two dd 9500 15's or one dd redline 800 18"?

[hispls 5,000+ posts]

Hardly hitting

That port looks very long for "DD box" tuning, you should use a piece of 2x4 to brace between top and bottom at the narrow point between the subs. Are you certain there are no leaks? How close is that port opening to anything else in the car? Have you tested a wide range of tones to get an idea where this is actually tuning? I'm guessing you're tuned way too low.

How close does the rear of that box set to the back of your car? Assuming that box is airtight on the seems and you get it braced there's no reason you can't so some more playing with that. Start by shortening the port (pics attached) and test it in a few places at different distances from the back wall, if that all sucks you can buy 12$ worth of sono tube and start testing round ports.

For port testing after you cut off the bit pictured

 

[ferguson621]

I completely agree with you guys....yeah that port is definitely to long. and i would love to build it properly but I just moved and my table saw and all of my wood working tools are packed away in the back of my unit so all I have on hand at the moment is a damn circular saw, a straight edge, and a plunge router, so im trying to get by with with what I have at the moment....and remember I changed the port so yeah its going to look like shit lol....I'll upload a picture of the one I'm building now....

I was trying to reach out but I didn't want to annoy anyone with all of my questions, im a visual person, if you put something 8n front of me I can usually reproduce it, like the two pictures you provided shredder


Do you see why I was so pissed after paying for that design? Its like he didn't give a fucck about it.....especially because he literally waited till the deadline which was 10 days, and finally sent it to me around midnight. Hes a real fuccking douche to say the least. You'd think he'd want people to come back. If he's that good then he'd know the design he came up with was worthless. I mean fuckk the box I threw together originally just to hear them was substantially louder. And im surprised it stayed together lmao.


And thank you hispls for the examples.....the box sits about 10 inches from the hatch. The new port i came up with is 20 inches wide, 7 inches tall, and 20 inches deep for a tuning of 40hz


And the second box that you guys like so much (joking) is exactly what was in the design i payed for except I added the galvanized pipe and made the port 5 inches instead of 3.....i had it at 3 inches at first though so it didn't look like that a couple days ago.

So since ive only got the sides, back, and top and bottom....how should I design the port? The dimensions are 45x35x15

 

[hispls 5,000+ posts]

the box sits about 10 inches from the hatch.

But it's really crowded into the rear so there's no room for the sound wave to get up to the front. Can you try to cut down the last box so that you have only that horizontal section of port like my last picture and test this from a few positions in your trunk? This should cost you NOTHING to snip off that extra wood and test some. Cut that last box down and test it all the way shoved back, all the way shoved forward, and one or two spots in between and see how the frequency response and overall output changes, this should give you some ideas on what works and what doesn't in your vehicle.

IF your only option is crowding the port like that you would probably do better to skimp on box volume some (8 cubes should do OK on 8K) and have better port position than trying for more volume and crowding things.

Also subs forward port back may work for you as well. A friend of mine does that in most of his builds in hatchback type vehicles with good results.

 

[ferguson621]

See i was also wondering about that......firing the subs forward and port back, but the subs are supposed to be as far away from the port as possible, so i assumed that it wouldn't work out as well because the subs would be parallel with the port.

I do have 8" dia pvc pipe to use also. So thats an option as well

Ok so I'll drop the second box down to 35x35x15 with two 8" ports at 18 inches makes it 6.8 cu ft net @ 40hz with 100 sq inches of port.

 

[hispls 5,000+ posts]

6.8 cu ft net

That sounds too small. I thought you were talking 10 cube earlier?

 

[ferguson621]

The newest one is 11.38 gross 8.7 net...port is 7x20x16 for a tuning of 40hz with 140 sq inches of port area

 

[hispls 5,000+ posts]

11.38 gross

This shouldn't ever be considered. Net volume is what the subs need to perform as advertised, you are subtracting the volume of port and port walls too, right?. 8 and change should be OK for 95s.

 

[ferguson621]

Yes I do know that net is what you want, i just figured I'd let you know the gross just because

And yes net was after port and sub displacement

 

[ferguson621]

Here's what I have so far

 

[ferguson621]

The new box and port made a HUGE difference lol.

 

[ferguson621]

So i found out they don't like 4 cubes each....the first one I made they had about 3.4 each.....so im going to cut the second box down and see how they sound. They're loud now, but they sound like they're bottoming out on certain songs.....like plastic slapping together. So my guess is they'll do better with 3.25-3.4 cubes each. I will post an update here shortly if anyone cares to know

And i finally made the port so im able to adjust the tuning now. Its great lol

 

[blazian87 10+ year member]

So i found out they don't like 4 cubes each....the first one I made they had about 3.4 each.....so im going to cut the second box down and see how they sound. They're loud now, but they sound like they're bottoming out on certain songs.....like plastic slapping together. So my guess is they'll do better with 3.25-3.4 cubes each. I will post an update here shortly if anyone cares to know

And i finally made the port so im able to adjust the tuning now. Its great lol

You can also just add wood inside to make the box smaller and then readjust with port tuning.

 

[ferguson621]

.....what the fuc was I thinking? Lol

I completely forgot.

Thank you lol

 

[hispls 5,000+ posts]

They're loud now, but they sound like they're bottoming out on certain songs.

If they're bottoming out you should try to either adjust the box tuning lower or adjust your subsonic filter higher or just be careful when playing those songs. Shrinking the box will lose you efficiency all around so if your answer is to just not be as loud you can just do that by keeping the volume knob down on those songs.

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I promise you 5 cube net with 40hz tuning is where you're going to start seeing some proper numbers but you will absolutely need to be careful about playing much below tuning. Keep in mind also you've got a fair bit over double the power they can realistically handle continuously. I suggest build the box efficient and learn how to turn that shit down on the songs that make the subs angry.

 

[ferguson621]

I understand what your saying

But before when they were in the smaller box, which was 6.8 cu ft they never bottomed out, and they were alot louder than they are now.

Thats why im puzzled as to why they arent louder now with having 4 cubes each.

After owning the hd8000 1 ohm version and currently the md8000.1 2 ohm version. I've decided I fuccking hate taramps.

For them to get loud i have to damn near have the gain turned all the way up. I dont like that shiit.