Need help w/ Kenwood KDC-248U!!

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**I just want to clarify that, while I enjoy a good sounding stereo, I am by no means an audiophile. **

I got this Kenwood KDC-248U head unit for XMas. I installed it in my truck a couple days ago and it worked fine.. until I pumped up the volume. The max volume is 35. I cranked it to about 25 or 26, and after 5-10 seconds, the music began to slowly get quieter, then distroted, and would further distort if I cranked up the volume further. The watts on this unit is 50Wx4 Max and 22Wx2 RMS.

This is the fourth stereo in this truck since I've owned it. Started out with the factory HU, which had a similar problem as this one is having, but it would only happen periodically, never was consistent.. This problem, of course, didn't happen until I swapped out the factory speakers with some Pioneer 3-ways. Can't find the box for em & I can't remember the wattage on them, but I know they were by no means a top-of-line model (IIRC they were ~200W Max and less than 40W RMS). Swapped out the factory crap with a Kenwood KDC-MP735U, which, although a better HU than the one I have now, it has the same power. Ran fine, no problems. Then I swapped that out for a POS Pyle HU, which actually ran fine. Didn't have the best sound quality, but no distortion either. I think it was 45Wx4 Max, don't know the RMS.

I am assuming the speakers are underpowered by the head unit, as that is usually why you would get a distortion like this at higher volumes.. But WHY?! The two other aftermarket HU's didn't have this problem, and I played them a good bit louder than this one thus far. I have triple checked my wiring and everything seems to be fine. Used wire nuts on all connections except the three power wires (two 12V and one ground) which I crimped w/ butt connectors. PLEASE HELP, THANKS!!!

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[Robert 2001 10+ year member]

Are u sure all your speakers are in phase? I run a kdc 138 disortion starts at 28/29 goes to 34

 

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you will hafta explain what that means, "in phase." sorry for sounding n00b-ish! also, i have found the distortion to start as early as 23-24 on heavier hitting songs.

EDIT: Just did a quick google search, and I do believe they are in phase, as I am pretty particular about matching positives & negatives. I installed these speakers about four years ago, and they have provided a good, heavy bass and pretty good sound through the years. If they were out of phase before, wouldn't I have noticed it on the other head units???

 

[brandinooooo 10+ year member]

I have a KDC-hd545u and its goes to 35 but distorts above 28. I NEVER turn mine past 28

 

---------- Post added at 02:27 PM ---------- Previous post was at 02:26 PM ----------

 

Also, what are you using to play the songs? On USB and cd it starts distorting at 24

 

[DoesDad 10+ year member]

I've got a Kenwood MP345U and I can't turn it past 27 or so(goes to 35 as well) I think they're just low end POS head units. LOL! Seriously. My wifes Alpine does the same thing....

 

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CD and tuner so far. I just find it weird that the older model KDC-MP735U was able to push harder than this thing. This sux.. guess I will have to downgrade my speakers??

 

[DoesDad 10+ year member]

i think you might be expecting too much out of your head unit. Kenwoods generally are 22 x 4 rms. I know it says 50 or 60 x 4 but that's the peak watts. Like I said I have an MP345U. I think it sounds decent for what it is. It was only a $60 head unit from Craigslist (only $129 on Amazon). I looked up yours and it's in the same neighborhood. While these head units do sound better than most stock you're going have to either play with the EQ settings on it to get the sound you want or amplify your front and rear speakers. "Downgrading" your speakers doesn't even sound right? Does it? LOL!

 

[Robert 2001 10+ year member]

Idk about the other models but mine has options for powering different size speakers and a vehicle offsets There is also a lpf and sub control. Do they all have these options? If yours does a wrong setting can really make it sound a bit off.

 

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@DoesDad - I am aware of the RMS power, thats why I listed it in the original post. It's close to the RMS power of my speakers, which is why I find it odd that the HU is apparently not putting out enough power for them to function properly at higher volumes. I looked at a few different models of new 200W pioneers and most are ~30W RMS.

@Robert 2001 - my old Kenwood one has those settings, but the new one doesnt. with the old one, my speakers sounded like crap when I set it to the specific size (at least compared to the default setting). I have tried fooling with some of the EQ stuff on the new one to no avail. I turned the bass down all the way (-8), the mid down to -4, and treble down to -1, and still got distortion at 24.