looking for quality passive sub with 8" drivers

Anybody know if there are any passive subs with a pair of 8" drivers? Am thinking of this configuration as these drivers will be very quick and sound better than a larger driver. I would drive the amp with a custom built amp that only operates at low frequencies so there is no need for a crossover.

Hsu no longer offers their 8" cylindrical models; pity.
By the time you buy/build your custom built amp, why not save the hassle and get used Vandersteen 2W's? They have tripple 8" drivers and 300w amp built in, and are eminently musical. You are correct that the pairing of smaller drivers yields a "quicker" sub. They take the signal from the amp (speaker level input) and blend seamlessly with smaller speakers. You can find them used for as little as $600-700. They come with a crossover which you can tailor the sub to your particluar amp sending the signal. Check out their website for more info: vandersteen.com You won't do better than that.
See if you can find any Cabasse Stromoblis'
8 inch drivers, passive and very quick
If the HSU cylinder subs interested you check out the SVS site. They have active and passive cylinder subs in 3 sizes I believe. I have no experience with them but it's the first thing I thought of when you mentioned hsu.
Thanks for the feedback. I know of the VAnderstten units but not interested in internally powered subs. I am tired of repairing them years later after the electrical components have vibrated to the point of a solder joint failing.

I'll look for the Cabasse mentioned and take another look at the SVS products.

Thank you.
If you want a passive sub with 8" drivers look no further than to the Shahinian Double Eagle or Hawk subwoofers. None better for the money, IMO (they're not cheap). Among the small number of truly musical, articulate passives around.
tyler will custom make a dual 8" passive sub in a vertical array in a black cabinet for 450...seems a fair deal....