My first thread----HELP!

[slowfive0 10+ year member]

Hey guys,

Great site! I'm a newbie attempting my first box build. Vehicle is a 2000 Chevy Ext. cab pickup. I'm building the box to go under the rear seat to house 2 12's. Here is my problem and question.

I don't know what the subwoofer requirements are? They are 12", Have MD2 on the cone. The sticker on the back of the magnet says:

Impact High Performance Drivers

There is a big M for a symbol?

74792 / MD2128

These are 10 years old if not a little more.

The box I measured up (haven't made it yet) will have approximately 1.25 cu/ft per speaker. I was leaning towards sealed just because of my inexperience and not knowing what the speakers were designed for.

What would you guys recommend for a volume and have you ever heard of these speakers? (I'm not against ported if I can make it work without knowing the speaker requirements.)

Also, should I divide the box up in the middle (separate chamber for each speaker)????

Thank you for any input! //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

P.S. I will be powering it up with a Rockford Fosgate amp (200) bridged---roughly same age as speakers.

Click to read more...

 

[mikescanlon 10+ year member]

pics of the woofers? have you tried em yet to make sure they operate/ sound good?

 

[slowfive0 10+ year member]

They work fine in my mustang. The original owner had installed the system. I recently pulled them out and wanted to put the system in my truck. Problem is the original box (sealed box design) won't fit. I want to say (going off memory), that the original box worked out to be 1.1 cu/ft per speaker.

No pics right now, but I could get some if it will help. Thanks.

pics of the woofers? have you tried em yet to make sure they operate/ sound good?

 

[Defconx3 10+ year member]

I think some pics would really help.

 

[slowfive0 10+ year member]

I can get some later tonight or first thing tomorrow (wife is at work and has the camera)....//content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

I think some pics would really help.

 

[mikescanlon 10+ year member]

sounds good buddy, until then just read the sticky's on each forum and you'll get the right mindset to do this thing

 

[jsanford1974]

Unless your going to fiberglass or adjust the height of the seat, I don't see how your going to get 1.25 cu ft per sub/side. I've made 2 boxes for extended cab chevy's. One had around .88 cu ft (in a 00 Silverado) and the other had around .95 (in a 02 Silverado, I learned a few things after the first). Both were built using 3/4 MDF. Both fit flush underneath the seat. Another problem I ran into was the mounting depth of the sub. I used 10" Kicker Comp VR's in my application. They sounded pretty good. Good luck.

 

[bikejunkie223 10+ year member]

I had a friend that had Impact 12's in a Chevy Luv back around 1991 or so. It hit so hard it made me sick. That was the first good car stereo I ever heard, and now I'm a freekin' junkie for this crap too. That volume should be fine. post pix when you get a chance. Most 12's do well with 1.25cu/ft sealed.

 

[slowfive0 10+ year member]

Hey guys,

Thanks for all of the great replies (Man that was fast)!!!! You guys don't screw around! //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

I re-ckd my calculations and found the following:

My "initial" layout of the box = .78 cu/ft

If I extend it out an 1" forward = .857 cu/ft (almost to front edge of seat)

If I extend it up an 1.5" = .99 cu/ft (obviously, will have to fabricate brackets)

If I extend it up an 1.5" and forward an 1" = 1.09 cu/ft

This is assuming an area of .12 for the speaker (just a guess). Not sure how accurate that is. The speaker magnet is 4.5" in diameter. The distance from the speaker face to the bottom of the magnet is 5". Hopefully, I'm close.

Attached are some pics for your reference. Thanks again!

 

[slowfive0 10+ year member]

WOW!!! So someone has heard of these speakers! LMAO! I can't find anything on the net about them and no one seems to know anything about them. Of course I probably haven't been asking the right people until now //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

I was getting the impression that they were some junky no name 20 dollar speakers....I hope they work ok with my current box size (about 1 cu/ft each)...

I had a friend that had Impact 12's in a Chevy Luv back around 1991 or so. It hit so hard it made me sick. That was the first good car stereo I ever heard, and now I'm a freekin' junkie for this crap too. That volume should be fine. post pix when you get a chance. Most 12's do well with 1.25cu/ft sealed.

 

[slowfive0 10+ year member]

You're absolutely right! When I went back and ckd, I realized what I did wrong. Looks like I have 1 cu/ft max. More like .86 if I don't raise the seat. I was allowing 1.5" speaker to floor clearance. Do you think that is enough? I can sink them into the enclosure if necessary to gain a little clearance. Thanks again for the replies.

Unless your going to fiberglass or adjust the height of the seat, I don't see how your going to get 1.25 cu ft per sub/side. I've made 2 boxes for extended cab chevy's. One had around .88 cu ft (in a 00 Silverado) and the other had around .95 (in a 02 Silverado, I learned a few things after the first). Both were built using 3/4 MDF. Both fit flush underneath the seat. Another problem I ran into was the mounting depth of the sub. I used 10" Kicker Comp VR's in my application. They sounded pretty good. Good luck.

 

[slowfive0 10+ year member]

Hey guys,

Per my previous replies, I screwed up on my initial measurements (actually math-LOL). I only have about .81 cu/ft to 1.05 cu/ft per speaker to work with. Depends on if I want to raise my seat.

Based off of that, I'm assuming that I can only do a sealed box design???? I would like to do a ported if possible though. Appreciate any feedback---Thanks!

 

[tRiGgEr 5,000+ posts]

Stop posting the same thing over and over

You can only run a sealed box with that space. And 1.5" of clearance will be enough.

 

[slowfive0 10+ year member]

LOL! I just did that because I forgot to include the space for the speaker clearance in my last post! Too much in a hurry.

So sealed it is!

What air space should I shoot for as I can't find any specs for these speakers? Thanks.

Stop posting the same thing over and over
You can only run a sealed box with that space. And 1.5" of clearance will be enough.

 

[tRiGgEr 5,000+ posts]

Use the maximum space you can attain. .75-1.25. The speakers are so old I would not be able to find the T/S specs to determine sealed box size...

You can always decrease the volume with solid objects. Increasing it after it's built would be much harder.