What's the difference between a crossover and filters? (update: bought HU)

[psteng19]

still having problems picking out an amp.
first off, is there a difference between HPF/LPF (filters) and crossovers?

if the head unit has HPF/LPF, do i need crossover/filters?

finally, is there a way i can hook up an amp to a crappy stock system?

got my sub and enclosure, too poor to afford a nice HU, so plan to run stock HU with amp and sub.

UPDATE: just bought a Pioneer DEH-P7300 CD Receiver for $260 on egay.

 

[Spoooon]

HP/LP filter on an amp is the same thing as a HP/LP filter on a crossover. A crossover will give you more flexibility in general.

You don't "need" a HP/LP filter, but all amps will have some kind of built in filter. If the amp has speaker level inputs, then yes. Otherwise, you'll need either some kind of speaker/RCA type converter or an aftermarket headunit with pre-outs.

 

[psteng19]

k, thanks spooon for helping me in my times of car audio distress.

 

[ArkAoss]

what is a pre out?

 

[psteng19]

i'm not sure, so don't quote me on this.
a pre-out is the output jacks located in the back of the head unit. they are to be plug into the input of the amp or EQ...?

 

[John]

<< i'm not sure, so don't quote me on this.
a pre-out is the output jacks located in the back of the head unit. they are to be plug into the input of the amp or EQ...? >>



Yep, RCA outs.

 

[Spoooon]

Does your amp have speaker level inputs? Which amp did you get btw?

 

[psteng19]

spooon, didn't get an amp yet. i'm looking very hard for one that fits my budget and will drive stock speakers/HU and a 10&quot; 120 watt RMS sub.

any recommendations?

btw, it's a 1995 Nissan Sentra stock system with Kenwood sub.
wut will i need, in terms of wattage, channels, etc?

 

[RossGr]

I am not into high tech auto audio but it seems there are some terms used without definiton here.
HPF = High pass Filter
LPF = Low pass Filer
Pre out = Preamplifier output.

A high pass filter Blocks the low frequencies contained in the main signal, use this to pass info to your midrange and tweeters

A low pass filter blocks the high frequency content, use this to feed signal to your woofer.

The HPF and LPF should have specs which tell you what the roll off frequency is, this is the point at which the attenuation becomes effective. Be sure the roll offs of your filters match the ability of your speakers.

The pre out signal is an UNAMPLIFIED signal which can be fed to the imput of an amplifer. Generaly the pre out will be uneffected by any volumn control.

If this is common knowledge amongst the audiophils pardon me for speaking the obvious.

 

[ArkAoss]

no prob, man, not an audiophile.
I know electronic's and built those type's of circuit's for projects in shop, but can't remember too well how to, thinking of going back to school to relearn it.

 

[Spoooon]

Good bargain brand: US Acoustics.

What woofer did you choose? Also, how many speakers do you have in your car?

edit: Remember, if you buy from Crutchfield and spend over $100, you can pay in 4 payments. It might be worth spending a little more to get that kind of flexibility.

 

[psteng19]

ok, so i won a dutch auction on egay for the Pioneer DEH-P7300 for $275 shipped, which i thought was a good price. the dude's got good ratings so i trust him/them.

i love the 3D screensavers
one of them is an F1 car racing around the track, the bird screensaver i'm not too fond of.

pioneer says that the built-in amp on the receiver is strong enough to power a small sub at low volumes (50X4 watts, 22 RMS). so i'm gonna trust what they say and skimp on the amp until i make some more cash. my cheesy sub (stupid kenwood website - it's the w2502 10&quot; 400watt max/120 watt rms sub) ain't too powerful anyway, so i'm not gonna try to turn anything up.

spooon - gonna run the 4 stock speakers for now - dunno about the power ratings on those but i know they suck. i bookmarked that link to SoundDomain with the amps. they look very good for the price. Thanks

 

[locker22]

btw...filters are usually not powered...they encur signal strenth loss. crossovers are usually powered, thus boosting signal. Also, to answer you question about hooking up an amp to a crappy stock system to an amp...yes you can...you may need line level adapters to take the speaker outs on your deck and convert them into rca's to feed to your amp...should cost about 15 a piece (need two)

 

[psteng19]

ok, thanks guys for all your help.

this will be my first car audio upgrade. kinda scared with all the wiring. i can follow the diagrams pretty much to wire up the stereo to the speakers, but i'm scared running the battery wiring and getting it to the HU and amp. don't know how i'm gonna get it thru the firewall and other worries...

wish me luck.
thanks

 

[Spoooon]

Well, most cars already have some holes in the firewall that you can use. IMO, I think it's better to pay people to do some things. I went ahead and paid to have my electrical stuff installed for me. They did the wiring from the battery to the trunk, fuses, power block, etc. I paid for parts and maybe 25-30 bucks labor. Definitily worth it. The headunit should be easier than you think. Good luck!