35 to 40 hz is not low at all for a 15. i have my 18 with three diff boxes, 32, 35, and 39.

 

I know, Digital Designs reccomends 35-40 for best all around sound...

 

with them tuned so high........how do you get the low, lows, like 20hz-30hz? cuz the subsonic filter would have to be set around there, right?

I know some amps just have the 'on/off' setting, but I belive mine lets me select the cutoff.....

 

cause the sub still hits those notes.

 

x2, i got my box tuned to 35 hz and it still picks up those notes pretty good

 

doent a subsonic filter completely cut it off? I thought it was to prevent those notes from being played......

 

somewhat. but if you tune your box too low, it will bottom out, trying to reproduce notes that it cannot reach.