I am wondering if anybody knows what the -3dB points are for the SVS Amp Interface by Marchand Electronics. I have spoke with Tom V of SVS who said he believes that the -3dB points are about 2hz lower than the 15hz, 20hz, 25hz markings. I emailed Marchand Electronics direct who said that the -3dB points are nominally as marked (ie. 15, 20, and the 25 hertz). Does anybody know thru testing or experiment of any kind what the -3db points are?