It sounds like it's probably about 200 or so...

 

I win, you're all stumped.

 

Being that the stock headunit has a typical bridged-output directly powered amplifier with 4 channels, and the speakers are about 4 ohms like most, the useable RMS power would be about 25 watts per channel. Overall real-world sustainable power would be a bit less, probably 18-20 watts/ch. "Peak" power available in this scenario would be 36w/ch, but that is not a usable number (unless you work in marketing).

The HK option adds an amplifier with an internal voltage converter which increases the potential power output. Most typical car audio amps do the same, except in the rare case of a very small add-on amp.

 

I agree.
I've discussed this with tacotim over a year ago and we think that the stock headunit will yield about 20 usable Watts/channel x 4 channels. The stock speakers are quite efficient so you'll be fine. Once you change the speakers to aftermarket you'd need to use very efficient speakers or you will find that you are running out of usable power from the stock headunit and you'll be getting plenty of distortion.

The solution, leave the stock headunit and speakers alone or swap the headunit for more power/more features, or swap the speakers to something better but very efficient, or replace both speakers and headunit/add an amp.

 

Thanks for the feedback!


Is there no "official" number out there?

 

I'll try to search around for an "official" number but here is a comment to me from Tacotim.

"The stock amp, if there is one, if not the radio, probably puts out 8.5
Volts RMS, or about 15-20 watts per channel into 4 ohms. Many stock systems can play fine into 2 ohm speakers, as long as it's not for long durations at high volumes. This doubles the power into the speakers. It's important to find out some of the limitations of the stock system to understand, first, if choosing the right speaker will really bring more out of the system (pretty low cost). You wouldn't want to scrap the stock system for something without the capability for more power, etc."

So best guess is about 20 watts x 4 channels. Peak would be a little higher.

 

Dredging up an old topic, but one I am currently interested in.


What is the actual difference between the standard HU and an H/K HU? I know the H/K adds an amp, but is it an internal or external amp?

 

Headunits for standard and H/K are the same, difference is that H/K has external DSP/amp that resides in the right rear fender well behind the access panel in the boot area. Go take a peek.

 

Ok, what about the internals? Like the setting on my H/K HU for "sound type" or whatever. Choices for the setting are things like Spatial, Electronic, H/K... Also the Driver setting that supposedly centers the sound on the driver or speed sensitive volume.

 

The headunits are all equipped with an interface to the HK amp to control the sound processor located there and to display it's settings. If you dont have the HK amp, the headunit does not bring it's settings up in the mode menu. It's the same with the changer and aux features; if they arent installed, then the settings dont show up in the menus, even though the base circuitry and firmware are in place to control them.

 

Cool. Plus I also saw Ryephile's post about swapping HU's. Things are looking better for finding an 05 HU to swap out so I can have MP3 again. :smile:

 

If you don't have the HK system, can an aftermarket amp be installed in this location to work w/ the stock HU?
Thanks