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dan5505
12-09-2007, 02:45 AM
http://i159.photobucket.com/albums/t124/dan5505/ported15infiq1.jpg
http://i159.photobucket.com/albums/t124/dan5505/ported15infiq2.jpg
http://i159.photobucket.com/albums/t124/dan5505/drawing1.jpg

Does anyone see any problems with this design. Just wana make sure it checks out before i start the build.

specs:
15" Fi Q
Outside Dimensions: 36x23x18 in
Net Volume: 3.5 cuft
Port Area: 90.75 sqin
Port Length: 57.6 in
Port Width: 5.5 in
Tuned to 32Hz

BuckyBoy
12-09-2007, 02:48 AM
I like it :D

dan5505
12-09-2007, 05:17 AM
I like it :D

Thanks

ill through some rendered images up, just cus im bored and have nothing else to do

http://i159.photobucket.com/albums/t124/dan5505/ported15infiqrender1.jpg

dan5505
12-09-2007, 03:35 PM
I think im guna put the port in the front. Are there any advantages/disadvantages of the above design vs this one?
http://i159.photobucket.com/albums/t124/dan5505/ported15infiqrevised1.jpg
http://i159.photobucket.com/albums/t124/dan5505/ported15infiqrevised2.jpg

dan5505
12-09-2007, 08:08 PM
a few more rendered...

http://i159.photobucket.com/albums/t124/dan5505/ported15infiqrevised3.jpg
http://i159.photobucket.com/albums/t124/dan5505/ported15infiqrevised4.jpg
http://i159.photobucket.com/albums/t124/dan5505/ported15infiqrevisted5.jpg

BuckyBoy
12-09-2007, 08:58 PM
I think the first design is better than the other one you posted. Have you decided which one you are gonna do?

miker
12-09-2007, 09:02 PM
I have no idea if this is right or not.... Kind of a question.

Would it help to put angled pieces in the corners that direct the waves? I'm not exactly sure how sound waves work, but w/ it like that wouldn't it mostly get trapped in that first row? I don't know... Maybe that is completely retarded...

dan5505
12-09-2007, 09:04 PM
I have no idea if this is right or not.... Kind of a question.

Would it help to put angled pieces in the corners that direct the waves? I'm not exactly sure how sound waves work, but w/ it like that wouldn't it mostly get trapped in that first row? I don't know... Maybe that is completely retarded...

The angled pieces are to reduce port noise. I dont think ill have a problem with it though since i have fairly large port area.

dan5505
12-09-2007, 09:05 PM
I think the first design is better than the other one you posted. Have you decided which one you are gonna do?

I havnt decided yet... I kinda like the look of having the port next to the sub, as in the second design. I wonder if that would cause more cancellation? I guess i dont know enough about it to know.

BrianChia
12-09-2007, 09:14 PM
I like the second design better because the main chamber has more ideal proportions.

profundus-sanus
12-09-2007, 09:17 PM
what program did you use to model the response? thats alot of port area for 1 15"

what vehicle?

SeanDub
12-09-2007, 09:19 PM
That's a hell of a lot of port area for a single 15. Bring it down to around 60 sq in.

dan5505
12-09-2007, 09:19 PM
what program did you use to model the response? thats alot of port area for 1 15"

what vehicle?

I used this site to calculate the minimum port area.
http://www.carstereo.com/help/Articles.cfm?id=31
the minimum was like 89.5 square inches. I went with 90.75
Its goin in a 99 Isuzu rodeo

IonSQL
12-09-2007, 09:21 PM
55-60sq in is what I'd go with...

dan5505
12-09-2007, 09:22 PM
Is there a disadvantage of having too large of a port area? the reason i went this big was to reduce port noise, plus thats what the above calculator told me.

IonSQL
12-09-2007, 09:26 PM
That calculator is too easily manipulated... stick with 14-16sq in per cf or usable area as a good rule of thumb...

dan5505
12-09-2007, 09:32 PM
Here is my previous design. It has a port area of 78 square inches. So you guys think i should go even smaller?

http://i159.photobucket.com/albums/t124/dan5505/ported15infiqoriginalrendered.jpg

dan5505
12-09-2007, 09:37 PM
I think i see the flaw in my calculation now. The calculator on this site is for minimum USABLE port area. http://www.carstereo.com/help/Articles.cfm?id=31

BrianChia
12-09-2007, 09:45 PM
Too much port area results in bad sound quality. You will lose sound through the port itself, and it starts to blur the line between a ported design and a transmission line design. The port should only produce sound at the tuned frequency and sound shouldn't leak out at other frequencies or you will have "muddy" bass. I would choose your original design but reroute the port so it makes as few turns as possible (ie. run it lengthwise against the back wall of the box).

dan5505
12-09-2007, 10:49 PM
ok, cool. So something like this one then. Do you think ill be ok with a port area of 78 or do you guys think i should go smaller.

http://i159.photobucket.com/albums/t124/dan5505/ported15infiqfinal.jpg

Crodski
12-09-2007, 10:56 PM
if u dont mind me asking....what software are u using?

dan5505
12-09-2007, 10:57 PM
if u dont mind me asking....what software are u using?

These were all modeled in solidworks.

Hintzyboy
12-09-2007, 11:03 PM
Too much port area results in bad sound quality. You will lose sound through the port itself, and it starts to blur the line between a ported design and a transmission line design. The port should only produce sound at the tuned frequency and sound shouldn't leak out at other frequencies or you will have "muddy" bass. I would choose your original design but reroute the port so it makes as few turns as possible (ie. run it lengthwise against the back wall of the box).

Umm... What???

The port has a peak in output at the tuning frequency, but it produces sound at other frequencies. Otherwise, there would be no point in building a ported box.

dan5505
12-09-2007, 11:08 PM
With the top on....

so... safe with 78 sqin port area?

http://i159.photobucket.com/albums/t124/dan5505/ported15infiqfinal2.jpg

BrianChia
12-09-2007, 11:15 PM
Umm... What???

The port has a peak in output at the tuning frequency, but it produces sound at other frequencies. Otherwise, there would be no point in building a ported box.

The port should produce frequencies from the air resonating within the port which peaks at the Fb. However, it shouldn't produce any sound from the backwave of the speaker itself. The backwave of the speaker should be damped within the main chamber and it should produce port resonance at the tuned frequency. The actual port should not be used to damp the backwave of the speaker. That would be a transmission line design (which requires stuffing within the line to dampen any harmonics). With too much port area and no stuffing it would be like building an open baffle speaker with ****** sound. Also a larger port causes phase cancellation issues and group delay which further affect sound quality.

Dan, 78 in^2 should definitely be plenty enough for 1 single 15". I would go with the deflectors in the corners, though, and use a roundover bit on all of the port's square edges.

dan5505
12-09-2007, 11:34 PM
Dan, 78 in^2 should definitely be plenty enough for 1 single 15". I would go with the deflectors in the corners, though, and use a roundover bit on all of the port's square edges.

ok, thanks. ill add the deflectors. Im assuming that i need to add the volume displaced by the deflectors to the end of the port right.

tommyk90
12-09-2007, 11:42 PM
Personally, I still think that 78 sq. inches is too much.

For a daily driving enclosure thats tuned low (like yours), 50-60 is the max that I would do.

If you decided to use aeroports you could get away with even less.

IonSQL
12-10-2007, 12:03 AM
^^ agreed

dan5505
12-10-2007, 12:29 AM
k, i reduced the port width to 4" giving me a port area of 66 sqin. i could also go 3.5" wide and have port area of 57.75 sqin. is it really going to matter though?

http://i159.photobucket.com/albums/t124/dan5505/ported15infiqsmallervent.jpg

dan5505
12-10-2007, 01:28 AM
here it is with 57.75 sqin port volume. i think this one is the winner (i hope). This is working out good though cus its decreased the size of this thing alot.

http://i159.photobucket.com/albums/t124/dan5505/ported15infiq5thdesign.jpg

BrianChia
12-10-2007, 01:43 AM
I like the last design the best. It also puts the port mouth further away from the side wall which is good.

SilverSquared
12-10-2007, 01:48 AM
this reminds me of the transmission-style box I had 2-12s in.....WOW is all I can say about the output. Extremely loud. Only problem was the box was HUGE.