As can be inferred from the subject title, I am looking for a solution for the 30 Hz to 300 Hz frequency range. I am completely ignorant about any design issues in this frequency range, hence my post. Please, let me first describe where I am now with my design.
I have a horn with average sensitivity of 106 dB/1w/1m, low distortion, and controlled directivity in the remainder of the audio frequency range. Examining the horn response, it would be possible to cross-over as low as 220 Hz, but for better distortion the preferred minimal cross-over point is about 250 Hz.
It is my understanding that a good practice would be to split the lower frequencies between two drivers/speakers, e.g., 20 Hz-60 Hz, and 60 Hz – 300 Hz; unfortunately, for the time being and a foreseeable future, space is at premium.
It is my further understanding that producing lower frequencies with reasonable sound pressure level (SPL) is a matter of moving lot of air, which translates to large (15” or 18”) woofers. Following that logic would appear that it would be preferable to acquire an 18” woofer with reasonable sensitivity. However, will such a woofer make it to 300 Hz without breakups? On the other hand, would a 15” provide low distortion at the lower frequencies? Would two 15” woofers be better? However, will they not require bigger cabinet? As you can see, I need help.
I understand that the ultimate solution is a matter of compromises. My main criteria are low distortion, good transient response, peak SPL about 110 dB. I am willing to compromise on the lowest frequencies, if necessary, as I listen mostly to classical music.
I can do rather sophisticated frequency shaping and steep filtering as a result of using digital signal processing. Wood working is not a problem, but design of a cabinet is.
Based on the foregoing, if you are still reading, could you help?