sub enclosure difficulty

Printed From: the12volt.com
Forum Name: Fiberglass, Fabrication, and Interiors
Forum Discription: Fiberglass Kick Panels, Subwoofer Enclosures, Plexiglas, Fabrics, Materials, Finishes, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=120945
Printed Date: May 15, 2024 at 8:35 PM

Topic: sub enclosure difficulty

Posted By: §ealed-fate
Subject: sub enclosure difficulty
Date Posted: March 25, 2010 at 1:32 AM

I am running 2 Kicker COMP CVR 15's 2ohm DVC's ... Says Peak power is 1000watts/800RMS watts on the bottom of the magnet, in a 91 Oldsmobile Delta 88 Royale. I am thinking this enclosure needs to be a ported box, the car has got a decent size trunk in it. I am currently using a sealed box my friend found in a dumpster, (lol) and I am looking to make a new box, or rather have my dad do it for me. This box seems good enough really untill it hits that certain note and it will sound like crap, so I am looking for a change.

I told my dad that certain boxes are tuned for certain speakers and there's different measurements for different enclosures, this is what I have gathered by reading and understanding however I could have misunderstood everything.
If anyone has a ported box for these speakers, and could share the dimensions with me I would appreciate it and would also as well make it easy for me. I've looked and I cannot find any dimensions for a box for these speakers anywhere. I have found stuff like Qms etc. but do not understand and Have tried to understand for a while now.

So yeah I am looking to build a ported box but have no clue where to begin because I do want it to be perfect and match my speakers. I am no carpenter, dad is though and if I was to be able to tell him dimensions then that's all I need, will be sure that he could just throw it together. Any advice would be appreciated.
Thanks

Replies:

Posted By: §ealed-fate
Date Posted: March 25, 2010 at 1:39 AM

Also if what amp I am using needs to be known, I am pushing these 2 15's on a 1600 watt Lanzar Max PRO ST MXA 242, which I am also having a problem with. It is stable at 2 ohms, said it gets 650 RMS bridged at 2 ohms, but it obviously doesn't like 2 ohm loads. Can't turn bass boost on or hardly mess with the gain without it blowing the amp fuse. Manual is lying to me I believe lol.

Posted By: anonymous1
Date Posted: March 25, 2010 at 1:55 AM

§ealed-fate wrote:

So yeah I am looking to build a ported box but have no clue where to begin because I do want it to be perfect and match my speakers.

Have you read the sub enclosure pages on this site? They cover all your concerns.

There are even calculators to assist you, but you need to get some information about the speaker besides "its big and weighs a lot"

Those specs will determine the optimal enclosure volume for ported or sealed boxes, the length and size of the port tube etc.

Please take some time to investigate these guides and gather the specs on your particular speakers.

Posted By: §ealed-fate
Date Posted: March 25, 2010 at 2:08 AM

I've tried but it's just all gibberish to me. I think another problem is, I can't find any specs on my woofers anywhere. I find some stuff most likely needed to determine how to build a box for the Kicker CVR 15's, but when I continue reading them its saying this speaker is only 500 watts, which it's not. So I feel as if I am reading directions to another woofer and afraid that's going to throw me off. I've read something about a WinISD program to enter in the QMS, QES, QTS values, but like I said I am not sure if I am entering the right values that go for my sub. This is only thing I have found that's even close to being my subs:

Model:
05CVR152
Nominal Impedance:
2
SPL dB 1W/1M:
90.2
Displacement, cc:
3992
Displacement, cu.in.:
243.6
Hole cutout, in dia:
13 7/8
Mounting Depth, in.:
8 1/8
Revc:
3.64
VC Inductance, mH:
4.068
Sd, SqM:
0.0881
BL:
20.81
Vas, Liters:
185.9
Vas, CuFt:
6.56
Mms, gms:
279.27
Fs:
23.2
Qms:
10.37
Qes:
0.342
Qts:
0.331
Pmax, watts:
500
EXmax, mm:
12.5
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I don't think I am looking at the right speaker. Totally clueless.

Posted By: KPierson
Date Posted: March 25, 2010 at 10:25 AM

You can't bridge your amp with two 2 ohm DVC subs you need to run it in stereo.

I'm assuming right now you have each coil wired in series giving you (2) 4 ohm subs that are then wired in parallel giving you a 2 ohm load. When you bridge the amp the load is cut in half yet again giving you a 1 ohm load which your amp can't handle.

Junk the amp and get something more reputable that is 1 ohm stable and your problem should go away.

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Kevin Pierson

Posted By: §ealed-fate
Date Posted: March 25, 2010 at 1:37 PM

I see hehe, that makes sense. And yeah that is exactly how I have my subs. Coils in series and parallel to amp. Sounds so good like that too, :( it's ashame to have to change them lol.

OK back to topic ;p would really like to understand all these values I've posted above.

Posted By: ianarian
Date Posted: March 25, 2010 at 7:58 PM

§ealed-fate wrote:

OK back to topic ;p would really like to understand all these values I've posted above.

Yaaa, I use XMAX, PMAX, Nom Imp and maybe mounting depth. After that the sub will be pushed until it fails or proves worthy of exceeding expectation and earning recognition.

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This is what I do for FUN!

Posted By: j.reed
Date Posted: March 27, 2010 at 1:58 AM

Everything you need to know about an enclosure for a CVR can be found right here. https://kicker.com/sites/default/files/CompVRTechManual.pdf

This will show you small, med and large recommendation enclosures, both sealed and ported and the projected frequency response for each enclosure. Even has spec enclosure sizes to be able to copy in small-large recommended sizes.

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Posted By: spldesigns
Date Posted: April 01, 2010 at 12:53 PM

those subs are only 500 watts, ive installed dozens of those same subs, look a little closer, maybe the 8 you see is really a 5, but yeah 1000max/500rms, for sure, 500 rms is half of 1000, and its usually half of max on most subs, but i usually give those subs about 1.5 cubic ft of air space for a slot port box, maybe 1.75 if you mostly listen to rap, better bottom octave with 1.75, then make your dimensions whatever for your trunk to equal 1.5-1.75, thats each sub, 3-3.5 for two subs, then go to the port length calculator to plug in dimensions, air space, what frequency you want to tune to, id use a freq. around 27hz if you listen to rap, maybe 45-50 if you listen to rock, and you will be all good

email me at innovativespldesigns@comcast.net if you need any assistance

Posted By: spldesigns
Date Posted: April 01, 2010 at 1:17 PM

by the way i wouldnt go any smaller of a box than i explained, those subs love extra large enclosures, i usually do installs when people still want to use their trunks, if you have the space i would go with a larger box, all the way up to 3-4 cubic feet air space with each sub for maximum sound quality, you loose a little thump going bigger, but it sooooooo gives you that maximum excursion all the way down where you feel it and see it, but you cant hear it, their great subs for the price, but like i said if your not going to competitions and like that banging thump go with a smaller sized box

Posted By: §ealed-fate
Date Posted: April 01, 2010 at 6:29 PM

Thanks everyone for their ideas. It has cleared up most of my concerne. And thanks alot spldesigns. Your post cleared up even more by giving me what you think would be best box for my subs.

Only question I really got now is what to build the box with. I believe my local hardware store only really have plywood (small town don carry much of anything) so I am thinking all Im gonna be able to work with is plywood but not sure what type. There are different types and sizes , any suggestion on that? I could probs drive 30 miles away and get better material but ...
And again thanks alot peeps

Posted By: j.reed
Date Posted: April 01, 2010 at 9:49 PM

MDF would be my first choice. 3/4" or a quality birch or oak ply 3/4" 2nd because of the price.

Also i dont know what the heck slpdesigns is thinking. 1.5 is only half the smallest recommend net for those 15s. You need at least 3cu.ft. NET per sub. 4.5 to 5 would be best PER sub.

Even With his 27Hz you would be peaking in low 30-35hz. In a proper sized enclosure and port area. Too low for most rap which is between 35-45Hz bass tones. Go with the factory enclosures i linked you and i promise you will be more then happy. Port from 32-35Hz. The closer to the larger recommendations the better.

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Posted By: j.reed
Date Posted: April 01, 2010 at 10:03 PM

spldesigns wrote:

those subs are only 500 watts, ive installed dozens of those same subs, look a little closer, maybe the 8 you see is really a 5, but yeah 1000max/500rms, for sure, 500 rms is half of 1000, and its usually half of max on most subs, but i usually give those subs about 1.5 cubic ft of air space for a slot port box, maybe 1.75 if you mostly listen to rap, better bottom octave with 1.75, then make your dimensions whatever for your trunk to equal 1.5-1.75, thats each sub, 3-3.5 for two subs, then go to the port length calculator to plug in dimensions, air space, what frequency you want to tune to, id use a freq. around 27hz if you listen to rap, maybe 45-50 if you listen to rock, and you will be all good

email me at innovativespldesigns@comcast.net if you need any assistance

If you an installer/ enclosure designer there is no way in hell you would touch my stuff. You are way off on the NET. The smallest recommended enclosure for one of those 15s is 3cu.ft. net. If you have installed dozens i think you would also know they also like larger enclosures as well. Heck 1.5 -1.75 is not even enough for a small sealed enclosure for one of those. Dont even get me started on your idea of tuning freqs. 1.75 would be the smallest net for even the 12". Then the fact he is down on power for them, small is not the way to go.

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Posted By: §ealed-fate
Date Posted: April 02, 2010 at 1:22 AM

I had e-mailed kicker about the box ... And they told me :
, "you will need 7.0 cubic feet minimum. The outside box dimensions are 40” wide X 16” high X 23.5” deep. Divide the box in half. Each side needs a port 14.5” X 2.75” at 19.5” deep into the box."

So I guess I will go with this I'm not sure lol. Still not sure if I know how to use this port calculator, think I am putting wrong numbers in lol.
Thanks everyone :) Been very helpful

Posted By: j.reed
Date Posted: April 02, 2010 at 1:42 PM

§ealed-fate wrote:

I had e-mailed kicker about the box ... And they told me :
, "you will need 7.0 cubic feet minimum. The outside box dimensions are 40” wide X 16” high X 23.5” deep. Divide the box in half. Each side needs a port 14.5” X 2.75” at 19.5” deep into the box."

So I guess I will go with this I'm not sure lol. Still not sure if I know how to use this port calculator, think I am putting wrong numbers in lol.
Thanks everyone :) Been very helpful

yeah they are telling you 7 cube for both GROSS. thats including port and driver displaement. Which works right out to 3cu.ft. net per sub. As i said before the SMALLEST it should be. With your power if you have the space go larger. AS for the port calc to work you need to use net volume for it to work correctly. Give measurements of the space you have and i can work the math for you if you want to try larger. IF not just go with what they gave you. thats the small recommended enclosure. Larger if you can fit will give better output and a smoother freq response though.

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Posted By: §ealed-fate
Date Posted: April 04, 2010 at 3:13 PM

To get the maximum measurements I will have to have a box pointing the subs to the trunk lid. But worried about where ports will go. But for that the measurement of my trunk will be 43" wide. 27" deep and 16" high. For that box how will the ports work? Thanks

Posted By: j.reed
Date Posted: April 04, 2010 at 4:33 PM

Well thats were. being able to put hands on is the best, if you had 17-17.75 or so in height you could then mount the subs facing the rear or into the cabin. 16 really is not enough to mount that sub that way. If i remember right it is around 15.75 outside diameter. To gain what you need, you could add a bit of an angle which would gain you extra mounting surface. That would also take away from the cubic foot a bit. You just need to find the balance of as large as you can go and make everything work well within the space available. The largest enclosure size would definitely make for a louder and smoother response enclosure with the power you have, but it also would need to work with the space you have available. You will see good results any where in between the min and max recommended. Thats why they do that. But if you can go towards the larger side with those kicker subs they will be much happier.

As for the port you can do it on the side or on the sub mounting side. You just don't want to restrict the airflow. If say the port is 3 inches wide. You will want it at least 3 inches away from a side wall, trunk wall or seat back to not restrict the airflow from the port.

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