had a system installed in my T/A and the first thing my buddies told me was that I needed to put a port in. I would have thought that the place that did the system would have done it if it needed it but the general concensus seems to be that I need to put one in. I went to best buy and circuit city and neither place had one. I'm wondering where I should go- I know a lot of you guys build your own boxes so there has to be a place you can get a trim piece or something so it's not just a hole in the box. Any info would be helpful. Thanks.

 

Just adding a port is NOT going to improve things.

A ported enclosure needs to be built to the proper size, with the proper port size. The properly sized ported enclosure for your sub will be much larger than the properly sized sealed one, so just sticking a port in your current box ain't gonna cut it.

Scroll down until you find my "How to buy a subwoofer" article, and if you don't want to read the whole thing, just check out the section on sealed and ported enclosures. It'll teach you more than you ever wanted to know about them.

 

There are tons of kinds of ports (round, square, oval, whatever) but all that really matters between these types is port area, mainly which will give the appropriate amount for a given install. If going rectangular (often the easiest route) it's best to keep your dimensions to a ratio of 5:1 or lower from what I've read.

Port length is a trade off with port area - the narrower the port the shorter it has to be. This sounds good - build a really narrow port that's only about 8" deep - until one realizes that air speed through the port increases as port area decreases. This is the primary cause of port noise.

Also, the larger the box volume the shorter a port has to be. Unfortunately, this plays against us thirdgen owners in that we don’t have a lot of space to work with. For a single woofer enclosure we’re looking at about 3 cubes tops if we want to keep the box in the well.

Finally, the port doesn’t count toward the box’s volume. So if your box is 3 cubes without the port and the port is 4” round by 10” deep your box volume will actually be around 2.13 cubes.

To put this into simple easy to chew numbers, for a 1.5 ft^3 box tuned to 30 Hz you’re looking at around 1.75 additional cubes devoted to a 4” round port that’s 22” long. Outer dimensions of the box will be 3.25 cubes, but the woofer will only see 1.5 cubes.

You can't just slap a port on there

Edit: well, you could. It would just sound like ***. It sounds like your friends are primarily concerned with output, yes?

 

one was concerned- said it's better for the subs in the long run to have a port. The other one's dad used to install systems. When I stopped by to show that friend, his dad came out and looked at it and said I needed about a 3" port. He was concerned more with sound. Personally, I know nothing about sound systems, that's why I paid the big bucks to have someone else do it.

 

Also, this isn't an actual box either- they took the cover off the storage area, put a board over it and that's my box.

 

ugh. You've got a plate. Plates suck. I hope you didn't pay too much for this installation.

You really want to improve your sound? Have a real box built instead of that plate. The difference in output and sound quality will blow your mind.

 

Yeeaa, go plaaaates!

I also hope you didnt pay too much for that, it cost me $10 in MDF and about an hour (I padded and carpeted it) to make my plate.

As for plates sucking, theoritcally they suck, and according to other's experiences, they suck. I'm still waiting for better weather to build my box so I can get a first hand comparison.

 

I paid a little over a grand for the entire system ( head unit, speakers, amp, sub, "box", and installation ). Yeah, I wasn't happy with the plate thing either, I thought he was actually going to build a box for it, in fact that's what he told me he was going to do. But anyway, I don't think my friends were thinking of a tube port, just like a hole in the "plate" to relieve pressure or something, I really have no idea. That's what my one buddy told me.

 

also, it's not secured down, either, because I didn't want a bunch of holes drilled into my car, so I'm wondering if the pressure thing is really going to effect how long my subs last anyway

 

I may not be completely accurate, but the subs rely on that pressure to prevent over-excursion (breaking). And putting in a port, or making a hole, will cause a lack of back pressure in the 'box', letting the speaker cone move pasts its maximum excursion.

An entirely sealed box will require more power to move the speaker against that pressure, but, at the same time, that pressure keeps the sub safe from moving too much and killing itself.

 

i can vouch for the difference between plates and real boxes. had 2 jl 12w3's in my old camaro, in a plate, and i'll go so far as to say it was more than twice as loud once i built a sealed box. it also sounded a lot better, took a lot more power, secured the woofers better, and looked a lot better.

i guess the only drawback is the added weight lol

 

Most all subs are designed to work in an enclosure but a few are designed for free air/infinite baffle applications.

Putting a hole in a baffle is like cutting a bigger hole in a sieve. Sure, it will drain water faster but how necessary is it? The baffle by its self will leak plenty of air.

If you want a real port, not a hole in a baffle, you have to start with a box first

 

You need freinds that know more about car audio...

 

Or start asking more questions here.

 

Aw, sounds like Jim just volunteered to be you're friend . J/K
Just check here before you grab the drill. A lot of good people in here (me excluded). And I hear there's going to be one more set of box planes out there soon.

 

Psh. We all know that's not true. You're probably the single most knowledgeable person on here when it comes to amps/heads

 

 

INCORRECT QUOTE ALERT. (Although I do consider myself a connoisseur. [2 : one who enjoys with discrimination and appreciation of subtleties <a connoisseur of fine wines>])

Stop it, you're scaring Jim. Or that face was for stepping on his toes.

 

I'm 110% sure that that's exactly how Jim first read it, therefore it is not an incorrect quote from his eyes

 

I like my friends just fine, thanks Gummie- that's kinda what I was thinking. It's not like it's sealed-off air-tight or anything, so any amount of pressure is going to escape around the edges anyway ( or that's what I was thinking anyway ). Thanks for the info guys