First post! New system, a lot to learn. Long

Doobie2

Hello all! I have just finished installing my system, in a 2006 Tundra, and I have a lot to learn about tweaking it. To start off I had DB6500's in the front and back, running off an Alpine MRP-F450 (70 x 4), and the tweeters are mounted in the upper front of the door panels, since that is where Toyota put the holes for the original system. I also have tweeters in the rear pillars. I installed a pair of Polk MM2084 8" woofers in a .35 Q logic box under the rear passenger side seat, an Alpine MRP-M450 (220 x1) drives them in a 2 Ohm setup that draws 400 from the amp. My head unit is a Pioneer Premier DEH-7800MP, I have an Alpine CDA 9885, but prefer the adjustability of the Pioneer. I have a two gauge wire from the battery to a block, and 4 Gauge to the amps. The grounds are to the frame but not the same bolt (common).
I was not totally happy with the DB 6500's so I splurged on a set of SR6500's in the front. I am considering MMC 6500 upgrade to the back set. I love the sound so far but also know its off. So far I have the active LP on the sub amp at 200HZ, NOM gain and no EQ . I am shaping the Sub with the HU at 80 HZ with a -18. I have the fronts and backs on the other amp set to pass, nom gain, and no EQ. The head unit is set to front LP at 80 and -12, same for the back. I have the front balance at +1 for the SR's, and the sub at -3 level with the EQ for all set at flat. I pretty much know that I have too much amp and not enough sub in the back, and wonderfull speakers up front with maybe not enough amp (70 x 40. I am leaving all shaping off and trying to break in the speakers and sub. I also have the SR tweets at -3 due to the fact that the original DB's were too darn bright.

I am sorry to run long but the devil is in the details. I am considering raising the SR tweets to -1.5, and I frankly have no clue as to the sub/mid settings. I am playing around, and some songs have been a revelation as far as SQ. WOW those SR's, come on break in. I have not set the HU/SUB gains yet, I am thinking an oscilloscope for the HU and same for AMP gain. Right now with NOM amp gains and the head unit at VOL 35 out of 60, it is loud and clear.
Please help me with your hard earned advice, I would like to avoid the OOPs part of the learning curve, and I value SQ above all.

MacLeod

First thing I would do is change the low pass filter on the sub amp from 200 Hz down to 80. 200 is way too high for a sub to be playing.

2nd, is this a regular cab truck, ext cab or crew? If its a reg cab or ext cab, you may want to consider dumping the rear speakers altoghther and use the Alpine amp to power the SR's. Front channels running the tweeters and rear channels running the mids.

Im not familiar with Pioneer head units so Im not quite sure why you have everything turned down -12 and -18 db. Thats seems odd.

Id high pass the mids at 63 Hz for now and see how they go.

For that small a space, a pair of 8's getting 200 watts each, that should sound pretty good. It wouldnt be enough bass to piss off the neighbors but it should blend well with the mids and should sound very musical. I wouldnt worry about that at all.

Doobie2

It is an access cab, sort of a 3/4 size back seat. The sub hits plenty well. I guess I was not real clear in my description of my setup, I am limiting the amount of the LP to the sub at 200 on the amp itself, but only sending up to 80hz to it with a -18 roll off with the active area of the HU. At the same time I am able to send everything above 80 to the fronts and rears with a roll off of -12 from the HU. This HU has separate active settings for freq and crossover for sub, front, and rears, along with 16 band EQ and time with phase for the sub. A quite controllable beast, and why I like it over the Alpine, but along with that amount of control comes the requirement to learn how to use it correctly.
I am considering bi amping the SR's with the Alpine, and I have an old 2 channel alpine T303 to use with the rears. I do like the rear fill. I am going to attempt to set the gains today following the other posts. I have been lurking here for weeks reading hundreds of posts trying to get up to speed and understand what to do.