2005 Silverado Z71 Ext Cab
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=87976
Printed Date: April 18, 2024 at 6:36 PM
Topic: 2005 Silverado Z71 Ext Cab
Posted By: djorgensen3
Subject: 2005 Silverado Z71 Ext Cab
Date Posted: December 29, 2006 at 6:52 AM
Hello all. I have been reading for a few days now and would like to tap into some great minds. I have a 2005 Silverado and replaced the center console/sub/amp setup for a center jump seat. I needed to do this to fit two adults and four children. Anyway I am going to build a sub enclosure for this truck and have purchased two Kicker S10L7 d4 and a Kicker 400.1 mono amp. I am only going to use one of the subs for this truck. I don't know what I'll use the other for yet. Which is the best direction to fire this sub, down or forward? I can raise the seat about 3/4 inch if necessary to forward fire it. any other tidbits of info you all can provide will be greatly appreciated.
Replies:
Posted By: Big Dog
Date Posted: December 29, 2006 at 10:23 AM
Under the rear seats or behind the rear seats is an alternative. They sell pre-fab boxes for both areas or you can make your own.
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Prepare your future. It wasn't the lack of stones that killed the stone age.
Posted By: djorgensen3
Date Posted: December 29, 2006 at 4:09 PM
Okay let me reword this question. I know there are pre-fab boxes that fire either forward or down for this truck. Whether I buy one of these or build one for myself, which is the better way to fire this sub for the best sound? I could also build a box and fire it up through the rear seat but I'm not sure that would sound very good. I listen to rock more often that not so I'm not into making this truck boom for miles. I prefer the sub to hit hard and low and fast and sound good at the same time.
Posted By: 3cc_installer
Date Posted: December 30, 2006 at 4:26 AM
Down fire! ------------- Jared Nixon - A.K.A Jsmoke
3rd Coast Customs
Lake Charles, Louisiana
Posted By: suburban boy
Date Posted: December 30, 2006 at 1:33 PM
i must agree down fire si the way to go
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Suburban boy
Posted By: Big Dog
Date Posted: January 03, 2007 at 7:41 AM
You're problem is actually to your advantage. 1) You listen to rock rather than Bass Mechanix. 2) Stuck with limited space = No choice but a small enclosure firing down like the boys say = no sonic boom just tight bass. Bring on the Black Sabbath baby!  ------------- Prepare your future. It wasn't the lack of stones that killed the stone age.
Posted By: djorgensen3
Date Posted: January 03, 2007 at 10:02 PM
Exactly what I wanted to hear. Okay I know that a sealed enclosure will give that tight bass but will it extend very low with the limited space I have or should I make it a ported enclosure? I can make the enclosure to take up both sides under the rear seat but use only one sub and put a por in the other side. It should give me approximately 1.4 ft^3 for the sub. I will make the port appropriately sized for the enclosure. Thanks for the help. I do appreciate it as I have been out of it for quite some time.
Posted By: schmiddy
Date Posted: January 04, 2007 at 3:15 PM
Get a very powerful sub amp with bass boost at about 40-50 Hz, and you can get pretty similar results from a small sealed enclosure. You won't wake the neighbors, but your low extension should be fine.
Posted By: Big Dog
Date Posted: January 04, 2007 at 3:29 PM
What schmiddy said.
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Prepare your future. It wasn't the lack of stones that killed the stone age.
Posted By: djorgensen3
Date Posted: January 04, 2007 at 10:16 PM
Okay so firing up through the seat is a no go?
Posted By: Big Dog
Date Posted: January 05, 2007 at 7:46 AM
The compression while firing downwards would create a nice tight snap and besides, you'll feel the bass as well as hear it...
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Prepare your future. It wasn't the lack of stones that killed the stone age.
Posted By: djorgensen3
Date Posted: January 05, 2007 at 8:04 PM
I just thought firing up would be easier to make the enclosure size correct but I will just make it wider for the one sub. So downfire it is. Thanks to everyone for your help!!
Posted By: schmiddy
Date Posted: January 06, 2007 at 7:05 AM
The enclosure size should be the same whether the driver is firing up, down, forward or backward. I would recommend learning a bit more about speaker design before moving ahead- relatively small differences in enclosure size can make a huge difference in sound. There are tons of resources on the internet; I would check the DIY speaker sites, as most car audio sites don't dig into this level of detail. All drivers have a resonant frequency. The main reason for an enclosure is to counteract the resonance of the speaker at that frequency and smooth the overall response. A sealed enclosure is basically an air spring the dampens the driver at that frequency; the size of the enclosure is pretty forgiving. There is an "optimal" size for accurate bass; a box smaller than that will sound boomier, a box larger than that will sound "faster" but have poorer low frequency extension. A vented enclosure is basically a resonator that acts out-of-phase with the driver at the resonant frequency; there really is only one correct box size and port length to let it do it's job properly. If this is your first sub design, I would stick with a sealed enclosure because it's much more forgiving. A properly designed sub should not sound any different whether the driver is pointing up, down, forward or backwards; sound radiates more or less equally in all directions at low frequencies, provided that the front of the driver has several inches of clearance. In theory, the sound would actually be cleaner with the sub facing forward/backward because gravity would not cause the cone to sag in one direction; however, my understanding is that most car audio subs have lower-compliance designs that minimize this effect. There is a way to calculate this from the Theile-Small parameters, but I forget how. It is related to the moving mass of the cone, and the stiffness of the suspension. I hope I'm not confusing the issue too much, but these are basics that you should understand if you want a good result with your sub design.
Posted By: djorgensen3
Date Posted: January 06, 2007 at 8:33 PM
I understand everything you have said. My point was to have the best quality low bass sound. I have already used several online enclosure calculators and have come up with several different volumes dependent upon which calculator I used. And those answers were different from the manufacturers recommendations. It seems that the online calculators suggest a much larger enclosure. It isn't my first sub enclosure but I have been out of it for quite a long time. So far what I've come up with is to build my own enclosure similar to the prefab boxes large enough for two subs but only use one. It will be as large as the manufacturers smallest ported recommendation but with the ability to try it sealed, as suggested by the online calculators, then ported to determine the best sound for my taste. I just wanted to know if firing up through the seat would muffle or muddy the sound from the sub. I realize sub bass is omnidirectional by I want good sound and some feel.
Posted By: dsintia
Date Posted: January 06, 2007 at 11:19 PM
I just dealt with the same issue this past weekend, you know the four kids and two adult thing... I fired downward in a forward staged sealed enlcosure with just over 1.1ft3 vas on an infinity perfect 12" with an alpine amp and it produces really tight bass. Good luck.
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Posted By: schmiddy
Date Posted: January 07, 2007 at 8:14 AM
Good deal... I think I misread your earlier post about a different sized enclosure for down vs. up-firing. Sounds like you've thought it through. One other thing to think about; if the enclosure is large enough to serve as a ported enclosure, it will most likely be very big for a sealed enclosure- very low Q. The bass will sound fast and tight (low group delay), but you won't have very good low extension and you'll need lots of power to drive it to sufficient volume. If you haven't tried WinISD yet, you might want to give it a whirl- there's a good tutorial on this site.
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