Will splitting RCA's drop the HU voltage output?

[squeak9798 5,000+ posts]

It seems like every couple weeks I have to try and tweek it to keep it at the volume I like, so I assumed I was going deaf, but then other people started noticing the same thing... so somewhere along the line, I'm steadily losing volume.

This makes me think that there is a problem with the equipment somewhere.

Either something wrong with the HU or a problem with the amplifier.

Unplug the RCA's from the amp, grab a DMM, play a test tone with the volume near maximum and measure the voltage on the RCAs (place the red DMM lead on the center pin of the RCA connector and the black DMM lead on the outer metal barrel).

 

[squeak9798 5,000+ posts]

The guys over at DIYMA said you do need a line driver if you use a Y adapter to split a signal.
I was considering this going 3way hydrid-active front stage. They said if you split the "high" into a midrange/tweeter, you would need a line driver to keep the voltage up.

However, your battery anology does make sense as well.

I tried running a few searches to find that thread because I was interested in seeing the responses...but I couldn't find it quickly so I gave up //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif But I would have to disagree with them. A line driver is not necessary at all.

It couldn't hurt to add a line driver either way.

Sure it could.

One, you're spending $$ on a device you do not need. And two, it's another component in the signal chain to introduce noise, etc.

 

[thylantyr 10+ year member]

The last variable to mention. A bad output stage design can cause voltage drops.

If someone did this type of circuit design they should have their career stripped and tortured in shemale island.

Hypothetical bad design;

HU preout voltage: doesn't matter, lets use 5v

HU max output current: 250uA

HU output impedance: 100 ohms

Amplifier input impedance: 20,000 ohms

Add a second amp with 20,000 ohms input impedance and the voltage is 2.5v, cut in half. lol

*or*

Only use one amplifier but if the impedance is less than 20k ohms, voltage drop {10k ohms = 1/2 the voltage}.