So I have this old amp (Jensen Power 900) and intend on hooking it up to my '08 Fit, just for a little boom. I have everything I need so far, just time to set it all up.

The problem is, the left input RCA jack is broken off. If I place a male RCA plug in it, I can probably tape it so it will stay still, but the negative part of the plug won't be reaching the amp.

(I don't have a way to get pictures atm, but it pretty much looks like this)


Could I use an RCA Y splitter to put my left and right signals into the right channel? It's only a one channel amp, and I'm only running one sub, so would that decrease my sound in half?

Jensen POWER-900 (power900) Monoblock Amplifier (POWER900) (My amp)

Thanks!

 

You should not connect two outputs directly together. Doing so is very hard on the output circuity of the head unit, as you have two amplifiers working against each other—in this case, of course, the amplifiers are line level drivers, but it's the same basic circuitry on a smaller scale. While it most likely won't damage anything, you could quite possibly cause bad behavior (distortion, sound cutting out, etc.) You also will lose any stereo imaging in your sound.

There are a few reasonable options:

• You can get the input jack replaced, which should be pretty simple and straightforward and inexpensive for anybody who does much electronic repair. I'd think this would be the best option overall.
• You could feed the subwoofer with only the left or the right signal, since the bass is nearly always much the same for both.
• You can also create a simple passive mixer network out of a few resistors to combine the signals for the two channels while still letting them be isolated from each other. See, for instance, the Figure 2 circuit in Why Not Wye? ("Stereo to mono summing box"). For your situation, it would perhaps be better to use larger resistors. The precise values aren't really critical, aside from wanting the two "input" resistors to be reasonably well matched.

Note that the last two options won't work if you're using the crossover circuit in the subwoofer amplifier (i.e. if you connect your main amps to the output RCAs from the sub amp). Since you're only feeding one side of the sub amp, you'll get a signal from only one of the two outputs.

 

Thank you for the reply!

I'm not sure if I was unclear in my original post, or if I'm not reading your post correctly. Pretty much it's the left input that's damaged.

That Why Not Wye page is very interesting, I never thought about that. Maybe I should make those passover boxes for the Y splitters I have in my home audio set up xD

I would be fine with doing this for now. My amp would only be receiving half of the signal (No bass from the left channel) but would it be losing volume? (example, would I have to turn it up twice as much to get the volume that two inputs would give me)

Thanks for all your help, I'm a little new with amps so bear with me!

 

Y splitters are fine if you're splitting a signal from one output to go to two inputs—so if you want to connect your CD player to two different amplifiers or whatever, there's no reason not to use a Y cable. What you don't want to do is have two outputs directly connected together, such as a CD player and a DVD player both going to the same input with a Y cable. Your home audio setup may be just fine.

Whether or not you'd lose any volume connecting only one channel up is hard to answer without additional details about your ultimate setup. Regardless, it's not a huge concern in general, though, because volume perception and measurement is logarithmic; doubling the power is, by definition, a three decibel increase, or maybe a couple of clicks on the radio volume knob. Any loss of volume could presumably be adjusted for by tweaking the amplifier gain settings a bit.

 

I'm terrible at soldering, especially tiny factory circuit boards like the one inside the amp. Could I take it somewhere to be fixed cheaply?

In the car, I would just have the left and right audio feeds going into one RCA jack. My home setup is fine because it's just splitting a mono signal into two RCA jacks so my powered subwoofer gets two channels, which makes it significantly louder. That's why I thought the same might apply in the Fit.

So I finished hooking up my amp today, and unfortunately I did not get it to work with the OEM stereo system. I could, however, plug my iPod into the amp using a 3.5mm Male to RCA cable. I think it sounded pretty fine for just one side. Now my problem is getting the amp to work with the OEM stereo (I made another post)

The other post is here, so if you have any suggestions about that post there. We can continue discussing Y splitters here xD