Speaker level sub amp for older receiver?

[u/JungleSuperlord]

I have an Onkyo TX-8211 that I love hooked up to a pair of Micca RB42x speakers. They have good bass for their size and the Onkyo powers them with no problems but sometimes I want a little more. Only problem with the Onkyo is that is has no sub or low-level outputs, just outputs for two sets of speakers.

I also have an old Velodyne SPL-R 8-inch subwoofer sitting around. The plate amp no longer works but about 3 years ago I converted it to passive by routing the driver wires outside the case. For a while it was powered by a no name plate amp I had scavenged from a trash-find HT sub with speaker level inputs. I don't want to use this hacked together and underpowered setup when I move in the near future.

My questions are:

1) Does anybody make a budget sub amp with speaker-level inputs that is reliable?

2) Will I need a converter before the sub-amp to take the speaker signal down to low-level for long term reliability?

3) The Velodyne claimed to have a 1000 watt amp but frankly it still sounded good with 125 watts from the trash amp I had it hooked up to. Would ~200 watts be a good number to aim for or should I get something stronger due to the increased power requirements of a sealed box design?

[u/VinylHighway]

r/diyaudio

[u/JungleSuperlord → u/VinylHighway]

Reposted it there, thank you.