3 preouts...but why???

[Big-Cat 10+ year member]

ok, i'm gonna be getting a system with in the next 3 weeks. I've got my subs picked out, my amp picked out, and everything accept for my hu. I'm getting 15's, and i figure it'll drown out the mids-highs and i'm gonna get some 6x9's later, when i get the money. But, i've been told by local places around here that i need a hu with 3 preouts. Isn't the preout for the speakers?? So i figured that if i only get 6x9's for my back, the subs then i'd be set, as far as an amp goes.... So why do i need the 3 preouts?? i mean...i want a deck with a mp3 player because it'll save a ton of money on CD's for me, and i also want the 3 preouts because i was told i need them by a lot of people. But if i can save like 100 or so bucks on the 3rd preout and just get 2, for my 6x9's and my subs...then wouldn't that work? //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

-Big-Cat

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[MikeofTulsa Moderator]

well the pre outs are for an external amp....basicly you would need 2 sets of preouts per amp...so 3 pre outs would have 6 outputs for your rca cables....but techinacly all you need is one set because you can jus get a y adapter for any extras you need.....so the 3 pre outs would be for convience only....good luck...

 

[Nolesman 10+ year member]

Goddyd4me is correct. Simplicity is devine. However 3 outputs arent necessary just depends on how bad you wanna fade. My system is set up so as soon as I can afford a new HU and get 3 outputs I can hook them up. In the meantime I have 2 outputs on my HU and I am surviving. I just have to use one output to fade speakers and one to fade my sub. Really its not a big deal once you set your gains correctly on your amp anyway.

 

[syntekz 10+ year member]

I was under the impression that each pre-out was for one amp. So if you had 3 pre-outs you could hook 3 amps to the head unit.

 

[MikeofTulsa Moderator]

it takes a pair....so one preout(which would be a pair of connectors) should have a left and a right output so a h/u w/ 3 preouts should have a total of six outputs

 

[Big-Cat 10+ year member]

so i was correct. I only need two preouts if i'm just going to get 6x9's and my subs. Because i'll have an amp for the subs, and an amp for the 6x9's. so it would be ok if i got a 2 preout deck, and only got some 6x9's for the back and some subs. This would work fine, right?

 

[MikeofTulsa Moderator]

correct...if your just wanting to run two amps all you need is two sets of preamps

 

[maylar 10+ year member]

The preouts are for driving external amps. One pair for fronts, one for rears, and if the deck has a 3rd pair you use it for subs. Decks with the 3rd set usually have equalization settings to provide adjustable lowpass (bass only) for the sub amp. If a deck only has 2 sets you tee into the rear preouts to feed both the rear speaker amp and the sub. Only down side is it limits your ability to fade front-rear without also affecting the subs. But as others have mentioned, you can compensate for that by setting amp gains.

 

[Si-R 10+ year member]

Originally posted by Goddyd4me well the pre outs are for an external amp....basicly you would need 2 sets of preouts per amp...so 3 pre outs would have 6 outputs for your rca cables....but techinacly all you need is one set because you can jus get a y adapter for any extras you need.....so the 3 pre outs would be for convience only....good luck...

You learn' somethin' new everyday

 

[beastyle 10+ year member]

technically you already have two connection lines their just not both rca //content.invisioncic.com/y282845/emoticons/cool.gif.3bcaf8f141236c00f8044d07150e34f7.gif

In the past i had a problem with the rca port on the radio, it gave a whistling sound all the time, i filtered it out with a ground signal loop but the effect was that my woofer (wuz sub in box with amp in box also) got no decent signal any more.

The solution for me was to only use the rca port from my HU to the external amp with the filter in between and to feed the subbox through the rearspeaker out of the HU which worked great and as far as it was hearable (bit harsch to compare with bass only) it sounded the same as the rca.

I agree with the settlement: "3 ports is for convencience and is luxury"

If i was you i would invest the spared money in some fancy design //content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif

 

[99DX 10+ year member]

I was under the impression that you need 1 set of pre outs for a 2 channel amp

and 2 sets of preouts for a 4 channel amp

system example

front po 4ch front speakers

rear po 4ch rear speakers

nonfade sub po to 2 chan/1mono sub amp

= ability to fade front and rear and control the sub from the deck to a certain extent.

am I wrong or just saying in plain english what was already said?

 

[jellydime 10+ year member]

This is true, 4 channel amps require 2 sets of rca inputs. Just think of it as single channels rather than sets...you need one wire per channel, so if you have a 2 channel amp, it will take two wires (one set)...if it is a 4 channel amp, it will take 4 wires (2 sets).

There is no reason for you to need 3 sets of preouts for your existing stereo, and even if you did want to upgrade and you wanted more versatility, you're better off getting a seperate equalizer/crossover...most of those have 2 sets of inputs that you can hook from your headunit, and 3 sets of outputs (typically 2 full range sets and a seperate subwoofer output with a seperate level control *nice*)

Keep it loud!

JELLYDIME

 

[flareside]

The latest amps have "pass-thru" capability so you can use just one pair of outputs (left, right RCA) and daisey chain multiple amps. Most amps also have selectable crossovers built-in. As long as you don't plan to fade, this is a good option, less routing of patch cords, less chance of noise from all the extra cables.

 

[dr. no 10+ year member]

Just splurge and get a decent head unit. I think the vast majority of good decks have three preouts. I thinks I't s nice to have a dedicated sub out.