4th Order Bandpass.


8" Subwoofer.

Tunning (FS).

Port: 4" Port.

Chambers: (3:1)
.50 Cubic Feet (Sealed).
1.5 Cubic Feet ( Ported).

Internal Specs:
36" X 10" X 10"
Total Cubes: 2.0

(not calculating mdf chamber ¾" separation).


Would this design work?

 

It’s not a ratio thing , it’s more about matching the acoustic impedance so the low side and high side properly to make a smooth response ( if that’s what you want) or a peak (if that’s what you want)

The actual volumes on each side could be whatever you need to model it in hornresp ideally or winisd

 

Thanks for "Winisd"!!

Could eyeballing it work for 4th orders?


I modified a prefab 4th-order bandpass designed for a 12"... Put a Kicker Solo Classic 10" and it sounded really good!

The ratio had nothing to do with it? Why did it work as a modification?

 

Great 👍 I'm Using WinlSD Pro.
Thankfully 😸

Now I know the "Front Chamber" tuning.

That curve looks good to me?

The volume is obviously wrong.

Now I know the Tuning for the "Front Chamber".

 

Are those volumes in cubic METERS? 5 & 3 m^3 is HUGE!!! And for my tastes that curve looks like it’ll be close to a one note wonder at… 30Hz? You said the volumes are wrong but ESPECIALLY with bandpass enclosures, volumes are critical. Generally 4th order boxes are tuned higher than a normal ported enclosure also. Put the specs of the sub in WinISD and let it recommend the right box. It defaults to the flattest response.

Bear with the extra lines in the photo (I was comparing a few different enclosures) but the light blue is a 4th order for an SQL-12 tuned to about 47Hz.

You really want it as flat as possible for a smooth response as it will change drastically in your vehicle (transfer function). Just as a comparison the yellow is the same sub in a sealed box and the red & green is the same sub again but in ported to 26 & 27Hz respectively.

I’m certainly no expert but one BIG thing to remember with bandpass boxes is they filter out the distortion you’d normally hear in a sealed or ported box. What might sound “fine” to you just might be the sub screaming for mercy. If you’re not afraid of blowing your sub go ahead and experiment with your prefab box but for me, I’d rather make sure the enclosure is made for that particular speaker.

 

Are those volumes in cubic METERS? 5 & 3 m^3 is HUGE!!! And for my tastes that curve looks like it’ll be close to a one note wonder at… 30Hz? You said the volumes are wrong but ESPECIALLY with bandpass enclosures, volumes are critical. Generally 4th order boxes are tuned higher than a normal ported enclosure also. Put the specs of the sub in WinISD and let it recommend the right box. It defaults to the flattest response.

Bear with the extra lines in the photo (I was comparing a few different enclosures) but the light blue is a 4th order for an SQL-12 tuned to about 47Hz.
View attachment 348751
You really want it as flat as possible for a smooth response as it will change drastically in your vehicle (transfer function). Just as a comparison the yellow is the same sub in a sealed box and the red & green is the same sub again but in ported to 26 & 27Hz respectively.

I’m certainly no expert but one BIG thing to remember with bandpass boxes is they filter out the distortion you’d normally hear in a sealed or ported box. What might sound “fine” to you just might be the sub screaming for mercy. If you’re not afraid of blowing your sub go ahead and experiment with your prefab box but for me, I’d rather make sure the enclosure is made for that particular speaker.

I know hahaha. The specs are giving me an issue adding: DD712, DD608.

I COULD do the Audio Pipe 12 (already on the software).

 

 

Thinking about the Bass Reflex I could build with a 608.