I have a cavalier 2 door. I'm thinkin' that I will use .5 inch plexi glass for the baffel for the 18". My trunk will have the two twelves on either side of the trunk sealed and the 18" pointing into the trunk. My amp rack will be in the middle of the trunk under .5 inch plexi 4 amps in total with 2 crossovers 1 3way and 1 2way. I really would have liked my 18 to be in a sealed box because "free air" is not always the best way but I don't have the trunk space to do that with the 2 twelves. So I'm going for look and LOUD. Will what I am thinking of doing going to work?

The reason I was pointing my 18' in is so the negative frequency of the 18" doesn't cancel out the 12's. The 18" will be set at 60 hrz and below, and the 12's up to 120 hrz. (I wish I had 2 tens instead) Then I will be running my 6.5" polk momo component driver in the rear deck for mid base. In the front doors I am going to run a set of Polk MOMO 6.5 component driver and 5.25 coaxial and the Polk MOMO tweeters will be in the upper dash piece for a little bigger sound stage.

My amps are coustic amps (made by MTX) a 1600db 800rms for the 18", a 1200s 600 rms @ 2 ohm for the 2 12's, a 1200s 300 rms stereo for the front Polk Component set and finally a 600s 150 RMS for the 5.25 and the rear drivers.

Will this work????????????????? Oh Ya the 18's and the 12's are Audiobahn

 

Accually Guys I did really want some sort of Idea if this plan is going to work and sound OK. I may not hit in the 150's but I hope to hit in the 140's.
Let me know if this is a good idea or if I should go try anouther idea. I have all th stuff but really need some input.
Thanks
Bill

 

.5" plexi for a 18" baffel????... sure its only an audiobuan, but still. id use doubled 3/4" MDF if I was you.

 

if I was you I would just use the 12"s and use one 1200s amp for each sub in a properly made box. then the 600s for the fronts and just use deck power for the rears. IMO probly sound better then all that other mumbo jumbo.

 

Well, it's going to be loud....

I think you're using too many drivers in this setup.....having the 18" and the 12" sharing the 60hz and lower freq. may cause some cancellation and reinforcement that may make the bass "muddy". The 6.5" drivers in the rear should be used for "fill" as opposed to midbass. Ideally, dedicated mid-bass drivers should be up front so they have the most impact where you are sitting, instead of dragging the soundstage to the rear.

Does the 3way Xover have the option to "passband" the mid or rear output?? If not, you may be able to use the 2 Xovers in series to create a true midbass channel.

Without knowing much about the Polk speakers, I would suggest the following if you can get that "passband" output :

1: In the front, use the tweeters from the 6.5" set and the 5.25", as your midrange and higher freq. Use the 6.5" driver from the component sets up front as midbass drivers.

2: In the rear, you can still use the other set of 6.5"s, but just for some rear fill...how much depends on your ears, not mine....

3: You should have the midbass configured as suggested above, if you really want to use the 18". They're generally not very good above 60 or 70hz or so, and they need the help from the smaller drivers. If you use the 12"s instead, it may cost you some very low notes, but the upper bass will sound better.

These are generalizations, and the details of how to wire this up will depend on getting more info about the equipment you have.

HTH

 

The crossover does have a bandpass switch and rear input. My Eclipse Deck has 3 5.5v outputs and the crossover has 3 separate inputs and outsputs. I would like to run the rears really for fillers. What would be the best freq. to run for the front then? I do have the drivers so really I can do almost anything. I do want the 18" because of the looks and I would like to run it for the low notes. I really wish I had 2 10's instead of twelves for the setup but I already have the 2 12's and money is getting tight. I still need to get a yellow top for my set up yet too. Can I change the freq. for the 12's to not run below 60hrz?

 

i would go for the 2 x 12;s or a single 18 the lows will be very devastating but for all around music the 12's will be alot better

 

Well that's kind of why I went with the Polk Momo speakers because they are very good musically. If I can get my hands on a pair of 10's would that be better?? I could try to trade someone for a pair of 10's or sell mine the buy some.

I thought by facing the 18" into the trunk and the 2 12's facing into the trunk that it would creat a bigger sound pressure. Would that be the case?