Well, um, gosh. I looked through the manual, and there does seem to be no bass management at all. There is an attenuation setting for Low Frequency Effects, but no settings for speaker size or presence of a subwoofer.
I wonder if this amp was originally sold as part of a package, and was made inexpensive by leaving out frills.
If it were me, I'd want to get a sub first, then shop around for a new receiver. I can easily understand your wanting to "improve" this one with a hammer, after reading the specs. 100 Watts at 1.0% THD is horrible. However, even with a big, fancy, capable receiver, you will eventually want that subwoofer.
Well, have fun with the hammer!! and do post some pics, please
