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Discussion Starter #1
I've read on the review section that the Seas G18RNX/P is a pretty solid driver and I think this is what I'm going with. It will be mounted in the doors of a supercab F-150. I've already sealed off the doors with about 3 layers of b-quiet extreme so all I'll have to do is build the mounting bracket to fit the stock holes. My question is, I don't know what pair of tweeters or crossovers to get.

Another thing, the amplifier that I have is a Kicker 800.4 so I can wire it either 100X4 @ 4 ohm 200X4 @ 2 ohm, or 400X2 @ 4 ohm. Would this amplifier be a good combo for what I want to do?
 

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Well it looks like I get to be the first to say that the LPG25nfa tweeter plays well with the SEAS drivers. Also, looks like you should use either the xover in your head unit or get an active type setup. You might be able to use your amp's filters if it has the ability to do HP,LP, and a subsonic setting. You can bandpass the drivers with the LP and subsonic and use the channel with the HP for the tweets. Depends though cause not all HP filters can be set wit 1.5khz. Most of the DIY speakers are 8 ohm, but your amp will still run these fine. The driver could use more power, but you can achieve sufficient results with 50 watts.
 

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Discussion Starter #3
My amp only goes up to about 200hz on the filters. I can run active with my headunit to filter out below 50,80, or 125 hz but that's about all it can do. Wiring this stuff up is kind of a mystery to me because I'm not sure what to do. Am I supposed to run the front 2 channels for the tweeters and the back two channels for the mids? Or should I use a passive crossover and bridge the front two channels for 1 mid and 1 tweeter, and do the same for the back channels?
 

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You can get some premade passive xover units from www.partsexpress.com. Just choose some with the frequency points you need to match your speakers. Then you can wire the 4 channel amp you have, bridge it down to 2 channels then just run your R side to channels 1-2 (bridged) and the L side to 3-4 (also bridged). Make sure you connect your RCAs accordingly to match the L and R sides.
 

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Discussion Starter #7
So bridging the channels on the amp won't give it too much power? I take it as well that the LPG tweets are 8 ohm. Also, those crossovers on PE seem pretty expensive, is there anything else out there that's cheaper?
 

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andrewbr500 said:
So bridging the channels on the amp won't give it too much power? I take it as well that the LPG tweets are 8 ohm. Also, those crossovers on PE seem pretty expensive, is there anything else out there that's cheaper?
No bridging the channels wont supply too much, as the SEAS will soak most of that up. What xovers are you looking at on PE? The 2 ways xover unit I am looking at in my catalog right now is only $19.95 (Dayton Audio PN260-140) or the cheaper version, the PE brand $16.90 (PN 260-198). Both are listed on page 139 of the 2005 catalog. They are pretty inexpensive if you ask me. Anywho...if you want you can try and find a passive xover, the Audio Control 2xs unit, you will need 2 of them, I got one off of Ebay for $25 earlier in the year, but lately they seem to going to over $40 or so.
 

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Discussion Starter #11
I have a Pioneer Premier DEH-P750.

As far as the crossovers I was looking at the wrong ones. The ones I saw were $60 a piece. The part numbers you posted are much better on the price. The ones I saw were the selenium ones that costed $65 a piece. On the description on the one you posted it says it's used for an 8 ohm hipass so I'm just making sure that the LPG25nfa is 8ohm.
 

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andrewbr500 said:
So bridging the channels on the amp won't give it too much power? I take it as well that the LPG tweets are 8 ohm. Also, those crossovers on PE seem pretty expensive, is there anything else out there that's cheaper?
I'd be careful putting 400w into a passive crossover. Some are built to handle that much power but others will just melt. Make sure you know the power handling spec of the crossover itself before you buy.

That being said, why not go active?

TT
 

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Why would you have the crossover wired to 8 ohms? The crossover can be wired to show the amp a 4 ohm load even though the drivers are different impedences. You just have to specify what your drivers' loads are to the crossover designer.

In case you don't fully understand, the amp will only see the impedence of what it is directly connected to. In the case of a passive crossover that would be the impedence of the crossover. In an active system the crossover is placed before the amplifier and the amp is running directly into the speaker. In this case the amp is seeing whatever the impedence of the driver is.
 

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Discussion Starter #15
Ah, ok that makes sense. I don't know much about crossovers so I'm still learning. So how do I adjust what ohm load the crossover is? I think I'm getting more and more lost.
 

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No idea how to adjust them. It would have to do with the capacitors that are used. We've reached the limit of my electrical knowledge.

TT
 

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I would look into a decent Audiocontrol electronic crossover for the mids and highs. Or upgrade to a Pioneer DEH-P860MP or Eclipse 8445 or 8053 or similar with a 3 way crossover.
 

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andrewbr500 said:
Ah, ok that makes sense. I don't know much about crossovers so I'm still learning. So how do I adjust what ohm load the crossover is? I think I'm getting more and more lost.
If my passive xOver building experience serves me right... the amp will see the impedance of the lowpassed driver... all high passed drivers in the network wont affect the final load the amp sees.

So in a 2 way network... if you have a 8ohm mid\bass driver, the amp will see an 8ohm load.

In a 3 way network... if the midbass driver is 4ohms, the amp will see a 4ohm load...

Someone correct me if wrong I am too lazy to look over my docs... but I feel pretty certain that is the way it works.
 

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Discussion Starter #20
I'm beginning to think that going active will be much easier. I've been looking around and I see the Soundstream MPQ-5X0 at a pretty good price. Would that be a good unit to use? If not, I think my objectives on what I want to do are pretty clear and if someone could suggest something else I'd welcome your comments.
 
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