my first sub.

[merlinx76]

For the Frg in this equation. Is that the freq that you just start to get room gain or is that supposed to be like a +3db point or something? I know it's only an approximation but I just want to know if I should plan my sub's -3db point at Frg or should I try and stay fairly flat down to that point?

 

[richie00boy]

You should coincide your sub -3dB point with that frequency.

 

[454Casull]

http://members.ozemail.com.au/~joeras/sub_index.htm

This design isn't really recommended for home theater usage.

 

[richie00boy]

Frg = 344 / (longest dimension / 2)
assuming metres

The theory assumes a fairly well sealed room and is the transistion between waveform reproduction and room pressurisation. I've seen curves bandied about from 6dB/oct to 12dB/oct boost. I've also seen a generic model that the curve begins at around 100Hz and rises up to give 10dB gain @ 20Hz.

Note wrong formula above, should be longest dimension * 2

 

[Jennice]

http://members.ozemail.com.au/~joeras/sub_index.htm

This design isn't really recommended for home theater usage.

Why not (apart from the recommendation on the web page)?

The drivers should be ok, or am I totally mistaken?

Jennice