silly question

technobass

some head units have front, rear, and sub pre-outs and some just have a pre out....if i have a head unit that just has a single preout will that output work for subs?

Jstas

If you have a single pre-out, it's full range.

Most head units with 2 or 3 sets of pre-amps will have controlled pre-amps.

2 sets of pre-amps will typically be a front and rear full-range set. The 3rd set that you have see for subs usually runs through an internal cross-over that can be limited variably to play between 200-0 Hz, what a subwoofer usually plays in.

PoweredByDodge

... and it'll work just be sure u're amp has a crossover on it... if it doesn't, get a harrison labs F-mod crossover @ 70 or 100 hertz... they're the size of half of a cigarette and htey plug in between the RCA line and teh amp... they do the x-over-ing for you... 30 bucks a set... www.crutchfield.com

Jstas

Yeah but for 30 bucks, you can also get this:


Profile QX-8 Sub X-over

It has both high and low level inputs and is variable from like 80 Hz to 120 Hz and has a bass boost that boost across the frequency range at about 6 decibels, plus or minus.

I have one when they had it as a California Series. The only issues I have had with it was the first one I got was a bum unit. I exchanged it after arguing with the tech at Crutchfield about how to wire a cross-over. Seems the tech thought he knew more about how to wire Profile's crossover than Profile did. Profile even told me it was most likely a bad unit and to get it exchanged.

Anyway, it's a good unit. It's an active cross-over so it needs power but piggy backing it off of the amp power and ground leads will work fine. I know most people think Profile blows goats and well, compared to alot of other stuff out there, it does. However, 400 watts for 150 bucks to power a sub is a pretty good deal. I was running 2 8 inch Kenwood subs with a Profile California Series stereo amp. 200wx2 and it was more than enough to shake the cars next to the truck it was in. Cheap and reliable, not necessarily teh cleanest but a good bargain. Light years ahead of Jensen too which is about your only other viable alternative in that price range. But that little bitty cross-over is a good unit and defintly worth the 30 bucks over the RCA in-line jobbies.

PoweredByDodge

i never saw that little jobber before... nice to know somebody makes something like that tha'ts affordable -- the fosgate similar version is like $150 bucks and does less stuff (no boost).

oh u do have to love the crutchfield tech guys.... one or two are really on top of stuff (Ringo), but most of the other ones cant wipe their ****$ without a user guide.