Affordable musically fast subwoofer


I am looking into acquiring an affordable and musically accurate subs, which will pick on the lower end notes of my Horn loaded single driver fullrange speakers. Besides those terrible 100+lbs subwoofers that retail 2-3k, is there something out there that is not necessarily hernia producing but that will actually be quick and musical enough for my horns?
The RELs are too expensive....decent used ones about1k+
The ACI Titan, seems to be decent, but still too heavy and moderatedly expensive at 1K+
The VBT Magellans, sophisticated, but the full set up, I wonder how good.
what about those mini SUNFIRE subs?
Any other ones that are easy to acquire in the used market?
bemopti123
You might consider the Monitor Audio subs. They don't go that deep, nor that loud, but they are well suited for music applications. They're well under $1k on the used market.
The Vandersteen subs are also well under $1K used and very fast and musical, due to the use of 3, 8" drivers rather than 1 large driver. Unfortunately, they do weigh about 90 lbs.
Vandersteen 2W or 2Wq. An outstanding bargain - three 8" woofers, 300 watts; very musical and unobtrusive.