Alright, I dunno how to explain this but the best way is to say my port whistles. It doesn't bother me because I can't hear it unless I play test tones around 20-35 but I am just wondering why it does this or if all ported boxes do this? I am guessing it has something to do with the resonance of the port (I learned a little bit about that in science class). I could be totally wrong but I was just wondering if any one could educate me on this subject.

Thankx guys.

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Vehicle: 2004 Chevy Aveo Hatchback
Battery: Stinger
Wire: W.S. 0 Guage (ground/power strait to battery)
Head Unit: Eclipse CD3000
Speaker Amp: Infinity Reference 7521a
Subwoofer Amplifier: Infinity Reference 1211a
Speakers: Kicker Titanium 5.25"
Subwoofer: Image Dynamics IDQ 15"

from what I know, the port whistles, they are from your port NOT being rounded for the most part, and its hitting it at a certain speed and dead stopping, Round your port edges if its a slot ported box, that will tkae care of this problem.

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I've seen many things in my time, but to achieve any of them is a different story!

you could probably stop this by flaring the ends of your port . I got rid of some of my port noise by rounding off the ends < both ends > of the port ,. I believe the noise comes from the air cutting across sharp edges , but I don't know for shure , just a guess .

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premier prs 880
focal k2p upgraded 6.5,s
tn52 tweets
2 jl 300/2,s
jl 500/1
2jl w7 8"s
tuned to 30 hz

I would suggest flaring the ends of your port. You can buy these flares and they attach to the both ends of the port. Here is a picture from
www.2loud4you.ca , one of the site's sponsors...(i hope they dont mind me using the picture ) 6_inch_port.jpg

advertising for a site sponsor .

the problem is air moving over the port edges, try even taking some sand paper (and sanding block) to the port edges, just enough to break the edge this will probly solve the problem, or if you want to go a bit more extreme you could use a router and roundover bit...

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Awesome, I will try rounding the edges and see what happens. Thanks guys.

__________________
Vehicle: 2004 Chevy Aveo Hatchback
Battery: Stinger
Wire: W.S. 0 Guage (ground/power strait to battery)
Head Unit: Eclipse CD3000
Speaker Amp: Infinity Reference 7521a
Subwoofer Amplifier: Infinity Reference 1211a
Speakers: Kicker Titanium 5.25"
Subwoofer: Image Dynamics IDQ 15"

You may not have a port flare problem!!! Port turbulance it a result of port velocity. Sounds like you have a problem only when hitting one frequency. I think this is caused by cross winds entering your port. Like blowing on a bear bottle. Get the port away from behind the sub.

I dont know this for sure but it really seems right to me.

I just thought of something. Try putting a little board inbetween your sub and port end to block it from any cross winds. See if that makes it any better.

Oh and anyone reading this lspade69 has a box with a port perpendicular to the sub. I made a box once with the port RIGHT behind the sub and perpendicular to it. Hitting the right freq made it whistle like a pipe organ!!!

Yea, I'm learning so much !.. Love this forum to death

one Q' .. Could i start bulding and making plans for a custom speaker box for a 10" sub, but not have bought the subwoofer yet ?.

Like build it, and make it all nice, (could use one of my buddies blown eclipsez) and then when i have the money, buy a sub for it ?.. Cuz I like my things to look nice and not half assed.. so time will be definetly put into this project .. Pics will follow also !

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i would not do a box for a blown sub
unlesss you are going to get the same sub later
i would do a box for what you are getting later (if i'm going to get a 15XXX then i would set that box up for that sub)
how do know it is nfg (blown)

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