Subwoofer Enclosure Modification

BonyCatfish

New Member
Okay I am running a 350w kenwood amp bridged to 175w on two 800w kenwood 12"s. I had best buy install everything, for the warranty etc, but the enclosure they suggested(and I bought) now seems wrong. I measured the enclosure and drew it up in google sketchup:

I did some calculations, and the volume is about 2'1". The guide to the sub recommends that it should have about 1.25 cubic ft. in a single box. My two questions:
1. My amp doesn't push the subs really loud, and I don't listen to music that needs incredibly "accurate" bass. Should I port this box and how would I go about it? The problem with porting the box is the the manual of the sub only has porting specifics when the sub is in a single box, whereas I have put both in one. I'd need to know how to calculate the specifics, or if I just port it in two places.
2. Obviously I would need to stuff the box if I ported it, but if I leave it sealed, would it be right to stuff it? How much stuffing would anyone suggest?

I really appreciate any input, and if there is not an easy answer to the question, please point me to a good reference for calculating ports/stuffing/etc. I know the basics of stuffing and porting, but not enough to just start cutting and stuffing.
Thanks, CC is the best.

Here are some of the sub specifics
Force Factor
15.4T*m
Moving mas
119.5g
Resonance Frequency
28Hz
Recommended Volume of a single sealed enclosure
1.25cu.ft. (min .8, max 1.75)
Recommended Volume of a single Ported Enclosure with recommended port sizes
Minimum-------- 1cu.ft. with a 3.5"diameter, 7" length port
Recommended--- 1.5cu.ft. with a 3"diameter, 7" length port
Max---------- 2cu.ft. with a 2.5"diameter, 7.5" length port

I have more numbers but I don't know what else you (or I) might need to know to figure this out. If someone can point me in the right direction, great, if someone can provide an answer, even better.
Thanks again!
 

R3dline

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to many numbers and figures, subs are out of style now anyways. just put some new door speakers in and call it a day. no one wants to hear you bumping down the street. its annoying
 


lotz6996

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is the box partitioned (divider in the middle), that would cut the numbers in half, and give better bass response. a sealed box gives tighter bass, i like them a little better. i would leave it sealed. and i think, which i might be wrong and someone will correct me, but a lb of pillow stuffing is appropriate for 1 sub.
 

eggyhustles

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Your first mistake was going to best buy.

Stick with sealed..ported boxes are not easy to design or build..the wrong ported box will sound like absolute s**t.
 


Cooper76

New Member
Don't go cutting up your box. You can try lightly stuffing it, but in my own experience's it doesn't do much to make it louder, which I think is what you are looking for. Your best bet is to buy another prefabbed enclosure. I know it means more money, but you will truly get more bang for your buck here. There is a lot that goes into designing and building sub enclosures, and it is just easier to pay the people that know how to build them.

I have run several of their box's with great results!
http://www.atrendusa.com/index.php

I am currently running one 12" in a vented enclosure with a 500 watt amp and hitting 138 db.
 

BonyCatfish

New Member
So if I was going to get a simple answer, my two options are to build my own enclosures or leave it how it is? Nobody would add stuffing to my current sealed enclosure either?
 

BonyCatfish

New Member
Amp
KAC-5204
Subs
KFC-W112S
They came bundled together in the P-W1200 pack (aka Kenwood Bass Package). Here it is on Amazon.
http://www.amazon.com/Kenwood-P-W1200-12-Inch-KAC-5204-KFC-W110S/dp/B001Q9ERBC
I figured if they were bundled together they would have the right wattages and be perfect, but the amp is actually only 150w when bridged(according to cea).
If the rated input power is 200w on the sub, aren't I losing a lot of potential using my current amp? For example, wouldn't the optimal amp be two-channel with an RMS of 2*200? Just looking at the peak wattage(I know peak wattage is a poor indicator) on both the amp and sub, if the peak of each sub is twice that of the amp, then shouldn't the amp be twice as powerful as it is, or even four times as powerful seeing how it is pushing two subs?
 

eggyhustles

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They're getting 75 each now..theatrically, you need double the power to get an extra 3db in volume..you have 2 subs so double the power on each will net you 6 db. Also, going from sealed to ported will net 3 db per driver..so you'll net 12db(which is a lot) giving them more power and getting a proper ported box made


Get a ported box built for them. Crutchfield says 1.4 each..so i'd shoot for around 1.5 each(gotta consider port and sub displacement) tuned to about 30hz. They're entry level subs, but 95% of the subs on the market can sound pretty decent if you get a properly design and built box for them. Unfortunately, for weaker drivers like the kenwoods, ported would be the only way to go for sq and some decent output

A box like that would be somewhat universal and will work with other subs once you eventually upgrade. Keep the old amp and old box and sell them as a package whenever u upgrade.

Do you have a budget? one of these would be perfect imo.
http://www.caraudiodeals.com/onx4125-p-4281.html

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=290520020150&viewitem=#vi-content

You'll get 125 x 2 for your front stage and 500 x 1 @ 4 ohms for your sub(s). The subs are 8 ohm drivers, so wired in parallel they'll be a 4 ohm load
 

BonyCatfish

New Member
That answers everything I needed right now and more, thank you very much. When I am ready to upgrade, that is where I'll go.
I would just ask one more question if anyone sees this- is there an enclosure carpet that people have found which matches the grey honda interior of a sixth-gen well or will just about anything work?
 

Slowens

Banned
if you have the "kit" that is posted on post #9 then the amp that came with this is garbage, as are the subs. the only thing kenwood does right are radios. But thats besides the point, 150 watts bridged, and thats peak not RMS. so your problem is NOT the sub eclosure, its your amp is under powering your subs. you should take that "kit" back to best buy and tell them to stick it up they're ass
 

BonyCatfish

New Member
I just bought this
http://www.teptronics.com/tx3000d.html
my subs are 8ohm impedance, right now in paralell to 4ohm. This amp says it has an RMS of 500w at 4 ohms. I figure if the subs are sharing the wattage, they are really only getting 250watts(they are rated at 200, peak 800). Anyways, am I blowing up these subs or not?
 
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