I’ve had my 2-1/4" w/ generic resonator($80) and Magnaflow street series muffler for about a year now. It has been pretty loud at wot, and definately buzzy when cold. It was also not super smooth sounding. The lack of smoothness just gave it a more throaty sound. I did get the feeling that I was scareing people when I want buy them while accelerating hard, and I didn’t want that too much. So I went and bought a Magnaflow resonator($115). It’s about and inch shorter then the generic one(18"), but I’d heard my friend’s Si hatch with the magnaflow res. and muff and it sounded smooth and of a reasonable volume.
The shop charged me $20 for install of the new res.
Now it’s much smoother, not quite as deep, and is still buzzy when cold(not as harsh though). I think is is quieter now too, especially for normal driving.
I wanted to get a longer magnaflow res, but I got a deal on this one b/c it was on display. I’m thinking of going back and having them weld the original res in series w/ the magnaflow one to really quiet it down(probably would be very deep too).
Just thought I’d share and tell people w/ buzzy exhaust issues to get as long of a resonator as you can. Magnaflow is good.