Subwoofer size vs. room size

[JensToft91]

This is what I'm thinking about doing. In a perfect world - would this be possible? 2 different subwoofers, one sealed to smooth the response above 40 hz. When it rolls off, the single bigger subwoofer is raised 6 db to balance the total response.

I still don't get why I can't mix a highpower sealed 8/10 inch with a vented 12 inch.

[devnull]

Get yourself a copy of multi sub optimizer and read through the help files. It's a pretty good read on setting up and using dissimilar subs. There's also a HUGE thread over at diyaudio on multiple subs

[billfitzmaurice]

I still don't get why I can't mix a highpower sealed 8/10 inch with a vented 12 inch.

The reason why is in part revealed with your chart. That combined response assumes that the two sources are less than 1/2 wavelength apart, so that their outputs are mutually coupled with no destructive interference. When the reason for using multiple subs is to smooth room response they won't be within 1/2 wavelength of each other, and there will be destructive interference, because otherwise the room response will be the same as with only the one sub.

[JensToft91]

Makes sense.

[AEIOU]

The actual equation is 12dB per octave increase in sensitivity where the longest room dimension is 1/2 wavelength, but that assumes a very tight room. Real world results are closer to 8dB IME. https://www.youtube.com/watch?v=Zs4eeZsNEYQ

A glass bowl full of rocks??? OMG You couldn't post a better link? OK, bypass the first half of the video and get straight to it.

[billfitzmaurice]

Now I recall why I had you ignored with your previous username. Bye-bye once again.