'04 Civic Sedan

MobileAudio219 · Post by **MobileAudio219** » Mon Dec 01, 2008 8:12 pm

thebigo wrote:yeah, I read about sanding the edges... and the ports are going to fire into the cabin through the speaker holes in on the rear deck, they aren't just firing up for no reason. Would it still be louder to fire them towards the rear than to port it into the cabin?

Yeah, I know what you meant.. :)

And yeah, it would still probably be louder with both facing the rear...

But every car/install is going to be a different, but a good rule of thumb to follow is subs/port firing towards the rear...

Theres some hatches and suvs that do well with the subs firing up, ports firing towards the rear...

The spl guys will try out a huge variety of box combinations just to find out what works best, thats why most spl systems are very pretty looking, because they're always changing something....

But firing the subs/ports towards the rear should work out very nicely for you...

Also, it's really important to add bracing in a large common chamber box like the one youre building, so make sure you figure that into box displacement!!!!!

Tim · Post by **Tim** » Tue Dec 02, 2008 1:36 pm

MobileAudio219 wrote:Yeah, I know what you meant.. :)
And yeah, it would still probably be louder with both facing the rear...
But every car/install is going to be a different, but a good rule of thumb to follow is subs/port firing towards the rear...
Theres some hatches and suvs that do well with the subs firing up, ports firing towards the rear...
The spl guys will try out a huge variety of box combinations just to find out what works best, thats why most spl systems are very pretty looking, because they're always changing something....
But firing the subs/ports towards the rear should work out very nicely for you...
Also, it's really important to add bracing in a large common chamber box like the one youre building, so make sure you figure that into box displacement!!!!!

very true I agree 100%. Case in point, I have a 02 bonneville with a pretty large trunk. At the time I was running 1 Kicker CVR 12 and about 400 watts, I had the sub firing toward the rear and it sounded great, so I thought hey I will try it firing up and see how it sounds, I lost practically ALL my low frequency extension. It sounded like I was running it with like 75 watts or something.

Tim

thebigo · Post by **thebigo** » Tue Dec 02, 2008 7:32 pm

ok, ill make something with a regular port... maybe ill make 2 boxes if i ever have the time...

thebigo · Post by **thebigo** » Tue Dec 02, 2008 8:20 pm

ok maybe i'm over thinking, maybe i'm not... when i calculate the volume of the braces (forgot to do that the first time!) do i have to calculate the volume of the subs too? I would assume that i would, unless when they give the recommended volume for the sub they include the sub volume...

cargodz · Post by **cargodz** » Wed Dec 03, 2008 4:20 am

That is correct... You have to account for sub displacement as well.

Jon · Post by **Jon** » Wed Dec 03, 2008 6:42 am

OP, I drive a 97 Civic daily and I have about 900W RMS. I have a Kinetik HC1400 under the hood and have never had any issues with electrical power. You will need to upgrade the ground from the battery to the chassis and the ground from engine to chassis as well. I can tell you that the quality of amps you use will make a big difference though. The higher efficiency the amp, the less power you need to push it. So keep that in mind over the watt rating. As for the stock alt, mine is doing fine driving my 900W RMS. As far as subs, you won't be able to find the set I have anymore, but they hit pretty good for a daily driver. I am not a competitor so DBs mean little to my setup. I can say that if you put one side of the back seats down while riding, it is much louder. I have my 2 Kicker s12d 12in in a sealed 1 cu ft box facing the rear of the trunk powered by a MTX Blue Thunder Pro 3002 amp. Yes it is a very old school setup, but it is very clean and still pounds at the same time.

loudwagon15s · Post by **loudwagon15s** » Wed Dec 03, 2008 7:23 am

if you can't afford flared ports and just want to use pvc, you can easily add a flare to one end by using a metal bowl and a heat gun, and use a roundover router bit to flare the outside of the port

http://www.subwoofer-builder.com/port-flares.htm

Bwcad1 · Post by **Bwcad1** » Wed Dec 03, 2008 7:41 am

that method sounds good in theory but doesn't work nearly as well as the PSP ports there is an algorithm used to get the optimum radius and conical shape there actually pretty mathematically intensive.

thebigo · Post by **thebigo** » Wed Dec 03, 2008 9:27 am

Ok, i drew up a box with a slot port facing the same way as the subs... 40l x 16h x 18d. I've got a 4x14.5 port with a length of 23in. The walls on the inside of the box make an L. Using the box itself as one side of the port, the other side measures 11.75 and the 3.75... How does that sound? I took in account the volume of the subs, braces, and port walls..

thebigo · Post by **thebigo** » Wed Dec 03, 2008 4:39 pm

...and what about putting polyfil in my box? My last box had it, should I put it in my new box?