Just built a box and I'm not happy with it...

[Boomin_tahoe 5,000+ posts]

Nah... he'll be back pounding out a 150db+ most likely.
2 18's on 4500 watts @ .5?
Install/tuning/port area and airspace have been addressed... let the Op make changes... in time
My single 18 on a 4k amp...

Boomin... hows them X's doin lately?

They're currently resting in my garage. For the past year now. Discovered a few waterleaks in the cargo area of my Tahoe which is literally torn apart to bare metal. To make things worse, the tranny went out in it so I can't even finish my install this year...… Oh well. Rather fix the things now and done right than later on down the road. Will be next summers project since I didn't get to finish it this past summer.

 

[East 10+ year member]

The box literally comes within about 6" from the hatch, it's a hella tight fit... But theres some room there. I took out one port and shortened the other 3 so that i'd have around 150 inches of port, 13.5 cubes, 36-37hz and honestly? it sounds worse... still only smashing lows.

I put my buddys slot port in my car, its much smaller box like 9 cubes? on 2 18" hdc3's running 1 ohm off my 4500 and it was louder... further from port, less port area, less power, smaller box and it was slamming at 1 ohm I couldn't believe it. So something is clearly wrong here. What do you guys suggest I do for a new box then? It's not that im lazy or scared to do tests, but this **** takes time and money and I've already invested alot of both into this fail box. I have no room to move the box around, and I can only plug and adjust so much on the ports. Only so much I can do without actually building a new box, but I don't want to do that without more information.

I figured it would be a lot louder for what it's and I'd be smashing 150's with ease... So please someone enlighten me what I should design my box towards for a good daily 150?

 

[Boomin_tahoe 5,000+ posts]

Why did you cut the ports length?? That will yield a higher tuning now. It's best to scrap that box completely and get with @shredder2 for a new re design. Just need max dims, and tuning preference and power working with. If he's not able to, i know a few box designers that may help you out.

 

[East 10+ year member]

Why did you cut the ports length?? That will yield a higher tuning now. It's best to scrap that box completely and get with @shredder2 for a new re design. Just need max dims, and tuning preference and power working with. If he's not able to, i know a few box designers that may help you out.

Because it wasn;t hitting highs, I'm aware what I've done, I typed it into my calulator man, I'm not a complete noob lol my tuning now with 3 ports is the same as it was with 4, just less port area... I'm assuming I'm loading off the hatching and its dropping tuning hence why im hitting lows with high tuning. My buddys box that was tuned the same but further from hatch hit much harder, guessing his tuning wasnt being affected as much? His is 170 inches of port, slot port, HDC 3 18's, tuned to 37hz running 1 ohm, MINE SHOULD be louder than his considering its .5 ohm, so what am I missing? his box is tiny and his subs arent as good as mine (hdc3 vs fi btl neo)

 

[Jeffdachef 5,000+ posts]

Lol i wouldn't sleep on the hdc3s they are generally a lot louder than other subs in the 40 to 50hz range.

 

[yamomluvsme]

It's cancellation. 148 is piss poor. My last 15 in the truck was 147s on music kick. And 145 sealed up.
What's the box look like in the car? I'd drop to two ports and tune to 40.
Do sub forward and ports up. And seal off behind the box.
Loafing doesn't make f3 go down. You have some funky cancellation and it's peaking hard from the lower qes

 

[Oldmang]

3k subs..neo too.
Hmm...
Personally Id lean towards a hi 30s tuning with the filters set correctly then pour on the power. Id bet your getting a ton of rise and a smaller enclosure might help. Id do 3 of those 8" aeros 40hzish in 9.5-10ft3 or so and plug one to lower tuning for daily use. You still probably need to add a bunch of power eventually to overcome rise.
They say rise is worse with neos remember (I'm thinking of switching to neo myself)... It might take a bit more amp to get 2 3k neo subs really moving.
Im curious if you've clamped power yet to see.
Ill bet youre seeing 2-3 ohm power at best even wired .5.

 

[East 10+ year member]

Lol i wouldn't sleep on the hdc3s they are generally a lot louder than other subs in the 40 to 50hz range.

Not sleeping on them but at .5 my subs are much better overall in quality i figured itd atleast keep up with them @ 1 ohm.

 

[East 10+ year member]

It's cancellation. 148 is piss poor. My last 15 in the truck was 147s on music kick. And 145 sealed up.
What's the box look like in the car? I'd drop to two ports and tune to 40.
Do sub forward and ports up. And seal off behind the box.
Loafing doesn't make f3 go down. You have some funky cancellation and it's peaking hard from the lower qes

I don't think forward with ports up is going to work out well, never had good experience with that configuration. and going from a 45 to a 48 is a big difference exp from kick to windshield. How am I going to seal off behind the box? this is a YUKON not a sedan

 

[East 10+ year member]

View attachment 19259
3k subs..neo too.
Hmm...
Personally Id lean towards a hi 30s tuning with the filters set correctly then pour on the power. Id bet your getting a ton of rise and a smaller enclosure might help. Id do 3 of those 8" aeros 40hzish in 9.5-10ft3 or so and plug one to lower tuning for daily use. You still probably need to add a bunch of power eventually to overcome rise.
They say rise is worse with neos remember (I'm thinking of switching to neo myself)... It might take a bit more amp to get 2 3k neo subs really moving.
Im curious if you've clamped power yet to see.
Ill bet youre seeing 2-3 ohm power at best even wired .5.

I was thinking that too, but the subwoofers move like a mofo, like crazy excursion. They are def moving a lot. I'm going to be throwing a 7500 on them eventually, but I should be able to get a 150 daily with ease out of the current setup. I plugged one port and tuned to 37, still smashes on lows doesnt play highs and honestly I feel like I lost output removing a port, maybe box is too big? I thought bigger boxes had more output tho?

Fi calls for 6-8 and im around 6.5-7 cubes each after removing a port. So now sure how box is too big?

 

[Jeffdachef 5,000+ posts]

Actually sub up, port up as close to the rear hatch as possible was one of my loudest configuration for 45 to 50hz ranges for my 18s. Just a thought.

 

[shredder2]

I was looking at a completely different sub I think.

 

[East 10+ year member]

can anyone tell me the optimal port area id need for 2 of these woofers in 12 cubic box?

 

[YukonXL04]

I wouldn't count out cancellation. I have a yukon XL with 4 12s, I have had various different sub setups in it and most of them had some sort of cancellation. The only one that didnt was subs and port back about 6" from the hatch. Everything else would slam lows but not highs, or bang out the highs but not the lows. All dependent on box, sub, and port placement.

Have you tried sitting in the back seat? See if your still hearing the same all lows and no high problem? Since you cant move your box, move yourself and see if hear the same problems at various different locations inside the truck. It's worked for me before

 

[East 10+ year member]

I wouldn't count out cancellation. I have a yukon XL with 4 12s, I have had various different sub setups in it and most of them had some sort of cancellation. The only one that didnt was subs and port back about 6" from the hatch. Everything else would slam lows but not highs, or bang out the highs but not the lows. All dependent on box, sub, and port placement.

Have you tried sitting in the back seat? See if your still hearing the same all lows and no high problem? Since you cant move your box, move yourself and see if hear the same problems at various different locations inside the truck. It's worked for me before

I took out a port, shortned the other 3 now im 37hz @ 14 cubes 150 inches of port and you know what? it actually seems it got quieter.. Like I said I put my buddys shitty 9 cft box in my car at 1 ohm on shitty hdc3's and it slaps highs, so im wondering if aeros just **** in my car? maybe i need to shrink the box, lower the tuning and move it further from the hatch. I think his si 170 inches of port, but with a slot port.