If you want to make your stero play louder, is it better to replace the infinity amp or the head unit. I live in the city and have a soft top and am fine with the features of the factory H/U but want more volume. (also no one will steal a factory H/U) I was going to have an Alpine PDX-5 installed but the shop told me the head unit regulates the signal in order to protect the speakers and It would be better to replace the H/U.

Any thoughts?

 

Head unit replace for sure the factory head unit puts out like 10 watts RMS per channel thats nothing after market head units put out about 40 to 45 watts RMS Just look at a nice pioneer or alpine head unit with a removable face and your good to go I have installed several of those before with great results I currently have a pioneer 4200ub and it's perfect

 

And it sounds so much cleaner

 

What hu is that?

 

I was going to have an Alpine PDX-5 installed but the shop told me the head unit regulates the signal in order to protect the speakers and It would be better to replace the H/U.

Whaaaa? I have never heard of this before. Now maybe the output voltage is not all that high, but I have my stock H/U with 2 Alpine amps and Image Dynamics speakers all around and it rocks. Still looks stock, which was also a primary concern

 

If you replace the Head unit should you bypass the infinity amp or connect to it. If you connect to it wont then the power to the speakers be the same? Meaning if the amp is driving the speakers and you change the H/U why would the speakers play any louder?

 

You are correct. If you replace the head unit and connect it to the OEM Infinity amp, and the new head unit has a higher output level....you will distort the inputs of the OEM amp...it's a "digital" amplifier, which means distortion sounds bad.

Those who have replaced the head unit only with a non factory head unit, are most likely not going through the OEM Infinity amp.

 

So that gets back to my original question. If you replace the infinity amp with an Alpine PDX-5 or other similar amp will you give your infinity system significantly more punch/volume or will it be limited by the factory head unit. I was told by a stereo retail shop that when you turn the factory H/U up loud the H/U flattens out the signal to protect the infinity speakers.

 

That sounds like the stereo retail shop is making up stories about things they have no idea what they're talking about.

When the factory head unit is connected to the Infinity Amp, "ALL" volume adjustments are done within the Infinity amp. The head unit sends out a "fixed" level output when it is connected to the Infinity amp. So when you turn the volume knob on the factory radio, the radio communicates with the amp over the CAN BUS and the volume of the audio is adjusted inside of the amp through the Can bus communications.

Tell, your stereo retail shop to get out an AC volt meter and connect it to the audio outputs coming from the factory radio while it is connected to the Infinity amp and tell them to take note how the audio signal does not adjust in level coming out of the head unit when you adjust the volume control. Thus...the radio doesn't flatten out nothing....since it does nothing to the audio signal coming out of the radio. By the sounds of it, they probably wouldn't know how to use a volt meter to take the measurement.

So don't just walk away from that radio retail shop.....run away. They're making up lies to try to sell you a radio and most likely speakers also since they're alluding to the factory Infinity speakers being too weak to handle a strong audio signal. It's probably not a good idea to buy from a store that you can't trust to give you correct information, when you're trying to make informed decisions. The fact that they'll make up lies to try to sell you something, should tell you that's not a place you can trust.

 

I hope the attachment works

So now I go to another installer and he shows me this wiring diagram and states that if you want to keep the factory head unit you cant just replace the infinity amp with the PDX5. This guy says I will also need an MTX re-Q5 to make it work properly. This thing is another 100+ bucks. Is this correct?