Problem daisy chaining amps! Help

[kr15 5,000+ posts]

Ok, so today I was installing a 4ch alpine that I received from 919motoring (amp was in good condition, well packed, etc..so im not implying a faulty amp)....

I initially hooked up the alpine to test for working order. Channels 1 and 2 worked fine and sounded good, however, 3 and 4 barely made any sound at all. Oh, i checked channels 2 at a time as I didnt have a splitter, hence checking 1 and 2, and then 3 and 4. Anyway, that is more a question for later. Considering that I could only get sound from 1 and 2, I hooked my 6x9s up to these channels. I ran the rca's from deck to ch 1and2 input on alpine. I then ran rcas from the Alpine "preouts" to the Brutus input...here is my problem, when I did this, it cut down my sub output by at least 50%. My sub wasnt hitting hard at all. Thinking that there might be an issue with the outs on the alpine, I ran rcas to the Brutus first, then from Brutus outs to Alpine ch 1 and 2 input. When I did this, the bass increased somewhat, but I had still lost about 25% of the bass output, also, when I did this, the Alpine amp then became inaudible. The 6x9s were lower than when my HU powered them...so both ways, the amps were underperforming. So my question is this; can my HU preouts just not support 2 amps? Do I need a line driver? My HU has 1 set of 2v outputs..do i need a new deck?

Any suggestions are appreciated...Thanks

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[kr15 5,000+ posts]

bump

 

[QuikSilverRS91 10+ year member]

I'm assuming when you checked channels 3 and 4 you made sure the gain wasn't all the way down? That just sounds a little strange to me.

 

[Blasphemy 10+ year member]

I had that same problem with my old radio and my Rockford amps. I couldn't figure it out so I got a new radio with more preouts.

 

[kr15 5,000+ posts]

I'm assuming when you checked channels 3 and 4 you made sure the gain wasn't all the way down?

yes

I had that same problem with my old radio and my Rockford amps. I couldn't figure it out so I got a new radio with more preouts.

ya, i most likely will get another deck with 3 preouts, i just want to make sure this is my problem

 

[kr15 5,000+ posts]

I was just out there with it some more...few more observations..I have some engine noise coming thru, or some type of interference...I also figured out why 3/4ch sounded how it did. As soon as I figure something out, other issues pop up...On chan 3/4, the amp would seem to deliver power just fine when only the left output was used, i tried both 6x9s on this channel and both worked fine...however, when I attempted to use the l/r channel at the same time, only the L output played, the right 6x9 didnt play..........so for now, i completely uninstalled the Alpine, hooked 69s back up to HU and left the Brutus to run the sub...I guess i'll be looking into another deck with multiple sets of preouts

 

[kr15 5,000+ posts]

bump... can someone confirm or deny that my HU just cannot support these components? Im likely just going to replace the HU if this is the issue

 

[The HACKER 10+ year member]

I would try running the rcas from the HU to each input on the amp one at a time to make sure nothings faulty with the amps. As well 2volt on a HU is a low voltage, Which means you'll end up using more gain then if with a 5volt or higher. Cant say for sure what it is but Id say def check the rca's to each amp input.

 

[bubbagumper6 5,000+ posts]

Re-set your gains. When you split your RCA's you get a voltage drop. Your gain is to match the voltage on your pre-outs which is now lower so the gain needs to be higher.

 

[The HACKER 10+ year member]

Re-set your gains. When you split your RCA's you get a voltage drop. Your gain is to match the voltage on your pre-outs which is now lower so the gain needs to be higher.

//content.invisioncic.com/y282845/emoticons/nerd.gif.c6fa51ddf7ff75f1c0371fbc648f70ae.gif haha jk

 

[kr15 5,000+ posts]

Re-set your gains. When you split your RCA's you get a voltage drop. Your gain is to match the voltage on your pre-outs which is now lower so the gain needs to be higher.

well does my 2v out basically turn into 1v outs?

 

[bubbagumper6 5,000+ posts]

well does my 2v out basically turn into 1v outs?

I don't know if it's necessarily cut in half but there's definitely a drop. But it doesn't really matter what input voltage the amp is seeing if you use the DMM/Test tone method

 

[kr15 5,000+ posts]

Ok, so i reran all the wiring. The alpine as well as the brutus worked fine when wired by themselves. However, when wired together, they acted funny again. There was that dreaded whining noise coming from my 6x9s. It acted in accordance with acceleration/deceleration. Also, even on full gain, the Alpine is no where near strong enough for my needs. I dont know if it just isnt strong enough to begin with, or if daisy chaining is affecting its ability. Nontheless, it worked perfectly fine when wired by itself. As to the Brutus, increased the gain slightly and that corrected that issue......So, Im back to needing a new deck as my setup just doesnt seem to want to be daisychained...I also will be getting a stronger 4ch...40rms on mids/highs isnt going to cut it against 1200rms to a 15