4th order bandpass question

[galacticmonkey 5,000+ posts]

To get the specs of a bandpass, I just use my judgement. Theres no real equation, or calculator or graph I use... I just kinda guestimate. Havent had any problems so far.

 

[Buck 5,000+ posts]

Best would be to upload the exact T/S specs of the driver into WinISD and fiddle around with all the volumes and tuning and have overlay the transient response over a typical ported and sealed box for reference. Just **** around with it until you get a transient response that models up nicely and then go about sketching a design that meets those specifications. Let me know if you want any help //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

That's what I've been doing for a little while. What I was trying to ask is if the ported chamber in a 4th order be slightly larger than the recommended box?

 

[Buck 5,000+ posts]

To get the specs of a bandpass, I just use my judgement. Theres no real equation, or calculator or graph I use... I just kinda guestimate. Havent had any problems so far.

How do you guess what tuning it should be at?

 

[galacticmonkey 5,000+ posts]

Depends on the application and the type of sound you want.

 

[Buck 5,000+ posts]

Depends on the application and the type of sound you want.

I know that //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

With a sealed box holding air in, I would think the lower end would be extended down to a lower frequency because the sub has more control.

 

[Buck 5,000+ posts]

The biggest question for me is what size to make the box.

 

[Buck 5,000+ posts]

The biggest question for me is what size to make the box.

What this guy said.

 

[Buck 5,000+ posts]

bump

 

[galacticmonkey 5,000+ posts]

For the most part a bigger sealed chamber will drop lower.

Do you just want me to design you something?

 

[mobeious 10+ year member]

The biggest question for me is what size to make the box.

really has alot to do with the vas of the subwoofer used as well as the Fs and xmax .. typicaly the larger the ported portion the more efficiant the box is but it is also is going to have more of a peak vs the smaller the ported section is the flatter the responce will be over a givin set of freq... if u would like a box designed click the contact button in my sig

 

[Buck 5,000+ posts]

For the most part a bigger sealed chamber will drop lower.
Do you just want me to design you something?

Nope. I just need a little guidance.

Just messing around on winisd I have .7 cubes sealed and 1.5 cubes ported, tuned to about 40 hz. Looks fairly good on the graph.

 

[mobeious 10+ year member]

Nope. I just need a little guidance.
Just messing around on winisd I have .7 cubes sealed and 1.5 cubes ported, tuned to about 40 hz. Looks fairly good on the graph.

winisd doesnt do crap for bandpasses

 

[galacticmonkey 5,000+ posts]

Never tried WinISD, but I know BBP is way off for bandpasses. And 40hz will be a low end monster and most likely wont do much for high bass.

Try 1 cube sealed, 2 cubes ported. Go for around 40in^ of port, tune to 45hz. That would be great for daily for a 12.

 

[mobeious 10+ year member]

i believe the sub he is refering to is a 8"

per 8 i would do .3 sealed into .4 ported 48hz with around 10sq of port that should give u a fairly good bandwidth

 

[Buck 5,000+ posts]

winisd doesnt do crap for bandpasses

//content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

Never tried WinISD, but I know BBP is way off for bandpasses. And 40hz will be a low end monster and most likely wont do much for high bass.
Try 1 cube sealed, 2 cubes ported. Go for around 40in^ of port, tune to 45hz. That would be great for daily for a 12.

I have trouble understand how I can go that big in the sealed portion.