Notices
Audio, Security, & Automotive Lighting Troubleshoot wiring problems and get equipment suggestions all in one place. Now expanded to include Automotive Lighting

new deck with only 1 rca sub output need help

Thread Tools
 
Old 11-26-2008, 04:24 PM
  #1  
ericgordon123
Member
Thread Starter
 
ericgordon123's Avatar
 
Join Date: Oct 2007
Posts: 71
Likes: 0
Received 0 Likes on 0 Posts
Default new deck with only 1 rca sub output need help

hey so i got a new deck, its a jensen lcd dvd screen with navi and everything.. the only thing is for the RCA subwoofer input, there is only 1 plug. the RCA's from my amp have 2 like a right and left. im confused how do i hook it up?

for now i have the subs hooked into rear surround just so there working but i dont think its the same?

let me know what to do

thanks.
Old 11-27-2008, 02:57 AM
  #2  
b00gers
 
b00gers's Avatar
 
Join Date: Jun 2001
Location: oakland, ca
Posts: 58,578
Likes: 0
Received 0 Likes on 0 Posts
Default

What model is this?
__________________
.
Old 11-27-2008, 08:30 AM
  #3  
cpvdh
Member
 
cpvdh's Avatar
 
Join Date: Feb 2006
Location: OR
Posts: 1,869
Likes: 0
Received 0 Likes on 0 Posts
Default

you mean there is only one OUTput for the sub from the deck, thats because its a mono output
if you are using a 2 or 4 channel amp, then research how to wire it correctly to run a subwoofer in mono
Old 12-16-2008, 06:47 AM
  #4  
ericgordon123
Member
Thread Starter
 
ericgordon123's Avatar
 
Join Date: Oct 2007
Posts: 71
Likes: 0
Received 0 Likes on 0 Posts
Default

its a JENSEN VM9512

so ive done research and i still cannont find out how to wire this correctly.

with 2 rca cables coming from my amp, theres only 1 rca output for a sub out of the deck. is there a splitter i could get?

are the 2 rca's from my amp a left and right? could i just splice them together?
Old 12-16-2008, 05:58 PM
  #5  
Tedmond
Senior Member
 
Tedmond's Avatar
 
Join Date: Nov 2007
Posts: 407
Likes: 0
Received 0 Likes on 0 Posts
Default

you can get a splitter for sure 1 - 2rca ends. but it might sound funny since its now out of phase. i would do this as a pro installers POV

get a high to low adapter (speaker output to rca) then wire it to the rear channels and adjust gains accordingly. that way you have both left and right and its a better source for your amps (less distortion if you got the powered one)
Old 12-17-2008, 10:16 PM
  #6  
russianpsyco
Senior Member
 
russianpsyco's Avatar
 
Join Date: May 2006
Location: Blaine, WA
Posts: 145
Likes: 0
Received 0 Likes on 0 Posts
Default

I got the same thing, different setup but also only one rca for the sub out. I have a 2 channel amp for my sub so all I did is connect the sub by bridging it over the 2 channels and hook up the sub out rca to one of the 2 rcas on the amp. it doesnt matter which one cause they both sound the same. Thats it, dont worry about the other rca.
Old 01-06-2009, 07:20 PM
  #7  
slade311
milk-n-cookies
 
slade311's Avatar
 
Join Date: Feb 2004
Location: south alabama
Posts: 89
Likes: 0
Received 0 Likes on 0 Posts
Default

i have the same problem.....
my old unit (just a regualar panasonic cd player) had two rca sub preamp outputs. they were 4 volt. i recently bought a jensen dvd/cd player with a flip out screen. it only has one rca out for the subs. i had to use a splitter to plug in my rca's from my amp. the new one is only 2 volts. i am getting maybe half the bass i was before even after having to max out my amp. i am sorely dissapointed. i am returning the one i just bought and gonna trade it for a panasonic dvd/cd player with a flip out screen. i was told by one person the loss of bass was from going from panasonic to jensen. someone else said it was because of going from 4 to 2 volts on the preamps and having only one sub out rca. WHAT IS THE REASON for such a drastic loss in bass??? the new panasonic that im about to trade in for also has only one? do all the new decks have one and why? i dont wanna go through all the switching and installing and be left with the same result of minimal bass. i have 3 alpine type r's that used to bang my trunk off but now it barely moves. someone please help. thank you.
Old 01-07-2009, 12:52 AM
  #8  
Driver
slow lane cruiser
 
Driver's Avatar
 
Join Date: Sep 2003
Location: NC
Posts: 110
Likes: 0
Received 0 Likes on 0 Posts
Default

One sub out is not a bad thing as long as your crossover setting on your head unit (if available) is set correctly and the amp itself is set up properly. In the case of having just one sub out RCA, what your head unit is doing is blending the L+R together. In most cases head units that do this have a crossover setting and output setting internally. (IE: one that can be adjusted manually through the in dash interface). Using a 1 RCA (mono)-to-2 RCA adapter into a L+R (stereo) input effectively cuts your power in half. What you need to do is set your amp to mono operation and use your L channel input. (If your amp will operate in mono) Otherwise do what the other guy said and bridge from your other speaker outputs to get stereo signal and adjust the gain on the amp accordingly. Keep in mind however that with a hardline setup like this the head unit will increase the gain (when you adjust the volume) going to the subs because it will be amplified by the internal amp on the headunit, (hence the need to adjust your gain on the amp itself) But the RCA outs are always line level outputs. Typically, but not always, the bass guitar and kick drum are mixed in the center of the mix, so having mono sub action isn't detrimental. A few Beatles songs have bass only on the left or right and that can be weird when listening to an improper mono setup (EX: when you only have L or R sent to the external amp). As far as crossover settings, I'm sure all of you know that it simply eliminates frequencies above the set limit.
EX:crossover set at 150Hz- nothing above 150Hz is utilized,
crossover set at 250Hz- nothing above 250Hz is utilized
Most of your bass resides in the 150-250Hz area, while most of the girth of kick drums reside in the 50-125Hz area.
Keep in mind- The Sub does not need anything above 350.PERIOD.
A key here is IF your head unit has a crossover setting make sure that it is set to a higher frequency than your amps crossover.
EX: headunit crossover set at 100HZ, and amp crossover set at 250Hz
well the head unit isn't sending the amp anything over 100Hz so you could just turn the crossover on the amp down to 100Hz and tell no difference other than a nominal volume gain BUT
if the head unit crossover is set to 300Hz and the amp set to 250 you are utilizing all of the signal from the head unit thus getting the most out of your amp.
In the case of the previous poster, I personally have had radically different results from amp to amp and head to head. Some head units just seem to drive the amp harder than others. So in my humble opinion as a recording engineer you may just need to tweak your amp gain to bring the thump back,
however if you are fairly good at setting car stereo stuff up and you feel that the amp is pushing pretty much all it's got then there may possibly be a weak signal comming from the headunit. I'd try to see if there is a output level for you RCS sub outs on your headunit.
Sorry for the essay but I'm a sound engineer and I've done alot of car stereo installations so I had to throw my 2cents in there, I'm no master expert, but I know my personal experience.
And, By the way, if your using RCA outputs you have NO NEED to worry about phase issues, But if you hardline it (using speaker wire straight form the head unit outputs) the just MAKE SURE you got the positive and negatives hooked up proper.
Out of Phase=Crappy Bass Response

Previous poster- After re reading I noticed that you said you had your amp maxed out, so I would definitely try to find an output gain setting on your head unit.

Last edited by Driver; 01-07-2009 at 01:17 AM. Reason: Re-Read




All times are GMT -8. The time now is 03:50 AM.