System not like I expected?!

[Buck 5,000+ posts]

That right there may be your problem. Is your enclosure ported or no? If it is not ported, then 1.5in is way too thick for an enclosure. You want some flexibility on your walls so your sub has more room to move that air. I try and make my boxes so the two side walls expand about 0.15mm, which gives me about an extra 1.25mm flexibility in my sub foam. This gives me better sounding thumps and after-tones, but slightly less return-response (not noticeable)
If it is ported, your sub may not be moving the "box air" properly. I suggest you try a different type of port. Instead of just a hole or a tube that protrudes inside the box, try a bi-force port. It is basically 2 @ .5" ported holes with J-shaped tubes stemming out from them. The two port ends are connected to a T joint with one port hole as a result. The two air ports force eachother to expel only a certain amount of air out of the resulting port, and you can adjust this. This allows for a tighter bass and more response. This method may sound ridiculous, but it is the same method used to make motorcycle racing exhaust pipes. Mechanics use backpressure and stroke pressure to make the highest-performing pipes (sound included)

What are you smoking? This is car audio.

 

[Buck 5,000+ posts]

What's your calculated airspace? With a box 18.25 x 16 x 20.5 with double baffle and surrounding sides you are looking at 2.551 cubes before port and sub displacement. You'd want about 2.5 net or so.

 

[Buck 5,000+ posts]

OP, send me all you have on the box and I'll let you know what's up.

 

[TaylorFade 10+ year member]

That right there may be your problem. Is your enclosure ported or no? If it is not ported, then 1.5in is way too thick for an enclosure. You want some flexibility on your walls so your sub has more room to move that air. I try and make my boxes so the two side walls expand about 0.15mm, which gives me about an extra 1.25mm flexibility in my sub foam. This gives me better sounding thumps and after-tones, but slightly less return-response (not noticeable)
If it is ported, your sub may not be moving the "box air" properly. I suggest you try a different type of port. Instead of just a hole or a tube that protrudes inside the box, try a bi-force port. It is basically 2 @ .5" ported holes with J-shaped tubes stemming out from them. The two port ends are connected to a T joint with one port hole as a result. The two air ports force eachother to expel only a certain amount of air out of the resulting port, and you can adjust this. This allows for a tighter bass and more response. This method may sound ridiculous, but it is the same method used to make motorcycle racing exhaust pipes. Mechanics use backpressure and stroke pressure to make the highest-performing pipes (sound included)

dafuq did I just read?

 

[FamousMassacre 10+ year member]

Ok so here is the box. I put the dimensions on it to save me from having to type it all out.
View attachment 26543095View attachment 26543096

Did you calculate the double port??

 

[FamousMassacre 10+ year member]

dafuq did I just read?

When someone asks about their box:

That right there may be your problem. Is your enclosure ported or no? You want some flexibility on your walls so your sub has more room to move that air. I try and make my boxes so the two side walls expand about 0.15mm, which gives me about an extra 1.25mm flexibility in my sub foam. This gives me better sounding thumps and after-tones, but slightly less return-response (not noticeable)

If it is ported, your sub may not be moving the "box air" properly. I suggest you try a different type of port. Instead of just a hole or a tube that protrudes inside the box, try a bi-force port. It is basically 2 @ .5" ported holes with J-shaped tubes stemming out from them. The two port ends are connected to a T joint with one port hole as a result. The two air ports force each other to expel only a certain amount of air out of the resulting port, and you can adjust this. This allows for a tighter bass and more response. This method may sound ridiculous, but it is the same method used to make motorcycle racing exhaust pipes. Mechanics use back pressure and stroke pressure to make the highest-performing pipes (sound included)

 

[Villainstone 10+ year member]

I posted pictures with dimensions.

OP, send me all you have on the box and I'll let you know what's up.

 

[Villainstone 10+ year member]

I dont know what it is but ik that I need to upgrade the electrical system in my car. The amp lights dim a lot when the volume is my normal listening volume.

Ok so just a precaution. If I could afford only one plus the big 3 should it be a bigger alt or a second battery?

 

[Buck 5,000+ posts]

Ok, so when designing your box, what cubic feet net did you get?

 

[Villainstone 10+ year member]

IDK why but now that you mention it I think that I did 2.5 gross not net. I hope not. Yeah sure my math is right but for the wrong **** dimensions. Ill have to check but the more I think about it the more I think the gross volume is 2.5 and I wanted that as my net. Post back after I check

 

[Villainstone 10+ year member]

Ok so I went through the math AGAIN lol. and it all adds up Ill got through it with you guys.

Ok the TOTAL INTERNAL volume of the box is 5525 cubic inches (13"Hx17"Dx25"W) or 3.2 CuFT.

My port has a volume of 1140.75CuIN (13"Hx29.25Lx1.5"W Times 2 for two ports)

Take the total volume and subtract the port volume and you get 4385CuIN or 2.53CuFT.

Now minus the displacement of the sub .15CuFt

In the end the NET INTERNAL volume is right about 2.5 and with the 2 vents at 30" puts me right around 35Hz.

So what could it be. Could it be my electrical system?

 

[phemps 10+ year member]

That right there may be your problem. Is your enclosure ported or no? If it is not ported, then 1.5in is way too thick for an enclosure. You want some flexibility on your walls so your sub has more room to move that air. I try and make my boxes so the two side walls expand about 0.15mm, which gives me about an extra 1.25mm flexibility in my sub foam. This gives me better sounding thumps and after-tones, but slightly less return-response (not noticeable)
If it is ported, your sub may not be moving the "box air" properly. I suggest you try a different type of port. Instead of just a hole or a tube that protrudes inside the box, try a bi-force port. It is basically 2 @ .5" ported holes with J-shaped tubes stemming out from them. The two port ends are connected to a T joint with one port hole as a result. The two air ports force eachother to expel only a certain amount of air out of the resulting port, and you can adjust this. This allows for a tighter bass and more response. This method may sound ridiculous, but it is the same method used to make motorcycle racing exhaust pipes. Mechanics use backpressure and stroke pressure to make the highest-performing pipes (sound included)

Ahhh mann. I was so excited when i saw you were located in Bethlehem as I am very local to you and I don't know anyone from here in the area. then i read this and im like UHHHHHH

 

[mlstrass 5,000+ posts]

That port set up sure isn't helping output. Why did you go that route?

 

[thehardknoxlife 10+ year member]

I needz a rubber box so I can take advantage of this flex box. Oh and add some bi-force ports. I never knew.....

WTF?

 

[Chriszle 10+ year member]

To answer one of your questions. Upgrading the alt is more important than the battery imo, but you need to have proper alt power and reserve to be honest. I strongly dislike the box design. 2 ports for one chamber is just asking for problems.