So, I went and bought an Optima Yellow top battery and installed it. All I can say is WOW what a difference! The 5x7's crackling has seriously diminished. I can turn the volume up way louder now, and the 5x7's don't crackle as much. The sub amp seems to run cooler. The bass is deeper and louder.

However....
I still think I am not getting enough power to these freaking power sucking amps tho. My lights seem to be dimming a bit more (cause I can get the system louder.) I think I may have to get a better alternator now..... And/or run two optimas. These amps are unregulated.... so, has anyone tried putting a voltage increase mod on their f150?

I think I need to run down to the stereo shop and start asking some questions

 

You have the same problem I did with the enclosure. Download a copy of WinISD and take a look at the box you have with your speakers. I'm seeing 46.5 Hz @ -3db. No matter how hard you tweek it out, it's not going to go low. That same driver in an 3.64 cube ported enclosre will go down to 21 hz @ -3db. I am gonna take a stab at it and say this is why your not feeling like it is getting loud! Throw some rummble in the mix and I think you might have a new respect for that amp you got.

Since you came up with the power issues, what is your wiring going to the Amps? Are your grounds completly bolted to the bare metal on your chassis? Have you tried the Magic 3?

Sounds like a multitude of small issues going on here that you just need to iron out but the box is your big enemy.


Download WinISD here

 

freaking server.... has a lengthy post and it hung up and never posted the dang thing.

and lost the post....

 

I am not as concerned about the low bass (it was just a side benefit.) My main pet peeve is the crackling of the 5x7's. I am figuring that since putting a new battery in has made a big difference on the crackling, that I should continue with making the electrical system better (since it still crackles a bit.) I think you hit the nail on the head about the ground... My ground is attached to a long copper bar that is in turn attached to the cab floor (and all surfaces were sanded down.) I was thinking at the time that this would be a better way to ground the stereo.... However on reflection I realize that since I grounded the system this way, I have two connection points, and without a way to make them contact better, that this is actually worse. This is where the magic 3 comes in, I am assuming? Is magic 3 like the old "tweak" stuff that I used in the late 80's? A connection enhancer? Could you give me a bit more info on this stuff?

I am thinking of some better ways to ground my system.... I have a few ideas, but some ideas from you guys wouldnt hurt...

Thanks a bunch..

 

Oh yeah, the wiring...

I wired this beast with a Rockford Fosgate 4 ga. amp wiring kit.

So, I am running about 15 feet of 4 ga. power from the battery and about 1 to 2 foot of 4 ga. to the cab floor via the method mentioned in the above post.

The power wire has a 140 amp fast blow circuit breaker near the battery.

 

According to this site, it looks like I am right on the edge of needing to upgrade my stereo power wire from 4 ga. to 2 ga.

 

You might want to run 1/0 from the battery to a distribution block somewhere near the amps then use all your 4 gauge out to the amps. I also think that your right on the edge of the cap as well but it might not make much difference.

Was reading the manual on the amps after I posted last and was curious how you have the subs wired? What ohm and bridged or not? What ohm are the subs? single/dual vc?

I would take the time to Magic 3 your truck.

1- alt + to batt +

2 - batt - to engine ground

3 - engine ground to chassis

Run 1/0 through all those spots then the only thing that can hold you back will be the alternator. Put an inline wafer fuse on the alternator wire.

You have some power hungry amps there. D class would have been nice for those subs!

 

I was talking to a co-worker about this, and he said the exact same thing...upgrade the wiring to/from the alt/batt/ground.
My current distro blocks are 1x0 ga in and 4x4ga out *I think* I will have to double check tho. The distribution blocks are mounted about 1 to 1.5 feet worth of power cable to the amps.

The subs are DVC 4ohm. I have the 2 VC's of each sub wired parallel to present a 2 ohm load stereo to the amp.

Thanks for the info

 

I found something that I might have forgotten.... I was looking at the solobaric L7 tech document (for the T/S parameters to plug into WinISD) , and I ran across a statement that said all sealed boxes must be 50% filled with polyfill. I have no doubts that this will make a big improvement in bass extension... hehe

 

Yeah, I tried stuffing mine too. I liked it better without.

The L7 paramaters are already there, at least in my copy. Select the L7 in a ported enclosure and take a look compared to the sealed enclosure. You can have them both open and look at the difference. Only thing that sucks is 7.25 cubes is a huge box!

 

About mid April, my bass started cutting in and out. Also, when I would start the truck, there was a high pitched ground loop whine. I could tap the top of the 750S and get the whine to go away. Finally all bass ceased. Nothing at all... So I broke down and bought a RF Power 1500BD. After installation, I still got no bass. I put an ohm meter across the L7's and viola dead short on one voice coil, and the other vc read like 6 ohms...(It is a dual 4 ohm model. I ran to the stereo shop and bought two new solobaric L7's (dual 2 ohm model.) I wired the vc's in series (=4 ohms) and then wired the 2 subs in parallel (back to 2 ohms) into the amp. After getting everything squared away again, the bass rattles my teeth! The bass quality is like night and day. All along I thought that my bass issues were the 750s (I still think the 750s has some serious issues) when it was the subs the were giving out. The bass is so clear and punchy now it almost hurts. One of the nice things is that the 1500BD looks exactly like the 750S.... same size and everything, so it matches my other amps perfectly. This time I bought retail, and so I have a warranty on the stuff I bought. I realize that I am not getting "all the bass" due to my small sealed box, but I really don't know how much more bass I can handle at this point. The bass is SO clear and tight, I can't imagine it any other way.

Another nice thing now, is since the 1500BD is so overpowered, I am running it at about 1/2 to 3/4 power. I could turn up the gain quite a bit more (without clipping) and get a lot more bass. I ran for 3 hours straight at full volume, touch the amp...and it is barely warm.

Also, if you guys are wondering, I am about $3200 dollars into this system so far. With some more powerful mid/tweet amps and 61/2 components still wanted. Will it ever end?!?! LOL