Turn the Reflex box in Bandpass:

[Teresh]

Hello. time ago I built a box for subwoofer 18ps76. Multilayer of poplar, thickness 1.5. The interior liters is 135 liters, the door is about 70 cm long (50cm x 10cm) and if I'm not mistaken tuned at about 35 hertz.
Now, I would like to add to the existing box an 'other box tuned to 80 to 90 Hz . I thought the easiest solution, a box with a tube (relfex box). But my friend asked me if I could replace it with a little horn cus this one have more gain.
I am not an expert in the area. To calculate the reflex box, I have no problems for the horn instead.

Place some pictures:

Actual box:

An externally hosted image should be here but it was not working when we last tested it.

What i want to build:

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

The other option of what i want to build:

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

Does anyone know how to do it with the horn?
Thanks in advance


PS: sorry for my english

 

[weltersys]

You can model the design you drew in Hornresp as a horn/BR combo.
As drawn, my guess is the "horn" won't be very effective in the frequencies of interest.

The little "skateboard ramps" won't be needed for low frequencies, neither will the foam, which robs a bit of level.

Have fun!

Art

 

[Teresh]

You can model the design you drew in Hornresp as a horn/BR combo.
As drawn, my guess is the "horn" won't be very effective in the frequencies of interest.

The little "skateboard ramps" won't be needed for low frequencies, neither will the foam, which robs a bit of level.

Have fun!

Art

Now the wood behind the reflex, moves too much when I give more than 300 watts to subwoofer. I would like to improve it a little bit.

What do you advise me to do?

 

[picowallspeaker]

Remove the back panel, so there won't be anything that it'll vibrate

Or

put some braces across front and back panel

 

[sreten]

Hi, IMHO it will cause more problems than it will solve, and it won't work well, rgds, sreten.

 

[picowallspeaker]

Hi , it is better to 'unmask' the source of the sound than putting more walls covering it.

 

[Shadydave]

Now the wood behind the reflex, moves too much when I give more than 300 watts to subwoofer. I would like to improve it a little bit.

Line the walls of the box with 3/4" X 2 or 2-1/2" pieces of good ply just like the stick walls in a normal house.
Make them 8 to 10" on center.
This will make the box very stiff.
Make sure yo do all sides, including the top and bottom.
Glue them well and use a couple of screws, from the outside if you can, in each piece of 3/4" ply.

Dave