Remote Subwoofer Control Question

i assume you're talking about the LC-1 from PAC, and not the LC-2?  Because the LC-1 is basically the same thing as that one on the ebay page, just they look different and are made by different companies.  I have the PAC one myself actually and it's been working great for like 4 years....

The LC-2 on the PAC page is basically the LC-1 but instead of a low-level, RCA-type connection for the control's input, it uses a high-level speaker wire type output.  It's basically a line output converter and a line level control (LC-1) all in one unit.

Since these are completely passive devices (i.e. they do not require additional external power), there is no way that they could "boost" the bass (or any of the frequencies for that matter).  Despite the presence of the center positions on the PAC knobs, I think that's really meaningless because setting the knob at anything less than 100% will end up reducing the signal level to some extent.  That center position is kinda arbitrary and I hardly ever have the knob there.

The LC-1 does come with attached RCA's but they're only about 8 inches long....

The Peripheral PRC1 is basically the exact same thing as the PAC LC-1.  Actually I think PAC owns Peripheral now or maybe the other way around, because the two products are identical as far as I can tell.  I got mine such a long time ago and at the time it was one of the only such things in existence I believe....but I really don't remember how much I paid for it, maybe $22?  or It may have been more like $30 I don't know....I got a couple of other accessories (in addition to the LC-1) for my head unit all around the same time and I'm getting confused as to how much each one was