I screwed up, can only fit 1 sub....Jon, Glass

 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 163
Registered: Aug-04
It's a good thing I measured before I bought. I have discovered that I can only fit a box that is about 24L x 17W x 16H. That's about room enough for a single 12 ported box.

I already have an MTX 801d amp (tested 583w rms 2ohm @ 12.5v). I have made a list of subs in my price range ($200).

Jonathan already suggested the Eclipse 8122.4 that is below, but please recommend TWO from the list.

-Rockford Fosgate T1 12D4

-JL 12w3v2

-Eclipse Aluminum 8122.4

-Memphis M3 124D

-Diamond Audio M6 12D4

-Infinity Perfect 12VQ

-Phoenix Gold Ti 12

Thanks
FNG
 

Silver Member
Username: Insearchofbass

Post Number: 240
Registered: Jun-04
2.926 cubic ft internal volume with those measurements one inch fiberglass insulation or pound of polyfill about..3.21 cf with two inches fiberglass or two pounds poly fill 3.50 cf. without displacements for ports or woofer using the demensions you gave us case that helps you make a decision or anyone else thats helping you
 

Silver Member
Username: Pat_l

Tucson, AZ USA

Post Number: 497
Registered: Apr-04
If i was you stick to the JL W3, my freind has two in his car and they are really good (well JL- the best). I would also consider the RF T1.
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 180
Registered: Aug-04
Anyone else wanna throw out a suggestion?
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1384
Registered: May-04
Aluminum would be my first choice, I guess the Perfect VQ would be my second (personally, I think the VQ is a waste of cash unless you have a lot of different boxes laying around. Go with the 12.1 if anything) W3s are good, but the Aluminum is on par with the W6v2, big difference. I wouldn't call JL the best, there are many other subs I like much better than JLs (and they're cheaper :-)) You'd want the 8122.DVC to get the most power from the amp, it'll be around 800W RMS, overpowering the sub, but the Aluminum tends to be underrated and you can always be conservative with the power.
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 182
Registered: Aug-04
I thought that's what you'd say! Now just have to wait for the $$$.
 

Bronze Member
Username: Erik123456

Arlington, Tx

Post Number: 13
Registered: Aug-04
id go aluminum, i have heard a ported 12 before and it pounded pretty well
 

Silver Member
Username: Insearchofbass

Post Number: 305
Registered: Jun-04
youll like that one fng i heard two they sound nice and pound better than the kove we were talking about in the other post concerning sq id say be ready for bout at least 140 spl with one
 

Silver Member
Username: Insearchofbass

Post Number: 306
Registered: Jun-04
when i said better i was reffering to the sq
 

Bronze Member
Username: Erik123456

Arlington, Tx

Post Number: 17
Registered: Aug-04
ive heard one and im guessing 145+ but it was ported in a big box
 

Bronze Member
Username: Erik123456

Arlington, Tx

Post Number: 18
Registered: Aug-04
make sure you get a ported box in a sealed they sound really high and not very good imo
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1388
Registered: May-04
I've had good results with either, but they do get loud ported with the right power.
 

Silver Member
Username: Insearchofbass

Post Number: 316
Registered: Jun-04
lol hold on to your hat either way 140s is bangin for everyday
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 186
Registered: Aug-04
I'm emailed Eclipse to get enclosure specs...anyone have them. Jonathan you told me before I think 2.25 cu ft tuned to like 32 or 35 hz. Question is, can that fit in 24 x 18 x 16???
Anyone want to do the math for me, cuz I'm clueless how to figure that stuff out....
 

Silver Member
Username: Insearchofbass

Post Number: 324
Registered: Jun-04
i did the math for you up above bro thats internal volume (ill let jon answer box size recomedation and port tune)
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 188
Registered: Aug-04
Doh...yeah you did! Thanks. So in Internal volume we're good, but I want it at about 2.25 cu. ft. Can we make the ports right and everything be kosher with dimensions that I listed above???
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1395
Registered: May-04
Eclipse is going to give you box recommendations that suck for everyday driving honestly, they'll recommend a box tuned around 40 hz(kills the low end extension of this sub, which it's really good at). Try about 2.25 cu ft net tuned to 32 hz. Can't remember the sub displacement, you'll have to email or call Eclipse to account for that. I recommend a slot port, as big as you can get as this sub can move some air. It'll fit in those dimensions easily, you'll just have to figure what kind of port area you want.
 

Silver Member
Username: Insearchofbass

Post Number: 335
Registered: Jun-04
in a 2.5 cf box tuned to 35.5 hz you would need two 4 inch pvc ports 21.75 inches deep total minus .75 for wood and if i read right you have 24 deep but would that leave you room for the ports to breath externally
 

Silver Member
Username: Insearchofbass

Post Number: 336
Registered: Jun-04
i did 2.25 cf sorry
 

Silver Member
Username: Insearchofbass

Post Number: 337
Registered: Jun-04
ok got it two slot vents 3.25 high by 3.5 wide should account for port volocity that would be 21.75 deep minus .75 for wood comes to a 32.2 hz tune in a 2.25 cf box after displacements
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 191
Registered: Aug-04
Yeah, the displacement is .13 from a previous message you sent
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 192
Registered: Aug-04
Is there anything to help figure out the correct area and depth of the slot port. Like an online utility or something you can download? Or is their some mysterious formula???
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 198
Registered: Aug-04
Anyone?
 

Bronze Member
Username: Koz1031

Monticello, In United states

Post Number: 62
Registered: Jul-04
try this on http://www.carstereo.com/help2/Articles.cfm?id=31
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 199
Registered: Aug-04
Okay, "think" I'm getting somewhere.

21"w x 15"h x 16.5"d = 2.285 cu ft with 3/4" MDF (correct me if I'm wrong)

Also 4" round port should be 11.55" long tuned to 32hz. How do I convert this info to a slot port ? Or is this not correct at all???
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1420
Registered: May-04
Keep the surface area of the slot port the same as the surface area of the round, and you'll be ok. For example, a 4" port round is 4x3.14, which is 12.56sq in of port area, so you'll need a slot port equivalent to that such as 12.56x1", 3.54x3.54 square port, etc. Length will be the same as the round one. WinISD helps you enter net volume and port size and tuning, and calculates the port length you'll need. Then, just add the volume of the port and subwoofer displacement to the net volume of the box to figure full dimensions. http://www.bcae1.com/spboxnew2.htm This site has a good ported box building tool, you'll just have to convert surface area of the slot port to round ahead of time (ex. if you want a 12"x3" slot port, then multiply 12x3, which is 36, and divide by 3.14, and you'll get the round port size that has the same surface area of the slot port).
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 200
Registered: Aug-04
Jon, sent a PM
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 205
Registered: Aug-04
Okay, just say for kicks I happen to decide on a sealed box for simplicity's sake. My amp is still gonna make this thing pound in a sealed box right? MUCH more than my little Polk 10 in its .60 cu ft little sealed Qlogic box. And I'm not gonna have to move the gain past half to make it hit...

What size sealed box for the SW8122.DVC?
 

Silver Member
Username: Insearchofbass

Post Number: 359
Registered: Jun-04
fng just use my port size i gave you but i made a mistake make it 21.75 deep each i did two ports for simplicity for you
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 206
Registered: Aug-04
That's a long a$$ port....are you sure about that???
Won't work anyway with the new dimensions I've got. I just want to know about the sealed if I get frustrated and want to take the eazy way okay. Does the fiberglass or the polyfill have to be used???
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1421
Registered: May-04
About .75-1 cu ft net volume works well. And I think the 8122.DVCs displacement isn't .13, they told me it's 1.0, which is about right for a 12" of this size.
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 207
Registered: Aug-04
Holy Hell Batman! That's big. Wonder where I got .13 Changes things for the ported box too....
I quit. I don't want to know anymore. Okay .75-1 cu ft net that's after sub displcement so the total internal volume of the sealed box would be 1.75-2 cu ft. It's still going to have to be built. Grrr....
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1428
Registered: May-04
OOPs, retract that, typo, it's .10 cu ft. So sorry about that. Didn't mean to make you mad
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 209
Registered: Aug-04
No...it was in jest, no worries....I was gonna flip... :-)

So 1 cu ft. will be fine, and sub displacement bring it down to .90 ! Do I need any of that polyfill stuff?

I'm gonna try it like this and if my 800w doesn't pound me to the ground so I can feel it, then I'll go ported.

In the mean time....is there anyone here that gets pleasure out of designing boxes and has the time....I'm raising my hand to volunteer.
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1429
Registered: May-04
Sounds a lot better, doesn't it? If you want a ported box tuned to 35 hz, I'll make it easy on you, built a 2.5 cu ft GROSS volume (no net calculations to make :-) ), put a 5" round port, 14.25" long in there, and put the sub in. Instant 35 hz tuned box, perfect for that sub (came from Eclipse, had written it down a while ago). The other Eclipse recommended box was around 40 hz and really small, so I wrote that one off. You can test that in WinISD to see the curve vs. sealed box, enter 2.4 cu ft (because you subtract sub displacement) and enter 35 hz. I know it can be frustrating calculating for a ported box. Also, I'm playing around with an Eclipse Aluminum my brother had, I was originally considering trying a T-line for it, but it was just way too much to calculate, so I'm gonna go ported with it. I'm going with a 2.2 cu ft tuned to 32 hz, if you want dimensions after I finish planning, just tell me and I'll email them to you after I draw them up. Note that the box will be fairly big because I'm doing a 12" by 3" slot port. But, it'll be a great all around enclosure for whatever you listen to.
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 211
Registered: Aug-04
FinallY!!!!! God Bless you. The only reason I was going for the slot port was because you had said it eliminates port noise. I don't want to buy this great sub and have it sound bad ya know?

Question though...plugged that info the website (http://www.bcae1.com/spboxnew2.htm ) and it says

"**ERROR** Check your dimensions. The port is too long to fit inside the enclosure. You may need to use a curved port, less port area or a higher tuning frequency."

Should I just ignore This?
I put in 15.25"h x 24"w x 16"d.
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1435
Registered: May-04
A 5" round is pretty large port, so noise won't be a problem, just file the outer and inner edges so no noise occurs (filing reduces turbulence, so no "whistles" occur). However wide the port is, that is how much clearance you need to a wall of the box (in your case, 5"). The program does this error because it assumes that your port is faced to the front of the enclosure, meaning the depth of the box would have to be 5" larger than the port length. Easy fix, put the port in the side of the box and let it run along the width (24") of the enclosure. Don't pay any attention to it.
 

Silver Member
Username: Insearchofbass

Post Number: 364
Registered: Jun-04
i didnt no they mad 5 inch pvc inner diameter but thats cool happy bumpin fng i no its going to kill your polk 10
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 213
Registered: Aug-04
Woo Freakin Hoo! The damn shiznit is solved. Now just gonna find 5" pvc. Do I just make it the pvc flush with the edge of the box or is one of those flange things still required on the exterior side of the pipe? If so where would I find a 5 inch one???
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 214
Registered: Aug-04
The biggest port tubes I can find ar like 4"dia by 12" by Lightning called a PNR Aeroport
http://www.crutchfield.com/S-vY660u0cTMq/cgi-bin/ProdView.asp?a=1&s=0&cc=01&g=74 5&id=detailed_info&i=495PNR4
Could use this and trim it down to 8.33" long.
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1438
Registered: May-04
Can't think of any special companies that make 5" port tube, but any hardware store should carry 5" PVC pipe, even if they don't have it in stock they can order some for you. Flared end should be able to be found there(not going to be a pretty one, though), but if you have the tools(or a friend who does), my preferred way for round ports is to rabbit out the MDF like so:
http://www.audiodiycentral.com/nt_porttube.shtml
Looks a lot better and seals up better as well. I'm sure at least one person you know has the tools to do this. If not, you could try to convince your local schools shop class to do this as a project, nothing like hands on experience :-)
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 215
Registered: Aug-04
I don't have those tools nor a friend with them either. Just moved to the area.
So what would changing to a 4" port do?
I used the calculator and it said I could do a 4" port that's 8.33"L tuned to 35hz with similar dimensions.
Would that be okay? (the more idiot proof the better.)

 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1445
Registered: May-04
More chance of port noise, plus you'd have to compensate for the box volume as it'll change with a smaller port. Give me a little while and I'll come up with something better for you. What tuning freq do you want, somewhere around 30 hz for SQ, or 35 for SQ/SPL?
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 223
Registered: Aug-04
Yeah, Good mix of SQ/SPL so 35HZ. Not many people have the luxury of doing this at work....how do you get off so easy?
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1446
Registered: May-04
Ok, try this. Build a box 16"H x 24"W x 16.75"D EXTERNAL dimensions with 3/4" MDF. 2 4" ports like the ones you linked to above (or others, your choice), each one 19 1/8" long. That's a 2.5 cu ft. net box tuned to 35 hz, and it'll move some air as well. The flares really only have to be on the outside of the box, you can just buy one of those kits for the flares, and use 4" ID PVC pipe to get the port length. File the inside edges of the PVC to make sure no turbulence occurs, and you'll be good to go.
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1447
Registered: May-04
I'm on a computer nearly all day because I have to reprogram PLCs, we've been doing a lot of product changes lately. I come here to give my mind a break from looking at numbers on a screen all day, it'll wear you out pretty quick. :-)
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 225
Registered: Aug-04
And you got out of the Car Stereo industry for that? :-) Must be about $$$

Question. I don't quite understand How come with the 5 inch port it was like 14.27" long.
Now it's 2(not 1) 4" ports and they are 19.25" long each??? How does that work?
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1453
Registered: May-04
They have more port area combined than the 5" port does(it'd be the same as a single really large port, but gives you the convenience of buying premade port tubes), meaning less resistance to airflow, requiring longer ports to put pressure back on the sub to get the tuning back down where it should be. I don't sit on a computer everyday, but have been doing so a lot lately due to continuous(unnecessary IMO) product changes, usually I focus on managing personnel and planning projects. Overall, I enjoy it more than car audio, there's a difference between hobby and job. It's nice to come to a forum and answer questions, and to work on my system in my spare time, but when you have a shop and financial pressures, ordering products, nagging ignorant customers, sending returns back, etc. come into play, it just takes all the fun out of it. "Plumbers pipes leak" is the expression that comes to mind, I enjoy car audio a lot more now that I'm out of it. I do make more $$$ than I did in car audio, but in the end its all about doing what you're happy with. Anything you have a passion for, even if it's scrubbing toilets (although not exactly my passion) and you apply yourself to it, you'll be successful. That's my soapbox for the day :-) You can plug those figures on bcae to see what I'm talking about.
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 231
Registered: Aug-04
Yeah, I got basically the same thing you did within a fraction of an inch on the Length measurement for the 2 4" tubes. I'm really not trying to trip or anything, And this thread is humongous I know. But I can plug in 1 4" ID 8.3" long port @ 35 hz and it's okay with that too. I guess I want to know why 1 4" port wouldn't work. It it because I'd get port noise, even with the flared flanges?
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1471
Registered: May-04
Yep. Port noise possibility, that sub will push some air. You'll get more SPl out of two ports as well. Not counting you'll have to drop the box size a little to get the net volume down. Two would work better.
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 233
Registered: Aug-04
Noted! I think we've got it!

One last question though. (don't sigh). My friend is getting a Perfect 12.1(on my suggestion). Hell be giving it 360w rms. Would he be okay go use the factory suggested 1.75 cu ft.(ported) Or is something else better suited. I'm thinking good sq/spl mix. This guy is practically a carpenter so he can build whatever,just wish he lived closer.
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 239
Registered: Aug-04
Also, in releation to same Question about the Infinity Perfect. Their website and several others recommend or require lining the interior walls with fiberglass....is this necessary ?
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1473
Registered: May-04
If that's what the specs call for, polyfill is necessary. I prefer slot ported boxes, but that's just me. I recommend using WinISD to compare different box ideas, you can get more SPL and same or better SQ with a custom ported box.
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 243
Registered: Aug-04
Anyone know a good place online to get Polyfill or this fiberglass that the manuf. refers to? You can't put polyfill in ported right, it has to be the sheets?
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1500
Registered: May-04
Hardware stores generally carry fiberglass chop mat, you'll need that. Should be somewhere around that carries it.
 

Silver Member
Username: Caraudiofng

Houston, TX

Post Number: 246
Registered: Aug-04
Yeah, I looked at home depot but only found 3/4"
« Previous Thread Next Thread »



Main Forums

Today's Posts

Forum Help

Follow Us