PORT QUESTIONS Truck center console w/ dual opposed 12” NVX 20-25hz

[066]

Hi my name is Dylan. Thanks for looking at my thread. Like the title says, I’m working on a center console. I have some probably basic questions but I haven’t been able to find what I’m looking for on Google. I am using WinISD btw.

Vehicle : 06 F250 Crew Cab

Location in the vehicle: center console w/ subs firing into rear passenger footwells

Space available (Length x Width x Height): ~15x15x47 outer

Subwoofer make and model:NVX VCW122

Subwoofer Size:12”

Number of Subwoofers:2

Type of Port (Kerfed, Slot, Aero, etc.): diy aero

What type of music do you like?: everything except country

Is your goal SPL or Everyday Music?: 90% everyday listening

Tuning Freq (Hz): 20-25 hz

Volume : mid to high

Questions

1) What would be the preferred port location in a situation like this? Would it be bad to face it towards the dash?

2) My plan is to integrate either 4” or 6” PVC into the 3/4” MDF box and roundover the ends. Is 1/2” roundover enough?

3) Tuning to 25 hz, port velo is peaking at 31ms. Is this acceptable with the flare? I hear 36ms is the number, just double checking what the consensus here is.
It peaks at 25ms when tuned to 20hz.

4) I also hear that when tuning in WinISD, you generally end up with lower tuning than what you expected. Is this still true?

I’m sure I have more questions but I’ll leave it there for now. I appreciate any help.

 

[066]

The front of the box will rest directly on the transmission hump and I’ll build some legs to elevate the rear.

 

[Ridinhi]

The front of the box will rest directly on the transmission hump and I’ll build some legs to elevate the rear.

Maybe I was on the short bus but I’m still trying to figure out which way subs/port face

 

[066]

The subs are downfiring towards the floor. The sub on the right will be in the middle of the rear floorboard and the ports will fire right out the back over the back seats. This is a still a center console build. Slow bus is me lol, I’m terrible at getting my point across.

 

[066]

Plus the plan changed from what I have in the title

 

[SlugButter]

I made the total height a little taller so I can space these ports a little more and they should clear the back seat. I’m gonna flare them at least for the looks lol. This is with a 1/2” roundover.
If the ports end up being an inch away from the sidewalls, is that gonna change the tuning? Or should I try to get them further away? They’ll be plenty far away from the front wall

This is the best picture I could do lol. I know the subs are lopsided hehe

The flare does make a difference on round ports with port turbulence. You might not hear port noise in a downfired box anyway, but I’ve become picky about flaring round ports. I have a 1.5 inch roundover and I do the flares on the inside and outside of the box. Even just removing the sharp edges with your half inch round over is a good idea. I like big flares on my round ports so I can do less port area and still avoid unwanted noise.

 

[066]

At full power (probably will live around 50% power), port velocity should peak at 32ms @25 hz. At 30hz it’s about 21ms.
Does this group delay look okay? About 45ms peak @ 25 hz and 26ms @ 30hz.
Any thoughts on port proximity to sidewalls? Is 1” distance enough for 4” ports?

Im aiming for 25 hz tuning btw.

 

[066]

A 1-1/2” roundover probably makes it like a real Aeroport huh? Do you use a couple layers of Mdf for that?

 

[SlugButter]

A 1-1/2” roundover probably makes it like a real Aeroport huh? Do you use a couple layers of Mdf for that?

Yeah. It has to be multiple layers of MDF or it will just eat all the way through.

 

[SlugButter]

 

[deez283]

The front of the box will rest directly on the transmission hump and I’ll build some legs to elevate the rear.

This is exactly how I did mine and it works great and sits level.

The transmission hump slants down front to back and I end up with plenty of room underneath.

 

[066]

I got the bottom, front/top corner, and back/port sections cut and glued. Just need to glue all that together and then the sides on.
Anybody have pictures showing how to mount from seat bolt to box? I’m thinking some 1-1/4” bar stock and bend to fit.

 

[winkychevelle]

I got the bottom, front/top corner, and back/port sections cut and glued. Just need to glue all that together and then the sides on.
Anybody have pictures showing how to mount from seat bolt to box? I’m thinking some 1-1/4” bar stock and bend to fit.

Bar stock works fine. Aluminum bar stock also works. Whatever is easier to bend.

 

[066]

Thanks. I bet aluminum will do great, good call.
Didn’t really consider until today how heavy this thing is gonna be but I think it’s gonna be pushing 170-180 lbs with subs.

 

[winkychevelle]

Thanks. I bet aluminum will do great, good call.
Didn’t really consider until today how heavy this thing is gonna be but I think it’s gonna be pushing 170-180 lbs with subs.

Yea mdf is heavy. Birch is better weight wise but mdf routes so much better and takes paint/coating better.

Get an upholstery shop to make you a rectangular cushion for the top with a small 1/2 inch bottom and use dowels to attach it to the top for an arm rest. If you precut the exact bottom shape they can build the cushion to your shape.

Might even have a family member that can sew corners. I'm gonna have my grandmother do mine. It won't take long for her and the material is cheap. Cushion foam is cheap and hobby lobby has plenty of fabric choice.

 

[066]

Total weight with subs is actually gonna be about 145. That was what I had in my mind at first so I’m happy with that. I would probably go for birch next time to save some weight though.

Good thinking on the cushion. What’s probably gonna happen is I’ll throw it in and leave it lol but I would like to do something nice.
Wondering if I should throw in a couple more horizontal braces. I have enough to do 2 more but it’s already got 2 and the pipes braces add horizontal bracing. This box feels very solid already, I just tend to overthink/ overdo things sometimes.
Otherwise I think the box is done.