Port length/tuning questions. Port length longer than depth of box.

[briber500]

I have 2 Pioneer 12's. They are 1000 rms and 3000max. they will be mounted inverted because port tubing is in the way so you can't mount normally. This is actually better because I maximize volume. Due to limited space my box is built with only 1.2 ft3 of volume. I wanted it tunned to around 38hz. I only have 4" round port diameter opening & tubing. To get that tuning I figured a port length of 18". My box is only 14" deep. My question is can I just 90 the tubing and add required length? If so I loose about 4" of port length with the 90, so do I add the 9" on the 90 or will it be shorter due to volume in the 90 thats not accounted for? How do I figure the volume of the 4" 90 bend to see if it affects the port length measurments? Does that even need to figured out? As long as box is tuned in the mid to high 30hz range Im cool with that.

[Jessica]

1.2cuft for both subs? I don't think that is enough for even one of those in a ported enclosure. Is that before you subtract the port displacement? Yikes.

[briber500]

The box is a trapazoid. I believe I have volume figured correctly @ 1.20 per sub/partition and thats with nothing in the box. The box has a partition in it seperating the subs. So when tubing goes in the box, that tubing displacement should be deducted from the 1.20? Another question I thought of here, so both subs are hooked in paralell off one mono block amp should I have both subs in one air space or keep seperated?

[Jessica]

What model number subs do you have? I am guessing that box is just big enough for one 12.

[briber500]

ts-w3002spl These: http://www.pioneerelectronics.com/PUSA/Car/Subwoofers/Champion+Series+PRO/TS-W3002SPL

Im having a hard time finding recomended enclosure specs.

Edit: Found it, woohoo!

Specifications for Pioneer TS-W3002SPL Sub

Watts MAX. Music Power: 3000 Watts
Watts Nominal Power Handling: 1000 Watts
Frequency Response: 18Hz ~ 700Hz
Sensitivity: 89dB
Ohm Rating: DVC (Dual 2 Ohm Coils)
Recommended Enclosure: 0.85 ~ 1.75 Cubic Feet
Dimensions: 13" x 8.1" (329 x 205mm)
Mounting Depth: 7.3" (185mm)

[White Lightning]

The 4" pvc port tuning in my enclosure goes through 80 inches (40 inches for each enclosure) of port with 6 90 degree turns for a final tuning of 24 htz (all external port tuning) ... Everything seems to work fine ...

[briber500]

The 4" pvc port tuning in my enclosure goes through 80 inches (40 inches for each enclosure) of port with 6 90 degree turns for a final tuning of 24 htz (all external port tuning) ... Everything seems to work fine ...

What do you mean "external"? Tubing is outside of box?

[White Lightning]

Absolutely ...

[briber500]

Thank you. I realized I posted in wrong section. This thread is probabally better suited in the port/enclosure section. Im going to reduce 4" pipe down to 2" and then I will only need 5" of length.

*edit* The 4" ports that were cut in to the top of the prefab box from manufacturer, were stripped of my 4"pvc tubes I had installed and were resealed with original plugs. I then cut 2" holes in bottom corners on face of box were subs mount. With size and length of the tubes its tuned to 28hz. The B-Legit song that Steve plays in his woofer flex vid makes my front door windows shake like crazy! Its slightly uncomfortable when it hits the lowest part of the bass drop. Whats incredible is Im only using about half of what those subs can put out. I plan on getting twice the size amp so I can exercise the subs to their full potential. Im impressed so far cant wait to see them at full potential!

[notorious97200]

You are saying that you will use a 2" pvc pipe, instead of a 4" one ? That is not enough port at all, even if you use 2 of them.

Two 2" pipes are not equal to one 4" pipe. Be careful !

and yes, you need to substract port volume to the interior volume, or use externeal ports.

What tuning do you want ? 28 or high 30's ?

Personnally I always tune between 32 and 35 Hz.

Good luck.