I would set the x over to 120hz or better, 100hz.

My other fosgate amp sucks. Model 100.4 ? the high pass is 120khz and up. So
I am losing some mids. 80hz and lower for the bass, 120khz and up for the high.

I personally would of liked the crossover LP cut off @ 100hz and HP cutoff right above that...

 

naw, I wouldn't worry. If your HU has a HP xover set it to high, (If your HU has SUB pre amp outs.)

That way your door speakers will not have to try to reproduce the low notes. That is the Subs job.

 

if you have an externalxover on your speakers(comps) does that pretty much eliminate the chance of blowing them? givin your not playing them at rediculous levels......with the "distortion" boost off (mines usually set to low)

 

You can still cook the voice coils with an aux. X over. Having the gain set at 100%is a nail in their coffin.

Having the bass boost helps in some situations. Having the gains low, the xx (18bd or whatever) amount of boost at 45hz sounds great at low volume.

My Pioneer Premier amp showed "80" on the gain at about the spot where 80% gain would be. I think it was a recommendation for the amp. I have never seen it on other amps I've had.

Some HUs have adjustable crossovers built in them and adjustable bass boost funstions too. I wouldn't use the HU boost and an amp boost together.