Contour Enthusiasts Group Archives Forums Modifications Audio local retailer has 12w6 subs, buy 2 get one free, and free box.. should I go for it?

I can get 3 brand new 12w6's in a 3chamber box (I measured this box and it fits in the trunk behind the back seat like a glove) for 600 bucks, is that a good deal? I was thinking of running these with a JBL 1200 watt rms mono amp that can drive a one ohm load (six 6 ohm coils in series)

opinions?

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*Rides*
-1999 Ford Contour SE Stock
-1987 Firebird Formula Dragster (not even approximately close to stock)

Go for it.. Good deal. I would buy it. Good choice for power, too.

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98.5 Contour-Zetec w/ auto (doh!!)-modified stock airbox
res and muffler removed glasspack added-Knauberized
Pioneer CD-Alpine speakers in all doors-2 pioneer 10" subs
mesh grille-side markers

Hell yea, that's a good price, and you would have a killer set up.

It seems like a good deal. Run those speakers in parallel for a 1 ohm load. If you run in series you'll end up with a 36 ohm load...:-)

First, what kind of material is the box made out of...ask if it's MDF. (Medium Density Fiberboard) If it's just particle board don't buy it. It'll break up with all that SPL over time. You can tell the dif between the two, MDF wood is very fine, it's basically just glued together sawdust with extreme pressure and heat. Particle board on the other hand is grainy, you'll be able to pick out each small chip of wood. It should be at least 3/4" thick...this is a must!!!!!! Anything smaller, leave it, MDF or not...although it's highly unlikely to find MDF less than 3/4".

Second, run your 12w6's in a series/parallel combination for a 4 ohm load. jlaudio.com gives you a diagram how to do it, it's actually really simple. Basically there are 2 voice coils on the w6's, one set of pos/neg connections on each side of the speaker. On each speaker connect one + to a - on the other side of the speaker...do this on all three. Now you should have a + and a - open on both sides of the speaker. Now connect all three's speakers positives together in parallel and all the negatives the same and you'll have 2 wires at the end. The speakers are designed to be used this way, they have 2 leads on each + and -. Read them out with a meter and you'll get 4 ohms. (3.94 actually, close enough)
I run my 3 12w6's the same way with 1000 watts mono and end up with 156db!! (of course, I built my box with type B bracing and a double face with Tube Driver Amplifiers)

Don't forget to use damping inside the box. use a whole bag of polyfil...you can get it at any fabric store, costs about 3 bucks.

Christian

the box is 3/4" mdf, built to JL specs for 12w6 subs. The amp I want will put out 1200 watts at 1 ohm, the subs have better sensitivity with the coils in parallel (don't know why) that same amp will only put out 600 watts at 4 ohms, why the hell would I want 4 ohms?

If the amp is 1 ohm stable in mono mode, I say go for it. Sometimes the reliability factor will hurt you a little so give it a try, it can't hurt.

The sensitivity issue can get a little tricky because you are dealing with dB which are based on a logarithmic scale. If you double your amplifier power, you raise your SPL by 3dB, which is noticeable to some but not be everybody. In order to double your sound output, you need to 10x your amplifier power. 100w x 10=1000w to be twice as loud.

The other way you can add dBs to your vehicle is by adding cone area. Everytime you double your cone area you add three dB of sound.

So adding another sub will give you the same result as doubling the power to 1 sub, with a few advantages, lower distortion because the cone is not required to move as far, and lower power requirements. The disadvantages are needing twice the box size.

On a DVC sub, the measurements are usually taken with the VC wired in parallel. This will give you the highest sensitivity because you are lowering the resistance on the amp. On a 10w6 you would get the following...

VC in series 12ohms=not a lot of power from your amp
VCs in parallel=ideally 4 times the amplifier output.

So, you end up with a 6db increase in sensitivity because you are quadrupling the amplifier output.

Does this make sense?

yeah, I'm trying to remember what I was reading it was for some other dvc sub, it was rated at like 84db 1w/1m in series and 87db 1w/1m in parallel..