preout volt(HU) & input sensitivity(amp)

[bgowdy 5,000+ posts]

im about to get my amp hooked up. and i was just looking and thought about the

input sensitivity on the amp. my HU is a pioneer deh-p3100ub the preout is 2.2v, 1k ohm. not sure what this means, then my amp has 100mv-2v or 2v-8v for input sens. do match the input sens on amp to preout of player??? this may be a noob question but im just curious

Click to read more...

 

[All_Logix 10+ year member]

That is the just of it yes. To give you a better understanding of what this does, the HU preout voltage means that at full tilt the preouts will produce 2.2 VAC, thats alternating current. The amplifier should be setup through the input sensitivity to understand that this is the highest possible value that the HU will send it in order to prevent what is called clipping. If the sensitivity is set to high then the amp will think it needs to send full power to the speakers even when the HU isn't turned up all the way, this is damaging to the speakers and generally sounds bad, if the sensitivity is low, the amp will never put out full power even when the HU is all the way up. To set the amp up properly I could read up on setting gains with DMM, also keep in mind that just because the HU says it produces 2.2V doesn't make it the gospel

 

[maylar 10+ year member]

Ideally you want the amp's sensitivity to match the HU preouts. With 2.2V preouts you'll probably never see that level except at full volume with a 0 dB source, so the 2V sens setting is likely a good match. However, if you have way more amp power than the speakers can take, you'll probably want to use the higher range so you can turn it down.