Amp Gain Maxed out to get decent bass from Sub

[ajb1205]

Here is my setup:

2018 F150 with non-BO stereo

Helix 6.5 components up front

Stock rear door speakers

4 gauge amp wiring kit

JL JX5001D mono block

JL 10" tw3 in selfmade box under rear seat

I decided to run speaker level inputs to my amp, for the time being, since I will be installing an Audison 8.9 in the near future. I tapped into the front drivers side speaker for this. My problem is that I have to have the gain maxed out, as well as the bass boost turned almost all the way up, to get any decent bass from the sub. At first i thought I had maybe tapped into the front tweeters (there are 2 sets of wires...white and white/brown...) so I tapped into the other wire set with the same result. Since the amp has both right and left speaker level input wires, I ended up splicing both + signals together and both - signals together. Same result once again. I really don't want to buy a LOC since it won't be used for very long at all. I suppose installing a LOC would help tell if the amp if working correctly.

Anyone have any ideas whats going on? The sub is wired to 2ohms, the amp is 2ohm capable (had the same sub/amp combo in my old truck and it sounded awesome...removed the sub when I sold it and bought the amp brand new).

Thanks guys.

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[Jeffdachef 5,000+ posts]

Every stock head unit has a built in high pass filter to prevent the door speakers from playing low frequencies in order to protect them from ripping apart. Now you have a cut bass signal that basically doesnt exist and all you are trying to do is to boost those signals with either an LOC or an amp. So either way just produces sh*t. All you can do is try and tap into the rear one and hope its not as cut as the fronts and then just wait for your DSP to come in.

To be honest, i'd get a dedicated dsp and a much more powerful amp than that audioson 8.9 which seems severely lacking on the power aspect.

 

[ajb1205]

I will try the back speakers and see what happens.

As far as the DSP/amp combo, this is my "thinking"...please let me know if I am wrong or what you would recommend changing:

Audison puts out 35w stereo or 130w bridged.

Channel 1 & 2 - tweeters

channels 3/4 & 5/6 bridged - front 6.5 door speakers

channels 7 & 8 - rear 6.5 door speakers

I will be running the fronts active and using the rear door speaks as just fill. I like the simplicity of one small, compact chassis and what I have heard is one of the best DSPs out there.

 

[Jeffdachef 5,000+ posts]

I will try the back speakers and see what happens.
As far as the DSP/amp combo, this is my "thinking"...please let me know if I am wrong or what you would recommend changing:

Audison puts out 35w stereo or 130w bridged.

Channel 1 & 2 - tweeters

channels 3/4 & 5/6 bridged - front 6.5 door speakers

channels 7 & 8 - rear 6.5 door speakers

I will be running the fronts active and using the rear door speaks as just fill. I like the simplicity of one small, compact chassis and what I have heard is one of the best DSPs out there.

i'd have the rear speakers on head unit power and get more power to the tweeters. With only 35 watts you'll easily run into the amp distorting when you turn the tweeter up to match the midrange's output. A lack of power will severely decrease ANY tweeter's sound quality capabilities. With 35 watts, anything close to moderate amounts of volume will suffer when the amp is pushed into distortion territory. The amp will tap out really fast and your tweeters will sound nasty.

Anything in the rear is useless for sound quality as well so seriously just ditch the rear speakers and relegate them to head unit power.

bridge for the mid and tweeter on the fronts only. Thats the only way feasible when running that audioson dsp/amp

HELIX P SIX DSP this would be the other choice if you are dead set on amplifying rears...

 

[ajb1205]

Makes sense 100%. Thanks for the info and help!