Amp Strapping Question

[loburbon]

ok heres the deal. i have a single dd 9518. i had 1 m3 on it at 1ohm. i did a 146.6@45hz. then i strapped 2 m3's on the sub at 1ohm. each amp seeing .5 it still did a 146.6@45hz. i'm stumped. shouldn't i see some kind of gain?

[Boon]

Not always. I know some guys that had 2 2515's in a wall. Did like 150.4 with 3kw on it. Added another 3kw and it did...... 150.4

In that case the subs were running out of steam but I don't see it happening with a 95. Check that it's wired right, check your gains, clamp the power to the sub?

[loburbon]

everything was wired right. i've been talkin with super steve from dd and he said the box was capped???????? i havent put any 45's in the box yet. nor have i resined the inside. he also said the paper cone on the 9500's were a weak point when you put that much power to them

[audiofanaticz]

everything was wired right. i've been talkin with super steve from dd and he said the box was capped????????

This means your box sucks for the most part. You did not design and or build it right. Without knowing your box specs, woofer & port displacement not much else can be said.

i havent put any 45's in the box yet. nor have i resined the inside.

Putting resin inside your box really dont gain Deebeez, If your lucky 0.2 deebeez is all you will gain. Resin mostly only makes the wood denser. I know a few Hardcore spl people that tested this and seen nothing in their vehicles by adding resin. 45 degree corners may help, or may hurt you more. It depends on your current box size. It will change your tuning freq because it takes up more internal displacement. Soaking up some box space may help you gain if the box is too small. Best way about going with 45s is to use clay and form them in and test or cut them out duct tape them inside and test. 45's could hurt you or help you. Testing is the only way. I say to use tape because if it lowers your score they are not perm in your box.

he also said the paper cone on the 9500's were a weak point when you put that much power to them

Not really true, Tho Im not about to argue with Steve. The paper cones are normally fine. Look at 90+% of the speakers made to this date and tell me what kind of cones they have. Yes they can be a weak point tho when your tossing extremely large amounts of power to the speaker for burps (the cones can and may fold, but the composite cones will do the samething too. Generally a carbon fiber dustcap stiffens the cone up a lot (way more then a regular paper dustcap or plastic like some other companies) When you order a DD sub with the carbon fiber dustcap (in most cases) they will still have the stock dustcap underneath adding a stiffer cone (at least on my 9518s I noticed this). However you shouldnt have to worry about folding your cones with 1 or even 2 m1s, unless like I said before your box is crap and are totally off on your porting and got way too much back pressure inside the box.

[loburbon]

ok where do i start, i dont suck at designing boxes or do i suck at building them. the box is 6.2cuft after displacements with 130sqin of port area. 28.75in deep for a tuning of 35hz. its sub up port to the driver side. also its m3's not m1's. and a 146 with 1 sub off 1 amp in the cargo area non wall is loud either way you look at it. this is the first box i've built in any of my vehicles that hasn't done a 150+ and i design all my boxes. and i know this about resin and 45's, i was just making that point up front because thats one of the first thing every one asks.

[Boon]

I would say the box is maybe a tinch too big for that power, the port is probably on the big side and is also way way too long for good numbers.

[loburbon]

hell i dont know. i've never messed with 18's. i always had the best luck with 12's and 15's. it's still a good number for a single sub in a non wall. but when i was building my yukon with the 4 15's and two m3's when i strapped the amps 148 is the best i ever got. i changed it to one m3 per 2 subs and did a 153.4. so i was running the same amps and same subs just one way was strapped the other way wasn't

[audiofanaticz]

Can you give me external dimensions of your current box, as well as all the ports dimensions?

I would try this, and go from there. This box is prob be a winner, and gain you at least 1.5 db's maybe more depending on your ride.

External box size:

Height = 18 inches

Width = 34 inches

Length = 25 inches

Port size:

Height = 16.5 inches

Width = 5.25 inches

Length = 20 inches

Which is 7.2 cubed

After woofer and port displacement it will be 5.3 cubed.

Square inches of port = 86.6

Tuning freq = 35 hz

Sub and port both on the front, and put the woofer as close to the port as possible. Your also going to have to bend the port along the back of the box.

Something like this.

Adding a second baffle would be wise, and would raise tuning freq a like bit, but under a 1hz.

I think your current box maybe a little to efficient and the extra power is just unloading the sub, but I cant be too certain without your current measurements.

[loburbon]

the box is 38 wide by 16h and 29d. its sub up port to the driver side. the port is 14.5x9 which is 130sqin. its 28.75 long for a final tuning of 35hz. here is a sketch of how it looks.

[audiofanaticz]

the box is 38 wide by 16h and 29d. its sub up port to the driver side. the port is 14.5x9 which is 130sqin. its 28.75 long for a final tuning of 35hz. here is a sketch of how it looks.

actually your current box is about 8.4 cubed, 5.10 cubed after sub and port displacement, tuned to 38.5 hz, with 130.5 square inches of port.

Your port area is way too big for that box, and should be ruffly 62-82 square inches.

If you fill your rear barn doors you will gain about .5 db's or more. Or sound deaden the hell out of them, but i prefer greatstuff.

I did a 146.7 with 1 fried 9518, 1500wrms and was burping at 41hz in my 99 hoe.