[Endesereth]

Hello again, this is my very first sub DIY and I am using a Dayton Titanic Mk III 15" sub that is tuned at about 28hz. It is gonna have about 5.25-5.4 ft3 of air in it and it is gonna be powered with a Bash 500W plate amp. The main thing I am wondering is that if I should keep going and building or should I just start over?(yes sadly I already started to build it lol, I kinda got to excited)

 

[ironglen]

With a tuning that high- you best be planning to use it for music only, or have a competent hpf to save it from lower freqs. if used for ht...otherwise a lower tuning in the 16-22hz range may be more suitable (and still require a hpf for ht use for safety sake). You wouldn't have to start over, just change your tuning if you will use it for ht duty.

 

[Mike P.]

Tell us what the sub will be used for and we can figure out what would be best.

 

[Endesereth]

I am mostly gonna be using the sub for music but, I will use it for home theater too. so to tune it lower I just make the port bigger right,:huh: and if so how big?(I'm new and I got most of the info I'm using from parts express)

 

[ironglen]

You'll likely have to change the length of the port rather than the diameter, if in indeed the port is large enough given the driver, power, and enclosure size- I'm at work, but maybe someone will run the model to see what you'll need. You are sure of the internal volume then? If so, we can just input the driver, power, desired port diameter, and desired tune resulting in the calculated port length; if you have a specifice port size, let us know so we can use it in the calculation.

 

[Mike P.]

Tuning the sub to 22 hz and modifying the Hi-Pass filter in the amp to 18.7 hz would give you a lot more output in the 20 - 30 hz range. Two 4" flared ports 24.5" long each would keep the port air speed in check.

 

[Endesereth]

I have no specific port size, I'll just go with whatever gets alot low frequency extension and hits it loud. If the power isn't enough I can try to persuade my parents to let me get the 1000watt dayton amp.As for the box I have decided that the internal volume of the box is gonna be 5.412 ft³ give or take(The size is assuming the port is 14'' long and 4'' in diameter. I can change this it doesn't matter.)
Thanks for helping me!

 

[Endesereth]

Sorry to ask but how do you modify the Hi pass filter and what should I change?(sorry if I'm a little annoying)

 

[Mike P.]

The size is assuming the port is 14'' long and 4'' in diameter. I can change this it doesn't matter.)

You need two 4" ports. One 4" port will have port chuffing from the air speed being too high.

Modifying the Hi pass filter invloves soldering in two different resitors on the curcuit board. Look up the amp on the parts Exress website, all the documentation is there. The model I posted above is with a Hi pass filter at 18.7 hz from the "1 db of boost" table as shown in the documentation.

 

[Endesereth]

ya sorry for the last post my computer didn't load the all the posts so I didn't see it, and thanks!