Powered sub suggestions to mate /w Harbeth P3ESRs

The room is 10 x 15 w/ 7 foot ceilings. Ill be sitting 5 feet away from the speakers. The system is vintage Mac. MX110z and MC225.

Looking to spend $500-$1000

I already have an HSU STF-1 Subwoofer that im borrowing from my HT setup that seems to work well but Im thinking I might be able to get better results if I spend a little more.

REL subwoofers have a reputation as a good match with Spendor and Harbeth speakers. Looks like there are a couple of units in your price range listed in the Audiogon classifieds.
I am using a REL with my Harbeths and could not be happier. (unless I had two RELs)
You might want to look into a Velodyne SMS-1 ($450) or SVS/Audyssey ($750) sub controller. My guess is that, together with your existing sub, this will provide the biggest incremental bang for your (half kilo to kilo) buck.

Good Luck


PS - If you search these threads for SMS-1, you'll see that I've written pretty extensively about this device.
I agree with Marty. Regardless of the sub you pick, you'll still have the same room issues.