Okay guys, I have another rather strange question. I was driving my truck, a 1982 F-150XLt Ranger Explorer, and Out of nowhere, The subs in the back faded out real bad. I could hardly hear them, and the sound quality dropped spectacularly. At the same time, the five-and a halfs in the same box as the subs did the same thing. After I turned it down, they went back to normal in a few minutes. This has been happenning very often lately. The Head unit is a Kenwood KDC-2022, the subs are plain labels, and the Speakers are Visonik's. The box was made by me outta plywood, caulk, carpet and nails. Any idea what could be causing this?

 

Sounds like an amp going bad or overheating.

 

Are these subs and 5's all hooked to the deck outputs? How hot are your cd's when this happens? Obviously I'm fishing, could it be too much of a load for your deck, what's the impedances of your custom boxes?

 

That's what I was thinking. If it was overheating then it would have just died, would it not?

 

The amps that I have had if they overheated they would shut down and come back on once cooled down, sometimes it didn't take long a minute or so but the problem would persist until I did something to get more air around them.

 

There... um... Are no amps... just hooked up to the Kenwood Head Unit. And the CD's are wicked hot when I pull them while it's doing this.

 

This is a classic case of using equipment beyond what it is designed for. Head units have never been intended for this type of use. If you don't completely ruin your entire system, I'll be shocked. The head unit amp has to be clipping the signal to your speakers all the time, which can only mean two things. The amp itself will fail, which is not surprising. It's made for low to mid volume listening at the most. With no subs, I might add. And the speakers' voice coils are probably damaged, or soon will be, which means they are finished.

 

The speakers are sounding the same as when I bought them, and I only run the head unit at 20-25 as the volume lvl, it goes up to 35. I should append, though, that the guy at NebFurMart showed me some thingies on the back of the head unit and said that that's where Subs are designed to go. That's where they are. Also, the speakers aren't fading. I was wrong about that part. and It's 3:51 o'clock. lol. And what do you mean that it's clipping the signal to the speakers?

Oh, so what should I do? Remeber, limited budget. Very limited.

 

The thingies on the back of the HU are probably pre amp outputs that are already low passed for subwoofer use. They are of no use without using a separate amplifier.

Do you have a "low pass" filter for the subwoofer, to allow only the low frequencies to the sub?

Without getting into a technical discussion, a clipped signal occurs when an amplifier is asked to deliver more current than it is capable of. The tops and bottoms of the waveforms the amp is trying to reproduce are literally clipped off, thus the term, clipping. The clipping introduces HUGE amounts of distortion, usually heard as a kind of crunching sound. And it can destroy voice coils because when clipping the signal, an amp can produce several times more power than when not clipping the signal. And, in this case, more power is not a good thing.

 

No, it's more of just a fast fade out, and then after 5 minutes of low power, it goes back up. There's no real distortion, or what you call clipping.