Lowest distortion (sub?)woofer up to 300hz?

I'm working on a pair of Yg Acoustics knock-offs. While I'm pretty sure I could go out and buy the woofers used (ScanSpeak 23Ws?), they're awfully expensive and, to be honest, a bit limited in terms of output. Can anyone recommend a very low distortion woofer or sub good for 110dB from 30hz-300hz that's a bit less bonkers? I hear the Soundsplinter 10" and Seas L26ROY are pretty good, and I might be able to get a pair secondhand for $300 or so...