box dimensions for 18'' subwoofer?
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=54476
Printed Date: May 29, 2024 at 2:45 AM
Topic: box dimensions for 18'' subwoofer?
Posted By: infector21
Subject: box dimensions for 18'' subwoofer?
Date Posted: April 23, 2005 at 9:15 AM
I need to know how many cubic feet this monster needs. I have a Chevy Tahoe and a Panasonic 18" subwoofer model # CJSW46 to go with it. Any ideas on a good box dimension or port diameters. I want to do a ported box and I would like to build my own making it a downfiring box raised about 2" off of the ground. Any help would be greatly appreciated!!
Replies:
Posted By: Captanham
Date Posted: April 23, 2005 at 9:33 AM
that thing is massive, but i can't find anywere that says what box size it is rated for? so i dont' really know what to tell you, i'd prolly do something like a 2.5 cube box with a 15 inch deep by like 10 x2 inch port firing down with it ------------- Bad Boys Customs
audio - video - security
If you use it. Suport it. Donate to the 12 volt!
Posted By: infector21
Date Posted: April 23, 2005 at 9:40 AM
do you think that 2.5 cu.ft. will be big enough? That sounds great. I know that it is 600 watts and that it states that its VAS is 406 liters. But I am not sure,
Posted By: Captanham
Date Posted: April 23, 2005 at 9:54 AM
like i said i'm not sure, i'm sure you could do anything up to like a 4 or 5, but with it being an 18 it's already going to be a little mushy, so i would figure you'd want to keep the box on the smaller side of things to try and tighten it up a bit maybe get a better range out of the sub, fso maybe even like a 3 cube, but i wouldn't go with the full size box, unless your just going for spl and you don't wanna listen to it ------------- Bad Boys Customs
audio - video - security
If you use it. Suport it. Donate to the 12 volt!
Posted By: infector21
Date Posted: April 23, 2005 at 10:02 AM
ahhhhh good point! a few more questions for you. Only one port? Should the port also be downfiring? and any suggestions on a brand amp and wattage level I should look into? I am able to get a couple of different amps close to wholesale at my local shop that I have made good friends with. I Just wanted another suggestion from an unbiased standpoint, Thanks again
Posted By: stevdart
Date Posted: April 23, 2005 at 10:03 AM
Please just don't start guessing for this thing. Panasonic has published some rather skimpy parameters for this sub, and you'll need more info to build an enclosure...especially for downfiring. Contact their tech support and get the full T/S parameters, then post them here.
-------------
Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: Captanham
Date Posted: April 23, 2005 at 10:07 AM
once again, panasonics site really doesn't say anything, it says 600 peak, so i would assume you'd wanna get a 2 channel or mono block that gives you a clean 300 - 400 watts rms, look for something like an alpine amp that will put out some good power with out any distortion, look at the thd of what you have available, and pick something name brand.. one port would be fine if you do a vent port, i wastn' talking about a round peice of pvc pipe kinda port, make a 2x10 or so vent on one of the edges of the box, but make sure the port goes in somewere around 15 inches or so, you can't just cut holes in the box.. the port might have to go a little further then that still, i don't really know because like i said, panasonics site really only tells me that it's an 18 inch sub and doesn't say much else... the reason i'm sayin to do a vent port it because it will give you less noise from the port with all that air then a tube port, and i think it would be fine to have it downfiring, just as long as you give the air somewere to go, like only put 3 sides on the box (i mean under it, the part that holds it up) something like that, you'll have to mess with it to get the best sound out of it i'm sure ------------- Bad Boys Customs
audio - video - security
If you use it. Suport it. Donate to the 12 volt!
Posted By: DYohn
Date Posted: April 23, 2005 at 10:07 AM
Since you started two threads with the same question I deleted the other one. Your owner's manual should have the T/S parameters for the sub. Use these to model an enclosure in a program like Win ISD. The Panasonic web site lists Fs, Qts and Vas, so a ballpark enclosure to get you started would be 122.56 litres (4.33 cubic feet) tuned to 32 Hz. Use a 4" diameter port 4.7" long. Like stevedart said there is not enough info to tell if this can be used downfiring, but my guess is NO. ------------- Support the12volt.com
Posted By: infector21
Date Posted: April 23, 2005 at 10:08 AM
I have been trying to get info on this sub for a month, I actually called and spoke with tech. support at Panasonic and they stated that they had no other information available than what was stated on there website. I told them to have a manager contact me back by email. and that was last Thurs. 4/21/05. no reply yet. I intend on calling again Monday. Isn't that a load of crap! I really don't want to have to guess either I am a by the book kind of guy anyway. When I do get the information I will be sure to Post it though. any advise in the meantime would be great as far as the amp goes.
Posted By: Captanham
Date Posted: April 23, 2005 at 10:11 AM
i still think that big of a box is going to make this thing sound like mush, but dyohn knows what he's talkin about.. i still would cut that down a little bit, dyohn, do you think the port would sound better vent or circular? ------------- Bad Boys Customs
audio - video - security
If you use it. Suport it. Donate to the 12 volt!
Posted By: DYohn
Date Posted: April 23, 2005 at 10:18 AM
I bet this woofer will sound like mush anyway no matter what you do, but no the size I listed is proper for a standard vented alignment based on the T/S parameters given. Either a slot or a round vent will work. Round vents are easier when the required length is so small. I would not use anything smaller that 4" diameter though. ------------- Support the12volt.com
Posted By: Captanham
Date Posted: April 23, 2005 at 10:20 AM
yea, i think it will but i dunno, i guess if the port gets too big it w ouldn't sound any better then the box bein too big... who knows... so what made you deside to go with an 18 instead of a set of 12's or something anyways? ------------- Bad Boys Customs
audio - video - security
If you use it. Suport it. Donate to the 12 volt!
Posted By: infector21
Date Posted: April 23, 2005 at 10:24 AM
What does it change by being downfired? The only reason I was wanting it possibly down is because I wanted to protect it and also so others could not see what I had( You know kind of a stealth box so to speak). It is not a problem though for me if it is not I have a cover that will cover the back that is about 24" off of the (ground) of the trunk . The only specs it came with is the exact same thing on the website. It is almost like it is a joke or something. No Customer service for it No tech support No info. and only like 3 company's sell it. Also if downfiring is not a good option is facing it toward the rear glass the best option? Would it hurt to put a good strong amp on them and just have the power down low? I kind of need a suggestion on an amp also. I can get Planet Audio,Orion,CerwinVega,Kicker, Then of course all the legacy and pyle crap. Thanks guys I appreciate your time and efforts!
Posted By: stevdart
Date Posted: April 23, 2005 at 10:33 AM
What I'm missing to calculate the sag factor for downfiring is the Xmax. https://www.accelerator-pedal.com/sag.htm If Panasonic doesn't know what the damn Xmax is I feel sorry for them trying to get into the subwoofer business. ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: DYohn
Date Posted: April 23, 2005 at 10:35 AM
Downfiring will destroy a speaker that is not designed for it much faster due to the sag caused by gravity. I suggest you find a nice 250 to 300 watt mono amplifier for this and mount it facing the rear glass, sure. Planet, Orion, Kicker are probably fine choices for an amp from yout list. ------------- Support the12volt.com
Posted By: infector21
Date Posted: April 23, 2005 at 10:37 AM
I Got the sub for $100 from a friend of a friend. The box was never even opened. he got in a bind for cash So I took advantage of the position. I feel Kind of bad.......NAH no I don't J/K
Posted By: Captanham
Date Posted: April 23, 2005 at 10:39 AM
i would sell it and get a pair of 10's or 12's haha ------------- Bad Boys Customs
audio - video - security
If you use it. Suport it. Donate to the 12 volt!
Posted By: stevdart
Date Posted: April 23, 2005 at 10:41 AM
It's worth about $100. Now use another $100 and build a box to the specs DYohn posted including the port dimensions, face it to the rear as he agreed with...and you'll be good to go. 250 watts from a clean mono power source will be all you'll need for that, as the sub is very efficient with a 92 db SPL factor and probably has a 250 to 275 watt RMS. And port through the firing side of the box.
-------------
Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: infector21
Date Posted: April 23, 2005 at 10:42 AM
okay that makes sense with the sag. I definetly want it to last a long time. Would it hurt to have like a 500-600 watt amp just turned down lower that is 2 channel. The reason I am asking is because I already have a other amps that I could use. I also have a 2000 watt legacy amp I could use.I do know that it is not really 2000 watts though! I just want the 18" to suck because of a POS amp
Posted By: Captanham
Date Posted: April 23, 2005 at 10:44 AM
even turned down that legacy is probably going to sound like crap, they always do, i'd put a little money into a better amp ------------- Bad Boys Customs
audio - video - security
If you use it. Suport it. Donate to the 12 volt!
Posted By: stevdart
Date Posted: April 23, 2005 at 10:45 AM
You should be using the Legacy amp as a wheel chock when you park on hills. Don't overpower this sub with the wrong amp. This is a SVC 4 ohm sub, so you can use a two-channel amp and bridge the sub, but the amp should put out no more than 300 watts continuous into a 4 ohm load bridged.
-------------
Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: infector21
Date Posted: April 23, 2005 at 10:49 AM
I may just build a box for it and sell it in a few months. According to Panasonic it is like a $800+ sub, There is one other online retailer that sell it for about $389. I wonder what would be a reasonable selling price for it. I could probably get about $400 with a box or 5 If I throw in that Legacy Amp.
Posted By: infector21
Date Posted: April 23, 2005 at 10:51 AM
Thats about the only thing it is good for. I tried to use it on one of my Orion H2 10" subs and it would barely move it. not to mention it sounded the like the worst Sub on earth.
Posted By: stevdart
Date Posted: April 23, 2005 at 10:52 AM
I saw it selling for 119 dollars on one of the pages I pulled up when I did a google search. But selling this, for you, in a 4+ ft box is going to be the hard part. There aren't a lot of vehicles that it will fit into easily and will be heavy as hell. Either use it or sell the driver by itself, IMO.
-------------
Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: infector21
Date Posted: April 23, 2005 at 10:59 AM
I don't think that I will have a big problem selling it here. I Live in Jackson, Ms. and there are a ton of people here that think bigger is better. Which I prefer 3 10"s myself / Quality but I can rattle the pics. off your house walls if I wanted to. I have them in a 93' Integra sounds great
Posted By: Captanham
Date Posted: April 23, 2005 at 12:58 PM
if you are going to sell it, sell it while it's new and unused in that box, that legacy is gold for ebay freaks, throw it in and sell the whole deal for like 250 300, it'll go quick ------------- Bad Boys Customs
audio - video - security
If you use it. Suport it. Donate to the 12 volt!
|