Subwoofer box - sealed or ported or bandpass which is good?

[Big Bass]

Hi there,

I want build a subwoofer box with 12 inch speaker. Which design is tried and tested and gives very good bass? And how do we make the ports? are they ready available for DIY guys or we can use wooden ports?

[anil]

@BigBass, there no "best" in sub-box design. It is to be decided based on taste and subwoofer manufacturers recommendations. A particular subwoofer is designed to fit for a particular box type, IMO.

I am no expert in sub-box building, but I found few good points that I would like to share.
Few Pros and Cons of box designs:

Sealed
pros:
- High power handling capacity
- Extended low frequency reproduction
- Excellent transient response
- Easy to build
- Not critical with the size

cons:
- Lower efficiency (needs more power)
If you use a 25-30 Hz subsonic highpass filter on the
line input of your amplifier you will achieve a tight and
well-defined bass in your bass-box.

Vented/Ported
pros:
- Less cone movement and lower distortion at port
tuning.
- Higher sound level at port tuning.
- Improved "bass kick".

cons
- Less cone control below port tuning.
- Higher frequencies can "leak" through the port.
- The sound from the port can be out of phase
compared with the sound from the speaker cone.

There is another type called Band Pass design, I think its difficult to build but sound great it seems.

[vicjain]

hi ,
ported boxes are bit tricky to make and u dont find many who can make exactly as per sub reqs,the dia and lenght of the port makes lot of diff in sound as well the size of the box too, normally u get those ready boxes with dealers which may not be designed as per specs of the subwoofer. i personally perfer sealed then ported or bandpass, coz its easy to make as per specs and also gives more tighter punch(bass). anywhere betwn .80cuft to .90cuft  it can be made, thus req lesser boot space too.
vipin

[Raghu]

FYI: Check Sparky's Pages for detailed information on subwoofer box designs. He is an expert in the field.