So i'm considering doing this upgrade very soon and am caught in the problem of which amp to choose. I was wondering what the frequency level is on the aura shakers and which amp to pair with them to get down that low. I was looking at the buttkickers and they go down to 9hz but couldnt find the aura info. And most amps I've seen dont have a crossover that goes that low anyways. I've looked at an audiosource amp-100 that should be able to run 4 aura's around 50 watts each and has the ability to go down to 20hz. Then i've been looking at the Dayton amps and wasnt sure which one might be a good option. SA70, SA100, APA150? The SA70 goes down to 60hz, SA100 down to 40hz and the APA150 down to 50hz. But i keep reading that where you really get to enjoy the shakers the most is below that cutoff. So I need some help...maybe other amp options?