POLK DB571's
 

I just installed these as posted here :

https://www.f150online.com/forums/sp...valuation.html


After driving with these and only these for a day and a half.. I cannot stand it!! I took out my Audiophile sub in preperation for the stealthbox.. It sounds so weird, there is no mid-bass... The only thing that I can think of is my Audiophile HU is really designed to be used with the factory speakers and there is a LPF inside the HU has been set to the factory speaker settings??? Is that possible? If that is the case..then I have some speakers that can handle some mid-bass and I cannot make the necessary adjustment that the speakers need since I am stuck in factory HU land and they are not amped.... I know that in an aftermarket HU there are no crossovers and the music is sent full range to the speaker and it is up to the cap or crossover to make it right.. Do you guys happen to know how an audiophile HU is setup ? Something else I noticed...my rear speakers are nowhere near as load as the fronts. Now I know that the HU has to do something there. I have faded used the factory "Ambiance" settings and all of the different staging settings and they all make the rears sound really weak and muffled. Any ideas??? I know once the stealthbox gets put in that all of the above is going to drowned out. :(

I know there are some of you that have done the exact same thing!!!

Any ideas???

I will be installing the 571's in my new truck but their just going in the rear doors. I use polk component up fronts, I also use an amp for door speakers. I'm sure the 571's are okay it's just that factory setup you have not to mention their only 2-way speaks so you can't blame them too much. I've never heard a stock factory that sounded great especially Ford's "high end" stereo. Also if your stealthbox gets put it and drowns out the rear speakers you have a problem there as well, yes the soundstage should be focused more up front but not 100% then you have no rear fill. Your rears should be audible but no over powering to where it sucks your towards the rear of the vehicle. I personally would never use any stock stereo components and if I didn't have the money to do it right I wouldn't do it at all.

I have heard of few comments from some that installed the audiophile unit without the factory subwoofer, saying that it lacks bass to the door speakers. It would seem there is an internal high pass crossover in the audiophile head unit. I have the non-audiophile OEM head unit and there is a lot of bass going to the speakers. I'll be able to set the high pass with the amp I'm installing along with a subwoofer.

Correct me if I am wrong ...would that not be a LPF?? A low pass crossover is typically set for the 30-250hz range. I think the low end of the low pass crossover may be set to around 65 to 70hz which would clip the low ends of the Polk db571's. I believe that the Polk's start at 50hz, if I remember correctly... I guess it is unknown what the OEM headunit is set for..WE might never know...All I know is that ...

They sound terrible with the Audiophile HU
They sound even worse without the factory sub to somewhat mask it

Any other ideas?

Scrap the Audiophile HU and you will see a VERY noticeable difference. Yes, there is a LPF xover in the HU.

Someone can correct me if I'm wrong, but I believe a low pass filter allows removes frequencies above the crossover point, while allowing "lows" to pass on to the speakers (typically subwoofers). A high-pass filter allows "high" frequencies to be sent to the speakers, while it blocks frequencies below the crossover point (typically other speakers when a subwoofer is present). That is what I meant above for the door speakers outputs.

I don't know that the audophile HU has a low pass to the subwoofer, but it might. The audiophile unit I had in my Expedition seemed to pick way more sound that should have been filtered out, IMO. It's also possible a low pass filter on the factory sub is in the box-mounted amplifier. My understanding is the signal from the audiophile for the subwoofer is pre-amp type output.

Thanks what I thought...
:D
Got one to recommend Low?

To anyone that reads this post........ If you are still running stock H/U....Do yourself a favor and go get an real H/U. I just put my p3100dvd in...wow what a difference.

A difference in what? The sound or the head unit features

Both. The aftermarket HUs have built in amplifiers that will deliver more power to your speakers than stock. The sound quality will be better as well.

I'm just messing with him