slot port vs center port. loading concerns

[cocoleveo7686 10+ year member]

Pros, cons, benefits. Yes i know its gonna be vehicle dependent but looking for people with experience in a trunk car...main concern is loading. Port length is around 36-38

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[Tripn88]

I bought some subs in a box with slot port to one side. You can clearly see the sub that isn't loading off the port wall moving much more than the other sub.

 

[Jeffdachef 5,000+ posts]

If its two subs, then center port with a divider is superior to an L slot port because the subs will load evenly. The L port causes uneven pressure because one sub is near the mouth of the port than the other.

For multiple subs sharing the same chamber, i'd recommend this type of box.



If not then center port with a divider works fine

 

[HI-C 10+ year member]

View attachment 26554046 I love the center port for 2 subs. Because it loads evenly and have equal pressure.

 

[cocoleveo7686 10+ year member]

If its two subs, then center port with a divider is superior to an L slot port because the subs will load evenly. The L port causes uneven pressure because one sub is near the mouth of the port than the other.
For multiple subs sharing the same chamber, i'd recommend this type of box.



If not then center port with a divider works fine

as far as i know i can do a middle port which im not a fan of, but cant do a labrynth port because tuning to 33hz. 3.2 cubes total with 60 sq inches of port. My dimensions are 15H by 37.5W by 21.5D

this is what my guy has come up with. Just conerned with sub loading. The Total port lengh is 38

 

[Jeffdachef 5,000+ posts]

as far as i know i can do a middle port which im not a fan of, but cant do a labrynth port because tuning to 33hz. 3.2 cubes total with 60 sq inches of port. My dimensions are 15H by 37.5W by 21.5D
this is what my guy has come up with. Just conerned with sub loading. The Total port lengh is 38

Those numbers seem really sketchy. 1.6 cubes for a single 12 is pretty sub-optimal, not gonna lie. I'd go with more cubic feet than having an overload of port area. 19 port per cube is too much and seeing how its tuned to 32hz, its not an spl burp box so you shouldn't be using that much unless you want it peaky.

Thing about a center port box is, the box is stronger from the port bracing the middle so you gain back a few cubic feet of air space from not needing to overly brace as much.

this one is 3.8, center port with a much better loud daily port ratio.

 

[fyerbyrd22 10+ year member]

Those numbers seem really sketchy. 1.6 cubes for a single 12 is pretty sub-optimal, not gonna lie. I'd go with more cubic feet than having an overload of port area. 19 port per cube is too much and seeing how its tuned to 32hz, its not an spl burp box so you shouldn't be using that much unless you want it peaky.
Thing about a center port box is, the box is stronger from the port bracing the middle so you gain back a few cubic feet of air space from not needing to overly brace as much.

this one is 3.8, center port with a much better loud daily port ratio.

he is running 2 dss ethos 12s and limited on space...the internal net space is correct for his power, they are similar to DC in the aspect of small boxes...and as far as his port area, it is high and expected peaky but they have been proven to like higher port area...i did my 148db drop in from 2 dc xl 10" m1 in my mustang trunk on 4k with about 20sq per cube...and it was musical..he will be fine...im the dealer, designer and builder btw lol

 

[CSCStang]

You could very well have loading issues with the sub to the left being so close to the port mouth. No way for the wave to develop before it leaves the port. I'd seriously consider a center port design, but that's just how I design my enclosures. Perfect for middle box bracing as well. I ran my hdc310 with 20" per and it was quite musical to my surprise though.

 

[cocoleveo7686 10+ year member]

You could very well have loading issues with the sub to the left being so close to the port mouth. No way for the wave to develop before it leaves the port. I'd seriously consider a center port design, but that's just how I design my enclosures. Perfect for middle box bracing as well. I ran my hdc310 with 20" per and it was quite musical to my surprise though.

thank you. we decided on 3.2 cubes 60 sq inches of port and kerf center port.

 

[mlstrass 5,000+ posts]

I've only seen unloading issues with subs getting 3-5X times RMS, for most daily setups it isn't usually an issue. I do prefer center port personally as you get "free" bracing....

 

[frogcase2002 10+ year member]

Yea iv build alot of enclosures for people and iv never had any "loading" issues people are talking about when doing port to the side of the subs

 

[Papermaker85 5,000+ posts]

It's only loading issue its a phasing issue.its small but everytging counts. I personally like to do decided chambers with subs up port back at the bottom of the box with a devider in the ports. With the ports being directly benith the woofers. It's preference though but I do try to avoid loading and keep phasing in mind..