Amp not putting out 100%....

[Beanz]

First how are your gains also?

[EricM9104]

You need to upgrade to at least 1/0 wire and a 150a fuse up front... Amp has 150a of fusing...

[brewer_brewer]

you should be able to support that amp with that electrical. you will have some voltage drop for sure but you have enough to support 1200 watts

i've run 1600 rms off of a 120 amp alt and a yellow top before and only dropped to 13 volts

its not ideal by any means though

start by upgrading that fuse, and go to 0 gauge wire if you can, also solder all of your connections, do the big 3 if you can

i'm thinking this is more of an amp setup problem then a voltage deal

[audiofanaticz]

I find it very funny that everyone is telling him he needs a 150 amp fuse...

Especially when he says he is using his old 80 amp fuse... I dont think that a 150 amp fuse upgrade will help much since he is not blowing his current fusing...

Your old amp was a PDX 600? What ohm where you running that amp at?

Im just curiouse because the pdx is only stable at 2 and 4 ohms and puts out the same power at both impedance load. Overall the pdx amp due to its design fights impedance rise better due to the fact that the amp does the same power at both ohm loads.

Where as the sundown is rated at:

1200 x 1 watts @ 1 ohm

600 x 1 watts @ 2 ohms

300 x 1 watts @ 4 ohms

So if you have a box/impedance rise of 4 ohms, your sundown amp is actually putting out 300watts rms less then the alpine pdx600.1 which again does 600wrms at 4 and 2 ohms.

/thread

[the mange]

I find it very funny that everyone is telling him he needs a 150 amp fuse...

Especially when he says he is using his old 80 amp fuse... I dont think that a 150 amp fuse upgrade will help much since he is not blowing his current fusing...

Your old amp was a PDX 600? What ohm where you running that amp at?

Im just curiouse because the pdx is only stable at 2 and 4 ohms and puts out the same power at both impedance load. Overall the pdx amp due to its design fights impedance rise better due to the fact that the amp does the same power at both ohm loads.

Where as the sundown is rated at:

1200 x 1 watts @ 1 ohm

600 x 1 watts @ 2 ohms

300 x 1 watts @ 4 ohms

So if you have a box/impedance rise of 4 ohms, your sundown amp is actually putting out 300watts rms less then the alpine pdx600.1 which again does 600wrms at 4 and 2 ohms.

/thread

I was running the pdx on 2 ohms with an ssd (dual 1s in series). For 600 watts the pdx slammed so I guess I'm just kinda surprised with my output right now with my BL and 1200d (@ 1 ohm, d2s in parallel). I'm just going to order my 1/0 tonight, as the fuse is already on its way.

My gain is set a little upwards of half, all bass eq head unit settings set to flat, except loudness, which is on medium.

[brewer_brewer]

do you have the bl in the same box as the ssd was?

[the mange]

do you have the bl in the same box as the ssd was?

Yeah its 2.4-2.5 ft^3 @ 33 hz with 45'd corners and some triangle pieces for bracing. Port area is ~35in^2

[audiofanaticz]

Well for starters, you went from a 800wrms sub to a 1000wrms sub. The BL is a pretty beefy sub in general compaired to a ssd, so its going to take more power to get it moving.

Is your box 2.4-2.5 cubed after port/sub/45s/bracing displacement? because if its not its sounding a bit on the small side.

Every box has impedance rise, usually a 2x rise is common in most boxes. a 2x rise brings you into a 2 ohm reactive load when your beating which is 600wrms from the sundown amp, so your looking at ruffly the same power still as you had with the pdx amp (which was wired at 2 ohms nominal with a 2x rise would be 4 ohms still equaling 600wrms) but now only with a more power hungry sub..

A new box is a must imo. Maybe at least 3-3.5 cubed after all displacements.

EDIT: Im still leaning towards the impedance rise killing your amps output power due to the fact that your not pulling enough current through your current 4gauge wiring and 80 amps of fusing. If your wiring was too small and you where pulling said 120-150 amps of current, you would of blown your 80 amps of fusing. Which you have not.

Upgrading your power wire is always a wise idea, but its not going to fix your problems until you fight the impedance rise with a better built box.

[the mange]

Well for starters, you went from a 800wrms sub to a 1000wrms sub. The BL is a pretty beefy sub in general compaired to a ssd, so its going to take more power to get it moving.

Is your box 2.4-2.5 cubed after port/sub/45s/bracing displacement? because if its not its sounding a bit on the small side.

Every box has impedance rise, usually a 2x rise is common in most boxes. a 2x rise brings you into a 2 ohm reactive load when your beating which is 600wrms from the sundown amp, so your looking at ruffly the same power still as you had with the pdx amp but now only with a more power hungry sub..

A new box is a must imo. Maybe at least 3-3.5 cubed after all displacements.

EDIT: Im still leaning towards the impedance rise killing your amps output power due to the fact that your not pulling enough current through your current 4gauge wiring and 80 amps of fusing. If your wiring was too small and you where pulling said 120-150 amps of current, you would of blown your 80 amps of fusing. Which you have not.

Upgrading your power wire is always a wise idea, but its not going to fix your problems until you fight the impedance rise with a better built box.

Yeah now that you mention it I couldn't possibly be drawing more than 80 amps if my fuse is still intact and working. Damn.

My current box is probably closer to 2.2 after all bracing and driver displacement.

I'd really like to build a 1/4 wave t-line for this setup tuned ~35. Would a t-line help my imp rise enough you think?

[audiofanaticz]

Well the displacement of a 12 inch BL alone is .18

No idea on your box outer dimensions, and port dimensions

but from the quick math i did of a 2.55 cubed box with 35 sq inches of port at 33hz your looking at around .6 cubic feet give or take.

So now your under 2 cubic feet of box volume after sub and port displacement not including your bracing (which is something not really needed on such a low powered setup, and such a small box) or the 45 degree corners.

Also 45ing every corner may hurt the woofers performance. It all depends on the design however. but you gotta remember that the 45s take up a tad of box volume depending on size.