohm = 4ohm
one clamshell; left channel
other one; right channel

I agree with your choice of install, both firing up, if you like the lower notes.
But remember, not all possibilities are drawn on the site, you could put both magnets in the center chamber.
I would say, that gives the most of the low notes but may have too little higher bass and you need that too!
It's your choice of course.

good luck and happy building.

Bart