# Help with HT slot port building? slot equal to 4" round 41" long port help??



## newtitan (Mar 7, 2005)

*Help with HT slot port building? slot equal to 4" round 41" long port help??*

Ive got this driver i want to hear in my HT, so Im wondering how would I go about building a slot port that is equal to what the manufacturer sent to me


heres what they recommended

1.6 cu ft vented tuned to 20 hz, and they recommended a 4" round port---41 "long


thats seems awfully small for a HT box, for a driver with 30mm xmax right?


I threw it into bass box pro, and while the 1.6 cu ft is right on with they gave me, if I choose "extended bass" and set the tuning to 20hz, I get 2.6 cu ft with a 4" port 41" long

1) soooo should I follow the smoother response 1.6 cu ft, or the extended bass modeling of the 2.6 assuming the same port and tuning?

2) are slot better than round ports for any reason?

3) should I say screw it and for the large sealed box lol, my house isnt the big anyway 



thx for any help

measured specs from my WT3



> Fs = 26.92 Hz
> Qms = 6.119
> Vas = 1.557 cu.ft
> Xmax = 30 mm
> ...


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## Amish (Oct 2, 2006)

*Re: Help with HT slot port building? slot equal to 4" round 41" long port help??*

1.6ft^3 sounds really tiny for a home setup, I'm used to seeing things in 5+ ft^3 enclosures (I'll be going huge with my Mk1 Tumult in a month or two).

1) What are you using this for? If HT moreso than stereo, I'd really push for the EBS style enclosure. Either way, I think I'd push for the EBS style enclosure, why not use the room of your house to your advantage?

2) In my limited experience with slot ports, they aren't as efficient as a round port. I've heard port noise in slot ports that I didn't expect based on their equivalent round port size. I'd like to play around some more, but so far I've preferred round ports.

3) No!  I went from a sealed enclosure for my above mentioned Tumult (which sounded amazingly musical) to a PR'd setup (similar to ported) and was blown away by the performance increase. You don't have the space limitations of a trunk anymore, go big!



For the slot port - you want the area of the port to be the same, round or slot. Then, you can keep the same port length. So, your 4" diameter port has an area ~ 12.5in^2. There is a recommended length to width ratio on slot ports, I want to say go no larger than 10:1, but the shorter the better.

Which driver is this? I know you determined your own, more accurate, T/S parameters - I'm just curious!


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## solacedagony (May 18, 2006)

*Re: Help with HT slot port building? slot equal to 4" round 41" long port help??*

How much power do you have for it? I think that should ultimately determine your box size. Model it up in WinISD/BassBox or that spread sheet setup so you can determine how much power it'll take before going past its limits. And tune it ~15 or 20hz.

Really, the bigger the box, the better. There are guys on a certain forum that I frequent that commonly put their HT subs in 20cuft sonotube enclosures. You get the most that you can on the bottom end without going IB.


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## newtitan (Mar 7, 2005)

*Re: Help with HT slot port building? slot equal to 4" round 41" long port help??*

its a tc3000, and thanks for all the help folks


I may just try to squeeze it in my truck somehow, and use my diyma in the house since they work better with my plate amp i have already


well see


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## Amish (Oct 2, 2006)

*Re: Help with HT slot port building? slot equal to 4" round 41" long port help??*

I've been running my DIYMA in the house in a temp setup while I've got the car ripped apart and I'm pretty happy with it. ~1ft^3 and a 1000W plate amp. Mind you this is low-volume music only so I have no clue how it would perform in a HT setup, but for now it sounds pretty good.


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