not pleased with 4-8" sundown

[WalledSonic]

41 minutes ago, bleedingblue said:

 

 

Ive had much more bass out of some old lanzar 12's with a 100 watts going to each of em. Of course that was back in the 90's when you didnt need 3000 watts to drive a sub. 

I also bought an epicenter, its different now than it used to be. 

 

 

Its easy to blame equipment when the setup is wrong. Unfortunately, your box designer didnt consider the extra volume required to add the proper port volume. The difference between new equipment and the old is that the new stuff can handle more power. 

This is what i did when i had to fix my buddy's under-ported enclosure, we added a proper external port

[audiofanaticz]

I can tell you now that you do not have enough room for proper airspace for those four 8s in a ported box with a port that is way to small diameter.
These woofers are beyond capable of crazy output in the correct sized box.

[Joe X]

1 hour ago, bleedingblue said:

 

 

Port is prob 3" in diameter (ID) and around a foot long by looking at it from memory. At work now so i cant measure it. 

 

3 4" ports would still not be enough in most cases, more like four and the box will be larger as a consequence.

[audiofanaticz]

Under a raised rear seat = four to six 6.5 inch subs ported, four 8s sealed or 2 8s ported, 2 shallow mount 10s ported and down firing. Maybe 1 single shallow mount 12 ported.

[bleedingblue]

2 hours ago, Wishuponasub said:

I agree with walled on this. The port is holding you back. Also if someone else wired it, or even if you did, have you double checked the final ohm load at the amp to ensure you haven't got mixed up?

I did not wire it up but it seems as though all 4 subs are moving all the same. 

Think i need to put the box dimensions in a calculater to see the proper port size. Anybody already done a box like this and already know the port size?

[bleedingblue]

1 hour ago, WalledSonic said:

Its easy to blame equipment when the setup is wrong. Unfortunately, your box designer didnt consider the extra volume required to add the proper port volume. The difference between new equipment and the old is that the new stuff can handle more power. 

This is what i did when i had to fix my buddy's under-ported enclosure, we added a proper external port

That is a big port. How  wideAnd long

[bleedingblue]

18 minutes ago, audiofanaticz said:

Under a raised rear seat = four to six 6.5 inch subs ported, four 8s sealed or 2 8s ported, 2 shallow mount 10s ported and down firing. Maybe 1 single shallow mount 12 ported.

Sounds like i need another box then maybe go with something else. I can hear noise every Once in a while

[audiofanaticz]

Just curious if you have any pictures of the box?
Also do you know what version sa-8s you have?

I know the newest version (v3) says its not recommended for sealed, but the v1, v1.5, and v2 do fine in sealed. One would almost have to model the v3 (if thats what you have to see how it performs in sealed enclosures).
Typically a properly built sealed box will crap all over a ported box that is either too small, to little port, or a combination of both those things. However seeing that your port is on the small side of things already your current box almost maybe be acting as if its sealed.
But out of curiosity I would grab a towel and stuff it in the port and give it a listen just to see if performance increases or decreases.

Im not sure on your building skills or the skills of the person your having build the box, but what a lot of people do to get the most space out of a under seat box is they will make the bottom of the box fiberglass that is a direct mold of the truck floor.
This gains you a lot of extra space, but it is more time consuming and a bit of work depending on your skill set.

[WalledSonic]

22 minutes ago, bleedingblue said:

That is a big port. How  wideAnd long

4.5" x 12.5" x 26" long.  The port is probably a bit too long for a 4th order, but its easier to cut some port length out than to try to add it back.  We may shorten it after the subs break in but we'll have to wait and see how it sounds first.

Good luck man, keep at it.  You'll get something to work out.  I originally designed my buddy's box for (3) 3" ports, but had to change the design completely once I realized I didnt size the port right.

[bleedingblue]

26 minutes ago, audiofanaticz said:

Just curious if you have any pictures of the box?
Also do you know what version sa-8s you have?

I know the newest version (v3) says its not recommended for sealed, but the v1, v1.5, and v2 do fine in sealed. One would almost have to model the v3 (if thats what you have to see how it performs in sealed enclosures).
Typically a properly built sealed box will crap all over a ported box that is either too small, to little port, or a combination of both those things. However seeing that your port is on the small side of things already your current box almost maybe be acting as if its sealed.
But out of curiosity I would grab a towel and stuff it in the port and give it a listen just to see if performance increases or decreases.

Im not sure on your building skills or the skills of the person your having build the box, but what a lot of people do to get the most space out of a under seat box is they will make the bottom of the box fiberglass that is a direct mold of the truck floor.
This gains you a lot of extra space, but it is more time consuming and a bit of work depending on your skill set.

The box hugs the floor. Looks like this one in the link but with port firing into the side door on the passenger side. . They are V3 subs the box could be another inch taller because it doesnt hit the bottom of the seats

 

https://www.google.com/search?tbm=isch&q=4+8+subwoofer+box&chips=q:4+8+subwoofer+box,g_4:silverado+crew+cab&sa=X&ved=0ahUKEwjRoOvbltPWAhVo0FQKHZ5YAdcQ4lYIPSgA&biw=594&bih=287&dpr=2#imgrc=jNzXT1SVtLS6sM: