really need help for amp h/u
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=38253
Printed Date: May 11, 2024 at 11:45 PM
Topic: really need help for amp h/u
Posted By: merl
Subject: really need help for amp h/u
Date Posted: August 28, 2004 at 8:55 PM
can i run two 8 ohm 10"subs with two 4 ohm 12" subs on a 4 channel amp? well, this is what i have, a two-channel amp ppi crutchfield amp which is 2x75 @4ohms, 150x2 @ 2ohms, and 300x1@ 4 ohms. also, the 4-channel ppi red rocker amp which is 75x4 @ 4 ohms, 125x4 @ 2 ohms, and 200x2 @ 4 ohms. the two-channel amp has the factory sticker-label stating the bridge wiring. also i'm running components/seperates which says theyre 4 ohms. what is the best way i can hook everything up together? can there be complications? thank you.
Replies:
Posted By: jeffchilcott
Date Posted: August 28, 2004 at 9:10 PM
first off, you need to pick one set of subs. If you try to run both your probably going to end up with less bass then with just one set. Its called crossphase.. You didnt state what kind of subs at all, that would help along with the recomended power for the subs. I would use the 2 channel for your subs, and the 4 channel for the internals, we need names of equipment though.
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Posted By: merl
Date Posted: August 28, 2004 at 11:33 PM
thanks for the response. the 10's are ppi c2's and the 12's are orion cobalts. i also have a hifonics vega viii electronic crossover, kenwood 6042a eq with a panasonic 602u. i have had a similar setup without the 10's. what i am really trying to get is mid and low bass. is that not possible? again thanks
Posted By: merl
Date Posted: August 28, 2004 at 11:35 PM
oh, it's a panasonic head unit. sorry.
Posted By: merl
Date Posted: August 28, 2004 at 11:42 PM
the components are blaupunkt cc 650. (6")
Posted By: jeffchilcott
Date Posted: August 29, 2004 at 2:08 PM
if you really really wanted to do this I would build vented boxes for the 12's and seal the 10s or vent them very high if your looking for mid from them....but I still dont recomend running 2 diffrent size subs on 2 diffrent amps. there is always problems
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2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place
Posted By: DYohn
Date Posted: August 29, 2004 at 2:22 PM
Sure you can do this. But you will need a more sophisticated crossover than that built into your head unit or amp, or a properly designed passive network. I'd suggest (depending on the speakers) that you cross your 12's below about 65Hz and cross the 8's between 65Hz and 250Hz, and cross your mains with a high-pass at 250 Hz. The disadvantage to this kind of scheme is the 8's will need to be run in stereo and placed properly, since frequencies above 80Hz (approx) are directional and you will need to place them for proper imaging - which means in the front of the car. Unless you don't care about imaging. ------------- Support the12volt.com
Posted By: merl
Date Posted: August 30, 2004 at 12:56 PM
hey thanks guys! oh, hey DYohn, the 8's are actually 10's. where would i set them @? and is still considered mid-bass? the crossover i'm running is a hifonics(older model). can these coexist without complications? jeffchilcott, how about the 4-channel amp? but again, the 10's are 8 ohms and the 12's are 4 ohms... do you guys think any of these'll conflict? or is there a way? i did'nt know about any of this stuff. back in the late 80's- early 90's, all i knew was deck, eq, amp, speakers and subwoofers. i did'nt know about ohms and bridge. so, in other words, i'm lost. if i can utilize all this stuff, can it work? i really appreciate all your help. thanks!
Posted By: stevdart
Date Posted: August 30, 2004 at 7:14 PM
I would leave the 8 ohm speakers out of the setup. You should get your midbass with the 6" drivers, from 80 Hz and above. Use the 12" subs for sub freqs 80 Hz and below. Bridge the subs to the 4 channel amp for 2 X 200 watts @ 4 ohms. And use the two channel amp for the pair of components. You'll get the best sound with what you've got to work with. If you want to add additional midbass drivers in the future for the front soundstage, look at 4 ohm drivers. Use the 8 ohm subs in the home.
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Posted By: jeffchilcott
Date Posted: August 30, 2004 at 9:33 PM
The olny way I see this even kinda working is facing the 10s forward with a higher tuning freq like 80-120hz..on 2 channels bridged. And the 12 facing rear ported to about 32 and the cutoff on the amp at 50. This might work but every vehicle is diff and you might get crossphase
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2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place
Posted By: merl
Date Posted: August 30, 2004 at 10:44 PM
i really do appreciate it. i will attempt and get back to you guys...
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