New sub build

[Jperyer]

Hi guys been awhile since my last build..

Previous build was two mmats pro cast 12” subs in ported boxes w/ crest audio 5.0

So new house and new dedicated home theater room

I have added 2 more subs for a total of 4 12” subs. On same amp..

I need help getting the right box designed. I am going to build it as I have all tools to do it.

Room size is 13’x24’x7’ceiling

Klipsch rf-82iix2
Klipsch Rf-81ii x2
Klipsch 250s x2
Klipsch ex-62ii

I know not diy on that aspect yet but one day..

Could someone help in getting me box designs that will work best in my room. I have apple products and can not download Winisd...

 

[TBTL]

You could try WINE WineHQ - WinISD & WinISD Pro

 

[Nenola]

Here's what I got from WinISD:

55 liter enclosure tuned to 29hz (4" port, 46cm long).

This is for a single driver.

 

[TBTL]

Looks good. If you have a DSP available and if you want to reach 20 Hz you could tune the boxes to 20 Hz and use the DSP to repair the amplitude response. Xmax is limited though so for home theater use I would not try to get much lower than 30 Hz. Use a 2nd order butterworth high pass at about the tuning frequency to prevent overexcursion.


How about the port air velocity and cone excursion at maximum power?

 

[TBTL]

Never mind, you have four of them. Then 20 Hz is possible. THX spec is 20 Hz at -6 dB if I remember correctly. If it does not go loud enough, you could always shorten the ports for a 25 or 30 Hz tuning. Increasing cabinet volume increases output around the tuning frequency and allows for the port to be shorter, so it might fit.


Room modes dominate the bass sound below the Schröder frequency (~300 Hz). Floyd Toole suggested that putting each subwoofer in a different corner results in good balance between a consistent amplitude response across the seats and a high output. Then equalize the response to flat using parametric EQ on a DSP.