HU to Amp: 1 RCA or 2?
#1
Registered User
Thread Starter
iTrader: (3)
Join Date: Mar 2006
Location: Malibu, California
Posts: 473
Likes: 0
Received 0 Likes
on
0 Posts
HU to Amp: 1 RCA or 2?
It's not extremely important yet because I'm not purchasing a sub yet, but:
I have an Alpine MRV-F345 that has dual RCA inputs (2xL, 2xR) and I only ordered one RCA cable, since I am only plugging my front speakers into my amp. However, I was under the impression that since I have four outputs (and I can bridge 3+4 for a sub), that I could plug my HU to Amp using one RCA (ch1+2) and that's it. From there, I thought I would run Ch1 and Ch2 to the front speakers, and bridge 3+4 to the sub.
When I do add the sub, will I need to run a second set of RCA cables from the HU to the Amp (to channels 3 and 4)?
I have an Alpine MRV-F345 that has dual RCA inputs (2xL, 2xR) and I only ordered one RCA cable, since I am only plugging my front speakers into my amp. However, I was under the impression that since I have four outputs (and I can bridge 3+4 for a sub), that I could plug my HU to Amp using one RCA (ch1+2) and that's it. From there, I thought I would run Ch1 and Ch2 to the front speakers, and bridge 3+4 to the sub.
When I do add the sub, will I need to run a second set of RCA cables from the HU to the Amp (to channels 3 and 4)?
#2
Living in 350Z
iTrader: (1)
Run a pair of cables now - I'd even run three.
The effort to run the three cables is expensive but the cables themselves is very cheap (you're not buying Monster Moon-Bat cables are you!). If you ever change to a 5/6 channel amplifier you'll already have all the connections from the headend run aft to the amplifier's location. Plus if you ever get a cable go bad you can use the "extra" cable already run saving you the labor of pulling another.
The effort to run the three cables is expensive but the cables themselves is very cheap (you're not buying Monster Moon-Bat cables are you!). If you ever change to a 5/6 channel amplifier you'll already have all the connections from the headend run aft to the amplifier's location. Plus if you ever get a cable go bad you can use the "extra" cable already run saving you the labor of pulling another.
#4
Registered User
iTrader: (2)
Join Date: Oct 2007
Location: Austin, TX
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
May as well run the cables while you have it open. If you don't want a sub, no need to do so, but if you're talking about a sub now you'll probably want one sooner or later, and running the second rca pair is easy and cheap.
First, check your amplifier (I'm not familiar with that alpine). It might have the ability to take the 1/2 input and sum or repeat it to your 3/4 channels. If it has something you can use, then you don't need that extra cable and this is all moot.
A head unit may have a non-fading sub output or even a separately attenuated output; either gives you more adjustability (though the amp may have a bass thingy) but you need to run the extra cable or pair.
First thing to do is get familiar with your amp. You could be all done if it has some decent features.
First, check your amplifier (I'm not familiar with that alpine). It might have the ability to take the 1/2 input and sum or repeat it to your 3/4 channels. If it has something you can use, then you don't need that extra cable and this is all moot.
A head unit may have a non-fading sub output or even a separately attenuated output; either gives you more adjustability (though the amp may have a bass thingy) but you need to run the extra cable or pair.
First thing to do is get familiar with your amp. You could be all done if it has some decent features.
#5
Registered User
Thread Starter
iTrader: (3)
Join Date: Mar 2006
Location: Malibu, California
Posts: 473
Likes: 0
Received 0 Likes
on
0 Posts
I have a feature that sents the signal at the input of 1/2 over to 3/4. It says this is for headunits that don't have two pre-amp outputs, only one. But my headunit has two.
Am I good to go though with the one RCA then?
Am I good to go though with the one RCA then?
#6
Registered User
iTrader: (7)
Join Date: Feb 2008
Location: Panama City Beach, FL
Posts: 890
Likes: 0
Received 0 Likes
on
0 Posts
if the amp says that it can use 2 rca's to run all 4 channels then it can
#7
Registered User
Thread Starter
iTrader: (3)
Join Date: Mar 2006
Location: Malibu, California
Posts: 473
Likes: 0
Received 0 Likes
on
0 Posts
I understand your frustration, but also understand that I have looked through the amp manual in detail, I'm just trying to fully understand everything before I install this system (tomorrow) and before I order a sub. I admit, I didn't look into the sub manual until now, but that is because I thought there was a technical specification on the main JL product page that I didn't know how to interpret.
Trending Topics
#9
Registered User
iTrader: (5)
Join Date: Oct 2006
Location: Jacksonville, FL
Posts: 317
Likes: 0
Received 0 Likes
on
0 Posts
I'm going to run 2 set of RCAs even though I will only have 1 RCA going to front comps' amp for now and then 2nd RCA once I get the sub in few weeks... I will have to tape the 2nd RCA off until I get the sub, right?
#10
Banned
iTrader: (8)
Join Date: Jul 2003
Location: Fairfax, VA
Posts: 2,637
Likes: 0
Received 0 Likes
on
0 Posts
Run as many cables as you can during your initial install, as Paul said above. Trust us, it gets tedious having to pull panels again and again.
As for RCA's, you are going to need 2 pair, one set for the fronts and the other for the sub. If you ordered the 4-Ch Install kit, you will get BOTH pairs of RCA's, so you should be good.
Alpine's description of the Input Selector switch in the owner's manual is really vague. If you are using 2 pairs of RCA cables, you definitely won't use the "1/2-3/4" setting. I really can't remember which setting to use (1/2 or 3/4), and it's frustrating me! If I had to make an educated guess though, I would say you use it on "3/4" so that you can control the sub.
As for RCA's, you are going to need 2 pair, one set for the fronts and the other for the sub. If you ordered the 4-Ch Install kit, you will get BOTH pairs of RCA's, so you should be good.
Alpine's description of the Input Selector switch in the owner's manual is really vague. If you are using 2 pairs of RCA cables, you definitely won't use the "1/2-3/4" setting. I really can't remember which setting to use (1/2 or 3/4), and it's frustrating me! If I had to make an educated guess though, I would say you use it on "3/4" so that you can control the sub.
Thread
Thread Starter
Forum
Replies
Last Post
m_0g
Audio, Video & Electronics (DIY)
12
06-03-2021 10:05 AM