What kind of amp for tri amp-ing?

[george graves]

So here's my planned (for now) set up.

Rear deck speakers driven off the headunit. Sub with it's own amp. Components in front driven off of.....???

I need an amp for the front components. I assume I can drive them individually straight off the amp if I'm using an amp with a crossover built in right? (So I don't have to find a place for those passive crossovers? Right?)

What should I be looking for in an amp? 4 channel of course, but what range of crossover points? I assume I need to block the low bass as well?

Help!

[StereoInstaller1]

George, very few amps come with high enough crossover points to do that. You need to be able to do 4.5Khz, typically.

You could source an outboard crossover that will do that, of course, or get a deck that has "3 way" mode.

[george graves]

Poopie. Deck is a Alpine 7894.

So for tri-amp, you need a active crossover? Or is there another way to do this. I know I'm missing something simple.

What's the other name for "tri-amp" - google doesn't bring up much.

[StereoInstaller1]

Generally, "Bi-amp" is considered a 2 way system, with a low pass and a high pass. Three way active crossovers have a low pass, a "band pass" (basically a high pass and a low pass on a single output) and a high pass, thus "tri-amped"

[george graves]

So you loose quite a bit with the passive crossovers then. Can you even fit them up front? Or do you usually put them in the trunk?

[StereoInstaller1]

Generally I put crossovers in the trunk for looks more than performance. Passive crossovers can also incorporate "Zobel Correction" to compensate for impedance curves causing non-linear load to the amps.

[Wh33lhop]

Correct me if I'm wrong but generally if you nix the crossovers and amplify components separately they just call it "running active."

[StereoInstaller1]

Correct me if I'm wrong but generally if you nix the crossovers and amplify components separately they just call it "running active."

Nope. Many names for the same thing. I keep the passive crossovers in mine for the zobel networks they have.

[Erik j]

I will sell you my JBL GTX47 active xover. It has plugs/adjustments to make 4 channels into 14 channels (3-way front, 3-way rear and a subwoofer)

[zshopa]

why do you need a 4 channel amp if you are only running 2 components off of it? not tryin to be rude i think im missing something,

[Erik j]

4 channel amp will run 2 tweeters, and 2 woofers. That way you can adjust the gain per set of speakers.

[zshopa]

2 tweeters and 2 midwoofers? 1 set of component speakers?

[Erik j]

Yes.

you have a 4 channel amp
Channels
1=R tweeter
2=L tweeter
3=R woofer
4=L woofer.

With that I can turn the woofers up or down independent of the tweeters. This will allow you fine tune the sound in the car better. The item I offered up (JBL GTX47) does the same thing, but has a powered crossover in it so you can adjust the frequency cutoffs.

[zshopa]

ive always just used a crossover with an adjustment, tweeters hooked up directly to the amp justsounds scary to me

The GTX47 sounds like the way to go

good luck wit the install, and take pics!

[Erik j]

GTX47