Connecting 2 amps to one Pre-Out

Phat beats and out-of-luck crooks. Again, read the Disclaimer first.

Moderator: The Mod Squad

Connecting 2 amps to one Pre-Out

Postby skoty » Sun Aug 03, 2008 4:27 pm

Already done a search. Anyway got a sony explode headunit with one sub pre-out. I'm running a fusion monoblock to power a 10" DVC soundstream sub. I would like another 2 channel amp to run my rear components. My fusion amp has an 'output' on it next to the RCA input. Can I run a secondary amp from there even though its being run from the one sub pre-out? Also can I run the power feeds directly from the first amp?
Profile - Cars Owned - AE82 Corolla GT / Corolla Dirt Track Car / N14 Pulsar GTI / S14 Silvia Qs / Nissan Van / Nissan Avenir GT

Current cars - Altezza RS200 and Mitsi Lancer GSR
User avatar
skoty
Toyspeed Member
 
Posts: 1557
Joined: Sat Dec 28, 2002 10:33 am
Location: Auckland

Postby Rumad » Sun Aug 03, 2008 4:46 pm

Yes to the first. Can just piggyback the rca's off your fusion amp (or vice versa) or just run a set of y-splitter plugs but either way will work.

To the second question: Can but highly inadvisable. as soon as your monoblock hits a big bass note it will get greedy and take every ounce of power it can and will leave your other amp starved for power (possibly driving it to 'clipping' status). So in short no, take the time to run a dedicated wire from the battery, or a distribution block close to the battery) to the new amp :)
Rumad
Toyspeed Member
 
Posts: 112
Joined: Mon Jan 26, 2004 11:42 pm
Location: Auckland

Postby scotty_ish » Sun Aug 03, 2008 7:53 pm

Rumad wrote:Yes to the first. Can just piggyback the rca's off your fusion amp (or vice versa) or just run a set of y-splitter plugs but either way will work.

To the second question: Can but highly inadvisable. as soon as your monoblock hits a big bass note it will get greedy and take every ounce of power it can and will leave your other amp starved for power (possibly driving it to 'clipping' status). So in short no, take the time to run a dedicated wire from the battery, or a distribution block close to the battery) to the new amp :)


Why distro close to the battery? As long as the primary cable is thick enough there is no reason not to distro it near the amps
User avatar
scotty_ish
Toyspeed Member
 
Posts: 165
Joined: Tue Mar 06, 2007 2:18 pm
Location: Christchurch

Postby skoty » Sun Aug 03, 2008 9:03 pm

scotty_ish wrote:
Rumad wrote:Yes to the first. Can just piggyback the rca's off your fusion amp (or vice versa) or just run a set of y-splitter plugs but either way will work.

To the second question: Can but highly inadvisable. as soon as your monoblock hits a big bass note it will get greedy and take every ounce of power it can and will leave your other amp starved for power (possibly driving it to 'clipping' status). So in short no, take the time to run a dedicated wire from the battery, or a distribution block close to the battery) to the new amp :)


Why distro close to the battery? As long as the primary cable is thick enough there is no reason not to distro it near the amps


Both the positive and negative feeds are high current 4-gauge cables
Profile - Cars Owned - AE82 Corolla GT / Corolla Dirt Track Car / N14 Pulsar GTI / S14 Silvia Qs / Nissan Van / Nissan Avenir GT

Current cars - Altezza RS200 and Mitsi Lancer GSR
User avatar
skoty
Toyspeed Member
 
Posts: 1557
Joined: Sat Dec 28, 2002 10:33 am
Location: Auckland

Postby Rumad » Sun Aug 03, 2008 10:27 pm

For the same reason you wouldnt want to piggyback off the monoblock amp (would effectively be doing the same thing)
Rumad
Toyspeed Member
 
Posts: 112
Joined: Mon Jan 26, 2004 11:42 pm
Location: Auckland

Postby Alex B » Sun Aug 03, 2008 10:33 pm

Have seen lots of installs with a decent sized wire from battery to rear distro (1 gauge etc) with no issues.
User avatar
Alex B
Toyspeed Member
 
Posts: 6539
Joined: Thu Nov 25, 2004 1:39 am
Location: London

Postby scotty_ish » Sun Aug 03, 2008 10:35 pm

:? Why even bother using a distro then? Just run two seperate runs of cable straight from the battery.
Tis easier to run a bigger cable and distro it into two smaller cables near the amps though, and much more common place
User avatar
scotty_ish
Toyspeed Member
 
Posts: 165
Joined: Tue Mar 06, 2007 2:18 pm
Location: Christchurch

Postby Rumad » Sun Aug 03, 2008 10:37 pm

yea spose
Rumad
Toyspeed Member
 
Posts: 112
Joined: Mon Jan 26, 2004 11:42 pm
Location: Auckland

Postby BigDon » Mon Aug 04, 2008 3:01 pm

Piggy back the rca out of the fusion amp just check what frequencies are being output from the Fusion throughput rcas so you can set the rear stage amp correctly. Some amps put out full range, some put out the inverse of what they are playing i.e the fusion will be lowpassed for your sub so may output frequencies up from what your low pass is set at.

Also if you run the rear stage amp off the sub amp rca if you adjust the sub output in the head unit (if your hu has it) this will effect the rear stage as well.

4 gauge should be sweet for your set up (Im assuming your less than 1000rms?). distro it as close to the amps as you can .Your rear stage amp should use way less power than the sub amp. If your lights are dipping when the bass hits its time to get a bigger battery.

I guess your already running a two channel for your front stage? Maybe consider replacing it with a 4 channel so it can run both front and rear and avoid the need for the extra cabling etc. If your running the front stage off the HU you would prob be better amping the front and running the rear of the HU
www.europeandirect.co.nz
1996 AE111 BZ-G: TRD equipped road legal Club Car (Manfeild 1.25s) (SOLD)
1995 AE111 BZ-G: Stereo and daily driver (SOLD)
2005 NZ New Evo 9 GT (specd to FQ360) daily driver
2012 NZ New Outlander VRX - V6 family wagon
User avatar
BigDon
Toyspeed Member
 
Posts: 348
Joined: Fri Nov 07, 2003 6:47 pm
Location: Wellington

Postby scotty_ish » Mon Aug 04, 2008 3:12 pm

If it was me id try and avoid the confusion with piggybacking off the fusion mono and just run rca y-spliiter cables. That is assuming the pre-out on the headunit is not low-passed, in which case you will not be able to run full-range speaker off it :(
User avatar
scotty_ish
Toyspeed Member
 
Posts: 165
Joined: Tue Mar 06, 2007 2:18 pm
Location: Christchurch

Postby BigDon » Mon Aug 04, 2008 4:07 pm

yeah but if you split the rca you split the signal voltage. Some amps can pass out the same preout voltage or higher via throughput which would be better.

Should be able to turn of any low pass on the HU anyway.
www.europeandirect.co.nz
1996 AE111 BZ-G: TRD equipped road legal Club Car (Manfeild 1.25s) (SOLD)
1995 AE111 BZ-G: Stereo and daily driver (SOLD)
2005 NZ New Evo 9 GT (specd to FQ360) daily driver
2012 NZ New Outlander VRX - V6 family wagon
User avatar
BigDon
Toyspeed Member
 
Posts: 348
Joined: Fri Nov 07, 2003 6:47 pm
Location: Wellington

Postby Stott69 » Sun Nov 09, 2008 12:09 pm

what if you had simalar set up to above but throw in a 1f cap in the mix? my battery is in the boot already, im running a sony 222 for my 6x9s, and a pyle PLA 2210 1800w to drive my kicker 10" square.
User avatar
Stott69
Toyspeed Member
 
Posts: 2605
Joined: Thu Oct 04, 2007 11:51 am
Location: Wainui Central!

Postby Emperor » Wed Nov 12, 2008 6:42 am

Yeah in regard to distro block, aslong as the cable from the battery to the boot is a good thickness (i'd personally use somethin like welding cable), the distro block will be fine at the back of the car.

As for the Cap, do all the lights in your car go dim every bass note? There's a few things that you need to thinkof before geting a cap. Basically all it does it charges itself up, so when you turn the volume up, there's heaps of power ready to use, only problem is they can cause some distortion through the speakers, so i've been told.

My 5 cents..
facebook.com/zeroclearanceswag
User avatar
Emperor
Toyspeed Member
 
Posts: 4815
Joined: Wed May 12, 2004 1:14 am
Location: Hamilton

Postby johndoe1025 » Wed Nov 12, 2008 8:54 am

spend the money where it matters and get a better head unit wth triple rca/5v preout?
EP82 GT-went mega hard for completely stock, 15.09 quarter, gone now :(

AE111 Levin BZG current! 4AGTE next? you never know....
User avatar
johndoe1025
Toyspeed Member
 
Posts: 416
Joined: Sat Sep 06, 2008 9:19 pm
Location: Auckland

Postby darkwolf » Wed Nov 12, 2008 11:31 am

Stott69 wrote:what if you had simalar set up to above but throw in a 1f cap in the mix? my battery is in the boot already, im running a sony 222 for my 6x9s, and a pyle PLA 2210 1800w to drive my kicker 10" square.


Similar deal to running it from a battery:

BATTERY---CAP---DISTRO---AMP1
||||||||||||||||||||||||||| \___AMP2

NB: You might wanna run a distro for the earth to the cap so you only have one earth point.

BUt as johndoe1025 says for the audio feeds it is better to have 3 outs and the higher the voltage the more sound as it requires less amplification.
Brute force and ignorance always prevails.

Failure comes from too little brute force, or too little ignorance.
User avatar
darkwolf
Toyspeed Member
 
Posts: 543
Joined: Sun May 08, 2005 10:33 pm
Location: CHCH Nearly


Return to Car Audio / Security

Who is online

Users browsing this forum: No registered users and 19 guests

cron