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Help! Suggestions for a "Possible" Setup!

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Old 04-03-2007, 11:45 PM
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Default Help! Suggestions for a "Possible" Setup!

Hey guys. First off, I don't know much about systems and audio stuff and I prematurely purchased a set of DUB200 12" Subwoofers for cheap on eBay. I know, I know. I'm pretty sure these are crap but nevertheless, I wish to hook one sub up. Here is what I was proposing:

DUB200 12" Sub
500 RMS
900 RMS

Kenwood Kac-8152D Mono Amp
300 Watts @ 4 Ohms
550 Watts @ 2 Ohms
1,100 Watts Peak

Help me out here! Thanx!
Old 04-04-2007, 12:31 AM
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Just to make sure I understand - you only want to hook up ONE sub, correct?

Also -- I noticed you posted two RMS ratings for the subs....did you mean for the second one to be peak power? The specs I find for those DUB200 12" are 400W-RMS and 800W peak..

Kenwood makes nice amps, and 550 @ 2 ohms (that's what you would power them at, right? I think those subs are only DVC 4 ohm...but not sure) would give you nice 'headroom' for powering your sub -- definitely can't go wrong with that amp, IMO.
Old 04-04-2007, 04:21 PM
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Thanx bro!

Yea, that's how messed up these subs are. I purchased them thinking it was 400/800, and it does say that on both sides of the box BUT on one side it says 500 RMS and 900 Peak! No Joke!

I bought these about a year ago with the intentions of hooking up 2 subs, but right now I'd rather just have a lil 'thump n' bump rather than all show. So right now, I'm just going to hook up one subwoofer.

Thanx again.
Old 04-04-2007, 05:18 PM
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Ok, from this site:http://www.sonicelectronix.com/item_...udiobahn.html#, I've got the following:

12" Performer subwoofer
Chrome basket
Subwoofer grill included
Carbon glass fiber cone
EPDM rubber surround
2" Dual 4 ohm voice coil
2 ohm or 8 ohm operation
Multi-connect lug lock terminals
RMS power handling: 400 watts
Frequency response: 20Hz - 500Hz
Efficiency: 92.7dB
Mounting dpeth: 6-3/8"
Hole cutout: 10-7/8"
Outer diameter: 12-1/8"

Subwoofer Specifications:

Subwoofer Size 12"
Dual Voice Coil Yes
Impedance 4 ohms
Peak Power Handling 800 watts approx.
RMS Power Handling 400 watts
Woofer Surround EPDM Rubber
Woofer Composition N/A
Sealed Box Volume 0.75 - 1.5 cubic ft.
Ported Box Volume 1.2 - 3.1 cubic ft.
Sensitivity 92.7dB
Frequency Response 20Hz - 500Hz
Xmax (millimeters) N/A
Top Mount Depth 6-3/8"
Cutout Diameter 12" round

So from this information and considering I know jack sh*t about amps and subwoofers, how do I hook this up? If the sub is 4 ohms, does this mean with the kenwood amp it would only be pushing 300 watts? or can still possible to run this at 2 ohms for the 550 bump?

I will be making the subwoofer box myself, given the volumes, is there a formula to use to figure out how big I need the box cut out to?

Thanx again!
Old 04-04-2007, 06:13 PM
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That Kenwood should have 2 sets of connections on there. So hooking up that sub will be pretty easy. You just hook up both positives and both negatives and the amp will run at 2 ohms, so the sub will get 550 watts with the gain turned up.

You want to go sealed or ported? Sealed is easier to make. You don't really need any figures on sealed, just make a box as big as you want that will fit in your trunk. That sub has some very broad recommendations for box size anyway.
Old 04-04-2007, 06:44 PM
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Originally Posted by 95bat
You don't really need any figures on sealed, just make a box as big as you want that will fit in your trunk.
I always try to stay within specs. The size of a box can dramatically alter SQ, performance, and maybe even the life of the sub. If he just makes a box as big as he wants and ends up with huge box, he may lose some clarity and tighter definition in the subs response and instead have a more "boomy", messier sound.

As for making the box - just measure/draw out your dimensions and calculate the volume in the box in cubic inches, then convert to cubic feet. There are many sites that I have seen calculators you just plug in certain widths you want, etc. and it shoots out a volume then you would just make the box according to those specs. However -- most of those calculators don't account for the width of the MDF (which you will want to be 3/4") so make sure you take that into account to find the internal volume. If my computer didnt crash recently, I would link you to the better calculator.

As for power - yes, you can get the total sub impedance at 2 ohms because they are DVC subs (so you have 2 voice coils, each voice coil with an impedance of 4 ohms). Wiring like impedances in parallel cuts the impedance in half to 2 ohms. You wouldn't put all 550wRMS through the sub, but you wouldn't need the gain on the amp set as high which results in a cleaner signal to your sub rather than everything maxed out to push it at 300wRMS.

95bat mentioned how you would wire so the amp would "see" 2 ohms, but in case it wasn't clear -- here is a picture:

Old 04-04-2007, 08:10 PM
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Thanx alot!!!!!! I really appreciate it. I got clearer and better answers here than I did at circuit city and best buy where one guy seemed to worry about his hair than my questions.
Old 04-04-2007, 08:30 PM
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Haha!! He was more worried about his hair because he knew more about that then car audio!! LMAO!!!
Old 04-04-2007, 08:30 PM
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Originally Posted by fredmr39
I always try to stay within specs. The size of a box can dramatically alter SQ, performance, and maybe even the life of the sub. If he just makes a box as big as he wants and ends up with huge box, he may lose some clarity and tighter definition in the subs response and instead have a more "boomy", messier sound.

As for making the box - just measure/draw out your dimensions and calculate the volume in the box in cubic inches, then convert to cubic feet. There are many sites that I have seen calculators you just plug in certain widths you want, etc. and it shoots out a volume then you would just make the box according to those specs. However -- most of those calculators don't account for the width of the MDF (which you will want to be 3/4") so make sure you take that into account to find the internal volume. If my computer didnt crash recently, I would link you to the better calculator.

As for power - yes, you can get the total sub impedance at 2 ohms because they are DVC subs (so you have 2 voice coils, each voice coil with an impedance of 4 ohms). Wiring like impedances in parallel cuts the impedance in half to 2 ohms. You wouldn't put all 550wRMS through the sub, but you wouldn't need the gain on the amp set as high which results in a cleaner signal to your sub rather than everything maxed out to push it at 300wRMS.

95bat mentioned how you would wire so the amp would "see" 2 ohms, but in case it wasn't clear -- here is a picture:

Yeah, I agree about the box, but the specs were .75 - 1.5 cubic feet. Whatever box he builds will be pretty close to those specs, since they're so generic.

Those Kenwood amps have dual connections, so he can run independent wires from each coil to the amp, kind of like a 2 channel amp, and the amp will operate at 2 ohms. It is a nice little feature on the Kenwoods.




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