i have had polk mm651's in front and rear pods for 4 years now and just purchased a jl audio mhx-280/4 amplifier for an upgrade.
the speakers alone have done me well. i can listen to my mp3 tunes at 75-80 mph without any trouble.
after hearing some systems at our recent fall ride in tomahawk wi i decided to do it.
the amp matches very well to the speakers. dyno testing on this amp shows true power at 96 watts rms at 3 ohms (speakers are 100 watt rms 2.7 ohms)
while i am doing this over the winter i thought i would have iron cross retro my hk head unit for bluetooth ($140) to finish off the system.
some have said that i should just upgrade the head unit for a bit more money and i would be happier.
i don't see where a different head unit would make any difference. can i get some help in understanding the reasoning behind this? thanks for taking the time and helping me with this everyone

 

The factory head unit is so prone to failure, you may get 1 month or 5 years out of the Bluetooth upgrade. Also sound quality will increase exponentially over the stock head unit. But if you are satisfied, don't fix what isn't broke. We all have different goals and budget's.

 

While this amp will make a difference it is hardly a match for those speakers. With the speakers being 100 watts RMS you need a minimum of 150 watts per channel to run this setup efficiently and not push your amp to its limits every time you crank up the system.

 

If you don't use the CB or Intercom then you can sell it for more then $140 and put that towards an after market HU, mounting kit and handlebar controls. IMO, putting $$$ into a HU that distorts at 1/2 volume is a waste.

 

As Slye has said an aftermarket headunit will give you much better clarity and reliability. The stock head unit is ok by itself but when you start to amplify the output signal you will notice the distortion the head unit is putting out 10 fold.

Like I was told many years ago you can have a 10 cent stereo with $100 speakers and it will still sound like a 10 cent stereo.
So I would suggest to replace the HU and get the most out of the money you have in your upgrade.

I was also at the FALL RUN. There were a few of us forum members up there that met up at BUBBAS for a meet and greet.

 

thanks for the input fellas. this is great.
a few have mentioned aftermarket sound quality over the hk unit. what do you mean by this exactly. do you mean better fm reception.
i do notice that my fm signal coming in isnt the most reliable that's kind of why i use my recorded cd to listen to all my music.
the head unit as you all know has a bass and treble controls aside from this why does it fall short of the aftermarket products.

 

Be aware that with most (not all, but most) Class D amplifiers you will completely lose FM reception. Just something else to consider.

 

Replaced my stock HK head unit with a $79 Sony. Noticeable difference in the quality of the tunes.

 

You're going to get a ton of info on this forum from the guys who know. I will tell you this...they know their stuff. I'm new to this, but simply -as I understand it-an aftermarket will have EQ's and preamp and low level outputs which will help improve sound quality and tunability immensely. There are also aftermarket HU's that the guys have tested that go to full volume with no distortion. I think it was the Kenwood 998 (someone will correct me if I'm wrong).

I can tell you that I was on a budget and did NOT replace the stock HU (2012 SG). Next year, I WILL be replacing the HU and maybe even upgrading the amp. I wish I had the funds to do it this year.

Anyway, I believe that it will make a huge difference, and it's on my list. Just my .02

 

For a rough idea the sound quality difference from a stock head unit to an after market on your sled is like comparing a radio from a 1977 Camaro to a 2016 Camaro. Just using this a a reference. They sounded good for their time but if you can improve it I would do it just saying.

As stated above the stock head units distort at half volume and distortion KILLS speakers. Then when you put an amp in the mix you will kill your speakers even faster